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Sample records for bluefin tuna thunnus

  1. Molecular characterization of southern bluefin tuna myoglobin (Thunnus maccoyii).

    Science.gov (United States)

    Nurilmala, Mala; Ochiai, Yoshihiro

    2016-10-01

    The primary structure of southern bluefin tuna Thunnus maccoyii Mb has been elucidated by molecular cloning techniques. The cDNA of this tuna encoding Mb contained 776 nucleotides, with an open reading frame of 444 nucleotides encoding 147 amino acids. The nucleotide sequence of the coding region was identical to those of other bluefin tunas (T. thynnus and T. orientalis), thus giving the same amino acid sequences. Based on the deduced amino acid sequence, bioinformatic analysis was performed including phylogenic tree, hydropathy plot and homology modeling. In order to investigate the autoxidation profiles, the isolation of Mb was performed from the dark muscle. The water soluble fraction was subjected to ammonium sulfate fractionation (60-90 % saturation) followed by preparative gel electrophoresis. Autoxidation profiles of Mb were delineated at pH 5.6, 6.5 and 7.4 at temperature 37 °C. The autoxidation rate of tuna Mb was slightly higher than that of horse Mb at all pH examined. These results revealed that tuna myoglobin was unstable than that of horse Mb mainly at acidic pH.

  2. Atlantic Bluefin Tuna (Thunnus thynnus Biometrics and Condition.

    Directory of Open Access Journals (Sweden)

    Enrique Rodriguez-Marin

    Full Text Available The compiled data for this study represents the first Atlantic and Mediterranean-wide effort to pool all available biometric data for Atlantic bluefin tuna (Thunnus thynnus with the collaboration of many countries and scientific groups. Biometric relationships were based on an extensive sampling (over 140,000 fish sampled, covering most of the fishing areas for this species in the North Atlantic Ocean and Mediterranean Sea. Sensitivity analyses were carried out to evaluate the representativeness of sampling and explore the most adequate procedure to fit the weight-length relationship (WLR. The selected model for the WLRs by stock included standardized data series (common measurement types weighted by the inverse variability. There was little difference between annual stock-specific round weight-straight fork length relationships, with an overall difference of 6% in weight. The predicted weight by month was estimated as an additional component in the exponent of the weight-length function. The analyses of monthly variations of fish condition by stock, maturity state and geographic area reflect annual cycles of spawning and feeding behavior. We update and improve upon the biometric relationships for bluefin currently used by the International Commission for the Conservation of Atlantic Tunas, by incorporating substantially larger datasets than ever previously compiled, providing complete documentation of sources and employing robust statistical fitting. WLRs and other conversion factors estimated in this study differ from the ones used in previous bluefin stock assessments.

  3. Atlantic Bluefin Tuna (Thunnus thynnus) Biometrics and Condition.

    Science.gov (United States)

    Rodriguez-Marin, Enrique; Ortiz, Mauricio; Ortiz de Urbina, José María; Quelle, Pablo; Walter, John; Abid, Noureddine; Addis, Piero; Alot, Enrique; Andrushchenko, Irene; Deguara, Simeon; Di Natale, Antonio; Gatt, Mark; Golet, Walter; Karakulak, Saadet; Kimoto, Ai; Macias, David; Saber, Samar; Santos, Miguel Neves; Zarrad, Rafik

    2015-01-01

    The compiled data for this study represents the first Atlantic and Mediterranean-wide effort to pool all available biometric data for Atlantic bluefin tuna (Thunnus thynnus) with the collaboration of many countries and scientific groups. Biometric relationships were based on an extensive sampling (over 140,000 fish sampled), covering most of the fishing areas for this species in the North Atlantic Ocean and Mediterranean Sea. Sensitivity analyses were carried out to evaluate the representativeness of sampling and explore the most adequate procedure to fit the weight-length relationship (WLR). The selected model for the WLRs by stock included standardized data series (common measurement types) weighted by the inverse variability. There was little difference between annual stock-specific round weight-straight fork length relationships, with an overall difference of 6% in weight. The predicted weight by month was estimated as an additional component in the exponent of the weight-length function. The analyses of monthly variations of fish condition by stock, maturity state and geographic area reflect annual cycles of spawning and feeding behavior. We update and improve upon the biometric relationships for bluefin currently used by the International Commission for the Conservation of Atlantic Tunas, by incorporating substantially larger datasets than ever previously compiled, providing complete documentation of sources and employing robust statistical fitting. WLRs and other conversion factors estimated in this study differ from the ones used in previous bluefin stock assessments.

  4. Ultrastructure of oogenesis in the bluefin tuna, Thunnus thynnus.

    Science.gov (United States)

    Abascal, Francisco J; Medina, Antonio

    2005-05-01

    Ovarian ultrastructure of the Atlantic bluefin tuna (Thunnus thynnus) was investigated during the reproductive season with the aim of improving our understanding of the reproductive biology in this species. The bluefin, like the other tunas, has an asynchronous mode of ovarian development; therefore, all developmental stages of the oocyte can be found in mature ovaries. The process of oocyte development can be divided into five distinct stages (formation of oocytes from oogonia, primary growth, lipid stage, vitellogenesis, and maturation). Although histological and ultrastructural features of most these stages are similar among all studied teleosts, the transitional period between primary growth and vitellogenesis exhibits interspecific morphological differences that depend on the egg physiology. Although the most remarkable feature of this stage in many teleosts is the occurrence of cortical alveoli, in the bluefin tuna, as is common in marine fishes, the predominant cytoplasmic inclusions are lipid droplets. Nests of early meiotic oocytes derive from the germinal epithelium that borders the ovarian lumen. Each oocyte in the nest becomes surrounded by extensions of prefollicle cells derived from somatic epithelial cells and these form the follicle that is located in the stromal tissue. The primary growth stage is characterized by intense RNA synthesis and the differentiation of the vitelline envelope. Secondary growth commences with the accumulation of lipid droplets in the oocyte cytoplasm (lipid stage), which is then followed by massive uptake and processing of proteins into yolk platelets (vitellogenic stage). During the maturation stage the lipid inclusions coalesce into a single oil droplet, and hydrolysis of the yolk platelets leads to the formation of a homogeneous mass of fluid yolk in mature eggs. 2004 Wiley-Liss, Inc.

  5. On the movements, aggregations and the foraging habitat of bluefin tuna (Thunnus thynnus and Thunnus orientalis)

    Science.gov (United States)

    Walli, Andreas G.

    To exploit the ocean's patchy resources, large open ocean fish species have evolved highly migratory foraging strategies. In this thesis, a synoptic study of Atlantic bluefin tuna (Thunnus thynnus) and Pacific bluefin tuna (Thunnus orientalis) and their environment was conducted to identify feeding behavior and foraging related horizontal and vertical movements, and to elucidate foraging habitat. First, electronic archival tags (n=561) were used to examine seasonal movements (1996-2005), aggregations and diving behaviors of Atlantic bluefin tuna (ABFT) to better understand their migration ecology and oceanic habitat utilization. Throughout the North Atlantic mean diving depth was significantly correlated with thermocline depth and dive behavior changed in relation to the stratification of the water column. Distribution behavior was characterized by seasonal aggregations and rapid movement phases. Throughout the North Atlantic, high residence times (167 +/- 33 days) were identified in four spatially confined regions on a seasonal scale. In these regions, mean diving depths were significantly shallower and dive frequency and internal temperature variance were significantly higher than during transit movements between the regions, suggesting foraging behavior. Residence time in high-use areas was correlated to primary productivity in northern latitudes and these areas represent critical foraging habitats with seasonally abundant prey. To be able to study feeding in wild bluefin tunas, the heat increment of feeding (HIF) in response to known quantities and caloric value of food ingested by captive individuals was evaluated. Feeding experiments were conducted using stomach and peritoneal placed archival tags in captive Pacific bluefin tuna (PBFT, n=31). Peritoneal temperature measurements indicate a significant correlation between food energy content and the duration from the start of post-grandial heat increment to the maximum thermal excess (TXmax ) in all ambient

  6. Trophic ecology of Atlantic bluefin tuna Thunnus thynnus larvae.

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    Catalán, I A; Tejedor, A; Alemany, F; Reglero, P

    2011-05-01

    Feeding intensity, diet composition, selectivity, energy ingestion and dietary niche breadth of larval Atlantic bluefin tuna Thunnus thynnus were studied on the eastern (Mediterranean) spawning grounds of the species. Larval T. thynnus were collected in the Balearic Archipelago (north-west Mediterranean Sea) during 2004 and 2005 using surveys specific for larval scombrids. Larvae between 2·6 and 8·7 mm standard length (L(S) ) are diurnal feeders, and 94% of the guts collected during daylight hours were full. The mean ±s.d. number of prey per gut was 7·1 ± 5·7, with mean ±s.d. ranging from 3·0 ± 1·6 in the smallest T. thynnus larvae to 11·1 ± 5·8 in 5·0-6·0 mm L(S) larvae. Up to 21 prey were found in a single larval gut (5·0-6·0 mm L(S) ) at the end of the day. Larvae progressively selected larger prey and exhibited increased carbon content concurrent with preflexion development of feeding and locomotory structures. Larvae of 5·0-6·0 mm L(S) exhibited positive selection of cladocerans over other prey (Chesson's index), whereas copepod nauplii dominated the diets of earlier stages. The dietary niche breadth measured increased initially but decreased at c. 5·5 mm L(S) . Appendicularians were found in the diet of larger larval sizes, but no piscivory was observed. Results are discussed in light of the sparse existing data for larval T. thynnus and other larval tuna species. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles. No claim to original US government works.

  7. Trace elements in the kidney tissue of Bluefin Tuna ( Thunnus ...

    African Journals Online (AJOL)

    Trace elements, namely lead (Pb), copper (Cu), manganese (Mn), nickel (Ni), zinc (Zn), and iron (Fe), found in kidney tissues were analyzed and compared between wild/fattened and female/male bluefin tuna (BFT) in the Eastern Mediterranean region of Turkey. One hundred (that is, 50 female and 50 male) individual ...

  8. Homeothermic fish and hemoglobin: primary structure of the hemoglobin from bluefin tuna (Thunnus thynnus, Scromboidei).

    Science.gov (United States)

    Rodewald, K; Oberthür, W; Braunitzer, G

    1987-07-01

    Some fish are warm-bodied, e.g. the bluefin tuna (Thunnus thynnus), which has a muscle temperature 12-17 degrees C higher than its environment. This endothermy is achieved by aerobic metabolism and conserved by means of a heat-exchanger system. The hemoglobins of bluefin tuna are adapted to these conditions by their endothermic oxygenation, thus contributing to the preservation of the body energy. This is a new and so far unique property of tuna hemoglobin. The primary structure of the alpha and beta chains of bluefin tuna hemoglobins is presented. The sequence was determined after enzymatic and chemical cleavages of the chains and sequencing of the peptides in gas- and liquid-phase sequencers. The alpha chains consists of 143 residues and are N-terminally acetylated. The beta chains have 146 amino acids and show two ambiguities at positions 140 and 142. The alpha chains differ from the human alpha chains in 65 amino-acid residues, the beta chains in 76. The hemoglobins of bluefin tuna, carp and man are compared and their different physiological properties are discussed in relation to the sequence data. From the primary structure of tuna hemoglobins, it is possible to propose a molecular basis for their peculiar endothermic transition from the T to the R structure.

  9. Digestive activity and stomach temperature in farmed bluefin tuna Thunnus thynnus measured by acoustic tag.

    Science.gov (United States)

    Díez, G; Moreno, G; Galaz, T; Dagorn, L; Murua, J

    2017-06-01

    Eight farmed Atlantic bluefin tuna Thunnus thynnus were tagged with temperature and depth transmitters inserted in chub mackerels Scomber colias to characterize their digestive activity, feeding physiology and behaviour in captivity. Results obtained in the experiment can be used to optimize daily T. thynnus feeding strategy in farms, reducing the early regurgitation of food and thus the environmental effects of inappropriate feeding practices. © 2017 The Fisheries Society of the British Isles.

  10. Changes in the distribution of atlantic bluefin tuna (Thunnus thynnus) in the Gulf of Maine 1979-2005.

    Science.gov (United States)

    Golet, Walter J; Galuardi, Benjamin; Cooper, Andrew B; Lutcavage, Molly E

    2013-01-01

    The Gulf of Maine, NW Atlantic Ocean, is a productive, seasonal foraging ground for Atlantic bluefin tuna (Thunnus thynnus), but commercial landings of adult size classes were up to 40% below the allocated total allowable catch between 2004 to 2008 for the rod and reel, harpoon, and purse seine categories in the Gulf of Maine. Reduction in Atlantic bluefin tuna catches in the Gulf of Maine could represent a decline in spawning stock biomass, but given wide-ranging, complex migration patterns, and high energetic requirements, an alternative hypothesis is that their dispersal patterns shifted to regions with higher prey abundance or profitability, reducing availability to U.S. fishing fleets. This study fit generalized linear models to Atlantic bluefin tuna landings data collected from fishermen's logbooks (1979-2005) as well as the distances between bluefin tuna schools and Atlantic herring (Clupeaharengus), a primary prey species, to test alternative hypotheses for observed shifts in Atlantic bluefin tuna availability in the Gulf of Maine. For the bluefin model, landings varied by day of year, latitude and longitude. The effect of latitude differed by day of year and the effect of longitude differed by year. The distances between Atlantic bluefin tuna schools and Atlantic herring schools were significantly smaller (pBank in spring and autumn surveys respectively (p<0.01, r(2)=0.24, p<0.01, r(2)=0.42). Fishermen's logbooks contributed novel spatial and temporal information towards testing these hypotheses for the bluefin tuna fishery.

  11. Seasonal movements, aggregations and diving behavior of Atlantic bluefin tuna (Thunnus thynnus revealed with archival tags.

    Directory of Open Access Journals (Sweden)

    Andreas Walli

    2009-07-01

    Full Text Available Electronic tags were used to examine the seasonal movements, aggregations and diving behaviors of Atlantic bluefin tuna (Thunnus thynnus to better understand their migration ecology and oceanic habitat utilization. Implantable archival tags (n = 561 were deployed in bluefin tuna from 1996 to 2005 and 106 tags were recovered. Movement paths of the fish were reconstructed using light level and sea-surface-temperature-based geolocation estimates. To quantify habitat utilization we employed a weighted kernel estimation technique that removed the biases of deployment location and track length. Throughout the North Atlantic, high residence times (167+/-33 days were identified in four spatially confined regions on a seasonal scale. Within each region, bluefin tuna experienced distinct temperature regimes and displayed different diving behaviors. The mean diving depths within the high-use areas were significantly shallower and the dive frequency and the variance in internal temperature significantly higher than during transit movements between the high-use areas. Residence time in the more northern latitude high-use areas was significantly correlated with levels of primary productivity. The regions of aggregation are associated with areas of abundant prey and potentially represent critical foraging habitats that have seasonally abundant prey. Throughout the North Atlantic mean diving depth was significantly correlated with the depth of the thermocline, and dive behavior changed in relation to the stratification of the water column. In this study, with numerous multi-year tracks, there appear to be repeatable patterns of clear aggregation areas that potentially are changing with environmental conditions. The high concentrations of bluefin tuna in predictable locations indicate that Atlantic bluefin tuna are vulnerable to concentrated fishing efforts in the regions of foraging aggregations.

  12. Seasonal movements, aggregations and diving behavior of Atlantic bluefin tuna (Thunnus thynnus) revealed with archival tags.

    Science.gov (United States)

    Walli, Andreas; Teo, Steven L H; Boustany, Andre; Farwell, Charles J; Williams, Tom; Dewar, Heidi; Prince, Eric; Block, Barbara A

    2009-07-07

    Electronic tags were used to examine the seasonal movements, aggregations and diving behaviors of Atlantic bluefin tuna (Thunnus thynnus) to better understand their migration ecology and oceanic habitat utilization. Implantable archival tags (n = 561) were deployed in bluefin tuna from 1996 to 2005 and 106 tags were recovered. Movement paths of the fish were reconstructed using light level and sea-surface-temperature-based geolocation estimates. To quantify habitat utilization we employed a weighted kernel estimation technique that removed the biases of deployment location and track length. Throughout the North Atlantic, high residence times (167+/-33 days) were identified in four spatially confined regions on a seasonal scale. Within each region, bluefin tuna experienced distinct temperature regimes and displayed different diving behaviors. The mean diving depths within the high-use areas were significantly shallower and the dive frequency and the variance in internal temperature significantly higher than during transit movements between the high-use areas. Residence time in the more northern latitude high-use areas was significantly correlated with levels of primary productivity. The regions of aggregation are associated with areas of abundant prey and potentially represent critical foraging habitats that have seasonally abundant prey. Throughout the North Atlantic mean diving depth was significantly correlated with the depth of the thermocline, and dive behavior changed in relation to the stratification of the water column. In this study, with numerous multi-year tracks, there appear to be repeatable patterns of clear aggregation areas that potentially are changing with environmental conditions. The high concentrations of bluefin tuna in predictable locations indicate that Atlantic bluefin tuna are vulnerable to concentrated fishing efforts in the regions of foraging aggregations.

  13. The complete mitochondrial genome of the juvenile Atlantic bluefin tuna Thunnus thynnus (Perciformes, Scombridae).

    Science.gov (United States)

    Li, Yanlu; Chen, Chao; Yu, Hong; Peng, Shiming; Sun, Shuguang; Wang, Lu; Meng, Xiangjun; Huang, Ying; Kong, Xiangdi

    2016-01-01

    The complete mitochondrial genome of the juvenile Atlantic bluefin tuna Thunnus thynnus collected from Sea of Japan was determined by next-generation sequencing. The mitogenome is a circular molecule 16,529 bp in length, including the typical structure of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region. The TAS, central CSB and CSB were detected in the control region. The gene contents of the mitogenome are identical to those observed in most bony fishes.

  14. Temperature effects on metabolic rate of juvenile Pacific bluefin tuna Thunnus orientalis.

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    Blank, Jason M; Morrissette, Jeffery M; Farwell, Charles J; Price, Matthew; Schallert, Robert J; Block, Barbara A

    2007-12-01

    Pacific bluefin tuna inhabit a wide range of thermal environments across the Pacific ocean. To examine how metabolism varies across this thermal range, we studied the effect of ambient water temperature on metabolic rate of juvenile Pacific bluefin tuna, Thunnus thynnus, swimming in a swim tunnel. Rate of oxygen consumption (MO2) was measured at ambient temperatures of 8-25 degrees C and swimming speeds of 0.75-1.75 body lengths (BL) s(-1). Pacific bluefin swimming at 1 BL s(-1) per second exhibited a U-shaped curve of metabolic rate vs ambient temperature, with a thermal minimum zone between 15 degrees C to 20 degrees C. Minimum MO2 of 175+/-29 mg kg(-1) h(-1) was recorded at 15 degrees C, while both cold and warm temperatures resulted in increased metabolic rates of 331+/-62 mg kg(-1) h(-1) at 8 degrees C and 256+/-19 mg kg(-1) h(-1) at 25 degrees C. Tailbeat frequencies were negatively correlated with ambient temperature. Additional experiments indicated that the increase in MO2 at low temperature occurred only at low swimming speeds. Ambient water temperature data from electronic tags implanted in wild fish indicate that Pacific bluefin of similar size to the experimental fish used in the swim tunnel spend most of their time in ambient temperatures in the metabolic thermal minimum zone.

  15. Age and growth rate of juvenile bluefin tuna Thunnus thynnus from the Mediterranean sea (Sicily, Italy

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    Mario La Mesa

    2005-06-01

    Full Text Available The microstructural analysis of the sagittal otoliths of juvenile Atlantic bluefin tuna, Thunnus thynnus, can be used to estimate the age and growth rate of young-of-the-year individuals born in the Mediterranean. Samples of juvenile bluefin tuna, obtained as by-catch of the local small-scale pelagic fishery for Atlantic bonito and dolphinfish, were collected off the northern coast of Sicily between late August and early November 2002. Otolith age readings were carried out on 56 specimens ranging between 195 and 400 mm fork length and between 112 and 1266 g total weight. Based on microincrement analysis along a counting path from the otolith core to the antirostrum, juvenile fishes were found to be between 77 days and 153 days old. The estimated growth rate was practically linear over the whole size range, accounting for about 2.0-2.37 mm/day. Derived from the length-weight relationship and the estimated length-at-age data, the mean weight-at-age was 168, 429 and 813 g for 2, 3 and 4 month-old juveniles respectively. Furthermore, the hatching date distribution of bluefin tuna, obtained by means of the back-calculation of ageing data, indicated a spawning period of at least two months, namely from mid-May to mid-July, with a peak in mid-June. Our data indicate that juvenile bluefin tuna have a very high growth rate in the first part of their life, reaching a weight of more than 1 kg in four months.

  16. Changes in the distribution of atlantic bluefin tuna (Thunnus thynnus in the Gulf of Maine 1979-2005.

    Directory of Open Access Journals (Sweden)

    Walter J Golet

    Full Text Available The Gulf of Maine, NW Atlantic Ocean, is a productive, seasonal foraging ground for Atlantic bluefin tuna (Thunnus thynnus, but commercial landings of adult size classes were up to 40% below the allocated total allowable catch between 2004 to 2008 for the rod and reel, harpoon, and purse seine categories in the Gulf of Maine. Reduction in Atlantic bluefin tuna catches in the Gulf of Maine could represent a decline in spawning stock biomass, but given wide-ranging, complex migration patterns, and high energetic requirements, an alternative hypothesis is that their dispersal patterns shifted to regions with higher prey abundance or profitability, reducing availability to U.S. fishing fleets. This study fit generalized linear models to Atlantic bluefin tuna landings data collected from fishermen's logbooks (1979-2005 as well as the distances between bluefin tuna schools and Atlantic herring (Clupeaharengus, a primary prey species, to test alternative hypotheses for observed shifts in Atlantic bluefin tuna availability in the Gulf of Maine. For the bluefin model, landings varied by day of year, latitude and longitude. The effect of latitude differed by day of year and the effect of longitude differed by year. The distances between Atlantic bluefin tuna schools and Atlantic herring schools were significantly smaller (p<0.05 than would be expected from a randomly distributed population. A time series of average bluefin tuna school positions was positively correlated with the average number of herring captured per tow on Georges Bank in spring and autumn surveys respectively (p<0.01, r(2=0.24, p<0.01, r(2=0.42. Fishermen's logbooks contributed novel spatial and temporal information towards testing these hypotheses for the bluefin tuna fishery.

  17. Characterization of two tropomyosin isoforms from the fast skeletal muscle of bluefin tuna Thunnus thynnusorientalis.

    Science.gov (United States)

    Ochiai, Yoshihiro; Ozawa, Hideo; Huang, Ming-Chih; Watabe, Shugo

    2010-10-15

    Fast skeletal muscle tropomyosin (TM) of tunas is composed of nearly equimolar amount of two isoforms designated alpha-TM and beta-TM expediently based on their migration behavior in SDS-PAGE, whereas corresponding TMs from the other fish species are homogenous (alpha-type). The presence of beta-TM is thus specific to tunas so far. The amino acid sequence of beta-TM from bluefin tuna Thunnus thynnus orientalis, which has not been revealed to date unlike alpha-TM, was successfully obtained in this study by cDNA cloning. The coding region of beta-TM cDNA comprised of an open reading frame of 855bp encoding 284 amino acid residues, like most of the TMs. Unexpectedly, the sequence of beta-TM showed high similarity to those of other vertebrate alpha-type TMs including tuna alpha-TM. Phylogenetic analysis also showed that beta-TM has the closest relationship with alpha-TM of tuna. This fact was quite unlike the relation of mammalian alpha- and beta-TMs. Based on the distribution of amino acid substitutions, it was suggested that tuna TM isoforms are the products of different genes. By thermodynamic analysis of native and reconstituted TMs, it was demonstrated that beta-TM is less thermostable than alpha-TM. Proteolytic digestion also supported the lower stability of the former. 2010 Elsevier Inc. All rights reserved.

  18. First data on growth and nucleic acid and protein content of field-captured Mediterranean bluefin (Thunnus thynnus and albacore (Thunnus alalunga tuna larvae: a comparative study

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    Alberto García

    2006-10-01

    Full Text Available The waters surrounding the Balearic archipelago are considered to be prime spawning habitats of the bluefin tuna (Thunnus thynnus and other tuna species such as albacore (T. alalunga in the Mediterranean. During the 2003 bluefin and albacore spawning season, a tuna larval survey (TUNIBAL 0703 was carried out to assess the distribution of bluefin larvae in relation to hydrographic mesoscale features. Tuna larvae were collected by means of surface plankton tows with a bongo gear with a quadrangular mouth measuring 1 m diagonally. The otolith microstructure of 157 and 71 field-captured larvae of Mediterranean bluefin and albacore, respectively, were analyzed to estimate the daily growth pattern. Furthermore, biochemical analysis to estimate DNA, RNA and protein content was done on another batch of 114 bluefin and 132 albacore larvae. The size range included pre-flexion to post-flexion larvae, from 2.8 to 8.6 mm in body length. bluefin and albacore larvae grew linearly in standard length (0.35 and 0.33 mm/day, respectively and potentially with respect to dry weight. No significant differences between species were observed in the size-weight relationship, or in the allometric relationship of body size and weight to otolith radius. However, the relationship of DNA and RNA to body size and weight showed a significant difference between species. Bluefin tuna larvae showed a greater nucleic acid content than albacore larvae. Protein content showed no significant differences with respect to body length.

  19. Electronic tagging of Atlantic bluefin tuna (Thunnus thynnus, L.) reveals habitat use and behaviors in the Mediterranean Sea.

    Science.gov (United States)

    Cermeño, Pablo; Quílez-Badia, Gemma; Ospina-Alvarez, Andrés; Sainz-Trápaga, Susana; Boustany, Andre M; Seitz, Andy C; Tudela, Sergi; Block, Barbara A

    2015-01-01

    We analyzed the movements of Atlantic tuna (Thunnus thynnus L.) in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT). Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012). Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya) using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground.

  20. Electronic tagging of Atlantic bluefin tuna (Thunnus thynnus, L. reveals habitat use and behaviors in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Pablo Cermeño

    Full Text Available We analyzed the movements of Atlantic tuna (Thunnus thynnus L. in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT. Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012. Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground.

  1. Pan-steatitis in farmed northern bluefin tuna, Thunnus thynnus (L.), in the eastern Adriatic.

    Science.gov (United States)

    Roberts, R J; Agius, C

    2008-02-01

    Clinical, gross and histopathological investigations were carried out into large-scale mortalities on eastern Mediterranean bluefin tuna, Thunnus thynnus (L.), farms. Fish showed only nervous signs and darkened colour. At post-mortem the liver was bronze coloured and the pyloric area waxy in consistency. There was no evidence of any other gross pathology. Histopathology showed severe hepatic necrosis and lipidosis. Peri-pancreatic lipoid tissue was heavily infiltrated with an inflammatory round cell infiltrate. Fish on all three farms had been fed on a North African pilchard diet rather than traditional local or Baltic species. Once the diet was modified, losses ceased. A diagnosis of pan-steatitis as seen in other farmed fish species, as well as in terrestrial animals, on particular fish-based diets was made, although the actual factor within the diet which induced the inflammatory effect is not known.

  2. Total mercury levels in muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) from the Mediterranean Sea (Italy).

    Science.gov (United States)

    Storelli, M M; Marcotrigiano, G O

    2001-07-01

    This study was carried out to determine the current levels of total mercury in the muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea with the purpose of ascertaining whether the concentrations exceeded the maximum level fixed by the European Commission Decision. In addition, specimens of each species were divided into different ranges of weight to investigate the influence of size on mercury accumulation in order to provide data upon which commercial fishing strategies and marketing of swordfish and bluefin tuna may be based. Higher mean levels of total mercury were found in bluefin tuna (1.02 microg g(-1) wet wt) than in swordfish (0.49 microg g(-1) wet wt). In 4.3% of swordfish and in 44.3% of bluefin tuna analyzed, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg = 1 microg g(-1) wet wt). Besides, for bluefin tuna the total mercury level variability observed, due to size, suggests that there should be greater regulatory control by the authorities.

  3. Immunocytochemical identification of two distinct gonadotropic cells (GTH I and GTH II) in the pituitary of bluefin tuna, Thunnus thynnus.

    Science.gov (United States)

    Kagawa, H; Kawazoe, I; Tanaka, H; Okuzawa, K

    1998-04-01

    Immunocytochemical identification of GTH I and GTH II cells in the pituitary of the bluefin tuna (Thunnus thynnus) was performed using antisera specific for the common alpha-subunit and the two distinct beta-subunits of tuna (Thunnus obesus) GTH I and GTH II. Cells of the dorsal part of the proximal pars distalis (PPD), in close association with somatotrophs, displayed immunoreactivity of GTHIbeta. GTH IIbeta immunoreactivity was present in cells of the central part of the PPD and the external border of the pars intermedia. Anti-GTHalpha immunostained both GTH Ibeta- and GTH IIbeta-immunoreactive cells and also thyrotrophs. Both GTH Ibeta- and GTH IIbeta-immunoreactive cells were observed in immature bluefin tuna, although there were greater numbers of GTH IIbeta immunoreactive cells. These results suggest that GTH I and GTH II are synthesized in separate cells in the pituitary of the bluefin tuna. The localization and appearance of the two distinct gonadotropic cells of the tuna are compared with the salmonid arrangement. Copyright 1998 Academic Press.

  4. Do captive conditions favor shedding of parasites in the reared Atlantic bluefin tuna (Thunnus thynnus)?

    Science.gov (United States)

    Mladineo, I; Segvić, T; Petrić, M

    2011-01-01

    Tuna (Thunnus spp.) has been characterized by long distance migrations, highly predatory behavior and longevity, all of which in turn, enable infections with a wide spectrum of different parasitic groups, reflecting in a remarkable diversity of tuna parasite communities. Since 2003, we have been monitoring parasite communities of Atlantic bluefin tuna (Thunnus thynnus) that are caught from the wild and transferred into cages during spring-summer months, as well as assemblages in fish that exit rearing cycle during the winter harvest period after 1.5 years. Interestingly in reared tuna, parasitic populations exhibit a significant decreasing trend at the end of the rearing cycle, rarely observed in other intensive productions that represent a suitable environment for the emergence, establishment and transmission of pathogens. In order to assess epizootiological behavior of tuna parasites assemblages at the beginning (B group) and at the end (A group) of 1.5 year rearing cycle, we examined data on parasite prevalence and abundance over 4 years. The aim was to evaluate parasite diversity indices and emerging differences between newly caught and harvested fish, as well as community compositions and their nestedness in respect to the event in the rearing cycle (capture or harvest time). In order to be able to predict classification of tuna in two categories (newly caught or heavily infected and harvested or less infected fish), based on empirical didymozoids abundances and year of sampling, we built a decision tree model. Results suggest that specificities of parasite assemblages and their dynamics in tuna before and after farming have no similar precedents in aquaculture. A trend of parasitic pauperization repeating in each rearing cycle over four-years time, in once diverse and species rich parasite communities is observed, however, structures of both B and A group rearing assemblages remain nested, with the same species being core parasites (Didymosulcus katsuwonicola

  5. Preliminary approach on early post mortem stress and quality indexes changes in large size bluefin tuna (Thunnus thynnus

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    R. Ugolini

    2010-01-01

    Full Text Available Bluefin tuna (Thunnus thynnus is very appreciated on Japan and USA market for the preparation of sushi and sahimi. The market price of the fresh product can vary from 8 to 33 Euro/kg (gate farm/producers prices according to size, shape, fat level, meat colour, consistency and freshness (absence of “hyake”, all parameters strictly connected to feeding quality and quantity, rearing and killing stress factors and refrigeration times and conditions after death. Excessive levels of stress during the slaughtering can affect meat quality, contributing to significantly decrease of tuna’s price. The present trial was carried out to evaluate the possible harvesting/slaughtering stress effect on reared bluefin tuna meat quality, starting from the examination of the most important stress and quality parameters changes during the early post mortem period.

  6. Movements of pacific bluefin tuna ( Thunnus orientalis) in the Eastern North Pacific revealed with archival tags

    Science.gov (United States)

    Boustany, Andre M.; Matteson, Robyn; Castleton, Michael; Farwell, Charles; Block, Barbara A.

    2010-07-01

    In this study, 253 Pacific bluefin tuna were archivally tagged off the coast of California, USA and Baja California, Mexico between August 2002 and August 2005. One hundred and fifty-seven fish were recaptured and 143 datasets were obtained and analyzed, yielding electronic tag datasets of up to 1203 days. Mean days at large for the 143 fish was 359 ± 248 (SD) days. A total of 38,012 geolocations were calculated from light-based longitude and SST-based latitude estimates, allowing us to examine the seasonal movement of juvenile bluefin tuna off the west coast of North America. Electronic tagged bluefin tuna showed repeatable seasonal movements along the west coast of North America. Bluefin tuna were found farthest south in the spring when they were located off southern Baja California, Mexico and farthest north in the fall when fish were found predominately off central and northern California. Fish showed latitudinal movement patterns that were correlated with peaks in coastal upwelling-induced primary productivity. Interannual variation in the locality of these productivity peaks was linked with a corresponding movement in the distribution of tagged fish. Overall geographical area occupied by tagged bluefin varied with primary productivity, with fish being more tightly clustered in areas of high productivity and more dispersed in regions of low productivity. In the spring through fall, bluefin tuna were located in areas with the highest levels of primary productivity available in the California Current ecosystem. However, in the winter months, tagged bluefin tuna were found in areas with lower productivity compared to other regions along the coast at that time of year suggesting that during the winter, bluefin tuna are feeding on aggregations of pelagic red crabs, sardines and anchovies that preferentially spawn in areas of reduced coastal upwelling.

  7. Temporal distribution of size and weight of fattened Bluefin tuna (Thunnus thynnus l. from Tunisian farms: (2005-2010

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    A. HATTOUR

    2013-12-01

    Full Text Available The present study analysis size and weight-frequency composition of Atlantic bluefin tuna (Thunnus thynnus thynnus fattened in Tunisian farms for the period 2005-2010 and compare these morphometric parameters with those from wild bluefin tuna landed on 2001 at Sfax port (Tunisia. A total of 6,757 wild and fattened bluefin tuna were measured as straight-line fork length and 49,962 were weighted. Average value of K for wild BFT was 1.59 and respectively 2.43, 2.32, 2.15, 1.61, 1.79 and 1.90 for Fattened BFT after 5-6 months from 2005 to 2010. Length frequency of fattened bluefin showed clearly a substantial increase in juvenile rate. The percentage which was 21.4% in 2005 reached 31.3% in 2009. For weight distribution, 73.3% of the fish caught in 2001 are below the annual mean (75.7 kg, while means 71 to 72% of fattened fish were under annual mean weight. Year 2009 is exceptional because only 57% of fattened fish were under the mean weight. This demonstrates that the fish caught are becoming increasingly small. Mean weight for fattening period (77 to 124 kg are obviously higher than those of the wild fish (75,7kg.This study showed an increment in the amount of specimen under first sexual maturity which will not have the chance to spawn.

  8. Effects of age on growth in Atlantic bluefin tuna (Thunnus thynnus).

    Science.gov (United States)

    Api, Martina; Bonfanti, Erica; Lombardo, Francesco; Pignalosa, Paolo; Hardiman, Gary; Carnevali, Oliana

    2018-01-12

    Atlantic Bluefin Tuna Thunnus thynnus (ABFT) is considered one of the most important socio-economic species but there is a lack of information on the physiological and molecular processes regulating its growth and metabolism. In the present study, we focused on key molecules involved in growth process. The aim of the present study was to associate molecular markers related to growth with canonical procedures like morphological measurements such as curved fork length (CFL) and round weight (RWT). The ABFT specimens (n = 41) were organized into three different groups A, B and C according to their age. The molecular analysis of liver samples revealed that igf1, igf1r and mTOR genes, involved in growth process, were differentially expressed in relation to the age of the fish. In addition, during the analyzed period, faster growth was evident from 5 to 8 years of age, after that, the growth rate decreased in terms of length yet increased in terms of adipose tissue storage, as supported by the higher fat content in the liver. These results are useful in expanding basic knowledge about the metabolic system of ABFT and provide new knowledge for the aquaculture industry. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Quantification of ovarian follicles in bluefin tuna Thunnus thynnus by two stereological methods.

    Science.gov (United States)

    Aragón, L; Aranda, G; Santos, A; Medina, A

    2010-08-01

    The numbers of different types of ovarian follicles (developing, degenerating and postovulatory follicles) were estimated in bluefin tuna Thunnus thynnus using two stereological procedures: the model-based method of Weibel & Gomez, which has become a tool of broad application in the quantification of oocytes in fishes, and the assumption-free 'disector' (sic) method of Sterio. The estimates of developing follicles (follicles containing lipid-stage, vitellogenic and migratory-nucleus oocytes) made by the model-based method tended to be lower than those obtained with the disector, though significant differences were not observed except for vitellogenic follicles. Counts of atretic follicles by the model-based method were higher than those made using the disector, the differences being remarkable between both techniques, particularly in the case of beta-atresia, where the statistical analysis indicated significantly unequal estimations with the two methods. In contrast, the amount of postovulatory follicles estimated by the disector, which would stand for the realized batch fecundity, was somewhat larger than that calculated with the model-based method.

  10. Liver melanomacrophage centres as indicators of Atlantic bluefin tuna, Thunnus thynnus L. well-being.

    Science.gov (United States)

    Passantino, L; Santamaria, N; Zupa, R; Pousis, C; Garofalo, R; Cianciotta, A; Jirillo, E; Acone, F; Corriero, A

    2014-03-01

    Melanomacrophage centres (MMCs), located in different organs of non-mammalian vertebrates, play a role in the destruction, detoxification or recycling of endogenous and exogenous materials. Cytochrome P450 monoxygenase 1A (CYP1A) is involved in xenobiotics biotransformation, and its liver expression is considered as a biomarker for detecting exposure to environmental pollutants. Atlantic bluefin tuna (ABFT), Thunnus thynnus L., liver samples were collected from: wild animals caught in the eastern Atlantic; juveniles reared in the central Adriatic; juveniles reared in the northern Adriatic; adults reared in the western Mediterranean. The samples were processed for basic histology, histochemistry and for CYP1A immunodetection. An unexpected high density of MMCs, containing ferric iron and lipofuscin-ceroids, was detected in the juveniles sampled in the northern Adriatic Sea. These individuals showed also a strong anti-CYP1A immunopositivity in hepatocytes and in the epithelium of bile ducts. This study supports the utility of MMCs as biomarkers of fish 'health status' and gives concern for a potential contaminant accumulation in ABFT. © 2013 John Wiley & Sons Ltd.

  11. Amino acid isotope incorporation and enrichment factors in Pacific bluefin tuna, Thunnus orientalis.

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    Christina J Bradley

    Full Text Available Compound specific isotopic analysis (CSIA of amino acids has received increasing attention in ecological studies in recent years due to its ability to evaluate trophic positions and elucidate baseline nutrient sources. However, the incorporation rates of individual amino acids into protein and specific trophic discrimination factors (TDFs are largely unknown, limiting the application of CSIA to trophic studies. We determined nitrogen turnover rates of individual amino acids from a long-term (up to 1054 days laboratory experiment using captive Pacific bluefin tuna, Thunnus orientalis (PBFT, a large endothermic pelagic fish fed a controlled diet. Small PBFT (white muscle δ(15N∼11.5‰ were collected in San Diego, CA and transported to the Tuna Research and Conservation Center (TRCC where they were fed a controlled diet with high δ(15N values relative to PBFT white muscle (diet δ(15N∼13.9‰. Half-lives of trophic and source amino acids ranged from 28.6 to 305.4 days and 67.5 to 136.2 days, respectively. The TDF for the weighted mean values of amino acids was 3.0 ‰, ranging from 2.2 to 15.8 ‰ for individual combinations of 6 trophic and 5 source amino acids. Changes in the δ(15N values of amino acids across trophic levels are the underlying drivers of the trophic (15N enrichment. Nearly all amino acid δ(15N values in this experiment changed exponentially and could be described by a single compartment model. Significant differences in the rate of (15N incorporation were found for source and trophic amino acids both within and between these groups. Varying half-lives of individual amino acids can be applied to migratory organisms as isotopic clocks, determining the length of time an individual has spent in a new environment. These results greatly enhance the ability to interpret compound specific isotope analyses in trophic studies.

  12. Immunocytohistochemical characterization of pituitary cells of the bluefin tuna, Thunnus thynnus L.

    Science.gov (United States)

    Rodríguez-Gómez, F J; Rendón-Unceta, M C; Piñuela, C; Muñoz-Cueto, J A; Jiménez-Tenorio, N; Sarasquete, C

    2001-04-01

    In this paper we report the first complete mapping of the pituitary in a tuna species. The various different adenohypophysis cell types of the bluefin tuna, Thunnus thynnus L. have been identified and located using different antisera against mammalian and piscine hormones and various histochemical techniques: PAS, Alcian Blue pH 2.5 and lectins -ConA and WGA(Neutral and Acidic Glycoproteins); Bromophenol Blue (Proteins) and Tioglycollate-Ferric-Ferricianide-FeIII (-S-S- groups). Prolactin (PRL) and adrenocorticotrophic (ACTH) cells were located in the rostral pars distalis (RPD) of the pituitary, while the proximal pars distalis (PPD) displayed gonadotrophic (GTH), thyrotrophic (TSH), somatotrophic (GH) and also a few PRL cells. Moreover, somatolactin (SL) and melanotrophic (MSH) cells were identified inside the pars intermedia (PI). Interestingly, some SL-immunoreactive fibers were also detected in the neurohypophysis. Some GTH cells were also located on the exterior surface of the PI. Glycoproteins containing mannose (Man) and/or glucose (Glc); N-acetyl-glucosamine (GlcNAc) and/or sialic acid sugar residues, as well as -S-S- groups, were observed in GTH, TSH and SL cells. The Bromophenol Blue technique stained amphiphilic SL, acidophilic GH cells and weakly ACTH cells. GH and ACTH cells were unreactive to PAS, Alcian Blue, Tioglycollate-Ferric-Ferricianide-FeIII and lectin (Con A and WGA) techniques. Finally, PAS reaction was positive in amphiphilic SL cells, which were PbH unreactive, while MSH and ACTH cells were stained with PbH technique.

  13. Amino Acid Isotope Incorporation and Enrichment Factors in Pacific Bluefin Tuna, Thunnus orientalis

    Science.gov (United States)

    Bradley, Christina J.; Madigan, Daniel J.; Block, Barbara A.; Popp, Brian N.

    2014-01-01

    Compound specific isotopic analysis (CSIA) of amino acids has received increasing attention in ecological studies in recent years due to its ability to evaluate trophic positions and elucidate baseline nutrient sources. However, the incorporation rates of individual amino acids into protein and specific trophic discrimination factors (TDFs) are largely unknown, limiting the application of CSIA to trophic studies. We determined nitrogen turnover rates of individual amino acids from a long-term (up to 1054 days) laboratory experiment using captive Pacific bluefin tuna, Thunnus orientalis (PBFT), a large endothermic pelagic fish fed a controlled diet. Small PBFT (white muscle δ15N∼11.5‰) were collected in San Diego, CA and transported to the Tuna Research and Conservation Center (TRCC) where they were fed a controlled diet with high δ15N values relative to PBFT white muscle (diet δ15N∼13.9‰). Half-lives of trophic and source amino acids ranged from 28.6 to 305.4 days and 67.5 to 136.2 days, respectively. The TDF for the weighted mean values of amino acids was 3.0 ‰, ranging from 2.2 to 15.8 ‰ for individual combinations of 6 trophic and 5 source amino acids. Changes in the δ15N values of amino acids across trophic levels are the underlying drivers of the trophic 15N enrichment. Nearly all amino acid δ15N values in this experiment changed exponentially and could be described by a single compartment model. Significant differences in the rate of 15N incorporation were found for source and trophic amino acids both within and between these groups. Varying half-lives of individual amino acids can be applied to migratory organisms as isotopic clocks, determining the length of time an individual has spent in a new environment. These results greatly enhance the ability to interpret compound specific isotope analyses in trophic studies. PMID:24465724

  14. Discovery of a spawning ground reveals diverse migration strategies in Atlantic bluefin tuna (Thunnus thynnus).

    Science.gov (United States)

    Richardson, David E; Marancik, Katrin E; Guyon, Jeffrey R; Lutcavage, Molly E; Galuardi, Benjamin; Lam, Chi Hin; Walsh, Harvey J; Wildes, Sharon; Yates, Douglas A; Hare, Jonathan A

    2016-03-22

    Atlantic bluefin tuna are a symbol of both the conflict between preservationist and utilitarian views of top ocean predators, and the struggle to reach international consensus on the management of migratory species. Currently, Atlantic bluefin tuna are managed as an early-maturing eastern stock, which spawns in the Mediterranean Sea, and a late-maturing western stock, which spawns in the Gulf of Mexico. However, electronic tagging studies show that many bluefin tuna, assumed to be of a mature size, do not visit either spawning ground during the spawning season. Whether these fish are spawning in an alternate location, skip-spawning, or not spawning until an older age affects how vulnerable this species is to anthropogenic stressors including exploitation. We use larval collections to demonstrate a bluefin tuna spawning ground in the Slope Sea, between the Gulf Stream and northeast United States continental shelf. We contend that western Atlantic bluefin tuna have a differential spawning migration, with larger individuals spawning in the Gulf of Mexico, and smaller individuals spawning in the Slope Sea. The current life history model, which assumes only Gulf of Mexico spawning, overestimates age at maturity for the western stock. Furthermore, individual tuna occupy both the Slope Sea and Mediterranean Sea in separate years, contrary to the prevailing view that individuals exhibit complete spawning-site fidelity. Overall, this complexity of spawning migrations questions whether there is complete independence in the dynamics of eastern and western Atlantic bluefin tuna and leads to lower estimates of the vulnerability of this species to exploitation and other anthropogenic stressors.

  15. Expression of vitellogenin receptor gene in the ovary of wild and captive Atlantic bluefin tuna (Thunnus thynnus).

    Science.gov (United States)

    Pousis, C; Santamaria, N; Zupa, R; De Giorgi, C; Mylonas, C C; Bridges, C R; de la Gándara, F; Vassallo-Agius, R; Bello, G; Corriero, A

    2012-05-01

    The cDNA sequences of vitellogenin receptor proteins (VgR(+) and VgR(-)), containing or lacking the O-linked sugar domain, were determined in Atlantic bluefin tuna (Thunnus thynnus L.). VgR(-) gene expression in the ovary was compared in captive-reared and wild Atlantic bluefin tuna during the reproductive cycle. Gonad samples from adult fish were sampled from 2008 to 2010 from stocks reared in captivity at different commercial fattening operations in the Mediterranean Sea and from wild individuals caught either by traditional tuna traps during their migration towards the spawning grounds in the Mediterranean Sea or by the long-line artisanal fishery. In addition, juvenile male and female Atlantic bluefin tuna were sampled from a farming facility, to obtain baseline information and pre-adulthood amounts of VgR(-). The total length of VgR(+) cDNA was 4006 nucleotides (nt) and that of VgR(-) was 3946 nt. Relative amounts of VgR(-) were greater in juvenile females and in those adults having only previtellogenic oocytes (119 ± 55 and 146 ± 26 folds more than juvenile males, respectively). Amounts of VgR(-) were less in individuals with yolked oocytes (ripening stage, May-June) and increased after spawning in July (92 ± 20 and 113 ± 13 folds more than juvenile males in ripening and post-spawning fish, respectively). These data suggest that regulation of VgR(-) is not under oestrogen control. During the ripening period, greater VgR(-) gene expression was observed in wild fish than in fish reared in captivity, possibly because of (a) differences in water temperature exposure and/or energy storage, and/or (b) an inadequate diet in reared Atlantic bluefin tuna. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. HCB, p,p'-DDE and PCB ontogenetic transfer and magnification in bluefin tuna (Thunnus thynnus) from the Mediterranean Sea.

    Science.gov (United States)

    Corsolini, Simonetta; Sarà, Gianluca; Borghesi, Nicoletta; Focardi, Silvano

    2007-06-15

    The bluefin tuna, Thunnus thynnus (Linnaeus 1758), is biologically and economically important in the Atlantic--Mediterranean ecosystems. Bluefin tuna feed on diverse food items depending on their age, thus they occupy different trophic levels during their lifespan. Hexachlorobenzene (HCB), p,p'-DDE and polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants (POPs) in the Mediterranean basin. The relationship between stable isotopes of nitrogen (N) and the POP residue levels in tissues has recently increased knowledge on the link between the trophic levels and the contaminant accumulation. Trophic levels were estimated by using 15N/14N ratio (delta15N) and HCB, p,p'-DDE, and forty-three PCBs were quantified in bluefin tuna from the southern Tyrrhenian Sea. Results showed that changes in PCB and p,p'-DDE concentrations were a function of size and trophic level, while no correlations were observed for HCB. Apart from HCB and PCB nos. 101, 207, 95, 158, and 60 + 56, which did not show any significant increase per trophic level, the other PCBs and the p,p'-DDE increased significantly. The ontogenetic magnification factor of PCBs was 6.6 +/- 0.5, which was significantly (12 times) higher (p < 0.05) than the values found for p,p'-DDE (1.4) and HCB (1.4).

  17. Atlantic bluefin tuna (Thunnus thynnus) population dynamics delineated by organochlorine tracers.

    Science.gov (United States)

    Dickhut, Rebecca M; Deshpande, Ashok D; Cincinelli, Alessandra; Cochran, Michele A; Corsolini, Simonetta; Brill, Richard W; Secor, David H; Graves, John E

    2009-11-15

    Atlantic bluefin tuna (ABFT) are highly valued and heavily exploited, and critical uncertainties regarding their population structure hinder effective management. Evidence supports the existence of two breeding populations of ABFT; a western population in the Gulf of Mexico and an eastern population in the Mediterranean Sea; both of which migrate and mix in the North Atlantic. Conventional tagging studies suggest low rates of trans-Atlantic migrations; however, electronic tagging and stable isotopes in otoliths indicate stock mixing up to 57% between management zones delineated by 45 degrees W longitude. Here we show that organochlorine pesticides and polychlorinated biphenyls (PCBs) can be used as tracers of bluefin tuna foraging grounds in the North Atlantic and confirm that stock mixing of juvenile tuna within the U.S. Mid Atlantic Bight is indeed high (33-83% eastern origin), and is likely spatially and temporally variable. We further demonstrate that >10% of the Mediterranean population is migratory, that young bluefin tuna migrate from the Mediterranean to western Atlantic foraging grounds as early as age 1, and then return to the Mediterranean Sea as young as age 5, presumably to breed. The tracer method described here provides a novel means for distinguishing bluefin tuna populations and ontogenetic shifts in migration in the North Atlantic.

  18. Molecular and morphological identification of Cardicola (Trematoda: Aporocotylidae) eggs in hatchery-reared and migratory Atlantic bluefin tuna (Thunnus thynnus L.)

    Czech Academy of Sciences Publication Activity Database

    Forte-Gil, D.; Holzer, Astrid S.; Pecková, Hana; Bartošová-Sojková, Pavla; Peñalver, J.; Dolores, E.M.; Muñoz, P.

    2016-01-01

    Roč. 450, JAN 1 (2016), s. 58-66 ISSN 0044-8486 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Aquaculture * Atlantic bluefin tuna * Blood fluke * Cardicola * Migration * Thunnus thynnus Subject RIV: EG - Zoology Impact factor: 2.570, year: 2016

  19. Muscle temperature in free-swimming giant Atlantic bluefin tuna (Thunnus thynnus L.).

    Science.gov (United States)

    Stevens; Kanwisher; Careymaltese cross FG

    2000-12-01

    Muscle temperature was measured by telemetry in giant Atlantic bluefin tuna whilst the tuna were free-swimming in large pounds. Muscle temperature tended to remain steady at about 24 degrees C; water temperature ranged from 9 to 17 degrees C. Muscle temperature was much less variable than stomach temperature in these fish. Muscle temperature varied less than 3 degrees C whereas stomach temperature varied by as much as 14 degrees C.

  20. Spawning Dynamics and Size Related Trends in Reproductive Parameters of Southern Bluefin Tuna, Thunnus maccoyii.

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    Jessica H Farley

    Full Text Available Knowledge of spawning behaviour and fecundity of fish is important for estimating the reproductive potential of a stock and for constructing appropriate statistical models for assessing sustainable catch levels. Estimates of length-based reproductive parameters are particularly important for determining potential annual fecundity as a function of fish size, but they are often difficult to estimate reliably. Here we provide new information on the reproductive dynamics of southern bluefin tuna (SBT Thunnus maccoyii through the analysis of fish size and ovary histology collected on the spawning ground in 1993-1995 and 1999-2002. These are used to refine previous parameter estimates of spawning dynamics and investigate size related trends in these parameters. Our results suggest that the small SBT tend to arrive on the spawning ground slightly later and depart earlier in the spawning season relative to large fish. All females were mature and the majority were classed as spawning capable (actively spawning or non-spawning with a very small proportion classed as regressing. The fraction of females spawning per day decreased with fish size, but once females start a spawning episode, they spawned daily irrespective of size. Mean batch fecundity was estimated directly at 6.5 million oocytes. Analysis of ovary histology and ovary weight data indicated that relative batch fecundity, and the duration of spawning and non-spawning episodes, increased with fish size. These reproductive parameter estimates could be used with estimates of residency time on the spawning ground as a function of fish size (if known and demographic data for the spawning population to provide a time series of relative annual fecundity for SBT.

  1. Oogenesis in the bluefin tuna, Thunnus thynnus L.: a histological and histochemical study.

    Science.gov (United States)

    Sarasquete, C; Cárdenas, S; de González, Canales M L; Pascual, E

    2002-01-01

    Histology and histochemistry are useful tools to study reproductive mechanisms in fish and they have been applied in this study. In the bluefin tuna, Thunnus thymus L., oocyte development can be divided into 4 principal phases based on the morphological features of developing oocytes and follicles. The primary growth phase includes oogonia and basophilic or previtellogenic oocytes classified as chromatin-nucleolus and perinucleolus stages. The secondary growth phase is represented by vitellogenic oocytes at early (lipid globule and yolk granule 1), mid (yolk granule 2) and late (yolk granule 3) vitellogenesis stages. The maturation phase involves postvitellogenic oocytes undergoing maturation process. During the spawning period, both postovulatory follicles, which indicate spawning, and atretic follicles can be distinguished in the ovary. Carbohydrates, lipids, proteins and specially those rich in tyrosine, tryptophan, cystine, arginine, lysine and cysteine, as well phospholipids and/or glycolipids and neutral glycoproteins were detected in yolk granules. Moreover, affinity for different lectins (ConA, WGA, DBA and UEA) was detected in vitellogenic oocytes (yolk granules, cortical alveoli, follicular layer and zona radiata), indicating the presence of glycoconjugates with different sugar residues (Mannose- Man- and/or Glucose -Glc-; N-acetyl-D-glucosamine- GlcNAc- and/or sialic acid- NANA-; N-acetyl-D-galactosamine- GalNAc-; L-Fucose -Fuc-). Histochemical techniques also demonstrated the presence of neutral lipids in globules (vacuoles in paraffin sections) and neutral and carboxylated mucosubstances in cortical alveoli. By using anti-vitellogenin (VTG) serum, immunohistochemical positive results were demonstrated in yolk granules, granular cytoplasm and follicular cells of vitellogenic oocytes. Calcium was also detected in yolk granules and weakly in follicular envelope. In females, the gonadosomatic index (GSI) increased progressively from May, during early

  2. Quantifying mercury isotope dynamics in captive Pacific bluefin tuna (Thunnus orientalis

    Directory of Open Access Journals (Sweden)

    Sae Yun Kwon

    2016-02-01

    Full Text Available Abstract Analyses of mercury (Hg isotope ratios in fish tissues are used increasingly to infer sources and biogeochemical processes of Hg in natural aquatic ecosystems. Controlled experiments that can couple internal Hg isotope behavior with traditional isotope tracers (δ13C, δ15N can improve the applicability of Hg isotopes as natural ecological tracers. In this study, we investigated changes in Hg isotope ratios (δ202Hg, Δ199Hg during bioaccumulation of natural diets in the pelagic Pacific bluefin tuna (Thunnus orientalis; PBFT. Juvenile PBFT were fed a mixture of natural prey and a dietary supplement (60% Loligo opalescens, 31% Sardinops sagax, 9% gel supplement in captivity for 2914 days, and white muscle tissues were analyzed for Hg isotope ratios and compared to time in captivity and internal turnover of δ13C and δ15N. PBFT muscle tissues equilibrated to Hg isotope ratios of the dietary mixture within ∼700 days, after which we observed a cessation in further shifts in Δ199Hg, and small but significant negative δ202Hg shifts from the dietary mixture. The internal behavior of Δ199Hg is consistent with previous fish studies, which showed an absence of Δ199Hg fractionation during Hg bioaccumulation. The negative δ202Hg shifts can be attributed to either preferential excretion of Hg with higher δ202Hg values or individual variability in captive PBFT feeding preferences and/or consumption rates. The overall internal behavior of Hg isotopes is similar to that described for δ13C and δ15N, though observed Hg turnover was slower compared to carbon and nitrogen. This improved understanding of internal dynamics of Hg isotopes in relation to δ13C and δ15N enhances the applicability of Hg isotope ratios in fish tissues for tracing Hg sources in natural ecosystems.

  3. Cardicola opisthorchis n. sp. (Trematoda: Aporocotylidae) from the Pacific bluefin tuna, Thunnus orientalis (Temminck & Schlegel, 1844), cultured in Japan.

    Science.gov (United States)

    Ogawa, K; Ishimaru, K; Shirakashi, S; Takami, I; Grabner, D

    2011-09-01

    A new aporocotylid blood fluke is described, based on specimens from the ventricle of the Pacific bluefin tuna, Thunnus orientalis (Temminck et Schlegel), cultured in Wakayama and Nagasaki Prefectures, Japan. The new species is morphologically similar to the members of the genus Cardicola Short, 1953, but shows distinct differences in the body form, location of the testis and the orientation of the ootype. The body of the new species is long and slender, whereas other Cardicola species are small and generally lanceolate. The testis is mostly located posterior to the caeca and anterior to the ovary, occupying 31-45% of body length, in contrast to the known Cardicola species, whose testis is typically intercaecal. The ootype is oriented anteriorly, while in most congeners, it is directed posteriorly or horizontally. Phylogenetic analyses of this aporocotylid, together with Cardicola orientalis Ogawa, Tanaka, Sugihara et Takami, 2010 from the same host, were conducted based on DNA sequences of the ITS2 rDNA and the 28S region of ribosomal RNA. The analyses revealed that the new blood fluke belongs to the genus Cardicola despite the marked morphological differences. Thus, this aporocotylid is named Cardicola opisthorchis n. sp. and the generic diagnosis is emended in this paper. In addition, 100% identity among the ITS2 sequences from the present species, Cardicola sp. from T. orientalis in Mexico and Cardicola sp. from the northern bluefin tuna, Thunnus thynnus (Linnaeus) in Spain suggests that C. opisthorchis n. sp. has a broad geographical distribution and that it infects both the Pacific and northern bluefin tuna. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Locus-specific EPIC-PCR primers for four distinct calmodulin genes of the Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel, 1844

    Directory of Open Access Journals (Sweden)

    Seinen Chow

    2017-01-01

    Full Text Available Abstract Nucleotide sequences of four distinct calmodulin genes (designated as CaM-A to -D of the Pacific bluefin tuna (Thunnus orientalis were compared. Nucleotide sequence divergence between the coding regions of four genes ranged from 16.0 to 21.6%, and locus-specific eight primer pairs targeting introns were designed. These primer pairs amplified expected size of fragments in five congeneric tuna species, and utility of these primer pairs was investigated using distant fish species.

  5. The development of the northern European fishery for north Atlantic bluefin tuna Thunnus thynnus during 1900-1950

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Myers, R.A.

    2007-01-01

    North Atlantic bluefin tuna, Thunnus thynnus, used to migrate to northern European waters (Norwegian Sea, North Sea, Skagerrak, Kattegat, and Øresund) where it supported important commercial and sportfisheries. The species disappeared from the region in the early 1960s and the species is now still...... increasing. The species was frequently sighted while fishermen were targeting other species (herring, mackerel) and occasionally was caught as bycatch with these and other species. Information from scientifically trained observers demonstrate that tuna schools were common in the North Sea for 2–3 months...... during the summers of 1923–1931. As fishermen realized that the species had market value, new catch methods were developed and employed. These included harpoon-rifle, improved hook and line methods, and hydraulically operated purse seines. Landings rose sharply as did the number of vessels...

  6. Discovering where bluefin tuna, Thunnus thynnus, might go: using environmental and fishery data to map potential tuna habitat in the eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Dimitrios Damalas

    2012-11-01

    Full Text Available Based on a dataset derived from commercial fisheries in the eastern Mediterranean Sea in 1998-2005, we applied generalized additive models (GAMs to investigate the relative influence of a range of environmental factors on catch rates of Atlantic bluefin tuna (Thunnus thynnus Linnaeus, 1785. GAM analyses were conducted by separately modelling (1 the probability of making a catch (encountering a school, and (2 the positive catch rates (school size. Results suggested intra-annual variations in tuna distribution and revealed interesting associations with some environmental features, lunar periodicity being the most distinctive one. Probability of encountering a school peaked in late spring months, eastwards, at water temperatures above 22°C and around the full moon. Size of school was more likely to be larger in northeasternmost regions and in the vicinity of land in late spring, when the percentage of lunar disc illumination was higher. A moderate but continuous annual decline in the probability of encountering a bluefin tuna school was detected from the models’ outputs. The models were used as an indication of preference or association for the selected environmental variables. Based on these associations, an indirect identification of the bluefin tuna potential habitat was obtained and used to map distributions in the eastern Mediterranean region.

  7. Spawning behaviour and post-spawning migration patterns of atlantic bluefin tuna (Thunnus thynnus ascertained from satellite archival tags.

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    Guillermo Aranda

    Full Text Available Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands (years 2009-2011. All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples.

  8. Spawning behaviour and post-spawning migration patterns of atlantic bluefin tuna (Thunnus thynnus) ascertained from satellite archival tags.

    Science.gov (United States)

    Aranda, Guillermo; Abascal, Francisco Javier; Varela, José Luis; Medina, Antonio

    2013-01-01

    Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus) was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands (years 2009-2011). All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples.

  9. Microarray gene expression profiles from mature gonad tissues of Atlantic bluefin tuna, Thunnus thynnus in the Gulf of Mexico.

    Science.gov (United States)

    Gardner, Luke D; Jayasundara, Nishad; Castilho, Pedro C; Block, Barbara

    2012-10-05

    Bluefin tunas are highly prized pelagic fish species representing a significant economic resource to fisheries throughout the world. Atlantic bluefin tuna (Thunnus thynnus) populations have significantly declined due to overexploitation. As a consequence of their value and population decline, T. thynnus has been the focus of considerable research effort concerning many aspects of their life history. However, in-depth understanding of T. thynnus reproductive biology is still lacking. Knowledge of reproductive physiology is a very important tool for determining effective fisheries and aquaculture management. Transcriptome techniques are proving powerful and provide novel insights into physiological processes. Construction of a microarray from T. thynnus ESTs sourced from reproductive tissues has provided an ideal platform to study the reproductive physiology of bluefin tunas. The aim of this investigation was to compare transcription profiles from the ovaries and testes of mature T. thynnus to establish sex specific variations underlying their reproductive physiology. Male and females T. thynnus gonad tissues were collected from the wild and histologically staged. Sub-samples of sexually mature tissues were also measured for their mRNA differential expression among the sexes using the custom microarray design BFT 4X44K. A total of 7068 ESTs were assessed for differential expression of which 1273 ESTs were significantly different (p2 fold change in expression according to sex. Differential expression for 13 of these ESTs was validated with quantitative PCR. These include genes involved in egg envelope formation, hydration, and lipid transport/accumulation more highly expressed in ovaries compared with testis, while genes involved in meiosis, sperm motility and lipid metabolism were more highly expressed in testis compared with ovaries. This investigation has furthered our knowledge of bluefin tunas reproductive biology by using a contemporary transcriptome approach

  10. Microarray gene expression profiles from mature gonad tissues of Atlantic bluefin tuna, Thunnus thynnus in the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Gardner Luke D

    2012-10-01

    Full Text Available Abstract Background Bluefin tunas are highly prized pelagic fish species representing a significant economic resource to fisheries throughout the world. Atlantic bluefin tuna (Thunnus thynnus populations have significantly declined due to overexploitation. As a consequence of their value and population decline, T. thynnus has been the focus of considerable research effort concerning many aspects of their life history. However, in-depth understanding of T. thynnus reproductive biology is still lacking. Knowledge of reproductive physiology is a very important tool for determining effective fisheries and aquaculture management. Transcriptome techniques are proving powerful and provide novel insights into physiological processes. Construction of a microarray from T. thynnus ESTs sourced from reproductive tissues has provided an ideal platform to study the reproductive physiology of bluefin tunas. The aim of this investigation was to compare transcription profiles from the ovaries and testes of mature T. thynnus to establish sex specific variations underlying their reproductive physiology. Results Male and females T. thynnus gonad tissues were collected from the wild and histologically staged. Sub-samples of sexually mature tissues were also measured for their mRNA differential expression among the sexes using the custom microarray design BFT 4X44K. A total of 7068 ESTs were assessed for differential expression of which 1273 ESTs were significantly different (p2 fold change in expression according to sex. Differential expression for 13 of these ESTs was validated with quantitative PCR. These include genes involved in egg envelope formation, hydration, and lipid transport/accumulation more highly expressed in ovaries compared with testis, while genes involved in meiosis, sperm motility and lipid metabolism were more highly expressed in testis compared with ovaries. Conclusions This investigation has furthered our knowledge of bluefin tunas

  11. Management actions and initiatives for bluefin tuna over the past ...

    African Journals Online (AJOL)

    spamer

    Management actions and initiatives for bluefin tuna over the past decade have been the subject of consid- erable controversy. Debate has centred particularly on stocks of the north Atlantic Thunnus thynnus, especially in the western North Atlantic, and of the southern hemi- sphere (southern bluefin tuna [SBT] Thunnus mac-.

  12. Oxygen equilibrium studies on hemoglobin from the bluefin tuna (Thunnus thynnus).

    Science.gov (United States)

    Ikeda-Saito, M; Yonetani, T; Gibson, Q H

    1983-08-15

    Oxygen equilibrium curves of the purified hemoglobin component I from the Atlantic bluefin tuna (Thunnus thynnus) have been determined between pH 6.5 and 8.75 at 25 degrees C, and for five temperatures between 10 and 30 degrees C at pH 7.0 and 7.5. From the equilibrium data oxygen equilibrium constants for four oxygenation steps, Ki (i = 1 to 4) were estimated. The number of the Bohr protons released on the ith oxygenation (delta Hi+), and the enthalpy and entropy changes at each oxygenation step (delta Hi and delta Si) were calculated. The Hill plot for oxygenation below neutral pH is biphasic; the top asymptote lies to the right of the bottom one and the linking limb between them exhibits a slope less than unity, exhibiting apparent negative co-operativity. The values of K1 and K2 exhibit little pH dependence, while those of K3 and K4 increase by two orders of magnitudes as the pH is changed from 6.5 to 8.75. In consequence, oxygen equilibrium above neutral pH exhibits a normal positive co-operativity. The oxygen equilibrium at lower temperature is biphasic as is that below neutral pH. The shape of the Hill plot is temperature-dependent. The affinity at low saturation decreases, and that at high saturation increases upon raising the temperature from 10 to 30 degrees C, resulting in crossing of the middle portion of the equilibrium curves at different temperatures. The delta H1 and delta H2 values are negative as are those of most other hemoglobins, but the delta H3 and delta H4 values are positive. Consideration of these results in a framework of the allosteric model extended to take account of differences between subunits has indicated that the deoxy quaternary structure is stabilized at low pH or low temperature, and that subunit heterogeneity gives rise to the biphasic oxygen equilibrium curve. An analysis of delta Hi+ suggests that the large number of the Bohr groups is responsible for the biased allosteric equilibrium towards the deoxy quaternary structure

  13. Isotopic discrimination factors and nitrogen turnover rates in reared Atlantic bluefin tuna larvae (Thunnus thynnus: effects of maternal transmission

    Directory of Open Access Journals (Sweden)

    Amaya Uriarte

    2016-11-01

    Full Text Available The use of stable isotope analysis to study animal diets requires estimates of isotopic turnover rates (half time, t50 and discrimination factors (Δ for an accurate interpretation of trophic patterns. The stable isotopes of carbon and nitrogen were analysed for eggs and reared larvae of Thunnus thynnus, as well as for the different diets supplied during the experiment. The results showed high values of δ15N in eggs and larvae (n=646 until 4 DAH. After this time lapse, the stable isotope values declined progressively until 12 DAH, when notochord flexion began. The δ13C showed an inverse trend, suggesting that maternal inheritance of the stable isotopes is evident until pre-flexion stages. This study proposes a model for estimating maternal isotopic signatures of bluefin broodstock. After notochord flexion, larvae were fed with aquaculture-bred gilthead seabream, which resulted in a rapid increase of bluefin larvae δ15N values together with a rapid decrease in δ13C values. The estimated nitrogen half-time to reach the steady state from the diet was 2.5±0.3 days and the discrimination factor was 0.4±0.3(‰. These results represent the first data set that has allowed isotopic nitrogen turnover rates and discrimination factors of the larval stages of bluefin tuna to be estimated.

  14. Microsatellite and mitochondrial DNA analyses of Atlantic bluefin tuna (Thunnus thynnus thynnus) population structure in the Mediterranean Sea.

    Science.gov (United States)

    Carlsson, Jens; McDowell, Jan R; Díaz-Jaimes, Píndaro; Carlsson, Jeanette E L; Boles, Sandra B; Gold, John R; Graves, John E

    2004-11-01

    Genetic variation was surveyed at nine microsatellite loci and the mitochondrial control region (868 bp) to test for the presence of genetic stock structure in young-of-the-year Atlantic bluefin tuna (Thunnus thynnus thynnus) from the Mediterranean Sea. Bluefin tuna were sampled over a period of 5 years from the Balearic and Tyrrhenian seas in the western basin of the Mediterranean Sea, and from the southern Ionian Sea in the eastern basin of the Mediterranean Sea. Analyses of multilocus microsatellite genotypes and mitochondrial control region sequences revealed no significant heterogeneity among collections taken from the same location in different years; however, significant spatial genetic heterogeneity was observed across all samples for both microsatellite markers and mitochondrial control region sequences (FST=0.0023, P=0.038 and PhiST=0.0233, P=0.000, respectively). Significant genetic differentiation between the Tyrrhenian and Ionian collections was found for both microsatellite and mitochondrial markers (FST=0.0087, P=0.015 and PhiST=0.0367, P=0.030, respectively). These results suggest the possibility of a genetically discrete population in the eastern basin of the Mediterranean Sea.

  15. Histopathology of five species of Didymocystis spp. (Digenea: Didymozoidae) in cage-reared Atlantic bluefin tuna (Thunnus thynnus thynnus).

    Science.gov (United States)

    Mladineo, I

    2006-07-01

    The first parasitological examinations of Atlantic bluefin tuna Thunnus thynnus thynnus reared in the Adriatic Sea revealed high numbers of different digenean trematodes, belonging to family Didymozoidae. Five species were the most frequently isolated: Coeliodidymocystis, abdominalis, Didymocystis wedli, Koellikerioides internogastricus, K. intestinalis and K. apicalis. Parasites were isolated from gills, gill rakers, intestine, serosa of pyloric caeca, and inner layers of the fundic region of stomach, encysted in pairs in connective tissue capsules originating from host tissue. Gross pathology revealed no pathological changes. Histological alterations comprised tissue reaction resulting in lymphocyte infiltration and formation of a collagenous envelope around the parasite cysts; the intensity of observed reaction depended on the size of the cyst and on the tissue infected. The most notable changes were observed in the intestine under provocation by K. intestinalis, while the most potentially pathogenic didymozoid under fish rearing conditions is D. wedli, which if present in high abundance can induce secondary bacterial infections.

  16. Increased liver apoptosis and tumor necrosis factor expression in Atlantic bluefin tuna (Thunnus thynnus) reared in the northern Adriatic Sea.

    Science.gov (United States)

    Corriero, Aldo; Zupa, Rosa; Pousis, Chrysovalentinos; Santamaria, Nicoletta; Bello, Giambattista; Jirillo, Emilio; Carrassi, Michele; De Giorgi, Carla; Passantino, Letizia

    2013-06-15

    The Atlantic bluefin tuna Thunnus thynnus (ABFT) is intensely fished in the Mediterranean Sea to supply a prosperous capture-based mariculture industry. Liver apoptotic structures and tumor necrosis factor (TNF) gene expression were determined in: wild ABFT caught in the eastern Atlantic; juvenile ABFT reared in the central Adriatic Sea; juvenile ABFT reared in the northern Adriatic Sea; adult ABFT reared in the western Mediterranean. The highest density of liver apoptotic structures was found in the juveniles from the northern Adriatic. Two partial TNF cDNAs (TNF1 and TNF2) were cloned and sequenced. TNF1 gene expression was higher in juveniles than in adults. The highest expression of TNF2 was found in the juveniles from the northern Adriatic. These findings might be related to the juvenile exposure to environmental pollutants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. A histological investigation of the occurrence of non-reproductive female bluefin tuna Thunnus thynnus in the Mediterranean Sea.

    Science.gov (United States)

    Zupa, R; Corriero, A; Deflorio, M; Santamaria, N; Spedicato, D; Marano, C; Losurdo, M; Bridges, C R; De Metrio, G

    2009-10-01

    The presence of non-reproductive Atlantic bluefin tuna Thunnus thynnus females in the Mediterranean Sea was investigated through histological analysis of the gonads. Three hundred and twenty-six ovary samples were collected from adults captured at different locations in the Mediterranean Sea during the reproductive seasons between 1998 and 2008. Only three specimens were considered to be in a non-reproductive state: two of them were in a reabsorbing state showing ovaries with early vitellogenic oocytes and extensive alpha and beta atresia of vitellogenic follicles; the third showed gonads with perinucleolar oocytes and was considered to be in a resting state. The low occurrence of non-reproductive individuals found in this study makes it unlikely that non-reproductive individuals aggregate with reproductive ones during their migration towards spawning grounds. Further research is suggested in order to investigate the potential presence of non-reproductive individuals on non-spawning grounds during the reproductive season.

  18. Impacts of environmental variability and global warming scenario on Pacific bluefin tuna ( Thunnus orientalis) spawning grounds and recruitment habitat

    Science.gov (United States)

    Kimura, Shingo; Kato, Yoshiki; Kitagawa, Takashi; Yamaoka, Naoki

    2010-07-01

    Pacific bluefin tuna ( Thunnus orientalis) have spawning grounds in waters stretching from south of Okinawa to east of Taiwan. This species is typical of fishes that spawn seasonally in small, limited areas. Any marked change in the marine environment of the spawning grounds is likely to have a direct impact on larval survival and growth. We conducted rearing experiments on larvae to investigate these impacts and found that a reduction in temperature resulted in poor growth during the juvenile stage, even if larval survival rates did not change. In the wild, this reduced growth rate is likely to reduce survival rates because smaller juveniles have poorer swimming ability and their ability to avoid predators is also reduced. This is especially important since the Kuroshio current, which connects the spawning grounds to the nursery grounds, transports larvae rapidly because of its faster surface current (the western boundary current), thus larvae arriving too quickly in coastal waters can be exposed to very cold temperatures. An ocean model (MIROC) simulation under a climate warming scenario ( IPCC, 2007) predicted that the temperature in the spawning ground would be 3 °C higher in 2100 than in present time, while the transport to nursery grounds would also be faster. In this case, the combination of several mechanisms would control the recruitment of juvenile bluefin. On the spawning grounds, high temperatures exceeding the optimal range would increase larvae mortality and any surviving larvae would reach the nursery grounds more quickly, but warmer coastal waters would have less negative impact on their growth. We forced a model of larval drift with MIROC output fields to study the complex response of bluefin tuna recruitment. As a result, the predicted survival rates of larvae arriving in Japanese coastal waters in 2100 would decline to 36% of present recruitment levels.

  19. Atlantic bluefin tuna Thunnus thynnus feeding ecology in the northern Gulf of Mexico: a preliminary description of diet from the western Atlantic spawning grounds.

    Science.gov (United States)

    Butler, C M; Logan, J M; Provaznik, J M; Hoffmayer, E R; Staudinger, M D; Quattro, J M; Roberts, M A; Ingram, G W; Pollack, A G; Lutcavage, M E

    2015-01-01

    A combination of stomach contents, nitrogen stable-isotope and tissue C:N values are presented to demonstrate feeding activity of Atlantic bluefin tuna Thunnus thynnus on the Gulf of Mexico (GOMEX) spawning grounds. Diets include teleosts, cephalopods, crustaceans and a pelagic tunicate (Pyrosoma atlanticum). Results reveal the need to classify the GOMEX as a T. thynnus feeding ground. © 2014 The Fisheries Society of the British Isles.

  20. Tissue turnover rates and isotopic trophic discrimination factors in the endothermic teleost, pacific bluefin tuna (Thunnus orientalis.

    Directory of Open Access Journals (Sweden)

    Daniel J Madigan

    Full Text Available Stable isotope analysis (SIA of highly migratory marine pelagic animals can improve understanding of their migratory patterns and trophic ecology. However, accurate interpretation of isotopic analyses relies on knowledge of isotope turnover rates and tissue-diet isotope discrimination factors. Laboratory-derived turnover rates and discrimination factors have been difficult to obtain due to the challenges of maintaining these species in captivity. We conducted a study to determine tissue- (white muscle and liver and isotope- (nitrogen and carbon specific turnover rates and trophic discrimination factors (TDFs using archived tissues from captive Pacific bluefin tuna (PBFT, Thunnus orientalis, 1-2914 days after a diet shift in captivity. Half-life values for (15N turnover in white muscle and liver were 167 and 86 days, and for (13C were 255 and 162 days, respectively. TDFs for white muscle and liver were 1.9 and 1.1‰ for δ(15N and 1.8 and 1.2‰ for δ(13C, respectively. Our results demonstrate that turnover of (15N and (13C in bluefin tuna tissues is well described by a single compartment first-order kinetics model. We report variability in turnover rates between tissue types and their isotope dynamics, and hypothesize that metabolic processes play a large role in turnover of nitrogen and carbon in PBFT white muscle and liver tissues. (15N in white muscle tissue showed the most predictable change with diet over time, suggesting that white muscle δ(15N data may provide the most reliable inferences for diet and migration studies using stable isotopes in wild fish. These results allow more accurate interpretation of field data and dramatically improve our ability to use stable isotope data from wild tunas to better understand their migration patterns and trophic ecology.

  1. Development and validation of a mixed-tissue oligonucleotide DNA microarray for Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758).

    Science.gov (United States)

    Trumbić, Željka; Bekaert, Michaël; Taggart, John B; Bron, James E; Gharbi, Karim; Mladineo, Ivona

    2015-11-25

    The largest of the tuna species, Atlantic bluefin tuna (Thunnus thynnus), inhabits the North Atlantic Ocean and the Mediterranean Sea and is considered to be an endangered species, largely a consequence of overfishing. T. thynnus aquaculture, referred to as fattening or farming, is a capture based activity dependent on yearly renewal from the wild. Thus, the development of aquaculture practices independent of wild resources can provide an important contribution towards ensuring security and sustainability of this species in the longer-term. The development of such practices is today greatly assisted by large scale transcriptomic studies. We have used pyrosequencing technology to sequence a mixed-tissue normalised cDNA library, derived from adult T. thynnus. A total of 976,904 raw sequence reads were assembled into 33,105 unique transcripts having a mean length of 893 bases and an N50 of 870. Of these, 33.4% showed similarity to known proteins or gene transcripts and 86.6% of them were matched to the congeneric Pacific bluefin tuna (Thunnus orientalis) genome, compared to 70.3% for the more distantly related Nile tilapia (Oreochromis niloticus) genome. Transcript sequences were used to develop a novel 15 K Agilent oligonucleotide DNA microarray for T. thynnus and comparative tissue gene expression profiles were inferred for gill, heart, liver, ovaries and testes. Functional contrasts were strongest between gills and ovaries. Gills were particularly associated with immune system, signal transduction and cell communication, while ovaries displayed signatures of glycan biosynthesis, nucleotide metabolism, transcription, translation, replication and repair. Sequence data generated from a novel mixed-tissue T. thynnus cDNA library provide an important transcriptomic resource that can be further employed for study of various aspects of T. thynnus ecology and genomics, with strong applications in aquaculture. Tissue-specific gene expression profiles inferred through the

  2. Ontogenetic transfer of chlorinated hydrocarbons in Mediterranean bluefin tuna (Thunnus thynuus)

    Energy Technology Data Exchange (ETDEWEB)

    Corsolini, S.; Borghesi, N.; Focardi, S. [Siena Univ., Siena (Italy); Sara, G. [Palermo Univ., Palermo, Sicily (Italy)

    2005-07-01

    This study examined 33 samples of bluefin tunas caught in the western Mediterranean Sea. The aim of the study was to examine the relationship between stable isotopes of nitrogen (N) combined with persistent organic pollutant (POP) residue levels and trophic levels. Tuna weighing between 15 and 225 kg were collected. Juvenile tunas were collected by purse seine in the Gulf of Palermo. Muscle samples were analyzed for d{sup 15}N using an isotope ratio mass spectrometer. Trophic levels were estimated using {delta}{sup 15}N values. A constant per-trophic-level fractionation of 3.4 per cent was assumed. Polychlorinated biphenyls (PCBs) were identified and quantified using a gas chromatograph equipped with a {sup 63}Ni electron capture detector (GC-ECD) along with a fused silica capillary column coated with DB-5. ANOVA was used to test the null hypothesis of no-difference among size class of isotope and POP content in the tuna samples. The heterogeneity of variances was tested using Cochran's C test prior to the analysis of variance and Student-Newman-Keulls (SNK) test to derive an appropriate mean comparison. Results of the study showed that the trophic levels and {sup 15} accumulations varied with the size of the tuna according to a significant linear law. POP concentrations increased significantly with size and trophic levels. However, no significant difference between hexachlorobenzene (HCB) values and age class were observed, and no magnification patterns were determined. It was concluded that ontogenetic magnification factor (OMF) for several PCBs were explained by differences in feeding habits and rates, as well as on age disparities. 17 refs., 1 tab., 2 figs.

  3. Levels of dioxin (PCDD/F) and PCBs in a random sample of Australian aquaculture-produced Southern Bluefin Tuna (Thunnus maccoyii)

    Energy Technology Data Exchange (ETDEWEB)

    Padula, D.; Madigan, T.; Kiermeier, A.; Daughtry, B.; Pointon, A. [South Australian Research and Development Inst. (Australia)

    2004-09-15

    To date there has been no published information available on the levels of dioxin (PCDD/F) and PCBs in Australian aquaculture-produced Southern Bluefin Tuna (Thunnus maccoyii). Southern Bluefin Tuna are commercially farmed off the coast of Port Lincoln in the state of South Australia, Australia. This paper reports the levels of dioxin (PCDD/F) and PCBs in muscle tissue samples from 11 randomly sampled aquaculture-produced Southern Bluefin Tuna collected in 2003. Little published data exists on the levels of dioxin (PCDD/F) and PCBs in Australian aquacultureproduced seafood. Wild tuna are first caught in the Great Australian Bight in South Australian waters, and are then brought back to Port Lincoln where they are ranched in sea-cages before being harvested and exported to Japan. The aim of the study was to identify pathways whereby contaminants such as dioxin (PCDD/F) and PCBs may enter the aquaculture production system. This involved undertaking a through chain analysis of the levels of dioxin (PCDD/F) and PCBs in wild caught tuna, seafloor sediment samples from the marine environment, levels in feeds and final harvested exported product. Detailed study was also undertaken on the variation of dioxin (PCDD/F) and PCBs across individual tuna carcases. This paper addresses the levels found in final harvested product. Details on levels found in other studies will be published elsewhere shortly.

  4. Brain morphology and immunohistochemical localization of the gonadotropin-releasing hormone in the bluefin tuna, Thunnus thynnus

    Directory of Open Access Journals (Sweden)

    G Palmieri

    2009-08-01

    Full Text Available The present study was focused on the morphology of the diencephalic nuclei (likely involved in reproductive functions as well as on the distribution of GnRH (gonadotropin-releasing hormone in the rhinencephalon, telencephalon and the diencephalon of the brain of bluefin tuna (Thunnus thynnus by means of immunohistochemistry. Bluefin tuna has an encephalization quotient (QE similar to that of other large pelagic fish. Its brain exhibits well-developed optic tecta and corpus cerebelli. The diencephalic neuron cell bodies involved in reproductive functions are grouped in two main nuclei: the nucleus preopticus-periventricularis and the nucleus lateralis tuberis. The nucleus preopticus-periventricularis consists of the nucleus periventricularis and the nucleus preopticus consisting of a few sparse multipolar neurons in the rostral part and numerous cells closely packed and arranged in several layers in its aboral part. The nucleus lateralis tuberis is located in the ventral-lateral area of the diencephalon and is made up of a number of large multipolar neurones. Four different polyclonal primary antibodies against salmon (sGnRH, chicken (cGnRH-II (cGnRH-II 675, cGnRH-II 6 and sea bream (sbGnRH were employed in the immunohistochemical experiments. No immunoreactive structures were found with anti sbGnRH serum. sGnRH and cGnRH-II antisera revealed immunoreactivity in the perikarya of the olfactory bulbs, preopticus-periventricular nucleus, oculomotor nucleus and midbrain tegmentum. The nucleus lateralis tuberis showed immunostaining only with anti-sGnRH serum. Nerve fibres immunoreactive to cGnRH and sGnRH sera were found in the olfactory bulbs, olfactory nerve and neurohypophysis. The significance of the distribution of the GnRHimmunoreactive neuronal structures is discussed.

  5. Individual Spawning Duration of Captive Atlantic Bluefin Tuna (Thunnus thynnus) Revealed by Mitochondrial DNA Analysis of Eggs.

    Science.gov (United States)

    Gordoa, Ana; Sanz, Nuria; Viñas, Jordi

    2015-01-01

    This study presents the first results on Atlantic bluefin tuna (Thunnus thynnus) individual spawning duration and its short-term temporal behavior. The study was based on direct measurements resulting from mtDNA analysis of the offspring of spawners held in transport cages during the 2013 spawning monitoring survey in Balearic waters. The number of females consisted of approximately 259 individuals with an average weight of 186 kg. The survey began on May 22 and ended on July 3. Spawning started on May 30 and was observed every night afterwards. The sampling of eggs for genetic monitoring was conducted for 9 days interspersed from the beginning of spawning to the end of the survey. A total of 946 eggs were analyzed and revealed 129 different haplotypes; 77 of these were not previously detected in the Mediterranean. A total of 69 haplotypes were observed in more than one spawning event and those with higher frequency lasted their maximum possible duration. The haplotypes present at the beginning of spawning were also identified at the end of the sampling, indicating a minimum spawning duration of 34 days, and individual annual fecundity was estimated at around 1290 eggs gr(-1). These results differed from those generally presumed until now and are indicative of a much higher fecundity. Females exhibited a regular spawning schedule but with the capacity to shift the spawning hour during the spawning season. These results were observed for the eastern population of Atlantic bluefin tuna and before extrapolating to the western population, their validity should be proved.

  6. Individual Spawning Duration of Captive Atlantic Bluefin Tuna (Thunnus thynnus Revealed by Mitochondrial DNA Analysis of Eggs.

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    Ana Gordoa

    Full Text Available This study presents the first results on Atlantic bluefin tuna (Thunnus thynnus individual spawning duration and its short-term temporal behavior. The study was based on direct measurements resulting from mtDNA analysis of the offspring of spawners held in transport cages during the 2013 spawning monitoring survey in Balearic waters. The number of females consisted of approximately 259 individuals with an average weight of 186 kg. The survey began on May 22 and ended on July 3. Spawning started on May 30 and was observed every night afterwards. The sampling of eggs for genetic monitoring was conducted for 9 days interspersed from the beginning of spawning to the end of the survey. A total of 946 eggs were analyzed and revealed 129 different haplotypes; 77 of these were not previously detected in the Mediterranean. A total of 69 haplotypes were observed in more than one spawning event and those with higher frequency lasted their maximum possible duration. The haplotypes present at the beginning of spawning were also identified at the end of the sampling, indicating a minimum spawning duration of 34 days, and individual annual fecundity was estimated at around 1290 eggs gr(-1. These results differed from those generally presumed until now and are indicative of a much higher fecundity. Females exhibited a regular spawning schedule but with the capacity to shift the spawning hour during the spawning season. These results were observed for the eastern population of Atlantic bluefin tuna and before extrapolating to the western population, their validity should be proved.

  7. Brain morphology and immunohistochemical localization of the gonadotropin-releasing hormone in the bluefin tuna, Thunnus thynnus.

    Science.gov (United States)

    Palmieri, G; Acone, F; Desantis, S; Corriero, A; Ventriglia, G; Addis, P; Genovese, S; Aprea, A; Spedicato, D; Losurdo, M; Deflorio, M; Di Summa, A; De Metrio, G

    2008-01-01

    The present study was focused on the morphology of the diencephalic nuclei (likely involved in reproductive functions) as well as on the distribution of GnRH (gonadotropin-releasing hormone) in the rhinencephalon, telencephalon and the diencephalon of the brain of bluefin tuna (Thunnus thynnus) by means of immunohistochemistry. Bluefin tuna has an encephalization quotient (QE) similar to that of other large pelagic fish. Its brain exhibits well-developed optic tecta and corpus cerebelli. The diencephalic neuron cell bodies involved in reproductive functions are grouped in two main nuclei: the nucleus preopticus-periventricularis and the nucleus lateralis tuberis. The nucleus preopticus-periventricularis consists of the nucleus periventricularis and the nucleus preopticus consisting of a few sparse multipolar neurons in the rostral part and numerous cells closely packed and arranged in several layers in its aboral part. The nucleus lateralis tuberis is located in the ventral-lateral area of the diencephalon and is made up of a number of large multipolar neurones. Four different polyclonal primary antibodies against salmon (s)GnRH, chicken (c)GnRH-II (cGnRH-II 675, cGnRH-II 6) and sea bream (sb)GnRH were employed in the immunohistochemical experiments. No immunoreactive structures were found with anti sbGnRH serum. sGnRH and cGnRH-II antisera revealed immunoreactivity in the perikarya of the olfactory bulbs, preopticus-periventricular nucleus, oculomotor nucleus and midbrain tegmentum. The nucleus lateralis tuberis showed immunostaining only with anti-sGnRH serum. Nerve fibres immunoreactive to cGnRH and sGnRH sera were found in the olfactory bulbs, olfactory nerve and neurohypophysis. The significance of the distribution of the GnRH-immunoreactive neuronal structures is discussed.

  8. GnRHa-mediated stimulation of the reproductive endocrine axis in captive Atlantic bluefin tuna, Thunnus thynnus.

    Science.gov (United States)

    Rosenfeld, H; Mylonas, C C; Bridges, C R; Heinisch, G; Corriero, A; Vassallo-Aguis, R; Medina, A; Belmonte, A; Garcia, A; De la Gándara, F; Fauvel, C; De Metrio, G; Meiri-Ashkenazi, I; Gordin, H; Zohar, Y

    2012-01-01

    A controlled-release implant loaded with GnRH agonist (GnRHa) was used to induce spawning in Atlantic bluefin tuna (Thunnus thynnus) during two consecutive reproductive seasons. The fish were implanted underwater and sampled between days 2 and 8 after treatment. At the time of GnRHa treatment, females were in full vitellogenesis and males in spermiation. There was a rapid burst of pituitary luteinizing hormone (LH) release at day 2 after treatment in GnRHa-treated fish, and circulating LH remained elevated up to day 8 after treatment. In contrast, control fish had significantly lower levels in the plasma, but higher LH content in the pituitary, as observed in many other cultured fishes that fail to undergo oocyte maturation, ovulation and spawning unless induced by an exogenous GnRHa. Plasma testosterone (T) and 17β-estradiol (E(2)) were elevated in response to the GnRHa treatment in females, while 11-ketotestosterone (11-KT) but not T was elevated in males. Even though oocyte maturation and ovulation did occur in GnRHa-induced fish, no significant elevations in 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) or 17,20β,21-trihydroxy-4-pregnen-3-one (20β-S), in either the free, conjugated or 5β-reduced,3α-hydroxylated forms was observed in fish sampled within 6 days after treatment. Interestingly, a significant peak in plasma free 17,20β-P levels occurred in both males and females at day 8 after treatment. Histological sections of the ovaries in these females contained oocytes at the migrating germinal vesicle stage, suggesting the role of this hormone as a maturation-inducing steroid in Atlantic bluefin tuna. In conclusion, the GnRHa implants activated effectively the reproductive endocrine axis in captive Atlantic bluefin tuna broodstocks, through stimulation of sustained elevations in plasma LH, which in turn evoked the synthesis and secretion of the relevant sex steroids leading to gamete maturation and release. Copyright © 2011 Elsevier Inc. All rights

  9. Burst feeding of Pelagia noctiluca ephyrae on Atlantic bluefin tuna (Thunnus thynnus) eggs.

    Science.gov (United States)

    Gordoa, Ana; Acuña, José Luis; Farrés, Roser; Bacher, Kathrin

    2013-01-01

    This study investigates the predation of P. noctiluca ephyrae on Atlantic Bluefin tuna (ABFT) eggs under different experimental conditions. The specific factors considered in the experimental design were: a) water mix conditions to explore predation under two-dimensional (2D) and three-dimensional (3D) prey distributions, b) prey density to investigate the ingestion rate capacity, and c) incubation time to inspect gut saturation. The eggs and jellyfish ephyrae were collected during the 2012 ABFT spawning survey off Ibiza (Balearic Isl., Western Mediterranean). The results showed that the proportion of feeding ephyrae increased with size. The mean clearance rate of feeding ephyrae, 4.14 L h(-1), was the highest ever recorded for ephyrae. Under calm conditions the eggs floated at the surface (2D spatial arrangement) and the clearance rates, at low prey densities, were at least twice those under mixed conditions (3D spatial arrangement). At high prey density, clearance rate did not differ between mix conditions, probably due to the fast gut saturation, which was reached in c.a. 15 min, as revealed by time series observations of gut contents. The fast saturation of ephyrae and their slow digestion time of approximately 18 h suggest the existence of a diel feeding periodicity. We conclude that in the Western Mediterranean, P. noctiluca ephyrae are capable of predating on ABFT eggs, a highly pulsed and spatially restricted resource that potentially switches from a 3D to a 2D configuration in the absence of wind-generated turbulence. The P. noctiluca and Atlantic Bluefin tuna egg system might represent an example of a general mechanism linking pelagic and neustonic food webs.

  10. Burst feeding of Pelagia noctiluca ephyrae on Atlantic bluefin tuna (Thunnus thynnus eggs.

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    Ana Gordoa

    Full Text Available This study investigates the predation of P. noctiluca ephyrae on Atlantic Bluefin tuna (ABFT eggs under different experimental conditions. The specific factors considered in the experimental design were: a water mix conditions to explore predation under two-dimensional (2D and three-dimensional (3D prey distributions, b prey density to investigate the ingestion rate capacity, and c incubation time to inspect gut saturation. The eggs and jellyfish ephyrae were collected during the 2012 ABFT spawning survey off Ibiza (Balearic Isl., Western Mediterranean. The results showed that the proportion of feeding ephyrae increased with size. The mean clearance rate of feeding ephyrae, 4.14 L h(-1, was the highest ever recorded for ephyrae. Under calm conditions the eggs floated at the surface (2D spatial arrangement and the clearance rates, at low prey densities, were at least twice those under mixed conditions (3D spatial arrangement. At high prey density, clearance rate did not differ between mix conditions, probably due to the fast gut saturation, which was reached in c.a. 15 min, as revealed by time series observations of gut contents. The fast saturation of ephyrae and their slow digestion time of approximately 18 h suggest the existence of a diel feeding periodicity. We conclude that in the Western Mediterranean, P. noctiluca ephyrae are capable of predating on ABFT eggs, a highly pulsed and spatially restricted resource that potentially switches from a 3D to a 2D configuration in the absence of wind-generated turbulence. The P. noctiluca and Atlantic Bluefin tuna egg system might represent an example of a general mechanism linking pelagic and neustonic food webs.

  11. Metazoan gill parasites of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from the Mediterranean and their possible use as biological tags.

    Science.gov (United States)

    Culurgioni, Jacopo; Mele, Salvatore; Merella, Paolo; Addis, Piero; Figus, Vincenza; Cau, Angelo; Karakulak, Firdes Saadet; Garippa, Giovanni

    2014-04-01

    The gills of 63 specimens of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from three localities of the Mediterranean (Sardinian, Tyrrhenian and Levantine Seas) were examined for metazoan parasites. The parasite fauna of T. thynnus from the Sea of Sardinia included 11 species: five didymozoid trematodes, three capsalid and one hexostomid monogeneans, and one caligid and one pseudocycnid copepods. Four didymozoids were found in fish from the Levantine Sea and only one didymozoid was recorded in fish from the Tyrrhenian Sea. Dividing the hosts into four size-groups (small, medium-sized, large and extra large), the pairwise comparison of prevalence and mean abundance of the new and literary data) showed differences according to host size. The differences in the composition of the parasitic faunas and in the prevalence of parasites, observed between the small tunas from the Tyrrhenian Sea and the medium-sized tunas from the Adriatic Sea, Levantine Sea and the North-East (NE) Atlantic Ocean, indicated that these groups form discrete units. The parasite fauna of the large tunas from the Sea of Sardinia is the richest among the bluefin tuna populations of the Mediterranean and the NE Atlantic, due to the presence of species not found elsewhere in bluefin tunas, such as Caligus coryphaenae Steenstrup et Lütken, 1861, Capsala magronum (Ishii, 1936) and C. paucispinosa (Mamaev, 1968). This fact and the prevalence of some parasites of this group (lower than those of medium-sized fish from the NE Atlantic and higher than the small and medium-sized tunas from the Mediterranean) suggest that the large-sized tuna group in the western Mediterranean is formed by Mediterranean resident tunas (poorly infected), and by tunas migrating from the Atlantic Ocean (heavily infected).

  12. Morphological, nutritional and safety traits of bluefin tuna (Thunnus thynnus reared in floating cages

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    B. M. Poli

    2010-04-01

    Full Text Available To evaluate the influence of fattening on morphological, nutritional and safety characteristics, two lots of bluefin tuna were sampled before (November: 2 C, 4 ? and after 5 months of fattening (April: 5 C, 5 ?. The specimens, after death, were refrigerated and analysed at different times over the period of a week for morphological and flesh physico-chemical parameters in six muscle sites. Tuna sampled in April had greater body weight (44.04 vs 36.41kg, trunk length (52.21 vs 48.22cm and minimum and maximum circumferences (13.74 vs 12.77 and 94.90 vs 89.10cm. No differences in other linear measures or body components were found. Fattening did not influence flesh colour or total lipid content, producing small differences in its chemical composition: greater C18:0, C18:1n9 and PUFAn6 percentages; higher putrescine and histamine (0.489 vs 0.335 and 0.666 vs 0.370mg/kg but lower spermine and spermidine (10.598 vs 17.387 and 2.420 vs 3.928mg/kg levels. Large differences in physico-chemical parameters were found between muscle sites and a significant interaction between sampling date and muscle site indicated non homogeneous changes in chemical composition of dorsal, ventral and red muscle after fattening. Sex only influenced fat content in viscera (C 12.84 vs ? 9.84%.

  13. Development of the posterior lateral line system in Thunnus thynnus, the Atlantic blue-fin tuna, and in its close relative Sarda sarda.

    Science.gov (United States)

    Ghysen, Alain; Schuster, Kevin; Coves, Denis; de la Gandara, Fernando; Papandroulakis, Nikos; Ortega, Aurelio

    2010-01-01

    The lateral line system of amphibians and fish comprises a large number of individual mechanosensory organs, the neuromasts, and their sensory neurons. The pattern of neuromasts varies markedly between species, yet the embryonic pattern is highly conserved from the relatively basal zebrafish, Danio rerio, to more derived species. Here we examine in more detail the development of the posterior lateral line (PLL) in embryos and early larvae of one of the most derived fish species, the blue-fin tuna Thunnus thynnus, and of its close relative, the Atlantic bonito Sarda sarda. We show that the basic features of embryonic PLL development, including the migratory properties of the PLL primordium, the patterning of neuromasts and their innervation, are largely conserved between zebrafish and tuna. However, Thunnus and Sarda embryos differ from Danio in three respects: the larger size of the neuromast cupula, the capability of mature neuromasts to migrate dorsally, and the presence of a single, precisely located terminal neuromast.

  14. Lipid metabolism-related gene expression pattern of Atlantic bluefin tuna (Thunnus thynnus L.) larvae fed on live prey.

    Science.gov (United States)

    Betancor, Mónica B; Ortega, Aurelio; de la Gándara, Fernando; Tocher, Douglas R; Mourente, Gabriel

    2017-04-01

    The present study is the first to evaluate lipid metabolism in first-feeding Atlantic bluefin tuna (ABT; Thunnus thynnus L.) larvae fed different live prey including enriched rotifers Brachionus plicatilis and Acartia sp. copepod nauplii from 2 days after hatch. Understanding the molecular basis of lipid metabolism and regulation in ABT will provide insights to optimize diet formulations for this high-value species new to aquaculture. To this end, we investigated the effect of dietary lipid on whole larvae lipid class and fatty acid compositions and the expression of key genes involved in lipid metabolism in first feeding ABT larvae fed different live prey. Additionally, the expression of lipid metabolism genes in tissues of adult broodstock ABT was evaluated. Growth and survival data indicated that copepods were the best live prey for first feeding ABT and that differences in growth performance and lipid metabolism observed between larvae from different year classes could be a consequence of broodstock nutrition. In addition, expression patterns of lipid metabolic genes observed in ABT larvae in the trials could reflect differences in lipid class and fatty acid compositions of the live prey. The lipid nutritional requirements, including essential fatty acid requirements of larval ABT during the early feeding stages, are unknown, and the present study represents a first step in addressing these highly relevant issues. However, further studies are required to determine nutritional requirements and understand lipid metabolism during development of ABT larvae and to apply the knowledge to the commercial culture of this iconic species.

  15. Δ6 fatty acyl desaturase gene in a southern bluefin tuna (Thunnus maccoyii cell line

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    Senni Juniawati Bunga

    2015-10-01

    Full Text Available Fish is the main source of ?-3 long chain polyunsaturated fatty acids (LC-PUFA such as eicosapentaenoic acid (EPA, 20:5?-3 and docosahexaenoic acid (DHA, 22:5?-3, which have positive effects on human health and can be beneficial in human diet context. Studies involving fatty acyl desaturase (Fads and elongase of very long chain fatty acids (Elovl enzymes that convert C18 PUFA to C20/22 LC-PUFA have been performed in some fish species. However, very little is known about LC-PUFA biosynthesis in tuna species. This study investigated the ?6 Fads gene performance in the SBT cell line. The ?6 Fads nucleotide sequences from various fish species were identified and retrieved to compare them with the SBT ?6 Fads nucleotide sequence. The ?6 Fads gene was performed using real time PCR (RT-PCR and then was compared it with ?-actin gene performance as a reference housekeeping gene. By performing multiple sequence alignments and comparing the highly conserved regions among fish ?6 Fads sequences, the SBT ?6 Fads nucleotide sequence was determined to be ? 75% identical to the other fish ?6 Fads sequences. The results showed that when the SBT ?6 Fads and ?-actin cDNAs were performed in a standard PCR system and the products were analysed by electrophoresing them on a 2% (w/v agarose gel, the target genes that were obtained were similar to the expected sizes. The observed band size for the ?6 Fads PCR product was 207 bp and for the ?-actin PCR product was 98 bp. The presence of the observed bands indicated that the primer pairs that were designed and used were successfully amplified the target genes. The results of this study might provide relevant information to support further investigating of the desaturase and elongase gene expression that might contribute to a better understanding of ?-3 LC-PUFA biosynthesis in fish. Key words: ?6 Fads gene, Southern Bluefin tuna, cell line, ?-3 LC-PUFA

  16. Comparative study of liver vitellogenin gene expression and oocyte yolk accumulation in wild and captive Atlantic bluefin tuna (Thunnus thynnus L.).

    Science.gov (United States)

    Pousis, C; De Giorgi, C; Mylonas, C C; Bridges, C R; Zupa, R; Vassallo-Agius, R; de la Gándara, F; Dileo, C; De Metrio, G; Corriero, A

    2011-01-01

    The sequence of vitellogenin A (VgA) and vitellogenin B (VgB) cDNAs in Atlantic bluefin tuna (Thunnus thynnus L.) were determined, and vitellogenin expression levels in the liver and oocyte yolk accumulation were compared in wild and captive-reared individuals. Liver and ovary samples were taken from 31 individuals reared experimentally in three commercial Atlantic bluefin tuna fattening sites in the Mediterranean Sea and from 33 wild individuals caught by commercial traps during the fish's migration towards their Mediterranean spawning grounds. The total length of VgA cDNA was 5585 nucleotides and that of VgB was 5267 nucleotides. The identity and similarity between deduced amino acid sequences of VgA and VgB were 60% and 78%, respectively. The Atlantic bluefin tuna VgA and VgB amino acid sequences have high similarities with those of other teleost fishes. Relative levels of VgA and VgB mRNAs were low in April, increased significantly during the reproductive period in May and June, and declined in July. There was a trend towards higher relative levels of VgA and VgB mRNAs in captive fish compared to wild individuals during the reproductive period. The surface occupied by eosinophilic yolk granules in fully vitellogenic oocytes, as well as the frequency of oocytes in late vitellogenesis, was significantly higher in captive compared to wild individuals. The study suggests that the experimental conditions under which Atlantic bluefin tuna individuals were reared allowed the occurrence of normal vitellogenesis, based on gene expression of VgA and VgB in the liver and yolk accumulation in the oocytes. The higher yolk accumulation and frequency of vitellogenic oocytes observed in the ovaries of captive fish suggest that improvements in feeding practices may result in an improved vitellogenic process. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Intra-pituitary relationship of follicle stimulating hormone and luteinizing hormone during pubertal development in Atlantic bluefin tuna (Thunnus thynnus).

    Science.gov (United States)

    Berkovich, Nadia; Corriero, Aldo; Santamaria, Nicoletta; Mylonas, Constantinos C; Vassallo-Aguis, Robert; de la Gándara, Fernando; Meiri-Ashkenazi, Iris; Zlatnikov, Vered; Gordin, Hillel; Bridges, Christopher R; Rosenfeld, Hanna

    2013-12-01

    As part of the endeavor aiming at the domestication of Atlantic bluefin tuna (BFT; Thunnus thynnus), first sexual maturity in captivity was studied by documenting its occurrence and by characterizing the key hormones of the reproductive axis: follicle stimulating hormone (FSH) and luteinizing hormone (LH). The full length sequence encoding for the related hormone β-subunits, bftFSHβ and bftLHβ, were determined, revealing two bftFSHβ mRNA variants, differing in their 5' untranslated region. A quantitative immuno-dot-blot assay to measure pituitary FSH content in BFT was developed and validated enabling, for the first time in this species, data sets for both LH and FSH to be compared. The expression and accumulation patterns of LH in the pituitary showed a steady increase of this hormone, concomitant with fish age, reaching higher levels in adult females compared to males of the same age class. Conversely, the pituitary FSH levels were elevated only in 2Y and adult fish. The pituitary FSH to LH ratio was consistently higher (>1) in immature than in maturing or pubertal fish, resembling the situation in mammals. Nevertheless, the results suggest that a rise in the LH storage level above a minimum threshold may be an indicator of the onset of puberty in BFT females. The higher pituitary LH levels in adult females over males may further support this notion. In contrast three year-old (3Y) males were pubertal while cognate females were still immature. However, it is not yet clear whether the advanced puberty in the 3Y males was a general feature typifying wild BFT populations or was induced by the culture conditions. Future studies testing the effects of captivity and hormonal treatments on precocious maturity may allow for improved handling of this species in a controlled environment which would lead to more cost-efficient farming. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Dispersal routes and habitat utilization of juvenile Atlantic bluefin tuna, Thunnus thynnus, tracked with mini PSAT and archival tags.

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    Benjamin Galuardi

    Full Text Available Between 2005 and 2009, we deployed 58 miniature pop-up satellite archival tags (PSAT and 132 implanted archival tags on juvenile Atlantic bluefin tuna (age 2-5 in the northwest Atlantic Ocean. Data returned from these efforts (n = 26 PSATs, 1 archival tag revealed their dispersal routes, horizontal and vertical movements and habitat utilization. All of the tagged bluefin tuna remained in the northwest Atlantic for the duration observed, and in summer months exhibited core-use of coastal seas extending from Maryland to Cape Cod, MA, (USA out to the shelf break. Their winter distributions were more spatially disaggregated, ranging south to the South Atlantic Bight, northern Bahamas and Gulf Stream. Vertical habitat patterns showed that juvenile bluefin tuna mainly occupied shallow depths (mean= 5-12 m, sd = 15-23.7 m and relatively warm water masses in summer (mean= 17.9-20.9°C, sd= 4.2-2.6°C and had deeper and more variable depth patterns in winter (mean= 41-58 m, sd= 48.9-62.2 m. Our tagging results reveal annual dispersal patterns, behavior and oceanographic associations of juvenile Atlantic bluefin tuna that were only surmised in earlier studies. Fishery independent profiling from electronic tagging also provide spatially and temporally explicit information for evaluating dispersals rates, population structure and fisheries catch patterns.

  19. Dispersal routes and habitat utilization of juvenile Atlantic bluefin tuna, Thunnus thynnus, tracked with mini PSAT and archival tags.

    Science.gov (United States)

    Galuardi, Benjamin; Lutcavage, Molly

    2012-01-01

    Between 2005 and 2009, we deployed 58 miniature pop-up satellite archival tags (PSAT) and 132 implanted archival tags on juvenile Atlantic bluefin tuna (age 2-5) in the northwest Atlantic Ocean. Data returned from these efforts (n = 26 PSATs, 1 archival tag) revealed their dispersal routes, horizontal and vertical movements and habitat utilization. All of the tagged bluefin tuna remained in the northwest Atlantic for the duration observed, and in summer months exhibited core-use of coastal seas extending from Maryland to Cape Cod, MA, (USA) out to the shelf break. Their winter distributions were more spatially disaggregated, ranging south to the South Atlantic Bight, northern Bahamas and Gulf Stream. Vertical habitat patterns showed that juvenile bluefin tuna mainly occupied shallow depths (mean= 5-12 m, sd = 15-23.7 m) and relatively warm water masses in summer (mean= 17.9-20.9°C, sd= 4.2-2.6°C) and had deeper and more variable depth patterns in winter (mean= 41-58 m, sd= 48.9-62.2 m). Our tagging results reveal annual dispersal patterns, behavior and oceanographic associations of juvenile Atlantic bluefin tuna that were only surmised in earlier studies. Fishery independent profiling from electronic tagging also provide spatially and temporally explicit information for evaluating dispersals rates, population structure and fisheries catch patterns.

  20. Seasonal and interannual variability of fat content of juvenile albacore ( Thunnus alalunga) and bluefin ( Thunnus thynnus) tunas during their feeding migration to the Bay of Biscay

    Science.gov (United States)

    Goñi, Nicolas; Arrizabalaga, Haritz

    2010-07-01

    The fat content of 2945 juvenile albacore and 618 juvenile bluefin tunas caught in the Bay of Biscay was measured. Individuals were caught in 2004, 2005, 2006 and 2007 from June to early November by pelagic trawling, trolling and baitboat gears. The results for the two species show different seasonal trends. The fat content of albacore tuna increased linearly throughout the fishing season, which reflects their feeding migration. The seasonal trend of bluefin tuna showed a minimum in early August, which may be related to a different behaviour, physiology or feeding strategy. An interannual increase of fat content was observed in albacore tuna and in age-2 to age-5+ bluefin tuna, which is possibly related to a density-dependence phenomenon. The seasonal increase of fat content was strongest and appeared in the four years studied for age-3 and age-4 albacore tuna, which can be related to a different vertical habitat or a more efficient use of their ecological niche by the individuals of these age-groups, relatively to the younger age-groups. Condition factor and girth/length ratio do not appear to be relevant indicators of fat content.

  1. Intestinal absorption of amino acids in the Pacific bluefin tuna (Thunnus orientalis): in vitro lysine-arginine interaction using the everted intestine system.

    Science.gov (United States)

    Martínez-Montaño, Emmanuel; Peña, Emyr; Viana, María Teresa

    2013-04-01

    The interaction between lysine (Lys) and arginine (Arg) in the proximal intestinal region of Pacific bluefin tuna (Thunnus orientalis) was evaluated using the everted intestine method. This in vitro intestinal system has been shown to be an effective tool for studying the nutrient absorption without the need to handle the tuna fish in marine cages as needed for digestibility and amino acid (AA) absorption. We used a factorial design with two sets of variables: low and high Lys concentration (10 and 75 mM) and four different Arg concentrations (3, 10, 20, and 30 mM). Both amino acids were dissolved in marine Ringer solution with a basal amino acidic composition consisting of a tryptone solution (9 mg mL(-1)). No interaction was observed between the absorption of Lys and Arg during the first 10 min of the experiment when low concentration of Lys and Arg was used in the hydrolyzate solution. However, there seemed to be a positive effect on Lys absorption when both amino acids were at high concentrations (30 and 75 mM, respectively). This type of studies will led us to test different formulations and/or additives to better understand the efficiency of AA supplementation as an alternative to in situ studies that are difficult to follow to design with the Pacific Bluefin Tuna.

  2. Heavy metals in liver and muscle of bluefin tunA (Thunnus thynnus) caught in the Straits of Messina (Sicily, Italy).

    Science.gov (United States)

    Licata, Patrizia; Trombetta, Domenico; Cristani, Mariateresa; Naccari, Clara; Martino, Daniela; Calò, Margherita; Naccari, Francesco

    2005-08-01

    The present investigation was carried out on the bluefin tuna (Thunnus thynnus) collected during the month of April 2003 from the Straits of Messina. The aim of this study is to determine heavy metal levels (Cd, Cu, Hg, Mn, Pb and Zn) in liver and muscle tissues of 14 Thunnus thynnus of different age and sex and to investigate the relationships between fish sex and size (length and weight) and metal concentrations in the tissues. The concentrations of the various metals were determined by a Varian atomic absorption spectroscopy instrument. The results show significant variations (p < 0.01) for Hg and Zn concentrations in muscle than in liver samples. Concentrations of Cd and Pb are below the instrumental detection limits in almost all muscle samples. Levels of Hg (3.03 +/- 0.55 microg/g) are above the MRLs only in muscle (1 microg/g) establishing toxicological risks for the consumer. Regression analysis shows a negative correlation between mercury level and weight and length in samples from both female and male. No significant difference between mean heavy metals concentrations and male or female tuna is seen. For greater food safety, it would be advisable to reduce the mercury intake by selecting safer fish, species and size and by the avoidance of tuna fish consumption by pregnant women, young children and old people, who are more sensitive to mercury exposure.

  3. The effect of Mistral (a strong NW wind episodes on the occurrence and abundance of Atlantic bluefin tuna (Thunnus thynnus in the trap fishery of Sardinia (W Mediterranean

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    Piero Addis

    2013-09-01

    Full Text Available From April to June Atlantic bluefin tuna, Thunnus thynnus, migrate along the western Sardinian coastline in a southward direction, where they are intercepted by the trap fishery. Fishermen claim that Mistral episodes facilitate the entry of tuna schools towards the traps, thus increasing capture rates. To test the fishermen’s hypothesis we conducted underwater visual counts of tuna in the trap chambers and analysed these data under the effect of wind. The results indicate a “stair-step” pattern in the abundance of tuna, demonstrating that major increases in abundance are associated with the Mistral. The second analytical approach involved a longer time scale to test whether higher Mistral occurrences corresponded to periods when higher captures were recorded. Using a linear regression model we found a significant correlation (p 15 knots seemed to have a negative effect on captures. This pattern may be caused by wind-induced advection of coastal waters generating a physical boundary that may have had a deterrent effect on tuna schools.

  4. Molecular Identification of Atlantic Bluefin Tuna (Thunnus thynnus, Scombridae Larvae and Development of a DNA Character-Based Identification Key for Mediterranean Scombrids.

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    Gregory Neils Puncher

    Full Text Available The Atlantic bluefin tuna, Thunnus thynnus, is a commercially important species that has been severely over-exploited in the recent past. Although the eastern Atlantic and Mediterranean stock is now showing signs of recovery, its current status remains very uncertain and as a consequence their recovery is dependent upon severe management informed by rigorous scientific research. Monitoring of early life history stages can inform decision makers about the health of the species based upon recruitment and survival rates. Misidentification of fish larvae and eggs can lead to inaccurate estimates of stock biomass and productivity which can trigger demands for increased quotas and unsound management conclusions. Herein we used a molecular approach employing mitochondrial and nuclear genes (CO1 and ITS1, respectively to identify larvae (n = 188 collected from three spawning areas in the Mediterranean Sea by different institutions working with a regional fisheries management organization. Several techniques were used to analyze the genetic sequences (sequence alignments using search algorithms, neighbour joining trees, and a genetic character-based identification key and an extensive comparison of the results is presented. During this process various inaccuracies in related publications and online databases were uncovered. Our results reveal important differences in the accuracy of the taxonomic identifications carried out by different ichthyoplanktologists following morphology-based methods. While less than half of larvae provided were bluefin tuna, other dominant taxa were bullet tuna (Auxis rochei, albacore (Thunnus alalunga and little tunny (Euthynnus alletteratus. We advocate an expansion of expertise for a new generation of morphology-based taxonomists, increased dialogue between morphology-based and molecular taxonomists and increased scrutiny of public sequence databases.

  5. Molecular Identification of Atlantic Bluefin Tuna (Thunnus thynnus, Scombridae) Larvae and Development of a DNA Character-Based Identification Key for Mediterranean Scombrids.

    Science.gov (United States)

    Puncher, Gregory Neils; Arrizabalaga, Haritz; Alemany, Francisco; Cariani, Alessia; Oray, Isik K; Karakulak, F Saadet; Basilone, Gualtiero; Cuttitta, Angela; Mazzola, Salvatore; Tinti, Fausto

    2015-01-01

    The Atlantic bluefin tuna, Thunnus thynnus, is a commercially important species that has been severely over-exploited in the recent past. Although the eastern Atlantic and Mediterranean stock is now showing signs of recovery, its current status remains very uncertain and as a consequence their recovery is dependent upon severe management informed by rigorous scientific research. Monitoring of early life history stages can inform decision makers about the health of the species based upon recruitment and survival rates. Misidentification of fish larvae and eggs can lead to inaccurate estimates of stock biomass and productivity which can trigger demands for increased quotas and unsound management conclusions. Herein we used a molecular approach employing mitochondrial and nuclear genes (CO1 and ITS1, respectively) to identify larvae (n = 188) collected from three spawning areas in the Mediterranean Sea by different institutions working with a regional fisheries management organization. Several techniques were used to analyze the genetic sequences (sequence alignments using search algorithms, neighbour joining trees, and a genetic character-based identification key) and an extensive comparison of the results is presented. During this process various inaccuracies in related publications and online databases were uncovered. Our results reveal important differences in the accuracy of the taxonomic identifications carried out by different ichthyoplanktologists following morphology-based methods. While less than half of larvae provided were bluefin tuna, other dominant taxa were bullet tuna (Auxis rochei), albacore (Thunnus alalunga) and little tunny (Euthynnus alletteratus). We advocate an expansion of expertise for a new generation of morphology-based taxonomists, increased dialogue between morphology-based and molecular taxonomists and increased scrutiny of public sequence databases.

  6. Morphology and lectin-binding sites of pyloric caeca epithelium in normal and GnRH-treated Atlantic bluefin tuna (Thunnus thynnus) Linnaeus 1758.

    Science.gov (United States)

    Zizza, Sara; Desantis, Salvatore

    2011-09-01

    Mucosal epithelium of pyloric caeca was studied in normal and in GnRH-treated Atlantic bluefin tuna Thunnus thynnus L., using morphological analysis, conventional and lectin glycohistochemistry. The lining epithelium consisted of columnar (absorptive) cells, goblet cells and intraepithelial leucocytes. The epithelium from normal animals was significantly taller than GnRH-treated samples. Conventional histochemistry displayed the same staining pattern in normal and hormone-treated specimens which showed a mixture of neutral and sulphated acidic glycoconjugates in the luminal surface and goblet cells, and neutral glycans in apical granules of enterocytes. Lectin histochemistry revealed a different glycoconjugate pattern in normal and GnRH-treated tunas. In normal specimens the luminal surface expressed sialoglycoconjugates which bound MAL II, SNA, KOH-sialidase-PNA, KOH-sialidase-SBA as well as asialoglycans stained with HPA, SBA, GSA I-B4 , LTA. N-linked glycans were highlighted by Con A and KOH-sialidase-WGA. In GnRH-treated tunas the luminal surface did not react with SNA, SBA and LTA. The columnar cells of normal tunas bound KOH-sialisase-PNA in the apical region, KOH-sialidase-PNA, KOH-sialidase-DBA, HPA, SBA, KOH-sialidase-SBA and KOH-sialidase-WGA in apical granules, GSA I-B₄ and LTA in the supranuclear region. GnRH-treated specimens showed some columnar cells that stained with KOH-sialidase-WGA in the apical granules and with GSA I-B4 in the supranuclear region. The goblet cells of normal animals produced mucins positive to PNA, HPA, KOH-sialidase-DBA, SBA, GSA II. The latter three binding sites lacked in GnRH-treated tunas. The results suggest that the mucosal epithelium of Thunnus thynnus L. pyloric caeca expresses a complex glycan pattern that is affected by GnRH-treatment. Copyright © 2010 Wiley-Liss, Inc.

  7. Impending collapse of bluefin tuna in the northeast Atlantic and Mediterranean

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Mosegaard, Henrik; Rosenberg, Andrew A.

    2009-01-01

    The abundance of bluefin tuna, Thunnus thynnus, in the east Atlantic and Mediterranean has declined in recent decades. The International Commission for the Conservation of Atlantic Tunas (ICCAT), the regional bluefin tuna management authority, has developed a plan to promote recovery by 2022, while...

  8. Evidence that severe acute stress and starvation induce rapid atresia of ovarian vitellogenic follicles in Atlantic bluefin tuna, Thunnus thynnus (L.) (Osteichthyes: Scombridae).

    Science.gov (United States)

    Corriero, A; Zupa, R; Bello, G; Mylonas, C C; Deflorio, M; Genovese, S; Basilone, G; Buscaino, G; Buffa, G; Pousis, C; De Metrio, G; Santamaria, N

    2011-11-01

    The effects of different stressors on the atretic degeneration of ovarian vitellogenic follicles, as well as on the ovarian mass, were examined in female Atlantic bluefin tuna, Thunnus thynnus (L.), from the Mediterranean Sea. The stressors taken into consideration were short-term starvation (up to 14 days), long-term cage rearing (1 year) and crowding-induced severe panic frenzy. Wild-caught individuals were used as a control group. Fish subjected to either severe panic frenzy or starvation exhibited a decrease in gonad mass and had significantly higher intensity of α atresia in the vitellogenic follicles (means: 78% and 58%, respectively; range: 36-100%) than either wild or long-term caged individuals (means: 32% and 30%, respectively; range: 19-44%). The extensive atresia in fish stressed by severe panic frenzy was observed as early as 24 h after the stressing event. The present study represents the first evidence of the extreme susceptibility of Atlantic bluefin tuna to severe acute stress during vitellogenesis; it also shows that starvation is associated with progressive reabsorption of vitellogenic oocytes. © 2011 Blackwell Publishing Ltd.

  9. Persistent organic pollutants (PCBs and DDTs) in small size specimens of bluefin tuna (Thunnus thynnus) from the Mediterranean Sea (Ionian Sea).

    Science.gov (United States)

    Storelli, M M; Casalino, E; Barone, G; Marcotrigiano, G O

    2008-05-01

    The concentration levels and pattern distribution of polychlorinated biphenyls (PCBs) and organochlorine pesticides (DDTs), were investigated in liver of small size specimens of bluefin tuna (Thunnus thynnus) from Mediterranean Sea (Ionian Sea). PCB concentrations (average: 526 ng g(-1) lipid wt) were comparable with DDT levels (average: 435 ng g(-1) lipid wt). The specific analysis of PCB congeners revealed a profile dominated by hexa-, penta- and heptachlorinated congeners, while among DDTs, the compounds with the higher concentration was p,p'-DDE, constituting 91.9% of the total DDT. The total 2,3,7,8-TCDD toxic equivalent (TEQs) of coplanar PCBs, including mono- and non-ortho congeners, was 0.55 pg g(-1) wet weight with. The congeners with highest TEQs values were non-ortho congeners followed by mono-ortho ones.

  10. Comparison of the lipid profiles from wild caught eggs and unfed larvae of two scombroid fish: northern bluefin tuna (Thunnus thynnus L., 1758) and Atlantic bonito (Sarda sarda Bloch, 1793).

    Science.gov (United States)

    Ortega, Aurelio; Mourente, Gabriel

    2010-09-01

    Lipids and essential fatty acids are determinants of the reproductive process in marine fish, affecting fecundity, egg quality, hatching performance, pigmentation and larval malformation. We have analyzed and characterized the lipids of eggs and unfed larvae of two wild caught scombroid fish, the Atlantic northern bluefin tuna (Thunnus thynnus) and Atlantic bonito (Sarda sarda). Dry matter and total lipid contents, polar and neutral lipid classes and total lipid fatty acid contents were determined in the eggs of bluefin tuna and eggs and unfed larvae during the development of Atlantic bonito. Bluefin tuna eggs had slightly but significantly more dry mass than bonito eggs but very similar lipid content. However, bluefin tuna eggs presented a higher polar lipid content due to increased proportions of phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI). Bonito eggs and larvae showed increasing dry mass and decreasing lipid content with development. The proportion of polar lipids increased due to increased PE, PS and PI, whereas choline-containing polar lipids (phosphatidylcholine and sphingomyelin) remained relatively constant. Free cholesterol also increased, whereas the levels of other neutral lipids, especially triacylglycerol and steryl ester fractions, decreased, presumably due to utilization for energy to drive development. Bluefin tuna eggs had higher levels of n - 3 and n - 6 highly unsaturated fatty acids due to higher docosahexaenoic and arachidonic acid contents, respectively, than bonito eggs. The results are discussed in relation to the lipid and fatty acid requirements of larval scombroid fish in comparison to those of other larval marine finfish species under culture conditions.

  11. Feeding habits of the Atlantic bluefin tuna, Thunnus thynnus (L. 1758), in the central Mediterranean Sea (Strait of Messina)

    Science.gov (United States)

    Battaglia, Pietro; Andaloro, Franco; Consoli, Pierpaolo; Esposito, Valentina; Malara, Danilo; Musolino, Simona; Pedà, Cristina; Romeo, Teresa

    2013-03-01

    The study of feeding habits of the Atlantic bluefin tuna was carried out in 123 specimens, ranging from 115 to 222 cm fork length (FL) and collected during spring seasons of 2010 and 2011 in the central Mediterranean Sea (Strait of Messina). The analysis of stomach contents allowed us to identify 91 taxa of prey items, mainly belonging to Teleostea (54), Cephalopoda (20) and Crustacea (13). The percentage of index of relative abundance ( IRI) shows the highest values for the myctophid Hygophum benoiti (% IRI = 22.854) and the stomiid Chauliodus sloani (% IRI = 15.124), followed by the oegopsid squid Illex coindetii (% IRI = 14.316). The broad spectrum of prey items could suggest a generalist behavior of this predator, with several species that occasionally occurs in its diet. However, if prey are grouped into food categories, the importance of mesopelagic and benthopelagic fishes can be appreciated (54.41 % of % IRI). The assessment of the hypothetical foraging rhythm of the Atlantic bluefin tuna highlighted that its feeding activity is concentrated on diel migrating fauna during night and on larger preys upon daylight. The predation on the high-energetic food as mesopelagic and bathypelagic fishes during the pre-spawning and the spawning period may bring an energetic advantage in tuna metabolism and gonadal maturation

  12. Differentiated stable isotopes signatures between pre- and post-flexion larvae of Atlantic bluefin tuna (Thunnus thynnus) and of its associated tuna species of the Balearic Sea (NW Mediterranean)

    Science.gov (United States)

    García, Alberto; Laiz-Carrión, Raúl; Uriarte, Amaya; Quintanilla, José M.; Morote, Elvira; Rodríguez, José M.; Alemany, Francisco

    2017-06-01

    The trophic ecology of bluefin tuna larvae (Thunnus thynnus) from the Balearic Sea, together with its co-existing tuna species such as albacore (T. alalunga), bullet (Auxis rochei) and little tunny (Euthynnus alletteratus) were examined by nitrogen and carbon stable isotope analyses. A total of 286 larvae were analyzed for this study, of which 72 larvae corresponded to bluefin, 57 to albacore, 81 to bullet tuna and 76 to little tunny. Tuna larvae were separated into the pre-flexion and post-flexion developmental stages. Within the size 3-9 mm standard length (SL), the stable isotope of nitrogen (δ15N) showed significant differences between species where bluefin tuna larvae ranked highest. Pre-flexion bluefin tuna and little tunny larvae showed significantly higher δ15N signatures than the post-flexion larvae. This effect is attributed to a biochemical trace of maternal δ15N signatures. However, neither albacore nor bullet tuna larvae showed this pattern in δ15N signatures, possibly owing to a compensation effect between lower maternal δ15N values transmitted to pre-flexion larvae and the early increase of δ15N values in post-flexion stages. One way ANOVA showed significant differences between species in the stable isotope ratio of carbon (δ13C) values, which suggests specific differences of carbon sources. Furthermore, a similar significant ontogenic effect between δ13C signatures of pre-flexion and post-flexion larvae is also evidenced in all four species. At pre-flexion stages, all species except bullet tuna larvae showed significant negative relationships between δ15N and larval standard length. At post-flexion stages, a significant linear relationship with larval size was only observed in albacore and bullet tuna larvae indicating a possible trophic shift towards early piscivory. With respect to δ13C values with larval size, all four species showed significant linear decreases. It may be explained by the metabolism of growth of somatic mass subject to

  13. Active nanocomposite films based on soy proteins-montmorillonite- clove essential oil for the preservation of refrigerated bluefin tuna (Thunnus thynnus) fillets.

    Science.gov (United States)

    Echeverría, Ignacio; López-Caballero, María Elvira; Gómez-Guillén, María Carmen; Mauri, Adriana Noemi; Montero, María Pilar

    2018-02-02

    This manuscript evaluates the potential application of active nanocomposite films based on soy protein isolate (SPI)-montmorillonite (MMT)-clove essential oil (CEO) to the preservation of muscle fillets of bluefin tuna (Thunnus thynnus) during refrigerated storage, and furthermore analyzes whether the clay diffuses from the package to food. SPI films with: CEO (SPI-CEO), MMT (SPI-MMT), or both CEO and MMT (SPI-MMT-CEO), were prepared and used to cover tuna fillets during 17days of storage at 2°C. Polyethylene films were also used as control. Protein films nanoreinforced with 10g MMT/100g SPI and activated with CEO were able to decrease microbial growth (evaluated by TVBN and microorganism counts) and lipid autooxidation (evaluated according to the TBA index, FTIR and color parameters) of tuna fillets during the storage period studied. The presence of clay seemed to favor the release of the active principles of clove oil by prolonging its antimicrobial (especially effective to inhibit Pseudomonas spp.) and antioxidant activity over time without observing the diffusion of the clay's own metals (Si and Al) from the nanocomposite materials to the muscle of fish. These results are encouraging for the use of nanocomposite films in food packaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Phthalates and perfluorinated alkylated substances in Atlantic bluefin tuna (Thunnus thynnus) specimens from Mediterranean Sea (Sardinia, Italy): Levels and risks for human consumption.

    Science.gov (United States)

    Guerranti, Cristiana; Cau, Alessandro; Renzi, Monia; Badini, Simone; Grazioli, Eleonora; Perra, Guido; Focardi, Silvano Ettore

    2016-10-02

    Atlantic blue fin tuna (Thunnus thynnus) is a species of great importance for Mediterranean Sea area, from both ecological and commercial points of view. The scientific literature reports few data on the contamination of this fish by emerging organic compounds such as perfluorinated alkylated substances(PFASs) and phthalates, being the latter never been studied in tuna. This study therefore investigated the presence of the PFASs perfluorooctane sulphonate (PFOS) and perfluoroctanoic acid (PFOA) and the phthalate di-2-ethylhexyl phthalate (DEHP), also monitored by its metabolite mono-2-ethylhexyl phthalate(MEHP), to assess both the state of contamination of Atlantic bluefin tuna specimen and the risk due to the toxicity of these compounds for human consumption. While PFOA was never found, detectable levels of PFOS (0.4-1.88 ng/g), DEHP (9-14.62 ng/g) and MEHP (1.5-6.30 ng/g) were found. The results were elaborated relating the accumulation to the size and age of the individuals and showed a correlation between the levels of different pollutants investigated.

  15. THE ROLE OF ICCAT IN BLUEFIN TUNA MANAGEMENT IN CROATIA

    Directory of Open Access Journals (Sweden)

    Ivana Miletić

    2011-03-01

    Full Text Available The scope of this study is to bring un updated and detailed analyses of the role of International Commission for the Conservation of Atlantic Tunas (ICCAT, as well as discuss applied measures of protection of the bluefin tuna in Croatia. On the yearly basis, ICCAT brings recommendations that have committing character for all the member countries and which include the minimum catch and farming quotas, temporal and spatial limitation of tuna fisheries, along a number of other controlling regulations. It is of wide importance for Croatia the type of measures directed for the management of east stocks of the bluefin tuna (Thunnus thynnus.

  16. Morphological characterisation and identification of four species of Cardicola Short, 1953 (Trematoda: Aporocotylidae) infecting the Atlantic bluefin tuna Thunnus thynnus (L.) in the Mediterranean Sea.

    Science.gov (United States)

    Palacios-Abella, José F; Rodríguez-Llanos, Javier; Mele, Salvatore; Montero, Francisco E

    2015-06-01

    Blood flukes of the genus Cardicola Short, 1953 are considered the most potentially pathogenic parasites in bluefin tuna cultures. Morphological study and genetic analyses of the ribosomal internal transcribed spacer ITS-2 and the mitochondrial cytochrome c oxidase 1 (cox1) gene fragments revealed the occurrence of four aporocotylid species (C. forsteri Cribb, Daintith & Munday, 2000, C. orientalis Ogawa, Tanaka, Sugihara & Takami, 2010, C. opisthorchis Ogawa, Ishimaru, Shirakashi, Takami & Grabner, 2011 and Cardicola sp.) in 421 Thunnus thynnus (L.) from the Western Mediterranean (274 fished from the wild and 147 from sea-cages). Cardicola opisthorchis was the most abundant species, with higher prevalence in the cage-reared fish than in those fished in the wild (21 vs 6%, p < 0.05). Adults of three species were recovered: C. forsteri from both gills and heart, C. opisthorchis from heart and C. orientalis from gills. The secondary gill lamellae were profusely infected by eggs of C. orientalis. A fourth species was found in four tunas, based on the molecular analyses of eggs apparently indistinguishable in size and shape from the eggs of C. orientalis. The findings provided evidence that infections with Cardicola spp. differed in relation to locality, host origin (wild vs cage-reared) and site of infection. It is necessary to estimate the possible different pathogenic effects of each species of Cardicola in order to take appropriate control measures.

  17. On Making Statistical Inferences Regarding the Relationship between Spawners and Recruits and the Irresolute Case of Western Atlantic Bluefin Tuna (Thunnus thynnus.

    Directory of Open Access Journals (Sweden)

    Clay E Porch

    Full Text Available Forecasts of the future abundance of western Atlantic bluefin tuna (Thunnus thynnus have, for nearly two decades, been based on two competing views of future recruitment potential: (1 a "low" recruitment scenario based on hockey-stick (two-line curve where the expected level of recruitment is set equal to the geometric mean of the recruitment estimates for the years after a supposed regime-shift in 1975, and (2 a "high" recruitment scenario based on a Beverton-Holt curve fit to the time series of spawner-recruit pairs beginning in 1970. Several investigators inferred the relative plausibility of these two scenarios based on measures of their ability to fit estimates of spawning biomass and recruitment derived from stock assessment outputs. Typically, these comparisons have assumed the assessment estimates of spawning biomass are known without error. It is shown here that ignoring error in the spawning biomass estimates can predispose model-choice approaches to favor the regime-shift hypothesis over the Beverton-Holt curve with higher recruitment potential. When the variance of the observation error approaches that which is typically estimated for assessment outputs, the same model-choice approaches tend to favor the single Beverton-Holt curve. For this and other reasons, it is argued that standard model-choice approaches are insufficient to make the case for a regime shift in the recruitment dynamics of western Atlantic bluefin tuna. A more fruitful course of action may be to move away from the current high/low recruitment dichotomy and focus instead on adopting biological reference points and management procedures that are robust to these and other sources of uncertainty.

  18. On Making Statistical Inferences Regarding the Relationship between Spawners and Recruits and the Irresolute Case of Western Atlantic Bluefin Tuna (Thunnus thynnus).

    Science.gov (United States)

    Porch, Clay E; Lauretta, Matthew V

    2016-01-01

    Forecasts of the future abundance of western Atlantic bluefin tuna (Thunnus thynnus) have, for nearly two decades, been based on two competing views of future recruitment potential: (1) a "low" recruitment scenario based on hockey-stick (two-line) curve where the expected level of recruitment is set equal to the geometric mean of the recruitment estimates for the years after a supposed regime-shift in 1975, and (2) a "high" recruitment scenario based on a Beverton-Holt curve fit to the time series of spawner-recruit pairs beginning in 1970. Several investigators inferred the relative plausibility of these two scenarios based on measures of their ability to fit estimates of spawning biomass and recruitment derived from stock assessment outputs. Typically, these comparisons have assumed the assessment estimates of spawning biomass are known without error. It is shown here that ignoring error in the spawning biomass estimates can predispose model-choice approaches to favor the regime-shift hypothesis over the Beverton-Holt curve with higher recruitment potential. When the variance of the observation error approaches that which is typically estimated for assessment outputs, the same model-choice approaches tend to favor the single Beverton-Holt curve. For this and other reasons, it is argued that standard model-choice approaches are insufficient to make the case for a regime shift in the recruitment dynamics of western Atlantic bluefin tuna. A more fruitful course of action may be to move away from the current high/low recruitment dichotomy and focus instead on adopting biological reference points and management procedures that are robust to these and other sources of uncertainty.

  19. Spawning of bluefin tuna in the black sea: historical evidence, environmental constraints and population plasticity

    DEFF Research Database (Denmark)

    Mackenzie, Brian R; Mariani, Patrizio

    2012-01-01

    The lucrative and highly migratory Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758; Scombridae), used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity...

  20. Proliferation and apoptosis of male germ cells in captive Atlantic bluefin tuna (Thunnus thynnus L.) treated with gonadotropin-releasing hormone agonist (GnRHa).

    Science.gov (United States)

    Corriero, A; Medina, A; Mylonas, C C; Bridges, C R; Santamaria, N; Deflorio, M; Losurdo, M; Zupa, R; Gordin, H; de la Gandara, F; Belmonte Rìos, A; Pousis, C; De Metrio, G

    2009-12-01

    The effects of administration of gonadotropin-releasing hormone agonist (GnRHa) on proliferation and apoptosis of male germ cells were evaluated on Atlantic bluefin tuna (Thunnus thynnus L.) reared in captivity. Fish (n=19) were treated with a sustained-release delivery system loaded with GnRHa during the natural spawning season of 2004 and 2005 (June-July). Untreated Control fish (n=17) and adult wild spawners were used for comparison. Fish were sacrificed 2-8 d after GnRHa implantation and body weight and gonad weight were recorded, and gonads and blood were taken. Germ cell proliferation and apoptosis were evaluated through the immunohistochemical detection of proliferating cell nuclear antigen (PCNA) and the terminal deoxynucleotidyl transferase-mediated d'UTP nick end labelling (TUNEL) method, respectively. Plasma 11 ketotestosterone (11-KT) levels were measured using an ELISA method. Mean gonado-somatic index and seminiferous lobule diameter did not differ between GnRHa-treated and Control fish, and were significantly lower in captive-reared individuals than in wild spawners. Significant increases in 11-KT plasma levels and spermatogonial mitosis, along with a reduction of germ cell apoptosis were demonstrated in GnRHa-treated fish compared to Controls. The results suggest that GnRHa administration was effective in enhancing germ cell proliferation and reducing apoptosis in captive males through the stimulation of luteinizing hormone (LH) release and testicular 11-KT production.

  1. Characterization of three pro-inflammatory cytokines, TNFα1, TNFα2 and IL-1β, in cage-reared Atlantic bluefin tuna Thunnus thynnus.

    Science.gov (United States)

    Lepen Pleić, Ivana; Secombes, Christopher J; Bird, Steve; Mladineo, Ivona

    2014-01-01

    Atlantic bluefin tuna (BFT) (Thunnus thynnus) is of great economic significance for world aquaculture and therefore it is necessary to ensure optimal and sustainable conditions for the farming of this species. Intensive culture of fish may be limited by infectious diseases that can impact on growth performance and cause heavy losses. However, to date there are no reports of cloning and expression analysis of any major immune genes of Atlantic BFT although some immune genes are known in other BFT species. Therefore the aim of this study was to characterize the first cytokine molecules in Atlantic BFT, through: 1) Isolation of full-length cDNA and gene sequences of TNFα1, TNFα2 and IL-1β, 2) comparison of these molecules to known sequences in other vertebrates, especially teleost fish, by multiple sequence alignment, phylogenetic tree analysis and homology modeling; 3) Quantification of in vivo expression of these cytokines in selected tissues in reared BFT over the duration of the farming process. The results indicated that these three cytokines could have value for monitoring Atlantic BFT health status. Curiously, the liver seemed to be an important site of cytokine production during poor health conditions in this species, perhaps reflecting its role as an important organ involved in fish defenses.

  2. Discrimination between Atlantic and Pacific Subspecies of Northern Bluefin Tuna (Thunnus thynnus) by Magnetic-Capture Hybridization Using Bacterial Magnetic Particles.

    Science.gov (United States)

    Takeyama; Tsuzuki; Chow; Nakayama; Matsunaga

    2000-07-01

    The previously developed magnetic-capture hybridization technique employing bacterial magnetic particles was applied to discriminate between Atlantic and Pacific subspecies of the northern bluefin tuna (Thunnus thynnus) using specific DNA sequences. Nucleotide sequences of a 925-bp fragment (ATCO) flanking the mitochondrial ATPase and cytochrome oxidase subunit III genes in these two subspecies were compared. Two regions having single-nucleotide and three-nucleotide differences between the subspecies were adopted to design DNA probes (NR1, 21-mer; NR2, 29-mer), and two internal primer sets were designed to amplify DNA fragments containing these regions. The DNA probes were immobilized on bacterial magnetic particles via streptavidin-biotin conjugation and subjected to magnetic-capture hybridization with the digoxigenin-labeled fragments amplified using the internal primers. The luminescence intensities of DNA on bacterial magnetic particles obtained by hybridization between the probes and the complementary fragments were higher than those obtained by hybridization with noncomplementary fragments. These data suggest that this system employing DNA on bacterial magnetic particles may be useful for discrimination of these two subspecies by recognizing a single-nucleotide difference.

  3. Fin spine bone resorption in atlantic bluefin tuna, Thunnus thynnus, and comparison between wild and captive-reared specimens.

    Directory of Open Access Journals (Sweden)

    Nicoletta Santamaria

    Full Text Available Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT has long been considered for age estimation studies. In the present paper spine bone resorption was assessed in wild (aged 1 to 13 years and captive-reared (aged 2 to 11 years ABFT sampled from the Mediterranean Sea. Total surface (TS, solid surface (SS and reabsorbed surface (RS were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions.

  4. Fin spine bone resorption in atlantic bluefin tuna, Thunnus thynnus, and comparison between wild and captive-reared specimens.

    Science.gov (United States)

    Santamaria, Nicoletta; Bello, Giambattista; Pousis, Chrysovalentinos; Vassallo-Agius, Robert; de la Gándara, Fernando; Corriero, Aldo

    2015-01-01

    Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT) has long been considered for age estimation studies. In the present paper spine bone resorption was assessed in wild (aged 1 to 13 years) and captive-reared (aged 2 to 11 years) ABFT sampled from the Mediterranean Sea. Total surface (TS), solid surface (SS) and reabsorbed surface (RS) were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions.

  5. Spatial and temporal variability in the trans-Pacific migration of Pacific bluefin tuna (Thunnus orientalis) revealed by archival tags

    Science.gov (United States)

    Fujioka, Ko; Fukuda, Hiromu; Tei, Yaoki; Okamoto, Suguru; Kiyofuji, Hidetada; Furukawa, Seishiro; Takagi, Junichi; Estess, Ethan; Farwell, Charles J.; Fuller, Daniel W.; Suzuki, Nobuaki; Ohshimo, Seiji; Kitagawa, Takashi

    2018-03-01

    Archival electronic tags were internally implanted in 713 age-0 Pacific bluefin tuna (PBF) caught in their nursery waters off the southern coast of Japan and in the East China Sea over an extended study period (1995-2015) to clarify the spatial and temporal variability of their trans-Pacific migration. Two hundred twenty-five of these tagged tuna were recaptured by fisheries (31.6%), and we successfully retrieved tag data from 14 of 21 individuals recovered in the Eastern pacific. Furthermore, one archival tag recovered in the Western Pacific revealed that the individual had performed a trans-Pacific migration, so in total 21 tagged PBF were shown to have migrated to the Eastern Pacific (2.9% of the total tags released). We successfully downloaded data from 15 of these 21 archival tags, which revealed that some age-1 PBF migrate rapidly (123.9 ± 82.8 km day-1) and directly from waters offshore of Japan to the eastern Pacific (160.0°E to 130.0°W), a journey that takes an average of 2.5 months (ranging from 1.2 to 5.5 months) through relatively cool waters (14.7 ± 2.0 °C). All juvenile PBF began their trans-Pacific migration shortly after exposure to cooler water temperatures (physiological challenge for this age class. Three patterns were identified in the timing of the departure of juvenile PBF from the western Pacific: departing 12-14 months post-hatch (N = 7) in early summer (May-July), departing 17-19 months post-hatch (N = 7) in late autumn (October-December), and departing 21 months post-hatch (N = 1) in late winter (February). The PBF tagged along the southern coast of Japan (SCJ) arrived in the eastern Pacific earlier than those tagged in the East China Sea (ECS), most likely due to the shorter travel distance. Additionally, the PBF that began their trans-Pacific migration in the earlier period remained in an offshore foraging zone (the Kuroshio-Oyashio transition region) for shorter periods (2.8 months on average) and at lower latitudes (35.0

  6. Characterization of the Boundary Layers on Full-Scale Bluefin Tuna

    Science.gov (United States)

    2014-09-30

    2. TECHNICAL APPROACH Simply using arc length Reynolds number and flat-plate equations to predict where transition occurs on a tuna body is...J. Song, A. Mathieu , R. F. Soper, and A. Popper, “Structure of the Inner Ear of Bluefin Tuna Thunnus Thynnus,” Journal of Fish Biology, vol. 68, pp

  7. Habitat use, vertical and horizontal behaviour of Atlantic bluefin tuna (Thunnus thynnus) in the Northwestern Mediterranean Sea in relation to oceanographic conditions

    Science.gov (United States)

    Bauer, Robert Klaus; Fromentin, Jean-Marc; Demarcq, Hervé; Bonhommeau, Sylvain

    2017-07-01

    We investigated the habitat utilization, vertical and horizontal behaviour of Atlantic bluefin tuna Thunnus thynnus (ABFT) in relation to oceanographic conditions in the northwestern Mediterranean Sea, based on 36 pop-up archival tags and different environmental data sets. Tags were deployed on early mature ABFT (127-255 cm) between July and November in 2007-2014, on the shelf area off Marseille, France. The data obtained from these tags provided 1643 daily summaries of ABFT vertical behaviour over 8 years of tag deployment. Based on a hierarchical clustering of this data, we could identify four principle daily vertical behaviour types, representing surface (≦ 10 m) and subsurface (10-100 m) orientation, moderate (50-200 m) and deep (≧ 200 m) diving behaviour. These vertical behaviour types showed seasonal variations with partly opposing trends in their frequencies. Accordingly, ABFT were more surface orientated during summer, while moderate diving behaviour was more common during winter. Depth time series data further revealed inverted day-night patterns for both of these periods. Tagged ABFT frequented the surface waters more regularly during daytime and deeper waters during the night in summer, while the opposite pattern was found in winter. Seasonal changes in the vertical behaviour of ABFT were accompanied by simultaneous changes in environmental conditions (SST, chla, thermal stratification). Accordingly, surface orientation and moderate diving behaviour appeared to be triggered by the thermal stratification of the water column, though less pronounced than previously reported for ABFT in the North Atlantic, probably indicating adaptive vertical behaviour related to the availability of epipelagic food resources (anchovies and sardines). Deep diving behaviour was particularly frequent during months of high biological productivity (February-May), although one recovered tag showed periodic and unusual long spike dives during summer-autumn, in relation to

  8. Ecological role of bluefin tuna (Thunnus thynnus) fish farms for associated wild fish assemblages in the Mediterranean Sea.

    Science.gov (United States)

    Stagličić, Nika; Šegvić-Bubić, Tanja; Ugarković, Pero; Talijančić, Igor; Žužul, Iva; Tičina, Vjekoslav; Grubišić, Leon

    2017-12-01

    The ecological effects of tuna fish farms are largely undocumented. This study confirmed their high capacity to attract surrounding wild fish. The aggregation effect persisted year round, without detectable seasonal differences. Farm impact was restricted to close proximity of the sea cages, and was more prominent over the bottom than in the water column strata. Tuna fish farms proved to be high energy trophic resources, as indicated by the enhanced fitness status of two focal species, bogue and seabream. Under abundant food supply, seabream appear to allocate the majority of energy reserves to gonad development. Farm associated bogue had greater parasite loads, with no detrimental effect on fitness status. Overall, tuna fish farms can be regarded as population sources for aggregated wild fish, and under the no fishing conditions within the leasehold areas, can serve as functional marine protected areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Lipid and fatty acid composition, and persistent organic pollutant levels in tissues of migrating Atlantic bluefin tuna (Thunnus thynnus, L.) broodstock

    International Nuclear Information System (INIS)

    Sprague, M.; Dick, J.R.; Medina, A.; Tocher, D.R.; Bell, J.G.; Mourente, G.

    2012-01-01

    Lipid class, fatty acid and POP levels were measured in migrating Atlantic bluefin tuna (ABT) tissues caught off the Barbate coast, Spain. Tissue lipids were largely characterized by triacylglycerol, reflecting large energy reserves accumulated prior to reproductive migration. Fatty acid compositions of muscle, liver and adipose exhibited similar profiles, whereas gonads showed a higher affinity for docosahexaenoic acid. Tissue POP concentrations correlated positively with percentage triacylglycerol and negatively with polar lipids. Highest POP concentrations were in adipose and lowest in gonads, reflecting lipid content. DL-PCBs contributed most to total PCDD/F + DL-PCB levels, with mono-ortho concentrations higher in tissues, whereas non-ortho PCBs contributed greater WHO-TEQs due to differences in TEFs. PBDE47 was the most prominent BDE congener in tissues, probably through biotransformation of BDE99 and other higher brominated congeners. The perceived POP risk from ABT consumption should be balanced by the well-established beneficial effects on human health of omega-3 fatty acids. - Highlights: ► Lipid classes, fatty acids and POPs were measured in Atlantic bluefin tuna tissues. ► Lowest POP concentrations were detected in gonads and highest in adipose. ► POP concentrations correlated positively with percentage triacylglycerol. ► The DL-PCBs contributed most to total PCDD/F + DL-PCB concentrations and TEQ levels. ► We assess the risk-benefit to human health associated with ABT consumption. - Lipids, fatty acids (particularly omega-3) and POPs were determined in Atlantic bluefin tuna to examine tissue distribution, and assess the risk-benefit to human health.

  10. A cascade of warming impacts brings bluefin tuna to Greenland waters

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Payne, Mark; Boje, Jesper

    in ecological isolation from others. Here we show that a large highly migratory top predator fish species has entered a high latitude sub-polar area. Bluefin tuna, Thunnus thynnus Linnaeus 1758, were captured in waters east of Greenland (65o N) in August 2012 during exploratory fishing for Atlantic mackerel...

  11. Determination of temporal spawning patterns and hatching time in response to temperature of Atlantic bluefin tuna (Thunnus thynnus in the Western Mediterranean.

    Directory of Open Access Journals (Sweden)

    Ana Gordoa

    Full Text Available This study analysed the temporal pattern of Atlantic bluefin tuna (ABFT spawning in the Balearic spawning ground and examined its reproductive performance after years in captivity. Furthermore, ABFT hatching time at different on-site temperatures was determined for the first time. Spawning surveys were carried out in 4 spawning seasons (2009-2012 aboard tuna transport vessels. Three groups of spawners were monitored: a captive group transported to the spawning region and monitored throughout the four spawning seasons and two wild groups caught in 2009 and 2010 which were transferred to a monitoring transport cage immediately after being caught. Surface plankton samples were collected nightly, beginning immediately after the first purse seine catches were made and concluding after spawning was observed to have ended. All groups displayed the same spawning hours, restricted between 2:00-5:00 a.m. The captive group, as they got older, shifted towards the earliest hour, suggesting an age influence on reproductive time. The onset of spawning varied annually from the end of May to the beginning of June at temperatures around 19 °C-20 °C, ending by the second week of July. The peak of spawning was consistently around the summer solstice, June 15th-30th. The results showed the negative effect of unstable oceanographic conditions in the spawning process which might influence the annual reproductive success of ABFT. The influence of temperature on hatching time was higher than that observed in other tuna species, twice as fast at 26 °C (23 h as at 19.5 °C (49 h. Overall, this study shows the strength of the internal mechanism in ABFT that controls spawning traits. Spawning in ABFT is cyclical and highly synchronised on diel and annual scales. We consider that the timing of spawning is rather influenced by day length and its adaptive significance is discussed.

  12. Determination of temporal spawning patterns and hatching time in response to temperature of Atlantic bluefin tuna (Thunnus thynnus) in the Western Mediterranean.

    Science.gov (United States)

    Gordoa, Ana; Carreras, Gustavo

    2014-01-01

    This study analysed the temporal pattern of Atlantic bluefin tuna (ABFT) spawning in the Balearic spawning ground and examined its reproductive performance after years in captivity. Furthermore, ABFT hatching time at different on-site temperatures was determined for the first time. Spawning surveys were carried out in 4 spawning seasons (2009-2012) aboard tuna transport vessels. Three groups of spawners were monitored: a captive group transported to the spawning region and monitored throughout the four spawning seasons and two wild groups caught in 2009 and 2010 which were transferred to a monitoring transport cage immediately after being caught. Surface plankton samples were collected nightly, beginning immediately after the first purse seine catches were made and concluding after spawning was observed to have ended. All groups displayed the same spawning hours, restricted between 2:00-5:00 a.m. The captive group, as they got older, shifted towards the earliest hour, suggesting an age influence on reproductive time. The onset of spawning varied annually from the end of May to the beginning of June at temperatures around 19 °C-20 °C, ending by the second week of July. The peak of spawning was consistently around the summer solstice, June 15th-30th. The results showed the negative effect of unstable oceanographic conditions in the spawning process which might influence the annual reproductive success of ABFT. The influence of temperature on hatching time was higher than that observed in other tuna species, twice as fast at 26 °C (23 h) as at 19.5 °C (49 h). Overall, this study shows the strength of the internal mechanism in ABFT that controls spawning traits. Spawning in ABFT is cyclical and highly synchronised on diel and annual scales. We consider that the timing of spawning is rather influenced by day length and its adaptive significance is discussed.

  13. Modelling retention and dispersion mechanisms of bluefin tuna eggs and larvae in the northwest Mediterranean Sea

    Science.gov (United States)

    Mariani, Patrizio; MacKenzie, Brian R.; Iudicone, Daniele; Bozec, Alexandra

    2010-07-01

    Knowledge of early life history of most fish species in the Mediterranean Sea is sparse and processes affecting their recruitment are poorly understood. This is particularly true for bluefin tuna, Thunnus thynnus, even though this species is one of the world’s most valued fish species. Here we develop, apply and validate an individually based coupled biological-physical oceanographic model of fish early life history in the Mediterranean Sea. We first validate the general structure of the coupled model with a 12-day Lagrangian drift study of anchovy ( Engraulis encrasicolus) larvae in the Catalan Sea. The model reproduced the drift and growth of anchovy larvae as they drifted along the Catalan coast and yielded similar patterns as those observed in the field. We then applied the model to investigate transport and retention processes affecting the spatial distribution of bluefin tuna eggs and larvae during 1999-2003, and we compared modelled distributions with available field data collected in 2001 and 2003. Modelled and field distributions generally coincided and were patchy at mesoscales (10s-100s km); larvae were most abundant in eddies and along frontal zones. We also identified probable locations of spawning bluefin tuna using hydrographic backtracking procedures; these locations were situated in a major salinity frontal zone and coincided with distributions of an electronically tagged bluefin tuna and commercial bluefin tuna fishing vessels. Moreover, we hypothesized that mesoscale processes are responsible for the aggregation and dispersion mechanisms in the area and showed that these processes were significantly correlated to atmospheric forcing processes over the NW Mediterranean Sea. Interannual variations in average summer air temperature can reduce the intensity of ocean mesoscale processes in the Balearic area and thus potentially affect bluefin tuna larvae. These modelling approaches can increase understanding of bluefin tuna recruitment processes and

  14. Lipid and fatty acid composition, and persistent organic pollutant levels in tissues of migrating Atlantic bluefin tuna (Thunnus thynnus, L.) broodstock.

    Science.gov (United States)

    Sprague, M; Dick, J R; Medina, A; Tocher, D R; Bell, J G; Mourente, G

    2012-12-01

    Lipid class, fatty acid and POP levels were measured in migrating Atlantic bluefin tuna (ABT) tissues caught off the Barbate coast, Spain. Tissue lipids were largely characterized by triacylglycerol, reflecting large energy reserves accumulated prior to reproductive migration. Fatty acid compositions of muscle, liver and adipose exhibited similar profiles, whereas gonads showed a higher affinity for docosahexaenoic acid. Tissue POP concentrations correlated positively with percentage triacylglycerol and negatively with polar lipids. Highest POP concentrations were in adipose and lowest in gonads, reflecting lipid content. DL-PCBs contributed most to total PCDD/F + DL-PCB levels, with mono-ortho concentrations higher in tissues, whereas non-ortho PCBs contributed greater WHO-TEQs due to differences in TEFs. PBDE47 was the most prominent BDE congener in tissues, probably through biotransformation of BDE99 and other higher brominated congeners. The perceived POP risk from ABT consumption should be balanced by the well-established beneficial effects on human health of omega-3 fatty acids. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Incorporation of habitat information in the development of indices of larval bluefin tuna (Thunnus thynnus) in the Western Mediterranean Sea (2001-2005 and 2012-2013)

    Science.gov (United States)

    Ingram, G. Walter; Alvarez-Berastegui, Diego; Reglero, Patricia; Balbín, Rosa; García, Alberto; Alemany, Francisco

    2017-06-01

    Fishery independent indices of bluefin tuna larvae in the Western Mediterranean Sea are presented utilizing ichthyoplankton survey data collected from 2001 through 2005 and 2012 through 2013. Indices were developed using larval catch rates collected using two different types of bongo sampling, by first standardizing catch rates by gear/fishing-style and then employing a delta-lognormal modeling approach. The delta-lognormal models were developed three ways: 1) a basic larval index including the following covariates: time of day, a systematic geographic area variable, month and year; 2) a standard environmental larval index including the following covariates: mean water temperature over the mixed layer depth, mean salinity over the mixed layer depth, geostrophic velocity, time of day, a systematic geographic area variable, month and year; and 3) a habitat-adjusted larval index including the following covariates: a potential habitat variable, time of day, a systematic geographic area variable, month and year. Results indicated that all three model-types had similar precision in index values. However, the habitat-adjusted larval index demonstrated a high correlation with estimates of spawning stock biomass from the previous stock assessment model, and, therefore, is recommended as a tuning index in future stock assessment models.

  16. Trophic ecology of Atlantic Bluefin Tuna (Thunnus thynnus) [corrected] larvae from the Gulf of Mexico and NW Mediterranean spawning grounds: A Comparative Stable Isotope Study.

    Science.gov (United States)

    Laiz-Carrión, Raúl; Gerard, Trika; Uriarte, Amaya; Malca, Estrella; Quintanilla, José María; Muhling, Barbara A; Alemany, Francisco; Privoznik, Sarah L; Shiroza, Akihiro; Lamkin, John T; García, Alberto

    2015-01-01

    The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6-10 mm standard length) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlying microzooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages.These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton-zooplankton-larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvae.

  17. Trophic ecology of Atlantic Bluefin Tuna (Thunnus thynnus [corrected] larvae from the Gulf of Mexico and NW Mediterranean spawning grounds: A Comparative Stable Isotope Study.

    Directory of Open Access Journals (Sweden)

    Raúl Laiz-Carrión

    Full Text Available The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C as trophic indicators for Atlantic bluefin tuna larvae (BFT (6-10 mm standard length in the highly contrasting environmental conditions of the Gulf of Mexico (GOM and the Balearic Sea (MED. These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlying microzooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages.These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton-zooplankton-larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvae.

  18. DISTRIBUSI PANJANG DAN ESTIMASI TOTAL TANGKAPAN TUNA SIRIP BIRU SELATAN (Thunnus maccoyii PADA MUSIM PEMIJAHAN DI SAMUDERA HINDIA

    Directory of Open Access Journals (Sweden)

    Ririk Kartika Sulistyaningsih

    2016-03-01

    Full Text Available Tuna sirip biru selatan (Thunnus maccoyii banyak ditangkap nelayan dengan alat tangkap rawai tuna di perairan selatan Jawa Timur pada musim pemijahan selama periode September – April. Untuk mendukung pengelolaan ikan tuna di Samudera Hindia dilakukan kegiatan pemantauan hasil tangkapan tuna secara kontinyu. Tulisan ini bertujuan untuk memberikan informasi tentang distribusi panjang dan estimasi total tangkapan tuna sirip biru selatan, sebagai basis data dan informasi yang diperlukan untuk penentuan kuota ikan tuna sirip biru selatan. Estimasi total tangkapan dihitung minimal 30% dari total jumlah kapal yang mendarat pada tiap-tiap perusahaan pengeskpor tuna. Pada penelitian ini berhasil dilakukan pencatatan hasil tangkapan pada 292 unit kapal dari 520 unit kapal yang mendaratkan ikan tuna. Total tangkapan tuna sirip biru selatan yang didaratkan di Pelabuhan Benoa – Bali pada musim pemijahan 2013/2014 lebih dari 900 ton. Jumlah tangkapan ini telah melebihi kuota hasil tangkapan tuna sirip biru selatan yang ditetapkan Commission for the Convervation of Shouthern Bluefin Tuna. Ukuran tuna sirip biru selatan terdistribusi mulai 103 – 208 cm, didominasi ukuran 148 cm. Panjang tuna sirip biru selatan pertama kali tertangkap pada saat memijah adalah 160 cm. Shouthern bluefin tuna (Thunnus maccoyii mostly caught by Indonesian fishers using longline in the spawning season in East Java waters, in September to April. This paper aims were give information about size distribution and to estimate the total catch of shouthern bluefin tuna as the data basis and information that needed to determine the quota of southern bluefin tuna. The target to estimate total catch was minimum of 30% from the total vessel landings in each processing plant. In this research total samplings were 292 boats from 520 boats landed. Total catch estimates of shouthern bluefin tuna landed in Benoa Port – Bali in the spawning season in 2013/2014 was more than 900 tonnes. This

  19. Trade-Based Estimation of Bluefin Tuna Catches in the Eastern Atlantic and Mediterranean, 2005–2011

    NARCIS (Netherlands)

    Gagern, A.; van den Bergh, J.C.J.M.; Sumaila, U.R.

    2013-01-01

    The Eastern Atlantic and Mediterranean stock of Bluefin tuna Thunnus thynnus (BFTE) has long been considered overfished and at risk of collapse. Although ICCAT quotas for this stock have decreased considerably over the past years, uncertainty exists about the degree of catch beyond this quota. The

  20. A review of the broodstock management and larviculture of the Pacific northern bluefin tuna in Japan

    OpenAIRE

    Masuma, Shukei; Takebe, Takayuki; Sakakura, Yoshitaka

    2011-01-01

    We reviewed research on the broodstock management and larviculture of the Pacific northern bluefin tuna (PBT) Thunnus orientalis in Japan. Japan has been at the forefront of PBT research since 1970 due to the participation by federal and prefectural governments and universities in a national project aimed to optimize productivity of the sea around Japan. In 1979, scientists at Kinki University succeeded in the first spontaneous spawning in captivity by the broodstock of 5 year-old PBT. Succes...

  1. Larval stages of the bluefin tuna blood fluke Cardicola opisthorchis (Trematoda: Aporocotylidae) found from Terebella sp. (Polychaeta: Terebellidae).

    Science.gov (United States)

    Sugihara, Yukitaka; Yamada, Toshiyuki; Tamaki, Akio; Yamanishi, Ryohei; Kanai, Kinya

    2014-04-01

    We found aporocotylid larval stages (sporocysts and cercariae) from five individuals of terebellid polychaete Terebella sp., which were collected from seabed substrate and ropes and floats attached to tuna cages in a tuna farm on the coast of Tsushima Island, Nagasaki, Japan. Nucleotide sequences of the regions of internal transcribed spacer 2 ribosomal DNA and 28S ribosomal DNA from these larval stages were 100% identical to those of Cardicola opisthorchis registered in GenBank. C. opisthorchis is a pathogen causing blood fluke infection of Pacific bluefin tuna Thunnus orientalis, which is considered to have a significant impact on the Japanese Pacific bluefin tuna aquaculture industry. This is the first description of the intermediate host of C. opisthorchis. This indicates that the life cycle of C. opisthorchis is completed within tuna farms in this area. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. PCB and OCP accumulation and evidence of hepatic alteration in the Atlantic bluefin tuna, T. thynnus, from the Mediterranean Sea.

    Science.gov (United States)

    Maisano, Maria; Cappello, Tiziana; Oliva, Sabrina; Natalotto, Antonino; Giannetto, Alessia; Parrino, Vincenzo; Battaglia, Pietro; Romeo, Teresa; Salvo, Andrea; Spanò, Nunziacarla; Mauceri, Angela

    2016-10-01

    Persistent organic pollutants (POPs) are known to act as "obesogens", being fat-soluble and affecting lipid metabolism. The Atlantic bluefin tuna, Thunnus thynnus, are top pelagic predators prone to bioaccumulate and biomagnify environmental contaminants. This study aimed at evaluating POPs-induced ectopic lipid accumulation in liver of adult tuna from the Mediterranean Sea. PCBs and organochlorine pesticides were measured in tuna liver, and marked morphological changes observed, namely poorly compacted tissues, intense vacuolization, erythrocyte infiltration and presence of melanomacrophages. The expression of perilipin, a lipid-droplet marker, positively correlated with the gene expression of PPARγ, a master regulator of adipogenesis, and its heterodimeric partner, RXRα. Changes in metabolites involved in fatty acid biosynthesis and ketogenesis were also observed. Although male bluefin tuna appeared to be more sensitive than females to the adverse effects of environmental obesogens, the alterations observed in tuna liver of both sexes suggest a potential onset of hepatic steatosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The imprint of anthropogenic CO2 emissions on Atlantic bluefin tuna otoliths

    Science.gov (United States)

    Fraile, Igaratza; Arrizabalaga, Haritz; Groeneveld, Jeroen; Kölling, Martin; Santos, Miguel Neves; Macías, David; Addis, Piero; Dettman, David L.; Karakulak, Saadet; Deguara, Simeon; Rooker, Jay R.

    2016-06-01

    Otoliths of Atlantic bluefin tuna (Thunnus thynnus) collected from the Mediterranean Sea and North Atlantic Ocean were analyzed to evaluate changes in the seawater isotopic composition over time. We report an annual otolith δ13C record that documents the magnitude of the δ13C depletion in the Mediterranean Sea between 1989 and 2010. Atlantic bluefin tuna in our sample (n = 632) ranged from 1 to 22 years, and otolith material corresponding to the first year of life (back-calculated birth year) was used to reconstruct seawater isotopic composition. Otolith δ18O remained relatively stable between 1989 and 2010, whereas a statistically significant decrease in δ13C was detected across the time interval investigated, with a rate of decline of 0.05‰ yr- 1 (- 0.94‰ depletion throughout the recorded period). The depletion in otolith δ13C over time was associated with the oceanic uptake of anthropogenically derived CO2.

  4. Levels and congener pattern of polychlorinated biphenyl and organochlorine pesticide residues in bluefin tuna (Thunnus thynnus) from the Straits of Messina (Sicily, Italy).

    Science.gov (United States)

    Di Bella, G; Licata, P; Bruzzese, A; Naccari, C; Trombetta, D; Lo Turco, V; Dugo, G; Richetti, A; Naccari, F

    2006-08-01

    The aim of this study is to assess the accumulation of OCs and PCBs in Thunnus thynnus and to elucidate the suitability of this species as a bioindicator for monitoring contaminations of these compounds in the marine ecosystems of the Straits of Messina. This investigation was conducted on fat, liver and muscle samples of 14 T. thynnus collected during April 2004. Quantitative determination of OCs and PCBs in the various samples examined has been carried out using GC-ECD and GC-MS. The results obtained show the presence of low concentrations of p,p'-DDE and PCB congeners (138, 153 and 180) in all fat, liver and muscle samples caught in the Straits of Messina. Concentrations of p,p'-DDE and PCB congeners (138, 153 and 180) in all the samples examined were below MRLs (CE n. 97/41, 1999/65 and 1999/71).

  5. Spawning of bluefin tuna in the Black Sea: historical evidence, environmental constraints and population plasticity.

    Science.gov (United States)

    MacKenzie, Brian R; Mariani, Patrizio

    2012-01-01

    The lucrative and highly migratory Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758; Scombridae), used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity, but its biogeographic range has contracted since the 1950s. Most recently, the species disappeared from the Black Sea in the late 1980s and has not yet recovered. Reasons for the Black Sea disappearance, and the species-wide range contraction, are unclear. However bluefin tuna formerly foraged and possibly spawned in the Black Sea. Loss of a locally-reproducing population would represent a decline in population richness, and an increase in species vulnerability to perturbations such as exploitation and environmental change. Here we identify the main genetic and phenotypic adaptations that the population must have (had) in order to reproduce successfully in the specific hydrographic (estuarine) conditions of the Black Sea. By comparing hydrographic conditions in spawning areas of the three species of bluefin tunas, and applying a mechanistic model of egg buoyancy and sinking rate, we show that reproduction in the Black Sea must have required specific adaptations of egg buoyancy, fertilisation and development for reproductive success. Such adaptations by local populations of marine fish species spawning in estuarine areas are common as is evident from a meta-analysis of egg buoyancy data from 16 species of fish. We conclude that these adaptations would have been necessary for successful local reproduction by bluefin tuna in the Black Sea, and that a locally-adapted reproducing population may have disappeared. Recovery of bluefin tuna in the Black Sea, either for spawning or foraging, will occur fastest if any remaining locally adapted individuals are allowed to survive, and by conservation and recovery of depleted Mediterranean populations which could through time re

  6. Spawning of bluefin tuna in the Black Sea: historical evidence, environmental constraints and population plasticity.

    Directory of Open Access Journals (Sweden)

    Brian R MacKenzie

    Full Text Available The lucrative and highly migratory Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758; Scombridae, used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity, but its biogeographic range has contracted since the 1950s. Most recently, the species disappeared from the Black Sea in the late 1980s and has not yet recovered. Reasons for the Black Sea disappearance, and the species-wide range contraction, are unclear. However bluefin tuna formerly foraged and possibly spawned in the Black Sea. Loss of a locally-reproducing population would represent a decline in population richness, and an increase in species vulnerability to perturbations such as exploitation and environmental change. Here we identify the main genetic and phenotypic adaptations that the population must have (had in order to reproduce successfully in the specific hydrographic (estuarine conditions of the Black Sea. By comparing hydrographic conditions in spawning areas of the three species of bluefin tunas, and applying a mechanistic model of egg buoyancy and sinking rate, we show that reproduction in the Black Sea must have required specific adaptations of egg buoyancy, fertilisation and development for reproductive success. Such adaptations by local populations of marine fish species spawning in estuarine areas are common as is evident from a meta-analysis of egg buoyancy data from 16 species of fish. We conclude that these adaptations would have been necessary for successful local reproduction by bluefin tuna in the Black Sea, and that a locally-adapted reproducing population may have disappeared. Recovery of bluefin tuna in the Black Sea, either for spawning or foraging, will occur fastest if any remaining locally adapted individuals are allowed to survive, and by conservation and recovery of depleted Mediterranean populations which could

  7. Spawning of Bluefin Tuna in the Black Sea: Historical Evidence, Environmental Constraints and Population Plasticity

    Science.gov (United States)

    MacKenzie, Brian R.; Mariani, Patrizio

    2012-01-01

    The lucrative and highly migratory Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758; Scombridae), used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity, but its biogeographic range has contracted since the 1950s. Most recently, the species disappeared from the Black Sea in the late 1980s and has not yet recovered. Reasons for the Black Sea disappearance, and the species-wide range contraction, are unclear. However bluefin tuna formerly foraged and possibly spawned in the Black Sea. Loss of a locally-reproducing population would represent a decline in population richness, and an increase in species vulnerability to perturbations such as exploitation and environmental change. Here we identify the main genetic and phenotypic adaptations that the population must have (had) in order to reproduce successfully in the specific hydrographic (estuarine) conditions of the Black Sea. By comparing hydrographic conditions in spawning areas of the three species of bluefin tunas, and applying a mechanistic model of egg buoyancy and sinking rate, we show that reproduction in the Black Sea must have required specific adaptations of egg buoyancy, fertilisation and development for reproductive success. Such adaptations by local populations of marine fish species spawning in estuarine areas are common as is evident from a meta-analysis of egg buoyancy data from 16 species of fish. We conclude that these adaptations would have been necessary for successful local reproduction by bluefin tuna in the Black Sea, and that a locally-adapted reproducing population may have disappeared. Recovery of bluefin tuna in the Black Sea, either for spawning or foraging, will occur fastest if any remaining locally adapted individuals are allowed to survive, and by conservation and recovery of depleted Mediterranean populations which could through time re

  8. Temporal and spatial variability of pelagic wild fish assemblages around Atlantic bluefin tuna Thunnus thynnus farms in the eastern Adriatic Sea.

    Science.gov (United States)

    Segvić Bubić, T; Grubišić, L; Tičina, V; Katavić, I

    2011-01-01

    The abundance and size structure of wild fishes aggregated around the sea-cages of two commercial Thunnus thynnus farms, including control locations, were assessed and compared over a 1 year period. The T. thynnus farms were located in the eastern Adriatic Sea, offshore of the islands of Ugljan and Brač. Fish assemblages were evaluated through visual census using scuba at 2 month intervals at two sites within each farm. The data suggest that wild fish assemblages at the study sites differed greatly; 20 species occurred at the Ugljan farm and 17 at the Brač farm, while only seven species were observed at the control locations. The abundance and diversity of wild fish assemblages were greater at the farms in comparison to control locations. The most abundant families were Sparidae and Belonidae (>80% of aggregated fishes). At both farms, the abundance and diversity of wild fishes were highest during summer, while diversity was lowest in winter and was mainly characterized by schools of bogue Boops boops and garfish Belone belone. Variability was also detected in spatial assemblages between farms; B. boops and B. belone were the most abundant species for the overall study at the Brač farm, while B. belone and saddled bream Oblada melanura were the most abundant at the Ugljan farm. The settlement also played a significant role in farm-associated fish assemblages, as both juveniles and advanced juveniles were common residents at farms. The majority of species which settled at the farms belonged to the sparids. Results indicate that aggregations of wild fishes at T. thynnus farms are persistent year-round, though the assemblage compositions and size structures of dominant species vary in respect to location and season. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  9. Comparative Assessment of the Reproductive Status of Female Atlantic Bluefin Tuna from the Gulf of Mexico and the Mediterranean Sea

    OpenAIRE

    Knapp, Jessica M.; Aranda, Guillermo; Medina, Antonio; Lutcavage, Molly

    2014-01-01

    Despite attention focused on the population status and rebuilding trajectory of Atlantic bluefin tuna (Thunnus thynnus), the reproduction and spawning biology remains poorly understood, especially in the NW Atlantic. At present, the eastern and western spawning populations are believed to exhibit different reproductive characteristics and, consequently, stock productivity. However, our study suggests that the two spawning populations, the Gulf of Mexico and the Mediterranean Sea, could show s...

  10. Mercury in fish products: what's the best for consumers between bluefin tuna and yellowfin tuna?

    Science.gov (United States)

    Cammilleri, Gaetano; Vazzana, Mirella; Arizza, Vincenzo; Giunta, Francesca; Vella, Antonio; Lo Dico, Gianluigi; Giaccone, Vita; Giofrè, Salvatore V; Giangrosso, Giuseppe; Cicero, Nicola; Ferrantelli, Vincenzo

    2018-02-01

    A total of 205 bluefin and yellowfin tuna samples were examined for mercury detection in order to verify possible differences and have a detailed risk assessment of the two tuna species. The results showed significant higher mercury concentration in muscle tissue of bluefin tuna respect yellowfin tuna (p < 0.001) with mean concentration of 0.84 mg/kg and maximum value of 1.94 mg/kg. These differences can be due the different biological and ecological aspects of the two tuna species and to different oceanographic aspects between Atlantic Ocean and Mediterranean sea. The results obtained in this study suggest an advisable containment of the sources of pollution and further studies on the closed-loop farming of bluefin tuna, in order to ensure the product safety.

  11. Single nucleotide polymorphism discovery in albacore and Atlantic bluefin tuna provides insights into worldwide population structure.

    Science.gov (United States)

    Albaina, A; Iriondo, M; Velado, I; Laconcha, U; Zarraonaindia, I; Arrizabalaga, H; Pardo, M A; Lutcavage, M; Grant, W S; Estonba, A

    2013-12-01

    The optimal management of the commercially important, but mostly over-exploited, pelagic tunas, albacore (Thunnus alalunga Bonn., 1788) and Atlantic bluefin tuna (BFT; Thunnus thynnus L., 1758), requires a better understanding of population structure than has been provided by previous molecular methods. Despite numerous studies of both species, their population structures remain controversial. This study reports the development of single nucleotide polymorphisms (SNPs) in albacore and BFT and the application of these SNPs to survey genetic variability across the geographic ranges of these tunas. A total of 616 SNPs were discovered in 35 albacore tuna by comparing sequences of 54 nuclear DNA fragments. A panel of 53 SNPs yielded FST values ranging from 0.0 to 0.050 between samples after genotyping 460 albacore collected throughout the distribution of this species. No significant heterogeneity was detected within oceans, but between-ocean comparisons (Atlantic, Pacific and Indian oceans along with Mediterranean Sea) were significant. Additionally, a 17-SNP panel was developed in Atlantic BFT by cross-species amplification in 107 fish. This limited number of SNPs discriminated between samples from the two major spawning areas of Atlantic BFT (FST  = 0.116). The SNP markers developed in this study can be used to genotype large numbers of fish without the need for standardizing alleles among laboratories. © 2013 The Authors, Animal Genetics © 2013 Stichting International Foundation for Animal Genetics.

  12. Comparative Assessment of the Reproductive Status of Female Atlantic Bluefin Tuna from the Gulf of Mexico and the Mediterranean Sea

    Science.gov (United States)

    Knapp, Jessica M.; Aranda, Guillermo; Medina, Antonio; Lutcavage, Molly

    2014-01-01

    Despite attention focused on the population status and rebuilding trajectory of Atlantic bluefin tuna (Thunnus thynnus), the reproduction and spawning biology remains poorly understood, especially in the NW Atlantic. At present, the eastern and western spawning populations are believed to exhibit different reproductive characteristics and, consequently, stock productivity. However, our study suggests that the two spawning populations, the Gulf of Mexico and the Mediterranean Sea, could show similar reproductive features and spawning strategies. Between 2007 and 2009, gonad samples from female Atlantic bluefin tuna were collected in the northern Gulf of Mexico (n = 147) and in the western Mediterranean Sea (n = 40). The histological and stereological analysis confirmed that sampled eastern and western bluefin tuna exhibit the same spawning duration (three months) but the spawning in the Gulf of Mexico begins one month earlier than in the Mediterranean Sea. Western bluefin tuna caught in the peak of the spawning season (May) showed a similar spawning frequency (60%) to the spawning peak observed in the Mediterranean Sea (June). Fecundity for the Gulf of Mexico fish () was lower but not significantly different than for fish sampled in the Mediterranean Sea (). Our study represents the first comparative histological analysis of the eastern and western spawning stocks whose findings, combined with new determinations of size/age at maturity and possible alternative spawning areas, might suggest basic life history attributes warrant further scientific and management attention. PMID:24911973

  13. Comparative assessment of the reproductive status of female Atlantic bluefin tuna from the Gulf of Mexico and the Mediterranean Sea.

    Science.gov (United States)

    Knapp, Jessica M; Aranda, Guillermo; Medina, Antonio; Lutcavage, Molly

    2014-01-01

    Despite attention focused on the population status and rebuilding trajectory of Atlantic bluefin tuna (Thunnus thynnus), the reproduction and spawning biology remains poorly understood, especially in the NW Atlantic. At present, the eastern and western spawning populations are believed to exhibit different reproductive characteristics and, consequently, stock productivity. However, our study suggests that the two spawning populations, the Gulf of Mexico and the Mediterranean Sea, could show similar reproductive features and spawning strategies. Between 2007 and 2009, gonad samples from female Atlantic bluefin tuna were collected in the northern Gulf of Mexico (n = 147) and in the western Mediterranean Sea (n = 40). The histological and stereological analysis confirmed that sampled eastern and western bluefin tuna exhibit the same spawning duration (three months) but the spawning in the Gulf of Mexico begins one month earlier than in the Mediterranean Sea. Western bluefin tuna caught in the peak of the spawning season (May) showed a similar spawning frequency (60%) to the spawning peak observed in the Mediterranean Sea (June). Fecundity for the Gulf of Mexico fish (28.14 eggs · g(-1)) was lower but not significantly different than for fish sampled in the Mediterranean Sea (45.56 eggs · g(-1)). Our study represents the first comparative histological analysis of the eastern and western spawning stocks whose findings, combined with new determinations of size/age at maturity and possible alternative spawning areas, might suggest basic life history attributes warrant further scientific and management attention.

  14. Comparative assessment of the reproductive status of female Atlantic bluefin tuna from the Gulf of Mexico and the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Jessica M Knapp

    Full Text Available Despite attention focused on the population status and rebuilding trajectory of Atlantic bluefin tuna (Thunnus thynnus, the reproduction and spawning biology remains poorly understood, especially in the NW Atlantic. At present, the eastern and western spawning populations are believed to exhibit different reproductive characteristics and, consequently, stock productivity. However, our study suggests that the two spawning populations, the Gulf of Mexico and the Mediterranean Sea, could show similar reproductive features and spawning strategies. Between 2007 and 2009, gonad samples from female Atlantic bluefin tuna were collected in the northern Gulf of Mexico (n = 147 and in the western Mediterranean Sea (n = 40. The histological and stereological analysis confirmed that sampled eastern and western bluefin tuna exhibit the same spawning duration (three months but the spawning in the Gulf of Mexico begins one month earlier than in the Mediterranean Sea. Western bluefin tuna caught in the peak of the spawning season (May showed a similar spawning frequency (60% to the spawning peak observed in the Mediterranean Sea (June. Fecundity for the Gulf of Mexico fish (28.14 eggs · g(-1 was lower but not significantly different than for fish sampled in the Mediterranean Sea (45.56 eggs · g(-1. Our study represents the first comparative histological analysis of the eastern and western spawning stocks whose findings, combined with new determinations of size/age at maturity and possible alternative spawning areas, might suggest basic life history attributes warrant further scientific and management attention.

  15. A validated methodology for genetic identification of tuna species (genus Thunnus).

    Science.gov (United States)

    Viñas, Jordi; Tudela, Sergi

    2009-10-27

    Tuna species of the genus Thunnus, such as the bluefin tunas, are some of the most important and yet most endangered trade fish in the world. Identification of these species in traded forms, however, may be difficult depending on the presentation of the products, which may hamper conservation efforts on trade control. In this paper, we validated a genetic methodology that can fully distinguish between the eight Thunnus species from any kind of processed tissue. After testing several genetic markers, a complete discrimination of the eight tuna species was achieved using Forensically Informative Nucleotide Sequencing based primarily on the sequence variability of the hypervariable genetic marker mitochondrial DNA control region (mtDNA CR), followed, in some specific cases, by a second validation by a nuclear marker rDNA first internal transcribed spacer (ITS1). This methodology was able to distinguish all tuna species, including those belonging to the subgenus Neothunnus that are very closely related, and in consequence can not be differentiated with other genetic markers of lower variability. This methodology also took into consideration the presence of introgression that has been reported in past studies between T. thynnus, T. orientalis and T. alalunga. Finally, we applied the methodology to cross-check the species identity of 26 processed tuna samples. Using the combination of two genetic markers, one mitochondrial and another nuclear, allows a full discrimination between all eight tuna species. Unexpectedly, the genetic marker traditionally used for DNA barcoding, cytochrome oxidase 1, could not differentiate all species, thus its use as a genetic marker for tuna species identification is questioned.

  16. A validated methodology for genetic identification of tuna species (genus Thunnus.

    Directory of Open Access Journals (Sweden)

    Jordi Viñas

    2009-10-01

    Full Text Available Tuna species of the genus Thunnus, such as the bluefin tunas, are some of the most important and yet most endangered trade fish in the world. Identification of these species in traded forms, however, may be difficult depending on the presentation of the products, which may hamper conservation efforts on trade control. In this paper, we validated a genetic methodology that can fully distinguish between the eight Thunnus species from any kind of processed tissue.After testing several genetic markers, a complete discrimination of the eight tuna species was achieved using Forensically Informative Nucleotide Sequencing based primarily on the sequence variability of the hypervariable genetic marker mitochondrial DNA control region (mtDNA CR, followed, in some specific cases, by a second validation by a nuclear marker rDNA first internal transcribed spacer (ITS1. This methodology was able to distinguish all tuna species, including those belonging to the subgenus Neothunnus that are very closely related, and in consequence can not be differentiated with other genetic markers of lower variability. This methodology also took into consideration the presence of introgression that has been reported in past studies between T. thynnus, T. orientalis and T. alalunga. Finally, we applied the methodology to cross-check the species identity of 26 processed tuna samples.Using the combination of two genetic markers, one mitochondrial and another nuclear, allows a full discrimination between all eight tuna species. Unexpectedly, the genetic marker traditionally used for DNA barcoding, cytochrome oxidase 1, could not differentiate all species, thus its use as a genetic marker for tuna species identification is questioned.

  17. Novel method for the discrimination of tuna (Thunnus thynnus) and bonito (Sarda sarda) DNA.

    Science.gov (United States)

    Lockley, A K; Bardsley, R G

    2000-10-01

    A novel method for the discrimination of bluefin tuna (Thunnus thynnus) from Atlantic bonito (Sarda sarda) was developed, based on species-specific amplification of a region of the mitochondrial cytochrome b gene by Polymerase Chain Reaction (PCR). The method, which uses a one-step amplification reaction, is more rapid to perform than any of the currently described techniques for species determination in fish. The species of origin of the DNA is indicated by the distinctive size of the PCR product on electrophoresis, but the test could readily be adapted to other forms of electrophoresis or fluorescence-based systems for quantification. Given the possibility of intraspecific variability in mitochondrial DNA and the consequent desirability of performing two independent tests, the new method constitutes a valuable addition to the range of tuna speciation methodologies currently available.

  18. Potential impact of climate change on the Intra-Americas Sea: Part 2. Implications for Atlantic bluefin tuna and skipjack tuna adult and larval habitats

    Science.gov (United States)

    Muhling, Barbara A.; Liu, Yanyun; Lee, Sang-Ki; Lamkin, John T.; Roffer, Mitchell A.; Muller-Karger, Frank; Walter, John F., III

    2015-08-01

    Increasing water temperatures due to climate change will likely have significant impacts on distributions and life histories of Atlantic tunas. In this study, we combined predictive habitat models with a downscaled climate model to examine potential impacts on adults and larvae of Atlantic bluefin tuna (Thunnus thynnus) and skipjack tuna (Katsuwonus pelamis) in the Intra-Americas Sea (IAS). An additional downscaled model covering the 20th century was used to compare habitat fluctuations from natural variability to predicted future changes under two climate change scenarios: Representative Concentration Pathway (RCP) 4.5 (medium-low) and RCP 8.5 (high). Results showed marked temperature-induced habitat losses for both adult and larval bluefin tuna on their northern Gulf of Mexico spawning grounds. In contrast, habitat suitability for skipjack tuna increased as temperatures warmed. Model error was highest for the two skipjack tuna models, particularly at higher temperatures. This work suggests that influences of climate change on highly migratory Atlantic tuna species are likely to be substantial, but strongly species-specific. While impacts on fish populations remain uncertain, these changes in habitat suitability will likely alter the spatial and temporal availability of species to fishing fleets, and challenge equilibrium assumptions of environmental stability, upon which fisheries management benchmarks are based.

  19. Characterization of the spawning habitat of Atlantic bluefin tuna and related species in the Balearic Sea (western Mediterranean)

    Science.gov (United States)

    Alemany, F.; Quintanilla, L.; Velez-Belchí, P.; García, A.; Cortés, D.; Rodríguez, J. M.; Fernández de Puelles, M. L.; González-Pola, C.; López-Jurado, J. L.

    2010-07-01

    Within the framework of the TUNIBAL project that focused on Atlantic bluefin tuna ( Thunnus thynnus) larval ecology, ichthyoplankton surveys were conducted from 2001 to 2005 off the Balearic archipelago, which is recognized as one of the main spawning areas of the eastern Atlantic stock of this species. In each survey, a regular sampling grid of about 200 stations, 10 nautical miles apart were sampled. CTD casts and oblique Bongo 60 and surface Bongo 90 plankton tows were carried out. The occurrence frequencies of Atlantic bluefin tuna, albacore tuna ( Thunnus alalunga) and bullet tuna ( Auxis rochei) larvae in quantitative Bongo 60 samples were 0.14, 0.29 and 0.49 respectively. Mean larval abundances in these positive samples were relatively high: 31 larvae 10 m -2 for Atlantic bluefin tuna, 17 for albacore tuna and 31 for bullet tuna. All species had patchy distributions since more than 90% of the stations showed larval densities under 10 larvae 100 m -3 (70% showed even less than 2 larvae 100 m -3), whereas in some isolated spots, we recorded abundances as high as 867 (Atlantic bluefin) or 872 (bullet tuna) larvae 10 m -2. These results allowed us to relate larval distribution to mesoscale hydrographic features and to characterize the spawning habitat of these species. Single Quotient Parameter analyses were applied to spatial (depth), physical (temperature, salinity, dissolved oxygen and geostrophic current velocities) and biological (mesozooplankton biomass) variables to determine the environmental preferences of each species for spawning. Results showed that the complex hydrodynamic scenarios around the Balearic Islands, due to the interaction between the inflowing surface Atlantic water masses (AW) and Mediterranean surface waters (MW), play a key role in determining the abundance and distribution of tuna larvae in this area, especially in the case of Atlantic bluefin tuna. Spawning of this species seems to take place mainly in offshore mixed waters, as

  20. Gulf of Mexico Ecological Forecasting - Atlantic Bluefin Tuna Population Assessment and Management using Synthetic Aperture Radar (SAR) Data

    Science.gov (United States)

    Laygo, K.; Jones, I.; Huerta, J.; Holt, B.

    2010-12-01

    Atlantic Bluefin Tuna (Thunnus thynnus) is one of the largest vertebrates in the world and is in high demand in sushi markets. It is a highly political species and is managed internationally by the International Commission for the Conservation of Atlantic Tuna. The Gulf of Mexico and the Mediterranean Sea are the only two known spawning sites in the world. However, there is a large variance in estimates of adult Atlantic Tuna spawning. This research focuses on extending Earth science research results to existing decision-making systems, National Oceanic and Atmospheric Administration (NOAA) and the National Marine Fisheries Service (NMFS)for population assessment and management of Atlantic Bluefin Tuna. The research team is a multi-sector and multi-disciplinary team composed of government (NOAA_NMFS), academic (University of South Florida Institute for Marine Remote Sensing) and commercial (Roffer’s Ocean Fishing Forecasting Service, Inc.) institutions. Their goal is to reduce the variance in the estimates of adult Bluefin Tuna spawning stock abundance in the Gulf of Mexico (GOM). Therefore, this paper will be derived from the innovative use of several earth orbiting satellites focusing on the use of synthetic aperture radar (SAR) data to identify Sargassum, which is a floating marine algae that may be relevant to the presence of Bluefin Tuna aggregations. The SAR imagery will be examined in combination with MODIS and MERIS Chlorophyll-a products to detect fine-scale surface current shear, eddy and frontal features, as well as biological slicks due to the presence of Sargassum. In addition, wind records from NOAA buoy data will be studied to analyze wind patterns in the Gulf of Mexico. The fine-resolution, all-weather capabilities of SAR provide a valuable complement to optical/IR sensors, which are often impacted by cloud cover. This study will provide an assessment of whether or not SAR can contribute to decision support efforts relevant to commercial fisheries

  1. A full lifecycle bioenergetic model for bluefin tuna.

    NARCIS (Netherlands)

    Jusup, M.; Klanjscek, T.; Matsuda, H.; Kooijman, S.A.L.M.

    2011-01-01

    We formulated a full lifecycle bioenergetic model for bluefin tuna relying on the principles of Dynamic Energy Budget theory. Traditional bioenergetic models in fish research deduce energy input and utilization from observed growth and reproduction. In contrast, our model predicts growth and

  2. Bluefin tuna fishing and ranching: a difficult management problem

    NARCIS (Netherlands)

    Stefano, de V.; Heijden, van der P.G.M.

    2007-01-01

    The fish processing industry and consumers in Japan are willing to pay high (and sometimes outrageous) prices for fresh bluefin tuna with fat content and flesh colour just right to be served raw as sashimi or sushi. This willingness was and still is the economic incentive for a high fishing pressure

  3. Expression analysis of the Atlantic bluefin tuna (Thunnus thynnus) pro-inflammatory cytokines, IL-1β, TNFα1 and TNFα2 in response to parasites Pseudocycnus appendiculatus (Copepoda) and Didymosulcus katsuwonicola (Digenea).

    Science.gov (United States)

    Pleić, Ivana Lepen; Bušelić, Ivana; Trumbić, Željka; Bočina, Ivana; Šprung, Matilda; Mladineo, Ivona

    2015-08-01

    Pro-inflammatory cytokines play an important role in teleost defence against numerous types of pathogens, therefore are often used as biomarkers during various infections. In order to evaluate Atlantic bluefin tuna IL-1β, TNFα1 and TNFα2 induction by PAMPs, we quantified their expression during in vitro stimulation of peripheral blood leukocytes by LPS and Poly I:C. Furthermore, their role in acute and chronic parasitic infection was examined during natural infection of Pseudocycnus appendiculatus (Copepoda) and Didymosulcus katsuwonicola (Digenea), as well as during leukocyte exposure to total protein extracts isolated from two parasite species. Induction of ABT IL-1β and TNFα2 by PAMPs and protein extracts from D. katsuwonicola and P. appendiculatus, as well as during natural infection with two parasites, suggests these cytokines play an important role in inflammation, being engaged in controlling parasite infections, in contrast to ABT TNFα1. Cellular innate response to the digenean D. katsuwonicola showed rather chronic character, resulting with parasite encapsulation in connective tissue. Mast cells, eosinophils, goblet cells, and occasional rodlet cells found at the site of infection, along with the induction of TNFα2, suggest the presence of a moderate inflammatory reaction that fails to seriously endanger digenean existence. In contrast, copepod P. appendiculatus, attached to the gill epithelium by clamping, caused direct tissue disruption with undergoing necrotic or apoptotic processes, and extensive proliferation of rodlet and goblet cells. Differential expression patterns of target cytokines in tissue surrounding two parasites and in vitro PBL model suggest that quality and quantity of tuna immune response is conditioned by parasite adaptive mechanisms and pathogenicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Modelling retention and dispersion mechanisms of bluefin tuna eggs and larvae in the Northwest Mediterranean Sea

    DEFF Research Database (Denmark)

    Mariani, Patrizio; MacKenzie, Brian; Iudicone, D.

    2010-01-01

    locations of spawning bluefin tuna using hydrographic backtracking procedures; these locations were situated in a major salinity frontal zone and coincided with distributions of an electronically tagged bluefin tuna and commercial bluefin tuna fishing vessels. Moreover, we hypothesized that mesoscale...... processes are responsible for the aggregation and dispersion mechanisms in the area and showed that these processes were significantly correlated to atmospheric forcing processes over the NW Mediterranean Sea. Interannual variations in average summer air temperature can reduce the intensity of ocean...

  5. Some trace elements in front and rear dorsal ordinary muscles of wild and farmed bluefin tuna (Thunnus thynnus L. 1758) in the Turkish part of the eastern Mediterranean Sea.

    Science.gov (United States)

    Percın, Fatih; Sogut, Ozlem; Altınelataman, Can; Soylak, Mustafa

    2011-04-01

    The levels of trace metals of front (F) and rear (R) dorsal ordinary muscles (dom) of wild and farmed bluefin tuna (BFT) were determined by atomic absorption spectrometry. Wilds were obtained from Antalya Bay and farmed were taken from a fish farm in Ildir Bay (Izmir), during spring to early summer. The accuracy of the method was checked standard reference material (NRCC-DORM-2 Dogfish Muscle). Mean trace element content of the wild samples (Fdom and Rdom, respectively) was found as: Cu, 0.790 and 0.591; Mn, 0.084 and 0.096; Ni, 0.101 and 0.124; Zn, 4.788 and 5.577; Fe, 7.670 and 9.222 (μg g(-1)wet wt.). Values for farmed were detected as Cu, 0.581 and 0.453; Mn, 0.111 and 0.139; Ni, 0.072 and 0.092; Zn, 4.631 and 3.380; Fe, 4.957 and 7.156 (μg g(-1)wet wt.). The results were compared with literature values. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  6. A reconstructed database of historic bluefin tuna captures in the Gibraltar Strait and Western Mediterranean

    Directory of Open Access Journals (Sweden)

    Josué M. Polanco-Martínez

    2018-02-01

    Full Text Available This data paper presents a reconstruction of a compilation of a small but consistent database of historical capture records of bluefin tuna (Thunnus thynnus; BFT hereafter from the Gibraltar Strait and Western Mediterranean (Portugal, Spain and Italy. The compilation come from diverse historical and documentary sources and span the time interval from 1525 to 1936 covering a period of 412 years. There is a total of 3074 datum, which reach up to 67.83% of the total implying a 32.17% of missing data. However, we have only reconstructed the captures for the time interval 1700–1936 and we provide these reconstructions only for this time interval and for 9 out of 11 series due to the scarcity and inhomogeneity of the two oldest capture time series. This reconstructed database provides an invaluable opportunity for fisheries and marine research as well as for multidisciplinary research in climate change. Keywords: Data reconstructions, DINEOF, Missing data, Historic Bluefin tuna captures, Gibraltar Strait and Western Mediterranean

  7. A reconstructed database of historic bluefin tuna captures in the Gibraltar Strait and Western Mediterranean.

    Science.gov (United States)

    Polanco-Martínez, Josué M; Caballero-Alfonso, Ángela M; Ganzedo, Unai; Castro-Hernández, José J

    2018-02-01

    This data paper presents a reconstruction of a compilation of a small but consistent database of historical capture records of bluefin tuna (Thunnus thynnus; BFT hereafter) from the Gibraltar Strait and Western Mediterranean (Portugal, Spain and Italy). The compilation come from diverse historical and documentary sources and span the time interval from 1525 to 1936 covering a period of 412 years. There is a total of 3074 datum, which reach up to 67.83% of the total implying a 32.17% of missing data. However, we have only reconstructed the captures for the time interval 1700-1936 and we provide these reconstructions only for this time interval and for 9 out of 11 series due to the scarcity and inhomogeneity of the two oldest capture time series. This reconstructed database provides an invaluable opportunity for fisheries and marine research as well as for multidisciplinary research in climate change.

  8. Natal homing and connectivity in Atlantic bluefin tuna populations.

    Science.gov (United States)

    Rooker, Jay R; Secor, David H; De Metrio, Gregorio; Schloesser, Ryan; Block, Barbara A; Neilson, John D

    2008-10-31

    Atlantic bluefin tuna populations are in steep decline, and an improved understanding of connectivity between individuals from eastern (Mediterranean Sea) and western (Gulf of Mexico) spawning areas is needed to manage remaining fisheries. Chemical signatures in the otoliths of yearlings from regional nurseries were distinct and served as natural tags to assess natal homing and mixing. Adults showed high rates of natal homing to both eastern and western spawning areas. Trans-Atlantic movement (east to west) was significant and size-dependent, with individuals of Mediterranean origin mixing with the western population in the U.S. Atlantic. The largest (oldest) bluefin tuna collected near the northern extent of their range in North American waters were almost exclusively of western origin, indicating that this region represents critical habitat for the western population.

  9. Climate effects on historic bluefin tuna captures in the Gibraltar Strait and Western Mediterranean

    Science.gov (United States)

    Ganzedo, Unai; Polanco-Martínez, Josué M.; Caballero-Alfonso, Ángela M.; Faria, Sérgio H.; Li, Jianke; Castro-Hernández, José J.

    2016-06-01

    Historical capture records of bluefin tuna (Thunnus thynnus; BFT hereafter) from the Gibraltar Strait and Western Mediterranean show pronounced short- and long-term fluctuations. Some of these fluctuations are believed to be associated with biological and ecological process, as well as distinct climate factors. For the period of study (1700-1936) of this work, we found a long-term increasing trend in the BFT captures and in the climate variables. After applying a statistical time series analysis of relevant climate variables and long-term tuna capture records, it is highlighted the role played by sea-surface temperature (SST) on bluefin population variations. The most relevant result of this study is the strong correlation found between the total solar irradiance (TSI) - an external component of the climate system - and bluefin captures. The solar irradiance could have affected storminess during the period under study, mainly during the time interval 1700-1810. We suggest physico-biological mechanisms that explain the BFT catch fluctuations in two consecutive time intervals. In the first period, from 1700 to 1810, this mechanism could be high storm and wind activity, which would have made the BFT fisheries activities more difficult by reducing their efficacy. In contrast, during the interval from 1810 to 1907, the effects of wind and storms could be on spawning behaviour and larval ecology, and hence on year class strength, rather than on fish or fisherman's behaviour. These findings open up a range of new lines of enquiry that are relevant for both, fisheries and climate change research.

  10. 78 FR 20258 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Science.gov (United States)

    2013-04-04

    ... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... Atlantic bluefin tuna (BFT) daily retention limit that applies to vessels permitted in the Highly Migratory... 73 inches). This retention limit is effective in all areas, except for the Gulf of Mexico, where NMFS...

  11. Lipid components and water soluble metabolites in salted and dried tuna (Thunnus thynnus L.) roes.

    Science.gov (United States)

    Scano, P; Rosa, A; Pisano, M B; Piras, C; Cosentino, S; Dessi', M A

    2013-06-15

    The salted and dried product of tuna roe (bottarga) is a seafood characteristic of the Mediterranean area and exported all over the world. Samples of bottarga from bluefin tunas (Thunnus thynnus, L.) caught in the southwest Mediterranean sea were analysed. The samples were characterised by high content of marine wax esters (55-67 mol% of lipid classes), of docosahexaenoic (22:6 n-3, 25 w%) and oleic (18:1 n-9, 19 w%) fatty acids. Cholesterol was detected as 7-9 w% of lipids. Free fatty acids, index of lipid hydrolysis, represented 32-39 mol% over total fatty acids. Among metabolites, nutrients as taurine, nicotinamide and β-alanine, were found. The microflora comprised staphylococci, enterococci (2.2 log(10)CFU/g) and lactic acid bacteria (3 log(10) CFU/g). The food-borne pathogens Staphylococcus aureus, Listeria monocytogenes and Salmonella spp. were not detected. These findings indicate tuna bottarga as valuable source of nutrients. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Trophic impact of Atlantic bluefin tuna migrations in the North Sea

    DEFF Research Database (Denmark)

    Mariani, Patrizio; Andersen, Ken Haste; Lindegren, Martin

    2017-01-01

    spectrum model to analyse the trophic impact of the returning tuna on the entire fish community, under scenarios with varying levels of tuna consumption and fishing mortality on the prey. We show that with high level of prey fishing mortality in the North Sea, the effect of a tuna re-colonization results...... and the stability of the fish community. The impact of a migrating top-predator is investigated here for Atlantic bluefin tuna in the North Sea. Bluefin tuna has been absent from the region for half-century, but recent years have seen recovery of migrations and a return of bluefin tuna in the area. We use a size...... in only limited trophic cascades. However, high tuna consumption or changes in fishing mortality may result in a sudden recruitment failure of small-pelagic fish due to cascading effects on the fish community. In present-day conditions, the level of tuna consumption that triggers recruitment failure...

  13. Habitat and behaviour of yellowfin tuna Thunnus albacares in the Gulf of Mexico determined using pop-up satellite archival tags.

    Science.gov (United States)

    Weng, K C; Stokesbury, M J W; Boustany, A M; Seitz, A C; Teo, S L H; Miller, S K; Block, B A

    2009-05-01

    This study presents the first data on movement, habitat use and behaviour for yellowfin tuna Thunnus albacares in the Atlantic Basin. Six individuals were tracked in the Gulf of Mexico using pop-up satellite archival tags. Records up to 80 days in length were obtained, providing information on depth and temperature preferences as well as horizontal movements. Thunnus albacares in the Gulf of Mexico showed a strong preference for the mixed layer and thermocline, consistent with findings for this species in other ocean basins. Fish showed a diel pattern in depth distribution, remaining in surface and mixed layer waters at night and diving to deeper waters during the day. The vertical extent of T. albacares habitat appeared to be temperature limited, with fish generally avoiding waters that were >6 degrees C cooler than surface waters. The vertical and thermal habitat usage of T. albacares differs from that of bigeye Thunnus obesus and bluefin Thunnus thynnus, Thunnus orientalis and Thunnus maccoyii tunas. These results are consistent with the results of earlier studies conducted on T. albacares in other oceans.

  14. Quantifying overlap between the Deepwater Horizon oil spill and predicted bluefin tuna spawning habitat in the Gulf of Mexico

    Science.gov (United States)

    Hazen, Elliott L.; Carlisle, Aaron B.; Wilson, Steven G.; Ganong, James E.; Castleton, Michael R.; Schallert, Robert J.; Stokesbury, Michael J. W.; Bograd, Steven J.; Block, Barbara A.

    2016-09-01

    Atlantic bluefin tuna (Thunnus thynnus) are distributed throughout the North Atlantic and are both economically valuable and heavily exploited. The fishery is currently managed as two spawning populations, with the GOM population being severely depleted for over 20 years. In April-August of 2010, the Deepwater Horizon oil spill released approximately 4 million barrels of oil into the GOM, with severe ecosystem and economic impacts. Acute oil exposure results in mortality of bluefin eggs and larvae, while chronic effects on spawning adults are less well understood. Here we used 16 years of electronic tagging data for 66 bluefin tuna to identify spawning events, to quantify habitat preferences, and to predict habitat use and oil exposure within Gulf of Mexico spawning grounds. More than 54,000 km2 (5%) of predicted spawning habitat within the US EEZ was oiled during the week of peak oil dispersal, with potentially lethal effects on eggs and larvae. Although the oil spill overlapped with a relatively small portion of predicted spawning habitat, the cumulative impact from oil, ocean warming and bycatch mortality on GOM spawning grounds may result in significant effects for a population that shows little evidence of rebuilding.

  15. Comparative Influence of Ocean Conditions on Yellowfin and Atlantic Bluefin Tuna Catch from Longlines in the Gulf of Mexico

    OpenAIRE

    Teo, Steven L. H.; Block, Barbara A.

    2010-01-01

    Directed fishing effort for Atlantic bluefin tuna in the Gulf of Mexico (GOM), their primary spawning grounds in the western Atlantic, has been prohibited since the 1980s due to a precipitous decline of the spawning stock biomass. However, pelagic longlines targeted at other species, primarily yellowfin tuna and swordfish, continue to catch Atlantic bluefin tuna in the GOM as bycatch. Spatial and temporal management measures minimizing bluefin tuna bycatch in the GOM will likely become import...

  16. Simple measurements reveal the feeding history, the onset of reproduction, and energy conversion efficiencies in captive bluefin tuna

    Science.gov (United States)

    Jusup, Marko; Klanjšček, Tin; Matsuda, Hiroyuki

    2014-11-01

    We present a numerical approach that, in conjunction with a fully set up Dynamic Energy Budget (DEB) model, aims at consistently approximating the feeding history of cultivated fish from the commonly measured aquaculture data (body length, body mass, or the condition factor). We demonstrate the usefulness of the approach by performing validation of a DEB-based model for Pacific bluefin tuna (Thunnus orientalis) on an independent dataset and exploring the implied bioenergetics of this species in captivity. In the context of validation, the results indicate that the model successfully accounts for more than 75% of the variance in actual fish feed. At the 5% significance level, predictions do not underestimate nor overestimate observations and there is no bias. The overall model accuracy of 87.6% is satisfactory. In the context of tuna bioenergetics, we offer an explanation as to why the first reproduction in the examined case occurred only after the fish reached seven years of age, whereas it takes five years in the wild and sometimes as little as three years in captivity. Finally, we calculate energy conversion efficiencies and the supply stress throughout the entire lifetime to theoretically underpin the relatively low contribution of growth to aerobic metabolism implied by respirometry and high feed conversion ratio observed in bluefin tuna aquaculture.

  17. Developmental origin of a major difference in sensory patterning between zebrafish and bluefin tuna

    Science.gov (United States)

    Ghysen, Alain; Dambly-Chaudière, Christine; Coves, Denis; de la Gandara, Fernando; Ortega, Aurelio

    2012-01-01

    SUMMARY The posterior lateral line system (PLL) of teleost fish comprises a number of mechanosensory organs arranged in defined patterns on the body surface. Embryonic patterns are largely conserved among teleosts, yet adult patterns are highly diverse. Although changes in pattern modify the perceptual abilities of the system, their developmental origin remains unknown. Here we compare the processes that underlie the formation of the juvenile PLL pattern in Thunnus thynnus, the bluefin tuna, to the processes that were elucidated in Danio rerio, the zebrafish. In both cases, the embryonic PLL comprises five neuromasts regularly spaced along the horizontal myoseptum, but the juvenile PLL comprises four roughly parallel anteroposterior lines in zebrafish, whereas it is a simple dorsally arched line in tuna fish. We examined whether this difference involves evolutionary novelties, and show that the same mechanisms mediate the transition from embryonic to juvenile patterns in both species. We conclude that the marked difference in juveniles depends on a single change (dorsal vs. ventral migration of neuromasts) in the first days of larval life. PMID:23189756

  18. Atlantic Bluefin Tuna: A Novel Multistock Spatial Model for Assessing Population Biomass

    Science.gov (United States)

    Taylor, Nathan G.; McAllister, Murdoch K.; Lawson, Gareth L.; Carruthers, Tom; Block, Barbara A.

    2011-01-01

    Atlantic bluefin tuna (Thunnus thynnus) is considered to be overfished, but the status of its populations has been debated, partly because of uncertainties regarding the effects of mixing on fishing grounds. A better understanding of spatial structure and mixing may help fisheries managers to successfully rebuild populations to sustainable levels while maximizing catches. We formulate a new seasonally and spatially explicit fisheries model that is fitted to conventional and electronic tag data, historic catch-at-age reconstructions, and otolith microchemistry stock-composition data to improve the capacity to assess past, current, and future population sizes of Atlantic bluefin tuna. We apply the model to estimate spatial and temporal mixing of the eastern (Mediterranean) and western (Gulf of Mexico) populations, and to reconstruct abundances from 1950 to 2008. We show that western and eastern populations have been reduced to 17% and 33%, respectively, of 1950 spawning stock biomass levels. Overfishing to below the biomass that produces maximum sustainable yield occurred in the 1960s and the late 1990s for western and eastern populations, respectively. The model predicts that mixing depends on season, ontogeny, and location, and is highest in the western Atlantic. Assuming that future catches are zero, western and eastern populations are predicted to recover to levels at maximum sustainable yield by 2025 and 2015, respectively. However, the western population will not recover with catches of 1750 and 12,900 tonnes (the “rebuilding quotas”) in the western and eastern Atlantic, respectively, with or without closures in the Gulf of Mexico. If future catches are double the rebuilding quotas, then rebuilding of both populations will be compromised. If fishing were to continue in the eastern Atlantic at the unregulated levels of 2007, both stocks would continue to decline. Since populations mix on North Atlantic foraging grounds, successful rebuilding policies will

  19. Atlantic bluefin tuna: a novel multistock spatial model for assessing population biomass.

    Science.gov (United States)

    Taylor, Nathan G; McAllister, Murdoch K; Lawson, Gareth L; Carruthers, Tom; Block, Barbara A

    2011-01-01

    Atlantic bluefin tuna (Thunnus thynnus) is considered to be overfished, but the status of its populations has been debated, partly because of uncertainties regarding the effects of mixing on fishing grounds. A better understanding of spatial structure and mixing may help fisheries managers to successfully rebuild populations to sustainable levels while maximizing catches. We formulate a new seasonally and spatially explicit fisheries model that is fitted to conventional and electronic tag data, historic catch-at-age reconstructions, and otolith microchemistry stock-composition data to improve the capacity to assess past, current, and future population sizes of Atlantic bluefin tuna. We apply the model to estimate spatial and temporal mixing of the eastern (Mediterranean) and western (Gulf of Mexico) populations, and to reconstruct abundances from 1950 to 2008. We show that western and eastern populations have been reduced to 17% and 33%, respectively, of 1950 spawning stock biomass levels. Overfishing to below the biomass that produces maximum sustainable yield occurred in the 1960s and the late 1990s for western and eastern populations, respectively. The model predicts that mixing depends on season, ontogeny, and location, and is highest in the western Atlantic. Assuming that future catches are zero, western and eastern populations are predicted to recover to levels at maximum sustainable yield by 2025 and 2015, respectively. However, the western population will not recover with catches of 1750 and 12,900 tonnes (the "rebuilding quotas") in the western and eastern Atlantic, respectively, with or without closures in the Gulf of Mexico. If future catches are double the rebuilding quotas, then rebuilding of both populations will be compromised. If fishing were to continue in the eastern Atlantic at the unregulated levels of 2007, both stocks would continue to decline. Since populations mix on North Atlantic foraging grounds, successful rebuilding policies will

  20. Atlantic bluefin tuna: a novel multistock spatial model for assessing population biomass.

    Directory of Open Access Journals (Sweden)

    Nathan G Taylor

    Full Text Available Atlantic bluefin tuna (Thunnus thynnus is considered to be overfished, but the status of its populations has been debated, partly because of uncertainties regarding the effects of mixing on fishing grounds. A better understanding of spatial structure and mixing may help fisheries managers to successfully rebuild populations to sustainable levels while maximizing catches. We formulate a new seasonally and spatially explicit fisheries model that is fitted to conventional and electronic tag data, historic catch-at-age reconstructions, and otolith microchemistry stock-composition data to improve the capacity to assess past, current, and future population sizes of Atlantic bluefin tuna. We apply the model to estimate spatial and temporal mixing of the eastern (Mediterranean and western (Gulf of Mexico populations, and to reconstruct abundances from 1950 to 2008. We show that western and eastern populations have been reduced to 17% and 33%, respectively, of 1950 spawning stock biomass levels. Overfishing to below the biomass that produces maximum sustainable yield occurred in the 1960s and the late 1990s for western and eastern populations, respectively. The model predicts that mixing depends on season, ontogeny, and location, and is highest in the western Atlantic. Assuming that future catches are zero, western and eastern populations are predicted to recover to levels at maximum sustainable yield by 2025 and 2015, respectively. However, the western population will not recover with catches of 1750 and 12,900 tonnes (the "rebuilding quotas" in the western and eastern Atlantic, respectively, with or without closures in the Gulf of Mexico. If future catches are double the rebuilding quotas, then rebuilding of both populations will be compromised. If fishing were to continue in the eastern Atlantic at the unregulated levels of 2007, both stocks would continue to decline. Since populations mix on North Atlantic foraging grounds, successful rebuilding

  1. Trade-Based Estimation of Bluefin Tuna Catches in the Eastern Atlantic and Mediterranean, 2005–2011

    Science.gov (United States)

    Gagern, Antonius; van den Bergh, Jeroen; Sumaila, Ussif Rashid

    2013-01-01

    The Eastern Atlantic and Mediterranean stock of Bluefin tuna Thunnus thynnus (BFTE) has long been considered overfished and at risk of collapse. Although ICCAT quotas for this stock have decreased considerably over the past years, uncertainty exists about the degree of catch beyond this quota. The extent of such catch is an important piece of information in stock assessment models as well as being an indicator of the effectiveness of fisheries management. We present a model using Bluefin tuna trade data to infer actual catches. Basing our calculations on 25 countries involved in BFTE trade, we estimate that between 2005 and 2011, allowable quotas were exceeded by 44 percent. This gap between catch and quotas has slightly increased over past years, leading to estimated excess catches of 57 percent for the period between 2008 and 2011. To improve assessments, preparation and design of BFTE management, we suggest that the estimated total removals reported in this paper be included in stock assessment models for BFTE. An implication of our findings is that ICCAT member states should take stronger measures to monitor and enforce compliance with quotas. PMID:23922870

  2. Trade-based estimation of bluefin tuna catches in the Eastern Atlantic and Mediterranean, 2005-2011.

    Directory of Open Access Journals (Sweden)

    Antonius Gagern

    Full Text Available The Eastern Atlantic and Mediterranean stock of Bluefin tuna Thunnus thynnus (BFTE has long been considered overfished and at risk of collapse. Although ICCAT quotas for this stock have decreased considerably over the past years, uncertainty exists about the degree of catch beyond this quota. The extent of such catch is an important piece of information in stock assessment models as well as being an indicator of the effectiveness of fisheries management. We present a model using Bluefin tuna trade data to infer actual catches. Basing our calculations on 25 countries involved in BFTE trade, we estimate that between 2005 and 2011, allowable quotas were exceeded by 44 percent. This gap between catch and quotas has slightly increased over past years, leading to estimated excess catches of 57 percent for the period between 2008 and 2011. To improve assessments, preparation and design of BFTE management, we suggest that the estimated total removals reported in this paper be included in stock assessment models for BFTE. An implication of our findings is that ICCAT member states should take stronger measures to monitor and enforce compliance with quotas.

  3. Environmental and biological characteristics of Atlantic bluefin tuna and albacore spawning habitats based on their egg distributions

    Science.gov (United States)

    Reglero, Patricia; Santos, Maria; Balbín, Rosa; Laíz-Carrión, Raul; Alvarez-Berastegui, Diego; Ciannelli, Lorenzo; Jiménez, Elisa; Alemany, Francisco

    2017-06-01

    Tuna spawning habitats are traditionally characterized using data sets of larvae or gonads from mature adults and concurrent environmental variables. Data on egg distributions have never previously been used since molecular analyses are mandatory to identify tuna eggs to species level. However, in this study we use molecularly derived egg distribution data, in addition to larval data, to characterize hydrographic and biological drivers of the spatial distribution of eggs and larvae of bluefin Thunnus thynnus and albacore tuna Thunnus alalunga in the Balearic Sea, a main spawning area of these species in the Mediterranean. The effects of the hydrography, characterized by salinity, temperature and geostrophic velocity, on the spatial distributions of the eggs and larvae are investigated. Three biological variables are used to describe the productivity in the area: chlorophyll a in the mixed layer, chlorophyll a in the deep chlorophyll maximum and mesozooplankton biomass in the mixed layer. Our results point to the importance of salinity fronts and temperatures above a minimum threshold in shaping the egg and larval distribution of both species. The spatial distribution of the biotic variables was very scattered, and they did not emerge as significant variables in the presence-absence models. However, they became significant when modeling egg and larval abundances. The lack of correlation between the three biotic variables challenges the use of chlorophyll a to describe trophic scenarios for the larvae and suggests that the spatial distribution of resources is not persistent in time. The different patterns in relation to biotic variables across species and stages found in this and other studies indicate a still elusive understanding of the link between trophic levels involving tuna early larval stages. Our ability to improve short-term forecasting and long-term predictions of climate effects on the egg and larval distributions is discussed based on the consistency of

  4. Global Sushi: The Political Economy of the Mediterranian Bluefin Tuna Fishery in the Modern Era

    Directory of Open Access Journals (Sweden)

    Stefano B. Longo

    2015-08-01

    Full Text Available The bluefin tuna fishery in the Mediterranean has a long history of human interaction. In recent times, this fishery has become the central source of bluefin tuna for core nations, particularly Japan. This process was set off in large part by the growth of global fish markets, driven by the valuable sushi and sashimi market, and overfishing of other bluefin stocks in other parts of the world. The transformation of this fishery from an artisanal trap fishery to a globalized industrial fishery has had a number of social and environmental consequences. Based on in-depth fieldwork and historical research, this paper examines the political economy of the bluefin tuna fishery in the Mediterranean, with a focus on Sicily. It provides a descriptive history of the changing conditions in this fishery, paying special attention to the modern fishery. This research contributes to the discussions regarding the globalization and industrialization of agri-foodsystems and environmental degradation.

  5. Estimating diets of pre-spawning Atlantic bluefin tuna from stomach content and stable isotope analyses

    Science.gov (United States)

    Varela, José L.; Rodríguez-Marín, Enrique; Medina, Antonio

    2013-02-01

    Stomach content analysis (SCA) and stable isotope analysis (SIA) coupled with isotopic mixing model analysis were used to estimate diet composition of pre-spawning Atlantic bluefin tuna (ABFT), Thunnus thynnus, caught by trap in the Strait of Gibraltar area. SCA provided poor information on diet as most of the stomachs appeared empty or contained only hard remains. Mixing model diet compositions estimated from muscle tissue SIA data did not show clear inter-annual variations and suggested that ABFT fed on prey that occupy high and intermediate level positions of the food web. Otherwise, diet compositions estimated from liver tissue SIA showed greater inter-annual variations and appeared to indicate that ABFT fed on prey located at lower trophic levels. The different dietary compositions inferred from muscle and liver samples were most probably due to the different turnover rates of these organs, which would provide trophic information at two distinct time scales. Our findings suggest that a combination of SCA and SIA is more suitable than using SCA alone to determine temporal and regional variations in ABFT diet composition.

  6. Analysis of the effect of atmospheric oscillations on physical condition of pre–reproductive bluefin tuna from the Strait of Gibraltar

    Directory of Open Access Journals (Sweden)

    Báez, J. C.

    2013-12-01

    Full Text Available The aim of this study was to explore the possible effects of atmospheric oscillations: North Atlantic Oscillation (NAO and Arctic Oscillation (AO, on the physical condition of bluefin tuna (Thunnus thynnus. We estimated a fitness ratio from 3,501 pairs of length–weight data based on bluefin tuna caught in bait–boat fisheries before the spawning season (January, February and March, for each length class and year. In order to obtain a single fitness ratio (K–mean per year we determined the average for all length classes. We also evaluated Le Cren’s condition index (KLC. We observed significant positive correlations between the atmospheric oscillations and both physical condition indexes. In the case of K–mean, the AO explained 75% of the observed variability. Regarding KLC, the NAO explained approximately 73% of the observed variability, while the AO explained 70% of the observed variability. The increase in physical conditions of bluefin tuna in association with positive atmospheric oscillations could be mediated by the increase in the prevalence of strong trade winds. We concluded that the increase in the prevalence of strong westerly winds, mediated by a positive AO or NAO, favours the trip from the Atlantic to the Mediterranean by reducing energy costs due to migration and by increasing the supply of nutrients at the surface by the mixing of deep water and surface water in local areas such as the Strait of Gibraltar.

  7. Spillover of the Atlantic bluefin tuna offspring from cages in the Adriatic Sea: A multidisciplinary approach and assessment.

    Directory of Open Access Journals (Sweden)

    Tomislav Džoić

    Full Text Available During routine monitoring of commercial purse seine catches in 2011, 87 fingerling specimens of scombrids were collected in the southern Adriatic Sea. Sequencing of the mitochondrial DNA control region locus inferred that specimens belonged to the Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758 (N = 29, bullet tuna, Auxis rochei (Risso, 1810 (N = 30 and little tunny, Euthynnus alletteratus, Rafinesque, 1810 (N = 28. According to previously published growth parameters, the age of the collected specimens was estimated at approximately 30-40 days, suggesting they might have been spawned in the Adriatic Sea, contrary to the current knowledge. A coupled modelling system with hydrodynamic (ROMS and individual based model (IBM-Ichthyop was set up to determine the location of the spawning event. Numerical simulations with the IBM model, both backward and forward in time, indicate commercial tuna cages in the middle Adriatic coastal area as possible spawning location. The two other non-commercial species likely opportunistically use the positive environmental (abiotic and biotic conditions to spawn in the same area.

  8. Spillover of the Atlantic bluefin tuna offspring from cages in the Adriatic Sea: A multidisciplinary approach and assessment

    Science.gov (United States)

    2017-01-01

    During routine monitoring of commercial purse seine catches in 2011, 87 fingerling specimens of scombrids were collected in the southern Adriatic Sea. Sequencing of the mitochondrial DNA control region locus inferred that specimens belonged to the Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758) (N = 29), bullet tuna, Auxis rochei (Risso, 1810) (N = 30) and little tunny, Euthynnus alletteratus, Rafinesque, 1810 (N = 28). According to previously published growth parameters, the age of the collected specimens was estimated at approximately 30–40 days, suggesting they might have been spawned in the Adriatic Sea, contrary to the current knowledge. A coupled modelling system with hydrodynamic (ROMS) and individual based model (IBM—Ichthyop) was set up to determine the location of the spawning event. Numerical simulations with the IBM model, both backward and forward in time, indicate commercial tuna cages in the middle Adriatic coastal area as possible spawning location. The two other non-commercial species likely opportunistically use the positive environmental (abiotic and biotic) conditions to spawn in the same area. PMID:29190825

  9. Depressed resilience of bluefin tuna in the western atlantic and age truncation.

    Science.gov (United States)

    Secor, D H; Rooker, J R; Gahagan, B I; Siskey, M R; Wingate, R W

    2015-04-01

    Following intense overfishing in the 1970s, the western stock of Atlantic bluefin tuna (Thunnus thynnus) experienced a long period of depressed abundance, which has been attributed to failure of the population to periodically produce large numbers of juveniles, the western stock mixing with the more highly exploited eastern stock (fisheries in the Northeast Atlantic Ocean and Mediterranean Sea), and regime shift in the population's ecosystem resulting in lower replacement rates. To evaluate the presence of relatively strong years of juvenile production, we analyzed age structure from a recent sample of otoliths (ear stones) collected from the western stock (2011-2013, North Carolina, U.S.A., winter fishery). Mixing levels for the recent sample were analyzed using otolith stable isotopes to test whether age structure might be biased through immigration of eastern stock bluefin tuna. Age structure from historical samples collected from United States and Canadian fisheries (1975-1981) was compared with more recent samples (1996-2007) to examine whether demographic changes had occurred to the western stock that might have disrupted juvenile production. Relatively high juvenile production occurred in 2003, 2005, and 2006. Otolith stable isotope analysis showed that these recruitments were mostly of western stock origin. However, these high recruitments were >2-fold less than historical recruitment. We found substantial age truncation in the sampled fisheries. Half the historical sample was >20 years old (mean age = 20.1 [SD 3.7]; skewness = -0.3), whereas 20 years old (mean age = 13.4 [SD 3.8]; skewness = 1.3). Loss of age structure is consistent with changes in fishing selectivity and trends in the stock assessment used for management. We propose that fishing, as a forcing variable, brought about a threshold shift in the western stock toward lower biomass and production, a shift that emulates the regime shift hypothesis. An abbreviated reproductive life span

  10. Habitat suitability of the Atlantic bluefin tuna by size class: An ecological niche approach

    Science.gov (United States)

    Druon, Jean-Noël; Fromentin, Jean-Marc; Hanke, Alex R.; Arrizabalaga, Haritz; Damalas, Dimitrios; Tičina, Vjekoslav; Quílez-Badia, Gemma; Ramirez, Karina; Arregui, Igor; Tserpes, George; Reglero, Patricia; Deflorio, Michele; Oray, Isik; Saadet Karakulak, F.; Megalofonou, Persefoni; Ceyhan, Tevfik; Grubišić, Leon; MacKenzie, Brian R.; Lamkin, John; Afonso, Pedro; Addis, Piero

    2016-03-01

    An ecological niche modelling (ENM) approach was used to predict the potential feeding and spawning habitats of small (5-25 kg, only feeding) and large (>25 kg) Atlantic bluefin tuna (ABFT), Thunnus thynnus, in the Mediterranean Sea, the North Atlantic and the Gulf of Mexico. The ENM was built bridging knowledge on ecological traits of ABFT (e.g. temperature tolerance, mobility, feeding and spawning strategy) with patterns of selected environmental variables (chlorophyll-a fronts and concentration, sea surface current and temperature, sea surface height anomaly) that were identified using an extensive set of precisely geo-located presence data. The results highlight a wider temperature tolerance for larger fish allowing them to feed in the northern - high chlorophyll levels - latitudes up to the Norwegian Sea in the eastern Atlantic and to the Gulf of Saint Lawrence in the western basin. Permanent suitable feeding habitat for small ABFT was predicted to be mostly located in temperate latitudes in the North Atlantic and in the Mediterranean Sea, as well as in subtropical waters off north-west Africa, while summer potential habitat in the Gulf of Mexico was found to be unsuitable for both small and large ABFTs. Potential spawning grounds were found to occur in the Gulf of Mexico from March-April in the south-east to April-May in the north, while favourable conditions evolve in the Mediterranean Sea from mid-May in the eastern to mid-July in the western basin. Other secondary potential spawning grounds not supported by observations were predicted in the Azores area and off Morocco to Senegal during July and August when extrapolating the model settings from the Gulf of Mexico into the North Atlantic. The presence of large ABFT off Florida and the Bahamas in spring was not explained by the model as is, however the environmental variables other than the sea surface height anomaly appeared to be favourable for spawning in part of this area. Defining key spatial and

  11. Discovery of intermediate hosts for two species of blood flukes Cardicola orientalis and Cardicola forsteri (Trematoda: Aporocotylidae) infecting Pacific bluefin tuna in Japan.

    Science.gov (United States)

    Shirakashi, Sho; Tani, Kazuki; Ishimaru, Katsuya; Shin, Sang Phil; Honryo, Tomoki; Uchida, Hiro'omi; Ogawa, Kazuo

    2016-04-01

    Fish blood flukes (Aporocotylidae) are important pathogens of farmed finfish around the world. Among them, Cardicola spp. infecting farmed tuna are considered to be serious threats to tuna farming and have received tremendous attention. We conducted periodical samplings at a tuna farming site in Japan between January and May, 2015 to determine the life cycle of Cardicola spp. We collected over 4700 terebellid polychaetes from ropes, floats and frames of tuna culture cages and found nearly 400 infected worms. Sporocysts and cercariae found in Nicolea gracilibranchis were genetically identified as Cardicola orientalis by 28S and ITS2 ribosomal DNA sequences. This was the first discovery of the intermediate host for this parasite species. Infection prevalence and the abundance of N. gracilibranchis significantly varied between sampling points and the highest number of infected terebellids were collected from ropes. We also demonstrated morphologically and molecularly that asexual stages found in a single Amphitrite sp. (Terebellidae) and adult worms isolated from farmed juvenile tuna were Cardicola forsteri. This is the first report of C. forsteri in Pacific bluefin tuna (PBT) Thunnus orientalis in Japan. Our results demonstrated that all three species of Cardicola orientalis, C. forsteri and Cardicola opisthorchis exist in Japanese farmed PBTs and that they all use terebellid polychaetes as the intermediate hosts. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Karakteristik Ikan Tuna sirip biru selatan (Thunnus maccoyii Hasil Tangkapan Kapal Rawai Tuna yang didaratkan di Pelabuhan Benoa

    Directory of Open Access Journals (Sweden)

    I Gede Adi Swastana

    2016-12-01

    Full Text Available Southern bluefin tuna (SBT is scientifically known Thunnus maccoyii, and just live in the southern hemisphere. SBT fish classified as the most exploited tuna fish in the southeastern part of the Indian Ocean, so it is protected by the International Union for the Conservation of Nature (IUCN. The aim of this study is too collected of SBT fish caught during January which is the peak of SBT landing in Benoa port. The study was conducted base on data sampling, observation and interviews on 33 ships were landing SBT fish during January 2016. Based on observations from 33 vessels, we found that the total of SBT fish that landed in Benoa port during January 2016 is 251 fresh fish and 366 frozen fish. However just 251 SBT fresh fish were sampled, and the result indicated the fresh SBT fish is dominated by weigh between 61-70 kg with number 61 fish with a total weight of 19.28 tonne. The SBT were caught dominated by fish that has FL (fork lenght ranging between 151-160 cm with number 69 fish. While the smallest SBT range between 131-140 cm with the number of 5 fish. These results indicate that SBT fish caught in the Souetheast Indian Ocean during January 2016 is generaly relative small fish (130–160 cm FL with a number of 163 fish and mature SBT fish (FL > 162 cm with a number of 88 and young SBT (FL < 130 cm with a number of 5 fish. Based on morphometric analysis, eyeball diameter of SBT range 6-8 cm, the length lateral head from the tip of the mouth to behind the gill cover ranging 46-54 cm, the length of body from the early dorsal or in front of the first dorsal fin ranging between 38-47 cm, the height of fish at the end of the anal or at the end ranging between 34-39 cm, the high of caudal peduncle ranging between 4-5 cm, th length of the dorsal base of the tail fish ranging between 53-63 cm, and the length of the base of tail anal from anal to tail ranging between 41-51 cm. Base on size and age composition, it is shown that the growth of SBT

  13. Karakteristik Ikan Tuna sirip biru selatan (Thunnus maccoyii Hasil Tangkapan Kapal Rawai Tuna yang didaratkan di Pelabuhan Benoa

    Directory of Open Access Journals (Sweden)

    I Gede Adi Swastana

    2016-07-01

    Full Text Available Southern bluefin tuna (SBT is scientifically known Thunnus maccoyii, and just live in the southern hemisphere. SBT fish classified as the most exploited tuna fish in the southeastern part of the Indian Ocean, so it is protected by the International Union for the Conservation of Nature (IUCN. The aim of this study is too collected of SBT fish caught during January which is the peak of SBT landing in Benoa port. The study was conducted base on data sampling, observation and interviews on 33 ships were landing SBT fish during January 2016. Based on observations from 33 vessels, we found that the total of SBT fish that landed in Benoa port during January 2016 is 251 fresh fish and 366 frozen fish. However just 251 SBT fresh fish were sampled, and the result indicated the fresh SBT fish is dominated by weigh between 61-70 kg with number 61 fish with a total weight of 19.28 tonne. The SBT were caught dominated by fish that has FL (fork lenght ranging between 151-160 cm with number 69 fish. While the smallest SBT range between 131-140 cm with the number of 5 fish. These results indicate that SBT fish caught in the Souetheast Indian Ocean during January 2016 is generaly relative small fish (130–160 cm FL with a number of 163 fish and mature SBT fish (FL > 162 cm with a number of 88 and young SBT (FL < 130 cm with a number of 5 fish. Based on morphometric analysis, eyeball diameter of SBT range 6-8 cm, the length lateral head from the tip of the mouth to behind the gill cover ranging 46-54 cm, the length of body from the early dorsal or in front of the first dorsal fin ranging between 38-47 cm, the height of fish at the end of the anal or at the end ranging between 34-39 cm, the high of caudal peduncle ranging between 4-5 cm, th length of the dorsal base of the tail fish ranging between 53-63 cm, and the length of the base of tail anal from anal to tail ranging between 41-51 cm. Base on size and age composition, it is shown that the growth of SBT

  14. Effects of the North Atlantic Oscillation on Spanish catches of albacore, Thunnus alalunga, and yellowfin tuna, Thunnus albacares, in the North–east Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, C.J.; MacIas, D.; Camiñas, J.A.; Fernandez, I.L.; Baez, J.C.

    2016-07-01

    Tuna are highly migratory pelagic species (HMPS) with great importance in commercial fishing. Several authors have highlighted the effect of climatic oscillations such as the NAO (North Atlantic Oscillation) on HMPS. This paper analyzes the effects of the NAO on two HMPS: albacore, Thunnus alalunga, and yellowfin tuna, Thunnus albacares. Fishing data from the Spanish fleet operating in the North Atlantic area were obtained from the International Commission for the Conservation of Atlantic Tunas (ICCAT) database. The results show a positive correlation between the NAO index and the Catch per Unit Effort (CPUE) for both albacore and yellowfin tuna, depicting a potential effect on their capturability. (Author)

  15. Hydrodynamics and energy-saving swimming techniques of Pacific bluefin tuna.

    Science.gov (United States)

    Takagi, Tsutomu; Tamura, Yumiko; Weihs, Daniel

    2013-11-07

    Weihs theoretically revealed that during the movement of fish with negative buoyancy, more kinetic energy is saved in the glide and upward (GAU) swimming mode than in the continuous horizontal swimming mode. Because kinetic energy saving depends on dynamic parameters such as the drag and lift of the body, the effects of variations in these parameters on energy saving for different species remain unknown. Here, the kinetic energy saving of Pacific bluefin tuna (PBT), Thunnus orientalis, exhibiting the GAU swimming mode was investigated. The dynamic properties of PBT were estimated by carrying out CFD analysis. The CFD model was produced by using a three-dimensional laser surface profiler, and the model was controlled such that it exhibited swimming motion similar to that of a live PBT swimming in a flume tank. The drag generated by tail beating, which significantly affects the kinetic energy during motion, was twice that generated in the glide mode. The faster the upward swimming speed, the lesser is the kinetic energy saving; therefore, when the upward swimming speed is more than twice the glide speed, there is no gain in the GAU mode. However, when SMR (Standard Metabolic Rate) is considered, if the energy based on SMR is assumed to be 30% of the total energy spent during motion, the most efficient upward swimming speed is 1.4 times the glide speed. The GAU swimming mode of PBT leads to energy saving during motion, and the upward swimming speed and the lift force produced by the pectoral fins for the most efficient drive are unique for different species of different sizes. © 2013 Elsevier Ltd. All rights reserved.

  16. TAKTIK PENANGKAPAN TUNA MATA BESAR (Thunnus obesus DI SAMUDERA HINDIA BERDASARKAN DATA HOOK TIMER DAN MINILOGGER

    Directory of Open Access Journals (Sweden)

    Andi Bahtiar

    2016-04-01

    Full Text Available Penangkapan ikan tuna di Samudera Hindia semakin kompetitif, sehingga setiap Nahkoda atau Fishing Master kapal rawai tuna perlu memiliki taktik penangkapan ikan yang efektif dan efisien. Pengetahuan mengenai tingkah laku ikan tuna merupakan informasi penting untuk merumuskan taktik penangkapan ikan yang efektif dan efisien. Penelitian taktik penangkapan ikan tuna, khususnya tuna mata besar (Thunnus obesus di Samudera Hindia berdasarkan data hook timer dan minilogger dilakukan mulai Juni 2007 sampai Januari 2010, dengan metode observasi langsung pada kapal rawai tuna yang berbasis di Pelabuhan Benoa. Hasil penelitian menunjukkan bahwa tuna mata besar aktif mencari makan mulai pukul 13:00-18:00, dan lebih banyak tertangkap pada kedalaman 194-470 m dengan suhu air antara 8,4-15,50C. Oleh karena itu taktik penanagkapan yang tepat untuk diterapkan adalah pengaturan waktu setting pada siang hari dan hauling pada malam hari dan memadukan antara konstruksi rawai tuna bersifat pertengahan (halfway longline dan dalam (deep longline.   Tuna fishing in Indian Ocean more competitive, so Fishermans or Fishing Masters of tuna longliner must have an effective and efficient of fishing tactics. Knowledge on tuna behavior is an important information to formulate the fishing tactics. A study on bigeye tuna fishing tactics based on hook timer and minilogger data of tuna longliner was conducted in Indian Ocean from June 2007 to January 2010. Onboard observation of tuna longliner has been done at Benoa Port. The results showed that the feeding periodicity of bigeye tunas started from 1pm to 6pm, and mostly caught at water depth of 194 to 470 m with the water temperature between 8.4 to 15.2 degree celcius so the set times during the day and the haul times at night and the combination of halfway tuna longline and deep tuna longline construction are the best fishing tactics to be applied.

  17. A cascade of warming impacts brings bluefin tuna to Greenland waters

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Payne, Mark; Boje, Jesper

    , Scomber scombrus Linnaeus 1758. The bluefin tuna were captured in a single net-haul in 9-11o C water together with 6 tonnes of mackerel, which is a preferred prey species and itself a new immigrant to the area. Regional temperatures in August 2012 were historically high and contributed to a warming trend...

  18. DISTRIBUSI SPASIAL DAN TEMPORAL IKAN TUNA MATA BESAR (Thunnus obesus DI SAMUDERA HINDIA BAGIAN TIMUR

    Directory of Open Access Journals (Sweden)

    Irwan Jatmiko

    2016-03-01

    Full Text Available Ikan tuna mata besar (Thunnus obesus merupakan salah satu hasil tangkapan yang penting bagi industri perikanan di Indonesia. Penelitian ini bertujuan untuk mengetahui distribusi spasial dan temporal ikan tuna mata besar di Samudera Hindia Bagian Timur. Pengumpulan data dilakukan oleh pemantau ilmiah (scientific observers pada kapal rawai tuna yang berbasis di Pelabuhan Benoa Bali, mulai Agustus 2005 hingga November 2013. Ikan tuna mata besar yang tertangkap sebanyak 5.340 ekor dan dari jumlah tersebut sebanyak 5.253 ekor diukur panjangnya. Distribusi spasial ikan tuna mata besar yang tertangkap rawai tuna Indonesia membentang dari 0°-33° LS dan 76°-128° BT. Persentase tertinggi ikan tuna mata besar dengan panjang >110 cm (Lm terdapat di sebelah barat Sumatera Barat dan di sebelah selatan Jawa Timur. Laju pancing menurut bulan penagkapan menunjukkan perbedaan yang nyata dengan laju pancing tertinggi terjadi pada Agustus sebesar 0,54 ekor/100 mata pancing. Nelayan direkomendasikan untuk melakukan operasi penangkapan di daerah dengan persentase ukuran panjang ikan tuna mata besar >110 cm (Lm tertinggi, sehingga species tersebut mempunyai kesempatan untuk melakukan pemijahan minimal sekali sepanjang hidupnya. Hal ini dimaksudkan untuk menjaga kelestarian sumberdaya ikan tuna mata besar di Samudera Hindia. Big eye tuna (Thunnus obesus is one of the important catch of the fishing industry in Indonesia. The study is aimed to investigate the spatial and temporal distribution of big eye tuna in the Eastern Indian Ocean. Data were collected by scientific observers on tuna long line vessels which were mainly based in Port of Benoa Bali from August 2005 to November 2013. Total number of big eye tuna caught were 5,340 individuals and as many as 5,253 of them were measured in length. The spatial distribution of  big eye tuna caught by Indonesia tuna long line are in the area between 0°-33° S and 76°-128° E. The highest percentage of big eye tuna with

  19. Comparative influence of ocean conditions on yellowfin and Atlantic bluefin tuna catch from longlines in the Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Steven L H Teo

    Full Text Available Directed fishing effort for Atlantic bluefin tuna in the Gulf of Mexico (GOM, their primary spawning grounds in the western Atlantic, has been prohibited since the 1980s due to a precipitous decline of the spawning stock biomass. However, pelagic longlines targeted at other species, primarily yellowfin tuna and swordfish, continue to catch Atlantic bluefin tuna in the GOM as bycatch. Spatial and temporal management measures minimizing bluefin tuna bycatch in the GOM will likely become important in rebuilding the western Atlantic bluefin stock. In order to help inform management policy and understand the relative distribution of target and bycatch species in the GOM, we compared the spatiotemporal variability and environmental influences on the catch per unit effort (CPUE of yellowfin (target and bluefin tuna (bycatch. Catch and effort data from pelagic longline fisheries observers (1993-2005 and scientific tagging cruises (1998-2002 were coupled with environmental and biological data. Negative binomial models were used to fit the data for both species and Akaike's Information Criterion (corrected for small sample size was used to determine the best model. Our results indicate that bluefin CPUE had higher spatiotemporal variability as compared to yellowfin CPUE. Bluefin CPUE increased substantially during the breeding months (March-June and peaked in April and May, while yellowfin CPUE remained relatively high throughout the year. In addition, bluefin CPUE was significantly higher in areas with negative sea surface height anomalies and cooler sea surface temperatures, which are characteristic of mesoscale cyclonic eddies. In contrast, yellowfin CPUE was less sensitive to environmental variability. These differences in seasonal variability and sensitivity to environmental influences suggest that bluefin tuna bycatch in the GOM can be reduced substantially by managing the spatial and temporal distribution of the pelagic longline effort without

  20. Comparative influence of ocean conditions on yellowfin and Atlantic bluefin tuna catch from longlines in the Gulf of Mexico.

    Science.gov (United States)

    Teo, Steven L H; Block, Barbara A

    2010-05-28

    Directed fishing effort for Atlantic bluefin tuna in the Gulf of Mexico (GOM), their primary spawning grounds in the western Atlantic, has been prohibited since the 1980s due to a precipitous decline of the spawning stock biomass. However, pelagic longlines targeted at other species, primarily yellowfin tuna and swordfish, continue to catch Atlantic bluefin tuna in the GOM as bycatch. Spatial and temporal management measures minimizing bluefin tuna bycatch in the GOM will likely become important in rebuilding the western Atlantic bluefin stock. In order to help inform management policy and understand the relative distribution of target and bycatch species in the GOM, we compared the spatiotemporal variability and environmental influences on the catch per unit effort (CPUE) of yellowfin (target) and bluefin tuna (bycatch). Catch and effort data from pelagic longline fisheries observers (1993-2005) and scientific tagging cruises (1998-2002) were coupled with environmental and biological data. Negative binomial models were used to fit the data for both species and Akaike's Information Criterion (corrected for small sample size) was used to determine the best model. Our results indicate that bluefin CPUE had higher spatiotemporal variability as compared to yellowfin CPUE. Bluefin CPUE increased substantially during the breeding months (March-June) and peaked in April and May, while yellowfin CPUE remained relatively high throughout the year. In addition, bluefin CPUE was significantly higher in areas with negative sea surface height anomalies and cooler sea surface temperatures, which are characteristic of mesoscale cyclonic eddies. In contrast, yellowfin CPUE was less sensitive to environmental variability. These differences in seasonal variability and sensitivity to environmental influences suggest that bluefin tuna bycatch in the GOM can be reduced substantially by managing the spatial and temporal distribution of the pelagic longline effort without substantially

  1. Comparative Influence of Ocean Conditions on Yellowfin and Atlantic Bluefin Tuna Catch from Longlines in the Gulf of Mexico

    Science.gov (United States)

    Teo, Steven L. H.; Block, Barbara A.

    2010-01-01

    Directed fishing effort for Atlantic bluefin tuna in the Gulf of Mexico (GOM), their primary spawning grounds in the western Atlantic, has been prohibited since the 1980s due to a precipitous decline of the spawning stock biomass. However, pelagic longlines targeted at other species, primarily yellowfin tuna and swordfish, continue to catch Atlantic bluefin tuna in the GOM as bycatch. Spatial and temporal management measures minimizing bluefin tuna bycatch in the GOM will likely become important in rebuilding the western Atlantic bluefin stock. In order to help inform management policy and understand the relative distribution of target and bycatch species in the GOM, we compared the spatiotemporal variability and environmental influences on the catch per unit effort (CPUE) of yellowfin (target) and bluefin tuna (bycatch). Catch and effort data from pelagic longline fisheries observers (1993–2005) and scientific tagging cruises (1998–2002) were coupled with environmental and biological data. Negative binomial models were used to fit the data for both species and Akaike's Information Criterion (corrected for small sample size) was used to determine the best model. Our results indicate that bluefin CPUE had higher spatiotemporal variability as compared to yellowfin CPUE. Bluefin CPUE increased substantially during the breeding months (March-June) and peaked in April and May, while yellowfin CPUE remained relatively high throughout the year. In addition, bluefin CPUE was significantly higher in areas with negative sea surface height anomalies and cooler sea surface temperatures, which are characteristic of mesoscale cyclonic eddies. In contrast, yellowfin CPUE was less sensitive to environmental variability. These differences in seasonal variability and sensitivity to environmental influences suggest that bluefin tuna bycatch in the GOM can be reduced substantially by managing the spatial and temporal distribution of the pelagic longline effort without

  2. Evaluating effectiveness of biological reference points for bigeye tuna (Thunnus obesus and yellowfin tuna (Thunnus albacares fisheries in the Indian Ocean

    Directory of Open Access Journals (Sweden)

    Yuying Zhang

    2017-03-01

    Full Text Available Biological reference point (BRP is one of the essential components in the management strategy evaluation that is used to determine the status of fishery stock and set management regulations. However, as BRPs can be derived from different models and many different BRPs are available, the effectiveness and consistency of different BRPs should be evaluated before being applied to fisheries management. In this study, we used a computation-intensive approach to identify optimal BRPs. We systematically evaluated 1500 combinations of alternative BRPs in managing the bigeye tuna (Thunnus obesus and yellowfin tuna (Thunnus albacares fisheries in the Indian Ocean. The effectiveness and consistency of these BRPs were evaluated using four performance measures related to fisheries landing performance and biomass conservation. Monte Carlo simulation was used to evaluate various uncertainties. The results suggest that the proposed computation-intensive approach can be effective in identifying optimal BRPs with respect to a set of defined performance measures. We found that the current maximum sustainable yield (MSY-based BRP combinations are effective target BRPs to manage the bigeye and yellowfin tuna fisheries with the “linear” harvest control rule (HCR. However, using the “knife-edge” HCR, better BRPs could be found for both the bigeye and yellowfin tuna fisheries management with improved fisheries and conservation performance. The framework developed in this study can be used to identify suitable BRPs based on a set of defined performance measures for other fisheries.

  3. Organic waste impact of capture-based Atlantic bluefin tuna aquaculture at an exposed site in the Mediterranean Sea

    Science.gov (United States)

    Vezzulli, Luigi; Moreno, Mariapaola; Marin, Valentina; Pezzati, Elisabetta; Bartoli, Marco; Fabiano, Mauro

    2008-06-01

    A variety of pelagic and benthic parameters were measured at an aquaculture farm used for the fattening of Atlantic bluefin tuna ( Thunnus thynnus) which is located at an exposed site (700 m from the coast, average bottom depth of 45 m and average current speed of 6 cm s -1) in the Mediterranean Sea. The objective was to test whether modern off-shore tuna fattening industries can exert a sustainable organic waste impact on the receiving environment as has been reported for the offshore culture of more traditional Mediterranean species such as sparids. In the water column, the concentration of phytopigments, organic matter, heterotrophic bacteria and the taxonomic abundance of mesozooplankton (at the species level) were assessed. In the sediment, we assessed the concentration of reduced sulphur pools, phytopigments, organic matter, heterotrophic bacteria and the taxonomic abundance of meiofauna (at the taxa level) and nematodes (at the genus level). For most parameters, we found no substantial differences between farm and control sites. Deviations of farm values from control values, when they occurred, were small and did not indicate any significant impact on either the pelagic and benthic environment. Deviations were more apparent in the benthic compartment where lower redox potential values, higher bacterial production rates and a change in nematode genus composition pointed out to early changes in the sediment's metabolism. In addition, indigenous potential pathogenic bacteria showed higher concentration at the fish farm stations and were a warning of an undesirable event that may become established following aquaculture practice in oligotrophic environments. The overall data from this study provide extensive experimental evidence to support the sustainability of modern offshore farming technology in minimizing the hypertrophic-dystrophic risks associated with the rapidly-expanding tuna-fattening industry in the Mediterranean Sea.

  4. Co-Occurrence and Habitat Use of Fin Whales, Striped Dolphins and Atlantic Bluefin Tuna in the Northwestern Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Robert Klaus Bauer

    Full Text Available Different dolphin and tuna species have frequently been reported to aggregate in areas of high frontal activity, sometimes developing close multi-species associations to increase feeding success. Aerial surveys are a common tool to monitor the density and abundance of marine mammals, and have recently become a focus in the search for methods to provide fisheries-independent abundance indicators for tuna stock assessment. In this study, we present first density estimates corrected for availability bias of fin whales (Balaenoptera physalus and striped dolphins (Stenella coeruleoalba from the Golf of Lions (GoL, compared with uncorrected estimates of Atlantic bluefin tuna (ABFT; Thunnus thynnus densities from 8 years of line transect aerial surveys. The raw sighting data were further used to analyze patterns of spatial co-occurrence and density of these three top marine predators in this important feeding ground in the Northwestern Mediterranean Sea. These patterns were investigated regarding known species-specific feeding preferences and environmental characteristics (i. e. mesoscale activity of the survey zone. ABFT was by far the most abundant species during the surveys in terms of schools and individuals, followed by striped dolphins and fin whales. However, when accounted for availability bias, schools of dolphins and fin whales were of equal density. Direct interactions of the species appeared to be the exception, but results indicate that densities, presence and core sighting locations of striped dolphins and ABFT were correlated. Core sighting areas of these species were located close to an area of high mesoscale activity (oceanic fronts and eddies. Fin whales did not show such a correlation. The results further highlight the feasibility to coordinate research efforts to explore the behaviour and abundance of the investigated species, as demanded by the Marine Strategy Framework Directive (MSFD.

  5. Validation of the method spectrophotometer in the histamine determination in fresh tuna (Thunnus Tunna)

    International Nuclear Information System (INIS)

    Chacon Silva, F.

    1998-01-01

    The objective of this study was to validate the spectrophotometer method described by Bateman et al. (1994) for the histamine determination in fresh tuna (Thunnus Tunna) and to evaluate the histamine concentration in samples of fresh tuna. To fulfill the recently exposed objectives, the figures of merit were determined like they are it: recovery limits of detection, sensibility and repetitive of the method spectrophotometry and applied the analysis at twenty samples of fresh tuna for copy of the Metropolitan area and three sample like reference of fresh tuna stored 4 degree centigrade by 15 days. The histamine recovery you determines enriching seven ours of fresh tuna with histamine to two levels different 0.613 mg/L and 2.21 mg/L. three samples were left without enriching and you subtract the average to the native histamine. You determines the one it limits of detection using the standard deviation to three levels of concentration of histamine 1.37 mg/L, 2.22 mg/L and 3.22 mg/L, the minimum quantity of hi stamina that you can determine for the method spectrophotometry settling down. The repetitive you determines using the standard deviation for 100 among the average of the histamine values, in seven you replies independent of the same sample. You determines the histamine content, in the fresh tuna Thunnus Tunna of the expends of the Metropolitan Area and in samples of reference stored 4 degrees centigrade by 15 days [es

  6. Genetic homogeneity in longtail tuna Thunnus tonggol (Bleeker, 1851) from the northwest coast of India inferred from direct sequencing analysis of the mitochondrial DNA D-loop region

    Digital Repository Service at National Institute of Oceanography (India)

    Kunal, S.P.; GirishKumar; Menezes, M.R.; Meena, R.M.

    Longtail tuna Thunnus tonggol is a neritic species of the family Scombridae, having a confined coastal distribution to tropical and temperate waters of the Indo-Pacific region In the present study, the population structure of longtail tuna...

  7. Environmental forcing and the larval fish community associated to the Atlantic bluefin tuna spawning habitat of the Balearic region (Western Mediterranean), in early summer 2005

    Science.gov (United States)

    Rodriguez, J. M.; Alvarez, I.; Lopez-Jurado, J. L.; Garcia, A.; Balbin, R.; Alvarez-Berastegui, D.; Torres, A. P.; Alemany, F.

    2013-07-01

    The Balearic region is a highly dynamic area located in the Western Mediterranean, straddling the transition between the Algerian and Provencal basins and constitutes one of the main spawning grounds for the large, migratory Atlantic bluefin (Thunnus thynnus) and other medium and small tuna species (Thunnus alalunga, Auxis rochei, Euthynnus alleteratus and Katsuwonus pelamis). In summer, despite been considered an oligotrophic region as the whole Mediterranean Sea, it harbors a relatively abundant and diverse larval fish community (LFC). In this study, we analyze the composition, abundance and the influence of abiotic and biotic factors on the horizontal structure of the LFC in the Balearic region, in early summer 2005, during the spawning season of Atlantic bluefin tuna. Hydrographically, 2005 was an unusual year with a summer situation of relatively lack of mesoscale features, weak surface currents and a general situation of high stability. A total of 128 taxa of fish larvae, belonging to 52 families, were identified. The average abundance was 1770 larvae 1000 m-3. Multivariate statistical analysis revealed LFC to have a strong horizontal structure. Cluster analysis and non-metric multidimensional scaling ordination identified two larval fish assemblages. These assemblages were mainly delineated by depth and, therefore, by the spawning location of adult fish. Our results also suggest that anticyclonic eddy boundaries constitute favourable habitats for fish larvae. Also, the scenario of higher than unusual hydrographic stability found during the cruise would be responsible for the relatively lack of mesoscale features and, consequently, for the lack of influence of these features on the horizontal distribution of fish larvae and on the horizontal structure of the LFC.

  8. Spatio-temporal population structuring and genetic diversity retention in depleted Atlantic Bluefin tuna of the Mediterranean Sea

    Science.gov (United States)

    Riccioni, Giulia; Landi, Monica; Ferrara, Giorgia; Milano, Ilaria; Cariani, Alessia; Zane, Lorenzo; Sella, Massimo; Barbujani, Guido; Tinti, Fausto

    2010-01-01

    Fishery genetics have greatly changed our understanding of population dynamics and structuring in marine fish. In this study, we show that the Atlantic Bluefin tuna (ABFT, Thunnus thynnus), an oceanic predatory species exhibiting highly migratory behavior, large population size, and high potential for dispersal during early life stages, displays significant genetic differences over space and time, both at the fine and large scales of variation. We compared microsatellite variation of contemporary (n = 256) and historical (n = 99) biological samples of ABFTs of the central-western Mediterranean Sea, the latter dating back to the early 20th century. Measures of genetic differentiation and a general heterozygote deficit suggest that differences exist among population samples, both now and 96–80 years ago. Thus, ABFTs do not represent a single panmictic population in the Mediterranean Sea. Statistics designed to infer changes in population size, both from current and past genetic variation, suggest that some Mediterranean ABFT populations, although still not severely reduced in their genetic potential, might have suffered from demographic declines. The short-term estimates of effective population size are straddled on the minimum threshold (effective population size = 500) indicated to maintain genetic diversity and evolutionary potential across several generations in natural populations. PMID:20080643

  9. Discrimination of juvenile yellowfin (Thunnus albacares and bigeye (T. obesus Tunas using mitochondrial DNA control region and liver morphology.

    Directory of Open Access Journals (Sweden)

    Ivane R Pedrosa-Gerasmio

    Full Text Available Yellowfin tuna, Thunnus albacares (Bonnaterre, 1788 and bigeye tuna, Thunnus obesus (Lowe, 1839 are two of the most economically important tuna species in the world. However, identification of their juveniles, especially at sizes less than 40 cm, is very difficult, often leading to misidentification and miscalculation of their catch estimates. Here, we applied the mitochondrial DNA control region D-loop, a recently validated genetic marker used for identifying tuna species (Genus Thunnus, to discriminate juvenile tunas caught by purse seine and ringnet sets around fish aggregating devices (FADs off the Southern Iloilo Peninsula in Central Philippines. We checked individual identifications using the Neighbor-Joining Method and compared results with morphometric analyses and the liver phenotype. We tested 48 specimens ranging from 13 to 31 cm fork length. Morpho-meristic analyses suggested that 12 specimens (25% were bigeye tuna and 36 specimens (75% were yellowfin tuna. In contrast, the genetic and liver analyses both showed that 5 specimens (10% were bigeye tuna and 43 (90% yellowfin tuna. This suggests that misidentification can occur even with highly stringent morpho-meristic characters and that the mtDNA control region and liver phenotype are excellent markers to discriminate juveniles of yellowfin and bigeye tunas.

  10. Discrimination of juvenile yellowfin (Thunnus albacares) and bigeye (T. obesus) Tunas using mitochondrial DNA control region and liver morphology.

    Science.gov (United States)

    Pedrosa-Gerasmio, Ivane R; Babaran, Ricardo P; Santos, Mudjekeewis D

    2012-01-01

    Yellowfin tuna, Thunnus albacares (Bonnaterre, 1788) and bigeye tuna, Thunnus obesus (Lowe, 1839) are two of the most economically important tuna species in the world. However, identification of their juveniles, especially at sizes less than 40 cm, is very difficult, often leading to misidentification and miscalculation of their catch estimates. Here, we applied the mitochondrial DNA control region D-loop, a recently validated genetic marker used for identifying tuna species (Genus Thunnus), to discriminate juvenile tunas caught by purse seine and ringnet sets around fish aggregating devices (FADs) off the Southern Iloilo Peninsula in Central Philippines. We checked individual identifications using the Neighbor-Joining Method and compared results with morphometric analyses and the liver phenotype. We tested 48 specimens ranging from 13 to 31 cm fork length. Morpho-meristic analyses suggested that 12 specimens (25%) were bigeye tuna and 36 specimens (75%) were yellowfin tuna. In contrast, the genetic and liver analyses both showed that 5 specimens (10%) were bigeye tuna and 43 (90%) yellowfin tuna. This suggests that misidentification can occur even with highly stringent morpho-meristic characters and that the mtDNA control region and liver phenotype are excellent markers to discriminate juveniles of yellowfin and bigeye tunas.

  11. Scale diversity in bigeye tuna (Thunnus obesus): Fat-filled trabecular scales made of cellular bone.

    Science.gov (United States)

    Wainwright, Dylan K; Ingersoll, Sam; Lauder, George V

    2018-03-14

    Tunas of the genus Thunnus possess many morphological and physiological adaptations for their high-performance epipelagic ecology. Although Thunnus anatomy has been studied, there are no quantitative studies on the structure of their scales. We investigated the scales of bigeye tuna (Thunnus obesus) from ten regions of the body using micro computed tomography (µCT)-scanning and histology to quantitatively and qualitatively compare regional scale morphology. We found a diversity of scale sizes and shapes across the body of bigeye tuna and discriminant function analysis on variables derived from µCT-data showed that scales across the body differ quantitatively in shape and size. We also report the discovery of a novel scale type in corselet, tail, and cheek regions. These modified scales are ossified shells supported by internal trabeculae, filled with fat, and possessing an internal blood supply. Histological analysis showed that the outer lamellar layers of these thickened scales are composed of cellular bone, unexpected for a perciform fish in which bone is typically acellular. In the fairing region of the anterior body, these fat-filled scales are stacked in layers up to five scales deep, forming a thickened bony casing. Cheek scales also possess a fat-filled internal trabecular structure, while most posterior body scales are more plate-like and similar to typical teleost scales. While the function of these novel fat-filled scales is unknown, we explore several possible hypotheses for their function. © 2018 Wiley Periodicals, Inc.

  12. Total mercury in canned yellowfin tuna Thunnus albacares marketed in northwest Mexico.

    Science.gov (United States)

    Ruelas-Inzunza, Jorge; Patiño-Mejía, Carlos; Soto-Jiménez, Martín; Barba-Quintero, Guillermo; Spanopoulos-Hernández, Milton

    2011-12-01

    Mercury (Hg) was determined in Thunnus albacares canned in oil (from 7 to 10 samples per brand) and water (from 5 to 10 samples per brand) of five leading brands in Mexico in 2008. Potential health risk was estimated on the basis of Hg concentration and rate (1.43 kg year(-1)per capita) of tuna consumption in Mexico. Highest Hg concentrations were 0.51 ± 0.26 and 0.40 ± 0.24 μ gg(-1) dry weight in water and oil, respectively. Averaged Hg concentrations in tuna canned in water in the current study were comparable to values in Katsuwonus pelamis from Alabama; regarding the oil presentation, Hg levels were lower than in canned tuna collected in Mexico and comparable to values in canned tuna (species not identified) from Turkey. Hazard quotients were 0.0166 and 0.012 in water and oil, respectively. For the analyzed brands and considering tuna consumption in Mexican population, reference dose for this element was not exceeded; therefore, no human health risk is likely to occur. More work is necessary in relation to exposure to Hg from other sources, rates of consumption in strata of population with elevated fish consumption, size of canned tuna and on the role of Se against Hg toxicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Polychlorinated biphenyls and organochlorine pesticides as intrinsic tracer tags of foraging grounds of bluefin tuna in the northwest Atlantic Ocean.

    Science.gov (United States)

    Deshpande, Ashok D; Dickhut, Rebecca M; Dockum, Bruce W; Brill, Richard W; Farrington, Cameron

    2016-04-15

    Researchers have utilized chemical fingerprints in the determination of habitat utilization and movements of the aquatic animals. In the present effort, we analyzed polychlorinated biphenyl (PCB) congeners and organochlorine pesticides in the samples of juvenile bluefin tuna caught offshore of Virginia, and in larger bluefin tuna from the Gulf of Maine and near Nova Scotia. For a given specimen, or a given location, PCB concentrations were highest, followed by DDTs, and chlordanes. Average contaminant concentrations from fish captured from the three locations were not significantly different; and PCBs, DDTs, and chlordanes correlated well with each other. Trans-nonachlor/PCB 153 ratios in bluefin tuna of eastern Atlantic (i.e., Mediterranean) origin are low compared to the corresponding ratios in fish in the western Atlantic. As the former migrate to the western Atlantic, these ratios gradually turnover due to the accumulation of biomass from forage contaminated with higher trans-nonachlor/PCB 153 ratio reflecting dissimilar use of chlordane pesticides on two sides of the Atlantic Ocean. The trans-nonachlor/PCB 153 ratio indicated that one juvenile bluefin tuna from offshore of Virginia and one large bluefin tuna from Gulf of Maine in the present study originated from foraging grounds in the Mediterranean Sea, and that they have made the trans-Atlantic migrations. The remaining individuals were determined to be either spawned in the Gulf of Mexico or the trans-nonachlor/PCB 153 ratio for the putative Mediterranean bluefin tuna was completely turned over to resemble the ratio characteristic to the western Atlantic. Based on the turnover time for trans-nonachlor/PCB 153 ratio previously determined, the residence time of juvenile bluefin tuna offshore Virginia was estimated to be at least 0.8 to 1.6years. A discriminant function analysis (DFA) plot of total PCB normalized signatures of PCB congeners showed three separate clusters, which suggested that bluefin tuna

  14. The Effect of Moon Phase on The Catch of Bigeye Tuna (Thunnus obesus in Eastern Indian Ocean

    Directory of Open Access Journals (Sweden)

    Irwan Jatmiko

    2016-08-01

    Full Text Available Tuna is one of the important export commodities to increase government income. One of economically important tuna species is bigeye tuna (Thunnus obesus which has a proportion of 21% of the total production of large tuna group. The objective of this study was to investigate the effects of different moon phase on the catch of bigeye tuna (T. obesus in Eastern Indian Ocean. Data collection was conducted by the scientific observers from August 2005 to June 2014 in the tuna longline vessels were based in the port of Benoa, Bali. Moon phase data were collected from August 2005 to June 2014 from National Aeronautics and Space Administration (NASA. Catch data were calculated using the catch rate formula which defined as the number of catches per 100 hooks. The number of catch rate then was sorted into each moon phases and were analyzed using one-way Anova. This study covered 62 trips and 1,480 numbers of operations or sets was conducted from sampled vessels. The result showed that the average catch rate of bigeye tuna differed significantly among the moon phases. Tukey post-hoc tests showed that the average catch rate at full moon was the highest among the groups with around 0.3/100 hooks. This study showed that moon phase had significant effect on the catch of bigeye tuna (T. obesus that increased the catch during full moon. Keywords: moon phase, catch rate, Eastern Indian Ocea, tuna, Thunnus obesus

  15. Screening of biodiesel production from waste tuna oil (Thunnus sp.), seaweed Kappaphycus alvarezii and Gracilaria sp.

    Science.gov (United States)

    Alamsjah, Mochammad Amin; Abdillah, Annur Ahadi; Mustikawati, Hutami; Atari, Suci Dwi Purnawa

    2017-09-01

    Biodiesel has several advantages over solar. Compared to solar, biodiesel has more eco-friendly characteristic and produces lower greenhouse gas emissions. Biodiesel that is made from animal fats can be produced from fish oil, while other alternative sources from vegetable oils are seaweed Kappaphycus alvarezii and Gracilaria sp. Waste tuna oil (Thunnus sp.) in Indonesia is commonly a side product of tuna canning industries known as tuna precook oil; on the other hand, seaweed Gracilaria sp. and Kappaphycus alvarezii are commonly found in Indonesia's seas. Seaweed waste that was used in the present study was 100 kg and in wet condition, and the waste oil was 10 liter. The seaweed was extracted with soxhletation method that used n-hexane as the solvent. To produce biodiesel, trans esterification was performed on the seaweed oil that was obtained from the soxhletation process and waste tuna oil. Biodiesel manufactured from seaweed K. alvarezii obtained the best score in flash point, freezing point, and viscosity test. However, according to level of manufacturing efficiency, biodiesel from waste tuna oil is more efficient and relatively easier compared to biodiesel from waste K. alvarezii and Gracilaria sp.

  16. Acanthocephalan (Echinorhynchus sp. infection of yellowfin tuna (Thunnus albacares from Nagapattinam, south east coast of India

    Directory of Open Access Journals (Sweden)

    Alagarsamy Sakthive

    2014-08-01

    Full Text Available Objective: To recored the infection of Acanthocephalan parasite, (Echinorhynchus sp. in adult yellowfin tuna (Thunnus albacares. This is the first report of acanthocephalan Echinirhynchus sp attached to yellowfin tuna and moreover prevalence, mean intensity and mean abundance was observed. Methods: Totally 1 001 yellowfin tuna fishes were collected throughout the year of 2012 from the coast of Nagapattinam (10°45' 36.25" N and 79°50' 59.54" E, Tamil Nadu, India. The collected fishes were washed with fresh water to remove debris and immediately stored in ice, and brought to the laboratory. Intestines were placed in normal saline (0.85% NaCl. The worms were fixed in alcohol/ formalin /(AFA fixative and in 70% ethanol until processed for identification. Results: Totally 1 001 yellowfin tuna was examined out of 387 (52.67% hosts were infected with acanthocephalan (Echinorhynchus sp.. The proboscis Echinorhynchus sp. was long, cylindrical with cylindrical with a uniform width measured (0.41±0.02 mm in length and (0.12±0.03 mm in width. The endo parasite prevalence, intensity and abundance was recorded as 52.67%, 12.46%, and 5.43% respectively. Conclusions: This current phenomena was carried out to report of acanthocephalan Echinorhynchus sp. attached the new host of yellowfin tuna from Nagapattinam coast. Moreover, parasitological investigations are required to determine endo parasites of host due to its importance and numerous occurring among most important marine food fishes in world wild.

  17. A cascade of warming impacts brings bluefin tuna to Greenland waters

    DEFF Research Database (Denmark)

    MacKenzie, Brian R.; Payne, Mark R.; Boje, Jesper

    2014-01-01

    to a warming trend since 1985, when temperatures began to rise. The presence of bluefin tuna in this region is likely due to a combination of warm temperatures that are physiologically more tolerable and immigration of an important prey species to the region. We conclude that a cascade of climate change......Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species...

  18. Developmental stages of fish blood flukes, Cardicola forsteri and Cardicola opisthorchis (Trematoda: Aporocotylidae), in their polychaete intermediate hosts collected at Pacific bluefin tuna culture sites in Japan.

    Science.gov (United States)

    Ogawa, Kazuo; Shirakashi, Sho; Tani, Kazuki; Shin, Sang Phil; Ishimaru, Katsuya; Honryo, Tomoki; Sugihara, Yukitaka; Uchida, Hiro'omi

    2017-02-01

    Farming of Pacific bluefin tuna (PBT), Thunnus orientalis, is a rapidly growing industry in Japan. Aporocotylid blood flukes of the genus Cardicola comprising C. orientalis, C. opisthorchis and C. forsteri are parasites of economic importance for PBT farming. Recently, terebellid polychaetes have been identified as the intermediate hosts for all these parasites. We collected infected polychaetes, Terebella sp., the intermediate host of C. opisthorchis, from ropes and floats attached to tuna cages in Tsushima, Nagasaki Prefecture, Japan. Also, Neoamphitrite vigintipes (formerly as Amphitrite sp. sensu Shirakashi et al., 2016), the intermediate host of C. forsteri, were collected from culture cages in Kushimoto, Wakayama Prefecture, Japan. The terebellid intermediate hosts harbored the sporocysts and cercariae in their body cavity. Developmental stages of these blood flukes were molecularly identified using species specific PCR primers. In this paper, we describe the cercaria and sporocyst stages of C. opisthorchis and C. forsteri and compare their morphological characteristics among three Cardicola blood flukes infecting PBT. We also discuss phylogenetic relations of the six genera of the terebellid intermediate hosts (Artacama, Lanassa, Longicarpus, Terebella, Nicolea and Neoamphitrite) of blood flukes infecting marine fishes, based on their morphological characters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Genetic diversity of Atlantic Bluefin tuna in the Mediterranean Sea: insights from genome-wide SNPs and microsatellites.

    Science.gov (United States)

    Antoniou, Aglaia; Kasapidis, Panagiotis; Kotoulas, Georgios; Mylonas, Constantinos C; Magoulas, Antonios

    2017-12-01

    Elucidating the patterns of the Atlantic Bluefin tuna [ABFT, Thunnus thynnus (Linnaeus, 1758)] population structure constitutes a challenging task of great importance. Most of the unique challenges stem from its biology, as well as the attributes of the marine realm in which it disperses. Accurate information is urgently needed for stock assessment, and the identification of critical features to the persistence and adaptation of populations in order to formulate and adopt effective strategies for ABFT conservation and management. Conclusions of a great number of ABFT genetic studies on the Mediterranean Sea stock structure are rather controversial and not yet conclusive. In this study, ABFT genomic diversity was investigated in the Mediterranean Sea, which is the most important area for the species' reproduction. Analyzing genome-wide SNPs and microsatellites from ABFT samples collected throughout the Mediterranean Sea did not provide strong evidence of genetic structure, pointing towards the existence of a single panmictic unit. An alternative view would recognize a failure to reject the null hypothesis of a panmictic unit as an effect of the study's sampling design, the type of markers used, and the effectiveness/suitability of analysis methods in respect to the species biological characteristics or any combination of the above. Unravelling the drivers of ABFT population diversity would require the consideration of important aspects of the species spawning behavior for the determination of the appropriate sampling design. Novel approaches and methods of analysis that will bring together experts in genetics/-omics, ecology and oceanography are deemed necessary. Analyzing ABFT genetic data under the discipline of seascape genetics could provide the analysis framework under which major abiotic and biotic forces controlling ABFT recruitment could be identified, elucidating the complicated population dynamics of the species, while multiple and continuous fisheries

  20. Effects of Stochasticity in Early Life History on Steepness and Population Growth Rate Estimates: An Illustration on Atlantic Bluefin Tuna

    Science.gov (United States)

    Simon, Maximilien; Fromentin, Jean-Marc; Bonhommeau, Sylvain; Gaertner, Daniel; Brodziak, Jon; Etienne, Marie-Pierre

    2012-01-01

    The intrinsic population growth rate (r) of the surplus production function used in the biomass dynamic model and the steepness (h) of the stock-recruitment relationship used in age-structured population dynamics models are two key parameters in fish stock assessment. There is generally insufficient information in the data to estimate these parameters that thus have to be constrained. We developed methods to directly estimate the probability distributions of r and h for the Atlantic bluefin tuna (Thunnus thynnus, Scombridae), using all available biological and ecological information. We examined the existing literature to define appropriate probability distributions of key life history parameters associated with intrinsic growth rate and steepness, paying particular attention to the natural mortality for early life history stages. The estimated probability distribution of the population intrinsic growth rate was weakly informative, with an estimated mean r = 0.77 (±0.53) and an interquartile range of (0.34, 1.12). The estimated distribution of h was more informative, but also strongly asymmetric with an estimated mean h = 0.89 (±0.20) and a median of 0.99. We note that these two key demographic parameters strongly depend on the distribution of early life history mortality rate (M0), which is known to exhibit high year-to-year variations. This variability results in a widely spread distribution of M0 that affects the distribution of the intrinsic population growth rate and further makes the spawning stock biomass an inadequate proxy to predict recruitment levels. PMID:23119063

  1. Effects of stochasticity in early life history on steepness and population growth rate estimates: an illustration on Atlantic bluefin tuna.

    Directory of Open Access Journals (Sweden)

    Maximilien Simon

    Full Text Available The intrinsic population growth rate (r of the surplus production function used in the biomass dynamic model and the steepness (h of the stock-recruitment relationship used in age-structured population dynamics models are two key parameters in fish stock assessment. There is generally insufficient information in the data to estimate these parameters that thus have to be constrained. We developed methods to directly estimate the probability distributions of r and h for the Atlantic bluefin tuna (Thunnus thynnus, Scombridae, using all available biological and ecological information. We examined the existing literature to define appropriate probability distributions of key life history parameters associated with intrinsic growth rate and steepness, paying particular attention to the natural mortality for early life history stages. The estimated probability distribution of the population intrinsic growth rate was weakly informative, with an estimated mean r = 0.77 (±0.53 and an interquartile range of (0.34, 1.12. The estimated distribution of h was more informative, but also strongly asymmetric with an estimated mean h = 0.89 (±0.20 and a median of 0.99. We note that these two key demographic parameters strongly depend on the distribution of early life history mortality rate (M(0, which is known to exhibit high year-to-year variations. This variability results in a widely spread distribution of M(0 that affects the distribution of the intrinsic population growth rate and further makes the spawning stock biomass an inadequate proxy to predict recruitment levels.

  2. Reproductive Biology of Albacore Tuna (Thunnus alalunga) in the Western Indian Ocean

    Science.gov (United States)

    Dhurmeea, Zahirah; Zudaire, Iker; Chassot, Emmanuel; Cedras, Maria; Nikolic, Natacha; Bourjea, Jérôme; West, Wendy; Appadoo, Chandani

    2016-01-01

    The reproductive biology of albacore tuna, Thunnus alalunga, in the western Indian Ocean was examined through analysis of the sex ratio, spawning season, length-at-maturity (L50), spawning frequency and fecundity. From 2013 to 2015, a total of 923 female and 867 male albacore were sampled. A bias in sex ratio was found in favor of females with fork length (LF) Ocean. The reproductive parameters will reduce uncertainty in current stock assessment models which will eventually assist the fishery to be sustainable for future generations. PMID:28002431

  3. Vertical Movements, Behavior and Habitat Utilization of Adult Yellowfin Tuna (Thunnus albacares) Tagged in West Philippine Sea, Mindoro Island, Philippines

    NARCIS (Netherlands)

    Macusi, Edison; Babaran, R.P.; Ingles, J.T.

    2015-01-01

    This paper describes the vertical movements, behavior and habitat utilization of an electronically tagged adult yellowfin tuna (Thunnus albacares) after 17 days of liberty in the Philippines based on analyses of 23,845 datapoints recorded from a recovered electronic popup tag. The exhaustive set

  4. Comparative distributions of alkalies, alkaline earths and lead among major tissues of the tuna Thunnus alalunga

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, C.; Settle, D.

    1977-01-01

    The occurrences of K, Rb, Cs, Ca, Sr, Ba and Pb have been determined in various tissues of the tuna fish Thunnus alalunga. K, Rb, and Cs are distributed uniformly throughout the organs of the fish; 95 percent of the Ca and Sr, and 70 percent of the Ba and Pb are contained in the skeleton. It is found that there are smaller amounts of Cs, Ba and Pb associated with the nutrient metals K and Ca in a marine animal compared to a terrestrial animal. This difference is a result of the purity of K and Ca in seawater and the smaller amounts of trace metals associated with them compared to the impurity of K and Ca in terrestrial rocks. Food-chain enhancement and depletion of metals can be evaluated by comparing ratios of trace metals to abundant nutrient metals in seawater and tuna. Cs in enriched relative to K in going from seawater to tuna by a factor of 13. Sr and Ba are both depleted by factors of 5 relative to Ca in going from seawater to tuna, while Pb is enriched relative to Ca by a factor of 14. Special clean laboratory procedures were used to prepare samples for accurate analysis by stable isotope dilution mass spectrometric techniques.

  5. Otolith chemistry discriminates natal signatures of yellowfin tuna (Thunnus albacares) in the Atlantic Ocean

    Science.gov (United States)

    Kitchens, L. L.; Rooker, J. R.

    2016-02-01

    In this study, the otolith chemistry of young-of-the-year (YOY) yellowfin tuna (Thunnus albacares) was examined to determine whether chemical signatures are distinct across different putative spawning areas in the Atlantic Ocean. Yellowfin tuna is a highly migratory species that is currently managed as a single panmictic stock in the Atlantic Ocean; however, uncertainty remains regarding the population structure of yellowfin in this region, particularly concerning the degree of mixing between spawning populations. Analysis of naturally occurring chemical tracers in otoliths provides a valuable means to reconstruct a fish's environmental history and is thus a promising approach for delineating stock structure of Atlantic yellowfin tuna. YOY yellowfin tuna otoliths were collected from 5 locations in the Atlantic Ocean (Gulf of Mexico, SE Caribbean, Brazil, Cape Verde, and Gulf of Guinea) from 2013-2015 and trace element (Li, Mg, Mn, Co, Cu, Sr, Zn, and Ba) and stable isotope (δ13C and δ18O) analyses were conducted to investigate regional variation in otolith chemical composition. Results show significant differences among nursery areas in both trace element (MANOVA, p<0.001) and δ13C and δ18O signatures (ANOVA, p=0.017 and p=0.001, respectively). Particularly high spatial separation was observed based on eastern Atlantic (Gulf of Guinea + Cape Verde) and western Atlantic (Gulf of Mexico + Brazil + Martinique) nursery areas, indicating the approach has promise for distinguishing migrants displaying trans-ocean movement. These chemical signatures will be used to assign adult yellowfin tuna to their nursery of origin, ultimately providing an improved understanding of the stock structure and movement of yellowfin tuna in the Atlantic Ocean.

  6. Spatial scale, means and gradients of hydrographic variables define pelagic seascapes of bluefin and bullet tuna spawning distribution.

    Directory of Open Access Journals (Sweden)

    Diego Alvarez-Berastegui

    Full Text Available Seascape ecology is an emerging discipline focused on understanding how features of the marine habitat influence the spatial distribution of marine species. However, there is still a gap in the development of concepts and techniques for its application in the marine pelagic realm, where there are no clear boundaries delimitating habitats. Here we demonstrate that pelagic seascape metrics defined as a combination of hydrographic variables and their spatial gradients calculated at an appropriate spatial scale, improve our ability to model pelagic fish distribution. We apply the analysis to study the spawning locations of two tuna species: Atlantic bluefin and bullet tuna. These two species represent a gradient in life history strategies. Bluefin tuna has a large body size and is a long-distant migrant, while bullet tuna has a small body size and lives year-round in coastal waters within the Mediterranean Sea. The results show that the models performance incorporating the proposed seascape metrics increases significantly when compared with models that do not consider these metrics. This improvement is more important for Atlantic bluefin, whose spawning ecology is dependent on the local oceanographic scenario, than it is for bullet tuna, which is less influenced by the hydrographic conditions. Our study advances our understanding of how species perceive their habitat and confirms that the spatial scale at which the seascape metrics provide information is related to the spawning ecology and life history strategy of each species.

  7. A Satellite Imagery, Ecosystem-Based GIS Study of Bluefin Tuna and Right Whale Distribution and Movements in the Gulf of Marine and NW Atlantic

    National Research Council Canada - National Science Library

    Lutcavage, Molly

    2002-01-01

    The goals of this research were to develop a GIS workstation to examine the distribution, relative abundance, and behavior of Atlantic bluefin tuna and the Northern right whale in relation to their environment and prey...

  8. Influences of oceanographic features on the distribution and abundance of yellowfin tuna, Thunnus albacares, larvae in the Gulf of Mexico

    Science.gov (United States)

    Cornic, M.; Rooker, J. R.

    2016-02-01

    Summer ichthyoplankton surveys were conducted in the northern Gulf of Mexico (NGoM) from 2007-2010 to characterize patterns of distribution and abundance of yellowfin tuna (Thunnus albacares) larvae in this region. Yellowfin tuna larvae were moderately abundant representing 9% of the overall Thunnus larvae collected (18765) and had a percent occurrence ranging from 13 to 57% among surveys. Interannual variations were detected with highest mean densities observed in 2009 (2.2 larvae per 1000m3) and the lowest mean densities observed in 2008 (0.7 larvae per 1000 m3). Generalized additive models were used to investigate the influence of oceanographic conditions on abundance of yellowfin tuna larvae. Increased densities were associated with high sea surface temperatures, positive sea surface heights, and intermediate salinities, revealing that these physicochemical conditions may be favorable for yellowfin tuna larvae. These results indicate that the NGoM is an important spawning and/or nursery habitat for yellowfin tuna and suggest that mesoscale features and physicochemical characteristics of water masses may impact distribution and abundance of yellowfin tuna larvae in the NGoM.

  9. Distinct Yellowfin Tuna (Thunnus albacares Stocks Detected in Western and Central Pacific Ocean (WCPO Using DNA Microsatellites.

    Directory of Open Access Journals (Sweden)

    Roselyn D Aguila

    Full Text Available The yellowfin tuna, Thunnus albacares (Bonnaterre, 1788, covers majority of the Philippines' tuna catch, one of the major fisheries commodities in the country. Due to its high economic importance sustainable management of these tunas has become an imperative measure to prevent stock depletion. Currently, the Philippine yellowfin tuna is believed to be part of a single stock of the greater WCPO though some reports suggest otherwise. This study therefore aims to establish the genetic stock structure of the said species in the Philippines as compared to Bismarck Sea, Papua New Guinea using nine (9 DNA microsatellite markers. DNA microsatellite data revealed significant genetic differentiation between the Philippine and Bismarck Sea, Papua New Guinea yellowfin tuna samples. (FST = 0.034, P = 0.016, which is further supported by multilocus distance matrix testing (PCoA and model-based clustering (STRUCTURE 2.2.With these findings, this study posits that the yellowfin tuna population in the Philippines is a separate stock from the Bismarck Sea population. These findings add evidence to the alternative hypothesis of having at least 2 subpopulations of yellowfin tuna in the WCPO and calls for additional scientific studies using other parameters to investigate this. Accurate population information is necessary in formulating a more appropriate management strategy for the sustainability of the yellowfin tuna not only in the Philippines but also in the WCPO.

  10. Growth and mortality rates of bigeye tuna Thunnus obesus (Perciformes: Scombridae in the central Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Guoping Zhu

    2009-06-01

    Full Text Available Age and growth parameters were estimated for bigeye tuna Thunnus obesus Lowe, 1839 sampled from China longline fisheries in the central Atlantic Ocean from October 2002 to July 2003 and from August 2004 to March 2005. The von Bertalanffy growth parameters were estimated at L8=217.9 cm fork length, k=0.23 year-1, and t0=-0.44 year. The total mortality rate (Z was estimated to be from 0.82 to 1.02, the fishing mortality (F and the natural mortality were 0.54 year-1 and 0.39 year-1, respectively. The exploitation ratio (E was 0.35. This study provides the detailed estimates of growth and mortality rate for bigeye tuna in the central Atlantic Ocean, which can be used as biological input parameters in further stock evaluations in this region. However, age analysis, additional validation of the size composition and stock structure are needed for future studies. Rev. Biol. Trop. 57 (1-2: 79-88. Epub 2009 June 30.

  11. Monitoring volatile and nonvolatile amines in dried and salted roes of tuna (Thunnus thynnus L.) during manufacture and storage.

    Science.gov (United States)

    Periago, M J; Rodrigo, J; Ros, G; Rodríguez-Jérez, J J; Hernández-Herrero, M

    2003-02-01

    Dried and salted roe, obtained from the reproductive organs of female tuna (Thunnus tynnus L.), is a typical fish-based food in the Mediterranean area of Spain. In the present study, we monitored the formation of volatile amines (trimethyamine nitrogen [TMA-N] and total basic volatile nitrogen [TBVN]) and nonvolatile amines (biogenic amines) in dried and salted tuna roe after processing and storage for 8 weeks at 4, 20, and 30 degrees C. The salting and drying process significantly increased the TBVN, cadaverine, tyramine, phenylethylamine, and tryptamine contents, and bacteria with histamine decarboxylase activity were detected both in raw and in dried and salted tuna roes. During storage of tuna roe, TMA-N and TBVN levels increased significantly after the fourth week of storage at 30 degrees C, whereas biogenic amine contents remained more or less constant. However, samples stored at 30 degrees C showed histamine formation after the first week of storage, with a concentration of < 50 ppm. The volatile and nonvolatile amine concentrations in tuna roe were below the consumer safety limit, with the exception of the total biogenic amine level in roe stored at 30 degrees C, which exceeded the European Community's recommended limit (300 ppm). These results indicate that in properly stored tuna roe, histamine formation will not represent a serious health risk to consumers unless the tuna roe has previously been mishandled.

  12. Immune reactivity in early life stages of sea-cage cultured Pacific bluefin tuna naturally infected with blood flukes from genus Cardicola (Trematoda: Aporocotylidae).

    Science.gov (United States)

    Pennacchi, Ylenia; Shirakashi, Sho; Nowak, Barbara F; Bridle, Andrew R

    2016-11-01

    Pacific bluefin tuna (PBT), Thunnus orientalis, due to its high average price on the market is an economically valuable fish species. Infections by blood flukes from the genus Cardicola (Trematoda: Aporocotylidae) represent a growing concern for the cage culture of bluefin tuna in Japan, Australia and Southern Europe. The accumulation of numerous Cardicola eggs in the fish gills causes severe pathology that has been linked to mortality in PBT juveniles up to one year old. The only effective treatment used to mitigate the infection is the oral administration of the antihelminthic drug praziquantel (PZQ) to the affected fish. However, with the need to minimise therapeutic drug use in aquaculture it is hoped that immunoprophylaxis can provide a future alternative to protect the PBT juveniles against Cardicola infection. Currently, little is known of the host immune response to these parasites and of their infection dynamics. In this study, using real-time qPCR we aimed to quantitatively detect C. orientalis and C. opisthorchis DNA within the gills and heart of cultured PBT juveniles and to investigate the host immune response at the transcriptional level in the gills. The research focused mainly during early stages of infection soon after young PBT were transferred to culture cages (from 14 to 77 days post-transfer). An increase (up to 11-fold) of immune-related genes, namely IgM, MHC-I, TCR-β and IL-1β was observed in the PBT gills infected with Cardicola spp. (28-77 days post-transfer). Furthermore, IgM (19-fold increase) and MHC-I (11.5-fold increase) transcription was strongly up-regulated in gill samples of PBT infected with C. orientalis relative to uninfected fish but not in fish infected with C. opisthorchis. Cardicola-specific DNA was first detected in the host 14 days post-transfer (DPT) to sea-cages which was 55 days earlier than the first detection of parasite eggs and adults by microscopy. Oral administration of PZQ did not have an immediate effect

  13. PENGARUH PERENDAMAN TULANG IKAN TUNA (Thunnus albacares DALAM LARUTAN NaOH TERHADAP KUALITAS GELATIN HASIL OLAHANNYA

    Directory of Open Access Journals (Sweden)

    Tazwir Tazwir

    2009-06-01

    Full Text Available Gelatin tulang ikan tuna (Thunnus albaceres dengan kualitas baik seringkali sulit diperoleh, karena kebanyakan produk ini mengandung lemak dan protein non kolagen yang cukup tinggi. Dalam memproduksi gelatin tulang tuna, lemak, dan protein non kolagen tersebut harus direduksi hingga batas minimum. Dalam penelitian ini dipelajari pengaruh perendaman tulang ikan tuna dalam larutan NaOH sebelum ekstraksi terhadap kualitas gelatin yang dihasilkan. Tahapan yang dilakukan adalah degreasing, pencucian, perendaman dalam NaOH dengan variasi konsentrasi 0; 0,4; dan 0,8%, kemudian perendaman dalam HCl, ekstraksi, filtrasi, evaporasi, dan pengeringan. Hasil penelitian menunjukkan bahwa karakteristik gelatin yang terbaik diperoleh dari perendaman tulang dalam NaOH 0,4%, yaitu dengan nilai rendemen 8,37%; viskositas 3,27-3,37 cPs; pH 5,03; dan kekuatan gel 157,8 g Bloom gel strength.

  14. Genes expressed in Blue Fin Tuna (Thunnus thynnus) liver and gonads.

    Science.gov (United States)

    Chini, Valentina; Cattaneo, Anna Giulia; Rossi, Federica; Bernardini, Giovanni; Terova, Genciana; Saroglia, Marco; Gornati, Rosalba

    2008-02-29

    Blue Fin Tuna (BFT), Thunnus thynnus, has been seriously endangered by global massive overfishing and by the pollution of marine environment. Feeding and fattening of caught tuna in marine cages is a recent resource, but the development of a self-sustained aquaculture activity, being independent from the supply of wild fish, is required from both industrial and conservation perspectives. At this scope, several technical problems have to be solved and the control of reproduction is the cardinal one. Beside the technological developments of farming facilities and protocols, a molecular approach seems promising for the studies of appropriate nutritional strategies, reproduction physiology and animal welfare, as well as lifestyle and response to endocrine disruptor pollutants. In this context, we have started an EST project on this species sequencing 2743, 2907, and 3014 clones from expression libraries of ovary, testis and liver, respectively, and 1499 clones from an ovary normalized library. Thanks to this project, we have identified several sequences with known function in other organisms, but not previously described in this species. Among the new genes, 712 were found only in the expression library of the ovary, 613 in that of the testis and 318 in that of the liver, while 324 additional genes were shared by two or more expression libraries; other 127 genes not found in the expression libraries were obtained from the ovary normalized library. This represents a contribution to the knowledge of the molecular basis of BFT and a necessary step for facilitating further molecular studies on this species. Accession numbers: EC 091633 to EC 093160; EG 629962 to EG 631176; EC 917676 to EC 919417; EG 999340 to EG 999999; EH 000001 to EH 000505; EH 667253 to EH 668984; EL 610526 to EL 611807; EC 42144 to EC 422414; and EH 379568 to EH 380065.

  15. Evaluating alternative management strategies for bigeye tuna, Thunnus obesus, in the Indian Ocean

    Directory of Open Access Journals (Sweden)

    Yuhe Tong

    2013-09-01

    Full Text Available Bigeye tuna (Thunnus obesus support a large commercial fishery in the Indian Ocean. However, explicit management strategies and harvest control rules are yet to be developed for the management of this fishery. We used a stochastic age-structured production model as an operating model to evaluate several potential management strategies under different assumptions of stock productivity. Five management strategies—constant fishing mortality, constant catch, quasi-constant catch, constant escapement, and status-dependent strategies—were evaluated and compared using the performance indicators including average catch, average spawning stock biomass, variation in catch, average fishing mortality and lowest biomass during the time period considered in the simulation. This study shows that (1 for the constant catch strategy, an annual catch of 90000 t would result in a low risk of stock being overfished while obtaining a stable catch; (2 for the constant fishing mortality strategy fishing mortality of 0.3 per year could yield a higher catch, but might have a high probability (64% of stock dropping below the spawning stock biomass (SSB that could achieve maximum sustainable yield (SSBmsy; and (3 for the quasi-constant catch strategy an annual catch of 110000 t was sustainable if the current SSB was higher than SSBmsy. Constant escapement and status-dependent strategies were robust with respect to different levels of virgin recruitment and steepness. This study suggests that it is important to incorporate uncertainties associated with key life history, fisheries and management processes in evaluating management strategies.

  16. CHARACTERISTICS OF GELATIN FROM SWIM BLADDER OF YELLOWFIN TUNA (THUNNUS ALBACORES AS INFLUENCED BY EXTRACTING TEMPERATURES

    Directory of Open Access Journals (Sweden)

    O. Kaewdang

    2015-09-01

    Full Text Available Gelatin was extracted from the swim bladder of yellowfin tuna (Thunnus albacores at different temperatures (60, 70 and 80°C with the extraction yields of 35.6%, 41.1% and 47.3% (dryweight basis, respectively. The α-chains of gelatin decreased with increasing extraction temperatures.Similar amino acid compositions were noticeable among all gelatins, in which glycine constituted the major amino acid. Imino acids ranged from 169 to 172 residues/1,000 residues. Thegel strength of gelatin extracted at lower temperature was higher than that of gelatins extracted at higher temperatures. Gelling and melting temperatures for swim bladder gelatin were 11.07-15.24 and 20.36-22.33°C, respectively. Higher gelling and melting points were observed for gelatin extracted at lower temperatures. Microstructure of gel of gelatin extracted at 60°C was finerwith smaller voids, compared with others. FTIR spectra of obtained gelatins revealed the significant loss of molecular order of the triple-helix. Thus, extraction temperatures showed the directimpact on characteristics of gelatin from swim bladder.

  17. Effect of Temperature on Isolation and Characterization of Hydroxyapatite from Tuna (Thunnus obesus Bone

    Directory of Open Access Journals (Sweden)

    Jayachandran Venkatesan

    2010-10-01

    Full Text Available The effect of temperature on isolation and characterization of hydroxyapatite (HAp from tuna bone was evaluated at different temperatures ranging from 200 °C to 1200 °C. The calcined bones were characterized by thermo gravimetric analysis (TGA, Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, field emission scanning electron microscopy (FE-SEM, energy dispersive X-ray spectroscopy (EDX and cytotoxicity assay. The FTIR and TGA results revealed the presence of inorganic and organic matrices in raw bone and a preserved carbonated group in the derived HAp. The XRD results of the derived HAp were coherent with the Joint Committee on Powder Diffraction Standards (JCPDS-09-0432/1996 data. In addition, FE-SEM results revealed the formation of nanostructured HAp (80–300 nm at 600 °C and crystal agglomeration was observed with an increase in temperature. The calcium to phosphorous weight ratio was determined by EDX results of treated bones. Derived HAp with various crystal sizes had no cytotoxicity on the MG 63 cell line. Based on the analysis, we conclude that varying the isolation temperature between 600–900 °C has tremendous impact on the production of HAp from Thunnus obesus with required properties.

  18. Carbon monoxide residues in vacuum-packed yellowfin tuna loins (Thunnus Albacares

    Directory of Open Access Journals (Sweden)

    Raffaele Marrone

    2015-09-01

    Full Text Available The use of carbon monoxide (CO in fresh fish has generated considerable debate. Carbon monoxide is used to treat fresh fish in order to retain its fresh red appearance for a longer period. It reacts with the oxy-myoglobin to form a fairly stable cherry red carboxy-myoglobin complex that may mask spoilage, because the CO-complex can be stable beyond the microbiological shelf life of the meat. The presence of CO in tuna fish (Thunnus Albacares has been investigated by means of optical spectroscopy. Formation of the CO adduct can be easily detected by the combined analysis of electronic absorption spectra in their normal and second derivative modes, monitoring the intense Soret band at 420 nm. Samples were judged as CO treated when their levels were higher than 200 ng/g. Only two positive samples out of 29 analyzed were detected. The high level of uncertainty (0.30 of the method requires the use of more specific and sensitive methods for confirmatory analysis.

  19. Carbon Monoxide Residues in Vacuum-Packed Yellowfin Tuna Loins (Thunnus Albacares).

    Science.gov (United States)

    Marrone, Raffaele; Mascolo, Celestina; Palma, Giuseppe; Smaldone, Giorgio; Girasole, Mariagrazia; Anastasio, Aniello

    2015-06-30

    The use of carbon monoxide (CO) in fresh fish has generated considerable debate. Carbon monoxide is used to treat fresh fish in order to retain its fresh red appearance for a longer period. It reacts with the oxy-myoglobin to form a fairly stable cherry red carboxy-myoglobin complex that may mask spoilage, because the CO-complex can be stable beyond the microbiological shelf life of the meat. The presence of CO in tuna fish ( Thunnus Albacares ) has been investigated by means of optical spectroscopy. Formation of the CO adduct can be easily detected by the combined analysis of electronic absorption spectra in their normal and second derivative modes, monitoring the intense Soret band at 420 nm. Samples were judged as CO treated when their levels were higher than 200 ng/g. Only two positive samples out of 29 analyzed were detected. The high level of uncertainty (0.30) of the method requires the use of more specific and sensitive methods for confirmatory analysis.

  20. Tuna and swordfish catch in the U.S. northwest Atlantic longline fishery in relation to mesoscale eddies.

    Science.gov (United States)

    Hsu, Ango C; Boustany, Andre M; Roberts, Jason J; Chang, Jui-Han; Halpin, Patrick N

    2015-11-01

    To analyze the effects of mesoscale eddies, sea surface temperature (SST), and gear configuration on the catch of Atlantic bluefin ( Thunnus thynnus ), yellowfin ( Thunnus albacares ), and bigeye tuna ( Thunnus obesus ) and swordfish ( Xiphias gladius ) in the U.S. northwest Atlantic longline fishery, we constructed multivariate statistical models relating these variables to the catch of the four species in 62 121 longline hauls made between 1993 and 2005. During the same 13-year period, 103 anticyclonic eddies and 269 cyclonic eddies were detected by our algorithm in the region 30-55°N, 30-80°W. Our results show that tuna and swordfish catches were associated with different eddy structures. Bluefin tuna catch was highest in anticyclonic eddies whereas yellowfin and bigeye tuna catches were highest in cyclonic eddies. Swordfish catch was found preferentially in regions outside of eddies. Our study confirms that the common practice of targeting tuna with day sets and swordfish with night sets is effective. In addition, bluefin tuna and swordfish catches responded to most of the variables we tested in the opposite directions. Bluefin tuna catch was negatively correlated with longitude and the number of light sticks used whereas swordfish catch was positively correlated with these two variables. We argue that overfishing of bluefin tuna can be alleviated and that swordfish can be targeted more efficiently by avoiding fishing in anticyclonic eddies and in near-shore waters and using more light sticks and fishing at night in our study area, although further studies are needed to propose a solid oceanography-based management plan for catch selection.

  1. Spatially explicit estimates of stock sizes, structure and biomass of herring and blue whiting, and catch data of bluefin tuna

    DEFF Research Database (Denmark)

    Huse, G.; MacKenzie, B. R.; Trenkel, V.

    2015-01-01

    on the other pelagic stocks during summer. The results show that there were substantial changes in the herring and blue whiting distribution during the 1990s and early 2000s. The earliest bluefin tuna catches noted were in 1907. The catches in the Norwegian Sea area peaked in the 1950s and there have been very...... small catches since the 1980s. The reported catches in the Mediterranean, on the other hand, peaked in the late 1990s and subsequently had a strong reduction....

  2. 210Po, Cd and Pb distribution and biomagnification in the yellowfin tuna Thunnus albacares and skipjack tuna Katsuwonus pelamis from the Eastern Pacific

    International Nuclear Information System (INIS)

    Ruelas-Inzunza, J.; Soto-Jiménez, M.F.; Ruiz-Fernández, A.C.; Ramos-Osuna, M.; Mones-Saucedo, J.; Páez-Osuna, F.

    2014-01-01

    Highlights: • Mean 210 Po activity (Bq kg −1 ) in liver was 119 in K. pelamis and 157 in T. albacares. • Trophic position of T. albacares (4.60) was higher than K. pelamis (3.94). • Pb was biomagnified between stomach content and muscle of T. albacares. - Abstract: We measured Cd and Pb in the muscle and stomach contents of Thunnus albacares and Katsuwonus pelamis to define the distribution of the elements in the tissues and their degrees of biomagnification. 210 Po was measured in the livers of both species and compared to the results of similar studies. The trophic position of the tuna species was determined by N isotope measurements. The average activity of 210 Po in the liver ranged from 119 to 157 (Bq kg −1 wet weight) in K. pelamis and T. albacares. The trophic position of T. albacares (4.60) was higher than that of K. pelamis (3.94). The Cd content of the muscle increased significantly with the trophic position of the tuna. δ 13 C in T. albacares and K. pelamis varied, with values of 3.13 and 1.88‰, respectively. The δ 15 N values in yellowfin tuna were higher than in skipjack tuna. The trophic position of T. albacares (4.60 ± 0.67) was therefore more elevated than that of K. pelamis (3.94 ± 1.06). Pb was biomagnified in T. albacares (transfer factor = 1.46)

  3. Tuna Species Substitution in the Spanish Commercial Chain: A Knock-On Effect.

    Science.gov (United States)

    Gordoa, Ana; Carreras, Gustavo; Sanz, Nuria; Viñas, Jordi

    2017-01-01

    Intentional mislabelling of seafood is a widespread problem, particularly with high-value species like tuna. In this study we examine tuna mislabelling, deliberate species substitution, types of substitution and its impact on prices. The survey covered the commercial chain, from Merca-Barna to fishmongers and restaurants in the Spanish Autonomous Community of Catalonia. To understand the geographic extent of the problem we also sampled Merca-Madrid, Europe's biggest fish market, and Merca-Málaga for its proximity to the bluefin tuna migratory route and trap fishery. Monthly surveys were carried out over one year. The results showed a high deficiency in labelling: 75% of points of sale and 83% of restaurants did not specify the species, and in those cases the name of the species had to be asked. A total of 375 samples were analysed genetically, the largest dataset gathered in Europe so far. The identified species were Thunnus albacares, Thunnus thynnus and Thunnus obesus. Species substitution began at suppliers, with 40% of observed cases, increasing to 58% at fishmongers and 62% at restaurants. The substitution was mainly on bluefin tuna (T. thynnus), 73% of cases. At restaurants, only during the bluefin fishing season, we observed a decrease of Bluefin tuna substitution and an increase of reverse substitution revealing some illegal fishing. The effect of species substitution on species prices was relevant: T. obesus increased its price by around €12 kg-1 when it was sold as bluefin. In view of the deficiency of labelling, the abuse of generic names and the lack of the bluefin catch document, we conclude that the Spanish regulations are ineffective, highlighting the need for policy execution, and the urgent need for information campaigns to Spanish consumers.

  4. Tuna Species Substitution in the Spanish Commercial Chain: A Knock-On Effect.

    Directory of Open Access Journals (Sweden)

    Ana Gordoa

    Full Text Available Intentional mislabelling of seafood is a widespread problem, particularly with high-value species like tuna. In this study we examine tuna mislabelling, deliberate species substitution, types of substitution and its impact on prices. The survey covered the commercial chain, from Merca-Barna to fishmongers and restaurants in the Spanish Autonomous Community of Catalonia. To understand the geographic extent of the problem we also sampled Merca-Madrid, Europe's biggest fish market, and Merca-Málaga for its proximity to the bluefin tuna migratory route and trap fishery. Monthly surveys were carried out over one year. The results showed a high deficiency in labelling: 75% of points of sale and 83% of restaurants did not specify the species, and in those cases the name of the species had to be asked. A total of 375 samples were analysed genetically, the largest dataset gathered in Europe so far. The identified species were Thunnus albacares, Thunnus thynnus and Thunnus obesus. Species substitution began at suppliers, with 40% of observed cases, increasing to 58% at fishmongers and 62% at restaurants. The substitution was mainly on bluefin tuna (T. thynnus, 73% of cases. At restaurants, only during the bluefin fishing season, we observed a decrease of Bluefin tuna substitution and an increase of reverse substitution revealing some illegal fishing. The effect of species substitution on species prices was relevant: T. obesus increased its price by around €12 kg-1 when it was sold as bluefin. In view of the deficiency of labelling, the abuse of generic names and the lack of the bluefin catch document, we conclude that the Spanish regulations are ineffective, highlighting the need for policy execution, and the urgent need for information campaigns to Spanish consumers.

  5. First attempt to assess the viability of bluefin tuna spawning events in offshore cages located in an a priori favourable larval habitat

    Directory of Open Access Journals (Sweden)

    Patricia Reglero

    2013-10-01

    Full Text Available Most of the Atlantic bluefin tuna caught by the purse-seine fleet in the Mediterranean Sea are transferred alive into transport cages and towed to coastal facilities where they are fattened. This major fishery is targeting aggregations of reproductive bluefin tuna that continue spawning within the transport cages. Our study is the first attempt to assess the viability of the spawning events within transport cages placed offshore in a priori favourable locations for larval survival. The study was conducted in June 2010 in the Balearic Sea, a main spawning area for bluefin tuna in the Mediterranean. The location of two transport cages, one with wild and one with captive tuna, coincide with the situation of the chlorophyll front using satellite imagery as a proxy for the salinity front between resident surface waters and those of recent Atlantic origin. The results showed that bluefin tuna eggs were spawned almost every day within the two cages but few or no larvae were found. The expected larval densities estimated after applying mortality curves to the daily egg densities observed in the cages were higher than the sampled larval densities. The trajectories of the eggs after hatching estimated from a particle tracking model based on observed geostrophic currents and a drifter deployed adjacent to the cage suggest that larvae were likely to be caught close to the cages within the sampling dates. Spawning events in captive tuna in transport cages may hatch into larvae though they may experience higher mortality rates than expected in natural populations. The causes of the larval mortality are further discussed in the text. Such studies should be repeated in other spawning areas in the Mediterranean if spawning in cages located offshore in areas favourable a priori for larval survival is likely to be considered a management measurement to minimize the impact of purse-seine fishing on tuna.

  6. Characterization of the ribosomal RNA gene of Kudoa neothunni (Myxosporea: Multivalvulida) in tunas (Thunnus spp.) and Kudoa scomberi n. sp. in a chub mackerel (Scomber japonicus).

    Science.gov (United States)

    Li, Ying-Chun; Sato, Hiroshi; Tanaka, Shuhei; Ohnishi, Takahiro; Kamata, Yoichi; Sugita-Konishi, Yoshiko

    2013-05-01

    Kudoa neothunni is the first described Kudoa species having six shell valves and polar capsules, previously assigned to the genus Hexacapsula Arai and Matsumoto, 1953. Since its genetic analyses remain to be conducted, the present study characterizes the ribosomal RNA gene (rDNA) using two isolates from a yellowfin tuna (Thunnus albacares) with post-harvest myoliquefaction and a northern bluefin tuna (Thunnus thynnus) without tissue degradation. Spores of the two isolates localized in the myofiber of trunk muscles, forming pseudocysts, and showed typical morphology of K. neothunni with six equal-sized shell valves radially arranged in apical view: spores (n = 15) measuring 9.5-11.4 μm in width, 7.3-8.6 μm in suture width, 8.9-10.9 μm in thickness, and 7.3-7.7 μm in length; and polar capsules measuring 3.6-4.1 μm by 1.8-2.3 μm. In lateral view, the spores were pyramidal in shape without apical protrusions. Their 18S and 5.8S rDNA sequences were essentially identical, but variations in the ITS1 (62.4 % similarity across 757-bp length), ITS2 (66.9 % similarity across 599-bp length), and 28S (99.0 % similarity across 2,245-bp length) rDNA regions existed between the two isolates. On phylogenetic trees based on the 18S or 28S rDNA sequence, K. neothunni formed a clade with Kudoa spp. with more than four shell valves and polar capsules, particularly K. grammatorcyni and K. scomberomori. Semiquadrate spores of a kudoid species with four shell valves and polar capsules were detected from minute cysts (0.30-0.75 mm by 0.20-0.40 mm) embedded in the trunk muscle of a chub mackerel (Scomber japonicus) fished in the Sea of Japan. Morphologically, it resembled K. caudata described from a chub mackerel fished in the southeastern Pacific Ocean off Peru; however, it lacked filamentous projections on the shell valves of spores. Additionally, it morphologically resembled K. thunni described from a yellowfin tuna also fished in the Pacific Ocean; spores (n

  7. Hubungan antara kelimpahan plankton dengan hasil tangkapan ikan tuna madidihang (Thunnus albacares di Perairan Kepulauan Banda, Ambon

    Directory of Open Access Journals (Sweden)

    Umi Chodriyah

    2017-08-01

    Full Text Available Study related to plankton community in the Banda Sea and its adjacent sea has been conducted by several authors; However, t information on the relationships between of plankton abundance and catches volume of yellowfin tuna Thunnus albacares has been never been examined. Therefore, the objective of this study was to analyze the relationships between plankton abundance and catch volume of yellowfin tuna in Banda Sea Waters, Ambon. The result showed that the highest abundance of phytoplankton (59.259 cell/m3 was found at station 10, around Ambon, Seram and Haruku Island which located in the waters between many river runoffs. While, the highest abundance of zooplankton was 5,483 ind/m3, located around Ambelau Island. Both diversity (H' and evenness (E index of phytoplankton were at the medium level, and there were no dominant species in this observation. Based on visual observation of remote sensing data, there was an indication of a relationship between the area with high concentration of chlorophyll-a (high phytoplankton biomass with CPUE value of yellowfin tuna. Studi mengenai komunitas plankton di Laut Banda dan sekitarnya telah banyak dilakukan, akan tetapi telaah hubungan antara kelimpahan dan distribusi plankton dengan aspek perikanan belum banyak dibahas. Tujuan dari penelitian ini adalah untuk mengetahui hubungan antara kelimpahan dan distribusi dari komunitas plankton dengan perikanan tuna di Perairan Kepulauan Banda. Kelimpahan fitoplankton tertinggi terdapat pada stasiun 10 yang terletak di daerah antara pulau Ambon, Seram dan Haruku (59.259 sel/m3 yang mempunyai akses ke muara-muara sungai di sekitarnya. Sedangkan kelimpahan zooplankton tertinggi terletak di sekitar Pulau Ambelau (stasiun 3, yakni 5.483 ind/m3. Tingkat indeks keanekaragaman (H’ fitoplankton sedang, indek keseragaman (E rendah hingga sedang, dan tidak ditemukan jenis tertentu yang dominan. Berdasarkan pengamatan visual data penginderaan jauh memberikan indikasi adanya

  8. PROFIL PEMIJAHAN IKAN TUNA SIRIP KUNING, Thunnus albacares DALAM BAK TERKONTROL DENGAN ANALISIS MITOKONDRIA DNA (mt-DNA

    Directory of Open Access Journals (Sweden)

    Gusti Ngurah Permana

    2016-11-01

    Full Text Available Variasi mitokondria DNA pada ikan tuna sirip kuning, Thunnus albacares menggunakan analisis RFLP (restriction fragment length polymorphism dapat menyediakan data yang akurat dan memberikan bukti tentang profil pemijahan ikan tuna dalam bak terkontrol. Genotipe mt-DNA yang berasal dari induk dibandingkan dengan genotipe yang ada pada telur untuk memonitor dan mengetahui profil dari pemijahan ikan tuna dalam bak terkontrol. Telur dikumpulkan setiap pemijahan dari tahun 2004-2006. Profil pemijahan dari induk betina diamati dari jumlah genotipe yang ditemukan pada telur. Hasil dari penelitian ini adalah 49 induk yang dianalisis ditemukan 42 genotipe, 6 genotipe yang teramati ditemukan pada telur dan 4 diantaranya memiliki genotipe tunggal sedangkan satu genotipe (DABEA dimiliki oleh dua induk. Prakiraan panjang cagak dan bobot induk pada saat memijah adalah 82,2-164 cm and 9,183-28,142 kg. Genotipe yang sama ditemukan hampir setiap hari pada saat sampling selama setahun. Hasil ini mengindikasikan bahwa ikan tuna sirip kuning dapat bertelur sepanjang tahun tergantung kepada suhu air dan kondisi pakan. Study of mitochondrial (mt-DNA variations of yellowfin tuna, Thunnus albacares using (RFLP restriction fragment length polymorphisms can provide evidence of spawning profile of the species in captivity. Mt-DNA genotypes of broodstock were compared with their eggs in order to monitor spawning profile. Spawned eggs were collected on every spawning from 2004 to 2006. The spawning profiles of these females were determined from the genotypes of the eggs. The result showed that from 49  broodstock individuals, 42 genotypes were observed, in which 6 genotypes were observed in their eggs and 4 of them established a single female’s identity and one type (DABEA was shared by two females. Fork length and weight of broodstock female when spawning were ranging from 82.2–164 cm and 9.183-28.142 kg. The same genotypes were observed in almost every sampling

  9. Physicochemical evaluation of the effects of irradiation and evisceration on the conservation of refrigerated blackfin tuna (Thunnus atlanticus)

    International Nuclear Information System (INIS)

    Monteiro, Maria L.G.; Marsico, Eliane T.; Vital, Helio C.

    2009-01-01

    Tuna is among the most traded fishes in Brazil, however efficiently delaying its fast deterioration is still a major practical challenge. Irradiation has been proposed as a safe and powerful alternative tool for conservation of seafood. This work investigated the effects of irradiation on the physicochemical quality of refrigerated blackfin tuna (Thunnus atlanticus). Analyses of pH, total volatile bases (TVB-N), ammonia and biogenic amines (histamine, cadaverine and putrescine) were performed in order to determine the degree of conservation. The samples were subjected to four different treatments aiming at evaluating the efficiency of irradiation, evisceration and both combined. The figures measured for those parameters, all of them related to the degree of conservation, were found to increase with time regardless of the treatment. In addition, data for irradiated samples remained consistently lower than for unirradiated ones, indicating a better level of preservation that led to an extended shelf life of 14 days. In contrast, excessive levels of those indicators of degradation were found in unirradiated samples after 7 to 10 days of storage. In addition, some evidence was found that evisceration slightly increased quality, consequently promoting a small extension in shelf life of unirradiated samples. Finally, it can be concluded with basis on the results of the physicochemical parameters studied that treatment of fresh refrigerated blackfin tuna by irradiation with 2.5 kGy efficiently preserved freshness and extended the shelf life of the product from 7 to 14 days. (author)

  10. Physicochemical evaluation of the effects of irradiation and evisceration on the conservation of refrigerated blackfin tuna (Thunnus atlanticus)

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Maria L.G.; Marsico, Eliane T. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Faculdade de Veterinaria. Dept. de Tecnologia de Alimentos], e-mail: marialuciaguerra@yahoo.com.br, e-mail: elianee@vm.uff.br; Vital, Helio C. [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (Brazil). Secao de Defesa Nuclear], e-mail: vital@ctex.eb.br

    2009-07-01

    Tuna is among the most traded fishes in Brazil, however efficiently delaying its fast deterioration is still a major practical challenge. Irradiation has been proposed as a safe and powerful alternative tool for conservation of seafood. This work investigated the effects of irradiation on the physicochemical quality of refrigerated blackfin tuna (Thunnus atlanticus). Analyses of pH, total volatile bases (TVB-N), ammonia and biogenic amines (histamine, cadaverine and putrescine) were performed in order to determine the degree of conservation. The samples were subjected to four different treatments aiming at evaluating the efficiency of irradiation, evisceration and both combined. The figures measured for those parameters, all of them related to the degree of conservation, were found to increase with time regardless of the treatment. In addition, data for irradiated samples remained consistently lower than for unirradiated ones, indicating a better level of preservation that led to an extended shelf life of 14 days. In contrast, excessive levels of those indicators of degradation were found in unirradiated samples after 7 to 10 days of storage. In addition, some evidence was found that evisceration slightly increased quality, consequently promoting a small extension in shelf life of unirradiated samples. Finally, it can be concluded with basis on the results of the physicochemical parameters studied that treatment of fresh refrigerated blackfin tuna by irradiation with 2.5 kGy efficiently preserved freshness and extended the shelf life of the product from 7 to 14 days. (author)

  11. Diagnostic accuracy of the light microscope method to detect the eggs of Cardicola spp. in the gill filaments of the bluefin tuna.

    Science.gov (United States)

    Palacios-Abella, José F; Rodríguez-Llanos, Javier; Víllora-Montero, María; Mele, Salvatore; Raga, Juan A; Montero, Francisco E

    2017-11-30

    Trematode blood flukes of the genus Cardicola are potentially lethal in bluefin tuna cultures. The present study proposed a new method to detect aporocotylid eggs in tuna gills. Aporocotylid eggs were detected by analysing a pair of gill filaments of five transversal areas of the eight holobranches of one hundred Atlantic bluefin tuna and observed with glycerol and a stereomicroscope with an oblique brightfield. Data were gathered according to holobranches, transversal areas and their combination. Eggs were uniformly distributed among the holobranches, but they had the highest prevalence in the second and fifth transversal areas, which is controversial with respect to previous studies of egg distribution. An abbreviated method called the T-two test, which had the highest sensitivity (96.8%), is proposed for the detection of Cardicola spp. infections instead of the analysis all the holobranches. The T-two test limits the time and cost of the egg parasite screening analysis. The analyses of ten samples could be sufficient to detect the presence of parasites in farmed bluefin tuna; fish from the wild are expected to be less infected and more samples (45) would therefore be necessary. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Overlap between Atlantic bluefin tuna spawning grounds and observed Deepwater Horizon surface oil in the northern Gulf of Mexico.

    Science.gov (United States)

    Muhling, B A; Roffer, M A; Lamkin, J T; Ingram, G W; Upton, M A; Gawlikowski, G; Muller-Karger, F; Habtes, S; Richards, W J

    2012-04-01

    The 2010 Deepwater Horizon oil spill impacted the northern Gulf of Mexico (GOM) during the spring spawning season of Atlantic bluefin tuna (BFT). Overlap between BFT spawning habitat and surface oil in the northern GOM was examined using satellite-derived estimates of oil coverage, and spawning habitat models. Results suggested that although eggs and larvae were likely impacted by oil-contaminated waters in the eastern GOM, high abundances of larvae were located elsewhere, especially in the western GOM. Overall, less than 10% of BFT spawning habitat was predicted to have been covered by surface oil, and less than 12% of larval BFT were predicted to have been located within contaminated waters in the northern GOM, on a weekly basis. Our results provide preliminary but important initial estimates of the effects of the spill on larval BFT mortality, as concern continues over the appropriate management responses to impacts of the spill. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Blood Volume, Plasma Volume and Circulation Time in a High-Energy-Demand Teleost, the Yellowfin Tuna (Thunnus Albacares)

    DEFF Research Database (Denmark)

    Brill, R.W.; Cousins, K.L.; Jones, D.R.

    1998-01-01

    We measured red cell space with 51Cr-labeled red blood cells, and dextran space with 500 kDa fluorescein-isothiocyanate-labeled dextran (FITC-dextran), in two groups of yellowfin tuna (Thunnus albacares). Red cell space was 13.8+/-0.7 ml kg-1 (mean +/- s.e.m.) Assuming a whole- body hematocrit...... equal to the hematocrit measured at the ventral aortic sampling site and no significant sequestering of 51Cr-labeled red blood cells by the spleen, blood volume was 46.7+/-2.2 ml kg-1. This is within the range reported for most other teleosts (30-70 ml kg-1), but well below that previously reported...

  14. SEBARAN DAN HUBUNGAN PARAMETER REPRODUKSI IKAN TUNA MADIDIHANG (Thunnus albacares DENGAN SUHU DAN KLOROFIL-a DI LAUT BANDA

    Directory of Open Access Journals (Sweden)

    Karsono Wagiyo

    2015-12-01

    Full Text Available Laut Banda diketahui mempunyai kondisi lingkungan yangmendukung sebagai daerah pemijahan ikan tuna madidihang (Thunnus albacares. Sebaran parameter reproduksi dan hubungannya dengan lingkungan perlu diketahui sebagai dasar pengelolaan sumberdaya yang lestari. Penelitian dilakukan tahun 2011-2012 dengan basis pendataan di Bandaneira. Pengamatan parameter reproduksi dilakukan terhadap ikan sampel melalui observasi dan enumerasi. Suhu dan klorofil-a diperoleh = dari analisis citra satelit. Penelitian mendapatkan persentase gonad matang (100 % dan indeks kematangan gonad tertinggi (3,75 serta nisbah kelamin seimbang, secara temporal ditemukan pada bulan antara September-Desember, secara spasial ditemukan di Perairan Gunung Api dan Selatan Kepulauan Lease. Tingkat kematangan gonad dan indeks kematangan gonad meningkat terjadi pada saat suhu mulai menghangat dan klorofil-a mulai menurun. Tingkat kematangan gonad dan indeks kematangan gonad menurun terjadi pada saat awal penurunan suhu dan awal kenaikan klorofil-a. Besides known as the Banda Sea region yellowfin tuna migration (Thunnus albacares is also a spawning area. Distribution of Reproduction parameter and their relationship with environmental parameter should be known as the basis for sustainable resource management. The reproduction parameter obtaianed by observation and enumeration. Temperature and chlorophyll-a obtained by satellite image analysis. Research gets a high percentage of the gonads mature (100% and gonad maturity index (3,75 and a balanced sex ratio, temporally be found in the September-December, spatially found in the waters of Pulau Gunung Api and Lease Islands. The maturity level of gonads and gonadal maturation index increases occurred when the temperatures begin to warm and chlorophyll-a start to decline. The maturity level of gonads and gonadal maturation index decreases occurred at the beginning of the early drop in temperature and increase in chlorophyll-a.

  15. Heavy metals in yellowfin tuna (Thunnus albacares) and common dolphinfish (Coryphaena hippurus) landed on the Ecuadorian coast

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, Cristiano V.M., E-mail: cristiano.araujo@icman.csic.es [Central Department of Research (DCI), Ecuadorian Aquatic Ecotoxicology (ECUACTOX) group, Universidad Laica Eloy Alfaro de Manabí - ULEAM, Manta (Ecuador); Centre of Functional Ecology (CFE), Department of Life Sciences, University of Coimbra, Coimbra (Portugal); Cedeño-Macias, Luis A. [Central Department of Research (DCI), Ecuadorian Aquatic Ecotoxicology (ECUACTOX) group, Universidad Laica Eloy Alfaro de Manabí - ULEAM, Manta (Ecuador); Faculty of Marine Sciences, Universidad Laica Eloy Alfaro de Manabí (ULEAM), Manta (Ecuador)

    2016-01-15

    Heavy metals are contaminants of great environmental concern due to their multiple origins (natural and anthropogenic), the ability to accumulate in organs and tissues, and the deleterious effects they can cause in organisms. Studies on the accumulation of metals in seafood, such as fish, have increased in importance due to the risk for human health when consuming fish contaminated by metals. The present work was aimed at verifying the concentrations of cadmium (Cd), mercury (Hg) and lead (Pb) in the muscular tissue and liver of yellowfin tuna (Thunnus albacares) and common dolphinfish (Coryphaena hippurus) from the Eastern Pacific Ocean landed in Manta city, Ecuador. Samples were analyzed by inductively coupled plasma mass spectroscopy (ICP-MS). Around half of the muscle samples of both species presented levels of Cd and Hg above the limits considered safe for human consumption established by the European Union. For Pb, most of the muscle samples were considered acceptable for consumption. Results indicate that both species should be consumed with some caution. Considering the tolerable weekly intake recommended for adults by the World Health Organization, results indicate that Hg is the main metal that limits the consumption of yellowfin tuna and common dolphinfish, with a recommended maximum ingestion, respectively, of 191 and 178 g per week for an adult. - Highlights: • Thunnus albacares and Coryphaena hippurus from Eastern Pacific (Ecuador) were sampled. • Muscle and liver of both species were assessed for Cd, Hg and Pb concentrations. • Levels of Pb were considered acceptable for both species. • High levels of Cd and Hg in both species can be considered unsafe for human health. • For both species the recommended maximum ingestion is around 180 g week{sup −1} for an adult.

  16. Growth and mortality rates of yellowfin tuna, Thunnus albacares (Perciformes: Scombridae, in the eastern and central Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Guoping Zhu

    2011-04-01

    Full Text Available Age and growth parameters were estimated for the yellowfin tuna Thunnus albacares (Bonnaterre, 1788. Atotal of 443 individuals were sampled from China longline fisheries in the eastern and central Pacific Ocean from February to November 2006. The von Bertalanffy growth parameters were estimated at L∞ = 175.9 cm fork length, k = 0.52 year-1, and t0 = 0.19 year. The total mortality rate (Z was estimated to be from 1.19 to 1.93 year-1, the fishing mortality (F and the natural mortality (M were calculated to be 0.91 year-1 and 0.65 year-1, respectively. The rate of exploitation (U was estimated to be 0.46. This study provides estimates of growth and mortality rate for yellowfin tuna in the eastern and central Pacific Ocean, which may be used as biological input parameters in future stock assessments for the oceanic region. However, age analysis with other techniques, additional validation of the size composition and stock structure are also needed.

  17. Mercury accumulation in Yellowfin tuna (Thunnus albacares) with regards to muscle type, muscle position and fish size.

    Science.gov (United States)

    Bosch, Adina C; O'Neill, Bernadette; Sigge, Gunnar O; Kerwath, Sven E; Hoffman, Louwrens C

    2016-01-01

    The concentrations and relationships between individual mercury species and total mercury were investigated in different muscle parts and sizes of Yellowfin tuna (Thunnus albacares). Fourteen Yellowfin tuna caught in the South Atlantic off the coast of South Africa had an average total Hg (tHg) concentration of 0.77 mg/kg wet weight. No differences were detected (p > 0.05) in tHg, MethylHg (MeHg) or inorganic Hg (iHg) accumulation among the four white muscle portions across the carcass, but both tHg and iHg were found in higher concentrations (p < 0.001) in dark muscle than white muscle. Positive linear correlations with fish weight were found for both tHg (r = 0.79, p < 0.001) and MeHg (r = 0.75, p < 0.001) concentrations. A prediction model was formulated to calculate toxic MeHg concentrations from measured tHg concentrations and fish weight (cMeHg = 0.073 + 1.365 · tHg-0.008 · w). As sampling sites and subsampling methods could affect toxicity measurements, we provide recommendations for sampling guidelines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. POPULATION STRUCTURE AND BIOREPRODUCTION OF BIGEYE TUNA (Thunnus obesus IN WESTERN PART OF SUMATERA AND SOUTHERN PART OF JAVA AND NUSA TENGGARA, INDIAN OCEAN

    Directory of Open Access Journals (Sweden)

    Ali Suman

    2015-12-01

    Full Text Available Bigeye tuna is an important fish resource in the Indian Ocean. This species like other tuna species needs to be managed properly in both national and international levels. Therefore some data and information on population structure and bioreproduction are required for management purpose. The current research was conducted to identify the population structure and bioreproduction of bigeye tuna (Thunnus obesus in west off Sumatera and south off Java and Nusa Tenggara of Indian Ocean where tuna fishing spots are important. This research was based on catch landed by fishermen from the Indian Ocean during 2010. Analysis of population structure was done using DNA genetic analyses and bioreproduction by using histology technique. Results show that the population structure of the bigeye tuna in the Indian Ocean consisted of two different sub populations namely sub population of west off Sumatra and sub population of south of Java and Nusa Tenggara waters. Most of catch (about 39% was categorized as immature fish (GI I. The immature fish was mostly found in west off Sumatera waters, meanwhile the catch in south off Java and Nusa Tenggara waters was mostly categorized as mature fish. This result may indicate that south off Java and Nusa Tenggara waters is a spawning ground of the bigeye tuna.

  19. Quality assessment of ice-stored tropical yellowfin tuna (Thunnus albacares) and influence of vacuum and modified atmosphere packaging.

    Science.gov (United States)

    Silbande, Adèle; Adenet, Sandra; Smith-Ravin, Juliette; Joffraud, Jean-Jacques; Rochefort, Katia; Leroi, Françoise

    2016-12-01

    Metagenomic, microbial, chemical and sensory analyses of Thunnus albacares from Martinique stored in ice (AIR - 0 °C), vacuum (VP - 4/8 °C) and modified atmosphere packaging (MAP - 4/8 °C) (70% CO2 - 30% O2) were carried out. The organoleptic rejection of AIR tuna was observed at day 13 when total bacterial counts equaled 10(6)-10(7) CFU g(-1). No extension of shelf-life was provided by VP and MAP. According to 16S rRNA gene sequence analyzed by Illumina MiSeq and PCR-TTGE, Rhodanobacter terrae was the main species of the freshly caught tuna. At the sensory rejection time, Brochothrix thermosphacta and Pseudomonas dominated the AIR products while B. thermosphacta alone or a mix of B. thermosphacta, Enterobacteriaceae and lactic acid bacteria (LAB) dominated the microbiota of MAP and VP products, respectively. The pH value remained stable in all trials, ranging from 5.77 to 5.97. Total volatile basic nitrogen (TVBN) and trimethylamine (TMA-N) concentrations were weak and not significantly different between batches. Lipid oxidation increased in the samples containing O2 (MAP > AIR). The initial concentration of histamine was high (75-78 mg kg(-1)) and stable up to 8 days but then significantly decreased in all trials to reach 25-30 mg kg(-1), probably due to the presence of histamine-decomposing bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Gamma Irradiation Effects On Thiamin And Riboflavin On Fresh Tuna (Thunnus thynnus) And Salmon (Onchorhynchus gorbuscha)

    International Nuclear Information System (INIS)

    Tanhindarto, Rindy P.; Fox, J.B.; Lakritz, L.; Thayer, D.W.

    2002-01-01

    An experiment have been conducted on the effect of gamma irradiation on thiamine and riboflavin in fresh tuna and salmon. Samples were irradiated at (20 ± 0,5) oC by gamma rays with doses of 0; 2,5 and 5 kGy. The purpose of the present experiment was to study on changes of thiamine and riboflavin contents on extraction of fresh tuna and salmon after and before irradiation. The results showed that irradiation up to 2,5 kGy changed the thiamine and riboflavin contents on fresh tuna as well as their destruction which was significantly increasing caused by irradiated treatment with the dose of 5 kGy. The fresh salmon did not significantly change of the thiamine and riboflavin contents treated by irradiation up to 5 kGy

  1. Feasibility of Solid Waste Tuna Loin of Yellowfin Thunnus albacares Raw Materials for The Product Diversification

    Directory of Open Access Journals (Sweden)

    Wayan Kantun Kantun

    2015-10-01

    Full Text Available Indonesia is one country in the world exporters of tuna in the form of fresh, frozen andprocessed. Tuna exported in processed form large enough to leave waste for exporting companies.The purpose of this study was to determine a feasibility study on solid waste exported tuna loin forraw material diversification. This research was conducted in Majene Makassar Strait. The study wasconducted using descriptive exploratory method by taking a sample of 3 times and each samplewas tested 3 times resulting in 9 times of testing for each of the observed variables. Chemical testwhich includes moisture, protein, fat, ash, carbohydrates, and histamine. Microbiological test thatis E. coli, Salmonella and the total number of bacteria. Data were analyzed by descriptive qualitativeand quantitative display via Tables, Graphics and Image in the form of average value. The resultsshowed that the chemical solid waste tuna loin has a water content ranged from 78.34 to 78.78%,protein content ranged from 14.32 to 16.41%, fat ranged from 1.56 to 1.66%, ash content rangedfrom 5.18 to 5. 58%, carbohydrate content ranged from 1.29 to 1.34%, and histamine ranged from2.08 to 3.21 mg / kg. Solid waste microbiologically tuna loin contains E.coli range from 1.2 to 1.9(<2, Salmonella negative and TPC ranged from 1.4 to 1.8 x 105 kol/g. The results of chemical andmicrobiological testing showed solid waste tuna loin still suitable as raw material diversificationproducts.

  2. Mercury levels of yellowfin tuna (Thunnus albacares) are associated with capture location.

    Science.gov (United States)

    Nicklisch, Sascha C T; Bonito, Lindsay T; Sandin, Stuart; Hamdoun, Amro

    2017-10-01

    Mercury is a toxic compound to which humans are exposed by consumption of fish. Current fish consumption advisories focus on minimizing the risk posed by the species that are most likely to have high levels of mercury. Less accounted for is the variation within species, and the potential role of the geographic origin of a fish in determining its mercury level. Here we surveyed the mercury levels in 117 yellowfin tuna caught from 12 different locations worldwide. Our results indicated significant variation in yellowfin tuna methylmercury load, with levels that ranged from 0.03 to 0.82 μg/g wet weight across individual fish. Mean mercury levels were only weakly associated with fish size (R 2  mercury load, and argue for better traceability of fish to improve the accuracy of exposure risk predictions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Revisiting the vulnerability of juvenile bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna caught by purse-seine fisheries while associating with surface waters and floating objects.

    Science.gov (United States)

    Scutt Phillips, Joe; Pilling, Graham M; Leroy, Bruno; Evans, Karen; Usu, Thomas; Lam, Chi Hin; Schaefer, Kurt M; Nicol, Simon

    2017-01-01

    Tuna fisheries catch over three million tonnes of skipjack tuna (Katsuwonus pelamis) each year, the majority of which come from purse-seine vessels targeting fish associated with man-made fish aggregating devices (FADs). A significant challenge for fisheries management is to maximize the efficiency of skipjack tuna catches whilst minimizing the bycatch of small and immature bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna, for which long-term sustainability is uncertain in 75% of the world's stocks. To better manage the issues common with this fishing method, an improved understanding of tuna behaviour around FADs is necessary. We probabilistically classified the vertical behavioural patterns of 50 bigeye and 35 yellowfin tuna (mean fork length 72cm and 70cm, respectively) electronically tagged throughout the western and central Pacific Ocean into shallow and deep states, using a state-space modelling approach. The occurrence of surface-association behaviours, defined as an individual remaining in a shallow state for 24-hours, was examined in relation to known capture events and FAD density. In general, surface-association events for both species were short and lasted on average less than three days, although events as long as 28 days were observed, and were more common in yellowfin when in archipelagic waters. Events were longest immediately following tagging in 62% and 17% of bigeye and yellowfin, respectively. Surface-association behaviour was not generally estimated just prior to recapture, being either non-existent or shorter than two days for 85% of bigeye and 74% of yellowfin. Current management measures in purse-seine tuna fisheries involve periodic or spatial closures for FAD use. If the chief benefit to purse-seine fishers of surface-association around floating objects is in locating schools in horizontal space at short-term time-scales, rather than holding fish near the surface for extended periods, controlling the number of sets made on FADs

  4. Revisiting the vulnerability of juvenile bigeye (Thunnus obesus and yellowfin (T. albacares tuna caught by purse-seine fisheries while associating with surface waters and floating objects.

    Directory of Open Access Journals (Sweden)

    Joe Scutt Phillips

    Full Text Available Tuna fisheries catch over three million tonnes of skipjack tuna (Katsuwonus pelamis each year, the majority of which come from purse-seine vessels targeting fish associated with man-made fish aggregating devices (FADs. A significant challenge for fisheries management is to maximize the efficiency of skipjack tuna catches whilst minimizing the bycatch of small and immature bigeye (Thunnus obesus and yellowfin (T. albacares tuna, for which long-term sustainability is uncertain in 75% of the world's stocks. To better manage the issues common with this fishing method, an improved understanding of tuna behaviour around FADs is necessary. We probabilistically classified the vertical behavioural patterns of 50 bigeye and 35 yellowfin tuna (mean fork length 72cm and 70cm, respectively electronically tagged throughout the western and central Pacific Ocean into shallow and deep states, using a state-space modelling approach. The occurrence of surface-association behaviours, defined as an individual remaining in a shallow state for 24-hours, was examined in relation to known capture events and FAD density. In general, surface-association events for both species were short and lasted on average less than three days, although events as long as 28 days were observed, and were more common in yellowfin when in archipelagic waters. Events were longest immediately following tagging in 62% and 17% of bigeye and yellowfin, respectively. Surface-association behaviour was not generally estimated just prior to recapture, being either non-existent or shorter than two days for 85% of bigeye and 74% of yellowfin. Current management measures in purse-seine tuna fisheries involve periodic or spatial closures for FAD use. If the chief benefit to purse-seine fishers of surface-association around floating objects is in locating schools in horizontal space at short-term time-scales, rather than holding fish near the surface for extended periods, controlling the number of sets

  5. Data reconstruction can improve abundance index estimation: An example using Taiwanese longline data for Pacific bluefin tuna.

    Directory of Open Access Journals (Sweden)

    Shui-Kai Chang

    Full Text Available Catch-per-unit-effort (CPUE is often the main piece of information used in fisheries stock assessment; however, the catch and effort data that are traditionally compiled from commercial logbooks can be incomplete or unreliable due to many reasons. Pacific bluefin tuna (PBF is a seasonal target species in the Taiwanese longline fishery. Since 2010, detailed catch information for each PBF has been made available through a catch documentation scheme. However, previously, only market landing data with a low coverage of logbooks were available. Therefore, several nontraditional procedures were performed to reconstruct catch and effort data from many alternative data sources not directly obtained from fishers for 2001-2015: (1 Estimating the catch number from the landing weight for 2001-2003, for which the catch number information was incomplete, based on Monte Carlo simulation; (2 deriving fishing days for 2007-2009 from voyage data recorder data, based on a newly developed algorithm; and (3 deriving fishing days for 2001-2006 from vessel trip information, based on linear relationships between fishing and at-sea days. Subsequently, generalized linear mixed models were developed with the delta-lognormal assumption for standardizing the CPUE calculated from the reconstructed data, and three-stage model evaluation was performed using (1 Akaike and Bayesian information criteria to determine the most favorable variable composition of standardization models, (2 overall R2 via cross-validation to compare fitting performance between area-separated and area-combined standardizations, and (3 system-based testing to explore the consistency of the standardized CPUEs with auxiliary data in the PBF stock assessment model. The last stage of evaluation revealed high consistency among the data, thus demonstrating improvements in data reconstruction for estimating the abundance index, and consequently the stock assessment.

  6. Data reconstruction can improve abundance index estimation: An example using Taiwanese longline data for Pacific bluefin tuna.

    Science.gov (United States)

    Chang, Shui-Kai; Liu, Hung-I; Fukuda, Hiromu; Maunder, Mark N

    2017-01-01

    Catch-per-unit-effort (CPUE) is often the main piece of information used in fisheries stock assessment; however, the catch and effort data that are traditionally compiled from commercial logbooks can be incomplete or unreliable due to many reasons. Pacific bluefin tuna (PBF) is a seasonal target species in the Taiwanese longline fishery. Since 2010, detailed catch information for each PBF has been made available through a catch documentation scheme. However, previously, only market landing data with a low coverage of logbooks were available. Therefore, several nontraditional procedures were performed to reconstruct catch and effort data from many alternative data sources not directly obtained from fishers for 2001-2015: (1) Estimating the catch number from the landing weight for 2001-2003, for which the catch number information was incomplete, based on Monte Carlo simulation; (2) deriving fishing days for 2007-2009 from voyage data recorder data, based on a newly developed algorithm; and (3) deriving fishing days for 2001-2006 from vessel trip information, based on linear relationships between fishing and at-sea days. Subsequently, generalized linear mixed models were developed with the delta-lognormal assumption for standardizing the CPUE calculated from the reconstructed data, and three-stage model evaluation was performed using (1) Akaike and Bayesian information criteria to determine the most favorable variable composition of standardization models, (2) overall R2 via cross-validation to compare fitting performance between area-separated and area-combined standardizations, and (3) system-based testing to explore the consistency of the standardized CPUEs with auxiliary data in the PBF stock assessment model. The last stage of evaluation revealed high consistency among the data, thus demonstrating improvements in data reconstruction for estimating the abundance index, and consequently the stock assessment.

  7. Spatial dynamics and mixing of bluefin tuna in the Atlantic Ocean and Mediterranean Sea revealed using next-generation sequencing.

    Science.gov (United States)

    Puncher, Gregory N; Cariani, Alessia; Maes, Gregory E; Van Houdt, Jeroen; Herten, Koen; Cannas, Rita; Rodriguez-Ezpeleta, Naiara; Albaina, Aitor; Estonba, Andone; Lutcavage, Molly; Hanke, Alex; Rooker, Jay; Franks, James S; Quattro, Joseph M; Basilone, Gualtiero; Fraile, Igaratza; Laconcha, Urtzi; Goñi, Nicolas; Kimoto, Ai; Macías, David; Alemany, Francisco; Deguara, Simeon; Zgozi, Salem W; Garibaldi, Fulvio; Oray, Isik K; Karakulak, Firdes Saadet; Abid, Noureddine; Santos, Miguel N; Addis, Piero; Arrizabalaga, Haritz; Tinti, Fausto

    2018-02-06

    The Atlantic bluefin tuna is a highly migratory species emblematic of the challenges associated with shared fisheries management. In an effort to resolve the species' stock dynamics, a genomewide search for spatially informative single nucleotide polymorphisms (SNPs) was undertaken, by way of sequencing reduced representation libraries. An allele frequency approach to SNP discovery was used, combining the data of 555 larvae and young-of-the-year (LYOY) into pools representing major geographical areas and mapping against a newly assembled genomic reference. From a set of 184,895 candidate loci, 384 were selected for validation using 167 LYOY. A highly discriminatory genotyping panel of 95 SNPs was ultimately developed by selecting loci with the most pronounced differences between western Atlantic and Mediterranean Sea LYOY. The panel was evaluated by genotyping a different set of LYOY (n = 326), and from these, 77.8% and 82.1% were correctly assigned to western Atlantic and Mediterranean Sea origins, respectively. The panel revealed temporally persistent differentiation among LYOY from the western Atlantic and Mediterranean Sea (F ST  = 0.008, p = .034). The composition of six mixed feeding aggregations in the Atlantic Ocean and Mediterranean Sea was characterized using genotypes from medium (n = 184) and large (n = 48) adults, applying population assignment and mixture analyses. The results provide evidence of persistent population structuring across broad geographic areas and extensive mixing in the Atlantic Ocean, particularly in the mid-Atlantic Bight and Gulf of St. Lawrence. The genomic reference and genotyping tools presented here constitute novel resources useful for future research and conservation efforts. © 2018 John Wiley & Sons Ltd.

  8. Biomagnification of mercury and its antagonistic interaction with selenium in yellowfin tuna Thunnus albacares in the trophic web of Baja California Sur, Mexico.

    Science.gov (United States)

    Ordiano-Flores, Alfredo; Rosíles-Martínez, Rene; Galván-Magaña, Felipe

    2012-12-01

    Mercury and selenium concentrations were determined in muscle of 37 yellowfin tuna (Thunnus albacares) captured aboard of Mexican purse-seiners boats off western coast of Baja California Sur, between Punta Eugenia and Cabo Falso, from October to December 2006. Also, its prey (mainly, jumbo squid Dosidicus gigas and pelagic red crab Pleuroncodes planipes) were analyzed from the stomach contents. All the mercury values obtained were lower that mercury content recommended by standard legal limits for seafood adopted by Mexican norms (typically 0.5-1.0μg g(-1)). Mercury concentrations vary between 0.06 and 0.51μg g(-1) in yellowfin tuna, and from 0.01 to 0.20μg g(-1) in its prey, suggesting that mercury can accumulate in prey tissues and that of their predator. Biomagnification factors (BMF) between predator-prey associations were calculated. The BMFs were >1, indicating that mercury biomagnifies along the food web of yellowfin tuna. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium/mercury molar ratios was for pufferfish (42.62)> diamond squid (15.09)>yellowfin tuna (10.29)>pelagic red crab (10.05)>panama lightfish (9.54)> jumbo squid (8.91). The selenium health benefit value (Se-HBV) was calculated to have an improved understanding of the health benefits and risk of fish consumption. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Modelling the Effects of Radioactive Effluent on Thunnus orientalis and Oncorhynchus gorbuscha

    Directory of Open Access Journals (Sweden)

    Zhixiong Chen

    2013-01-01

    Full Text Available The contamination of the Pacific Ocean by the radioactive pollutants released from the Fukushima Daiichi Nuclear Power Plant has raised legitimate concerns over the viability of marine wildlife. We develop a modified Crank-Nicholson method to approximate a solution to the diffusion-advection-decay equation in time and three spatial dimensions to explore the extent of the effects of the radioactive effluent on two marine species: the Pacific Bluefin Tuna (Thunnus orientalis and the Pacific Pink Salmon (Oncorhynchus gorbuscha.

  10. Enzymatic Hydrolysis of Yellowfin Tuna (Thunnus albacares By-Products Using Protamex Protease

    Directory of Open Access Journals (Sweden)

    Huong Thi My Nguyen

    2011-01-01

    Full Text Available Long-term proteolysis of tuna by-products (head, viscera and tail by the wide spectrum protease Protamex has been investigated and compared. After hydrolysis, two fractions (soluble aqueous phase and insoluble sludge were collected. Chemical compositions of each fraction and molecular mass distributions of soluble peptides were determined. Degrees of hydrolysis obtained after 12 h of hydrolysis of head, viscera and tail were 32.3, 16.8 and 22.2 %, respectively. Nitrogen recovery in the soluble fractions was 73.6 % for the head, 82.7 % for the viscera and 85.8 % for the tail. Lipid distribution indicated that the majority of lipids remained in the sludge. Such proteolysis appears useful for the production of very different fractions: one rich in peptides of medium to small molecular mass and poor in lipids, and another one containing the insoluble proteins and the majority of lipids.

  11. Histamine formation and the freshness of yellowfin tuna (Thunnus albacares stored at different temperatures

    Directory of Open Access Journals (Sweden)

    B.K.K.K. Jinadasa

    2015-12-01

    Full Text Available This study was conducted to investigate the effect of storage temperatures on the shelf life of yellowfin tuna (YFT loins by studying of microbial, chemical and organoleptic changes. Shelf life of YFT was determined through changes in total aerobic bacterial plate counts (APC, total volatile basic nitrogen (TVB-N trimethylamine (TMA, organoleptic properties and histamine development during storage at 0, 4 and 7°C. Based on TVB-N value indices, YFT maintained an acceptable shelf life for 21, 17 and 12 days at 0, 4 and 7°C, respectively. Nevertheless, YFT was rejected earlier by the sensory panellists than their TVB-N value indicated. Histamine development was found to be lower than the European Union safety level for 100 mg/kg fish during storage at 0 and 7°C for 21 and 17 days, respectively. Aerobic bacteria initially dominated the micro-flora on YFT; however, as storage time increased, aerobic bacteria became dominant at cold storage, but the numbers exceeded the International Commission on Microbiological Specifications for Foods (ICMSF limit of 107 cfu/g in storage at 7°C after 17 days. Therefore, it can be concluded that the storage of fresh YFT in below 4°C has good enough to the shelf life of products (two weeks.

  12. VARIASI GENETIK IKAN TUNA SIRIP KUNING, Thunnus albacares DENGAN ANALISIS ELEKTROFORESIS ALLOZYME DAN Mt-DNA

    Directory of Open Access Journals (Sweden)

    Gusti Ngurah Permana

    2007-04-01

    Full Text Available Sampel ikan tuna sirip kuning, T. albacares diambil dari tiga lokasi (perairan Bali, Sulawesi Utara, dan Maluku Utara dan dilakukan analisis variasi genetik dengan metode elektroforesis allozyme menggunakan 15 enzim dan mt-DNA dengan 4 enzim restriksi. Hasil penelitian ini diperoleh 4 lokus enzim polimorfik yaitu: Idh-*2 (isocitrate dehydrogenase, Gpi-2* (glucose phoshate dehydrogenase , Mdh-1* (malat e dehydrogenase, dan Est-1* (esterase. Frekuensi alel allozyme terlihat adanya perbedaan yang nyata (Fst = 0,12; P<0,05 antar lokasi yaitu Bali (A, B, C, D, Sulawesi Utara dan Maluku Utara (A, B, C. 15 komposit haplotipe ditemukan pada populasi Bali, Sulawesi Utara, dan Maluku Utara. Haplotype diversity pada populasi Bali 0,886; Sulawesi Utara 0,790; dan Maluku Utara 0,785; dengan rata-rata dari haplotype diversity adalah 0,857. Jarak genetik dari ketiga populasi berkisar antara 0,003--0,023 (rata-rata 0,016. Populasi Maluku Utara dan Sulawesi Utara mempunyai jarak genetik terdekat yaitu 0,003. Hal ini merupakan indikator bahwa Sulawesi Utara dan Maluku Utara sering digunakan sebagai jalur migrasi dengan adanya kesamaan alel yang ditemukan pada kedua populasi tesebut, jika dibandingkan dengan populasi Bali (0,023.

  13. Forage fauna in the diet of bigeye tuna (Thunnus obesus in the western tropical Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Teodoro Vaske Júnior

    2012-03-01

    Full Text Available A total of 291 stomachs of bigeye tuna caught in the Western tropical Atlantic Ocean ranging between 60 and 195 cm fork length, were analyzed between October 2004 and November 2005. The vertical distribution of prey was studied in relation to their feeding strategies. A total of 83 prey items were identified of which 46 were fishes, represented mainly by brephoepipelagic, and meso-bathypelagic fishes; 20 cephalopods, 13 pelagic crustaceans, one tunicate, one heteropod and one pteropod. The Caribbean pomfret Brama caribbea was the most important food item, followed by other mesopelagic fishes such as Alepisaurus ferox, Omosudis lowei, Gempylus serpens, Brama brama and Diretmus argenteus. The squid Ornithoteuthis antillarum was the main preyed-on cephalopod, and the crustaceans Caridea and Brachyuran megalopae were also important food items. The feeding may occur continuously, all the time, or at least during the greater part of the day or night, as part of the feeding strategy to prey upon a vertically scattered small prey distributed in the water column. The relative equality in the proportions of surface, mid-water and deep-water prey organisms reflects the behavior of constant vertical displacement in the search for prey. Although the bigeye tuna prefers subthermocline layers, most of its prey items perform diel migrations and can be preyed on both near the surface and in deeper waters.Um total de 291 estômagos de albacoras-bandolins capturadas no oceano Atlântico tropical oeste variando entre 60 e 195 cm de comprimento furcal, foram analisados entre outubro de 2004 e dezembro de 2005. A distribuição vertical das presas foi estudada em relação às estratégias alimentares. Um total de 83 itens alimentares foi identificado dos quais 46 foram peixes representados principalmente por peixes brefoepipelágicos e mesopelágicos, 20 cefalópodes, 13 crustáceos pelágicos, um tunicado, um heterópode e um pterópode. A palombeta

  14. Mitochondrial respiration in the ventricular myocardium and in the white and deep red myotomal muscles of juvenile tuna fish (thunnus thynnus L.).

    Science.gov (United States)

    Modigh, M; Tota, B

    1975-03-01

    The respiratory activity of mitochondria isolated from the outer and inner layers of the ventricular myocardium and from the white and deep red myotomal muscles of juvenile Thunnus thynnus has been compared. The highest values for the succinate oxidase and succinate cytochrome c reductase activities have been found in the mitochondria of the outer myocardial layer, followed by mitochondria of the deep red muscle, the inner myocardial layer and the white muscle in that order. Differences in mitochondrial NADH-cytochrome c reductase activity run parallel, in a lower order of magnitude, to the differences in the oxidation of succinate. This finding is discussed in relation to the different metabolic attitudes of the muscle tissues towards anaerobic glycolysis. The outer myocardial layer of the juvenile tuna ventricle has been shown to have a higher metabolic activity than the inner layer, in contrast to the situation in adult ventricular myocardium.

  15. 50 CFR Appendix A to Part 635 - Species Tables

    Science.gov (United States)

    2010-10-01

    ... Albacore tuna, Thunnus alalunga Bigeye tuna, Thunnus obesus Blue shark, Prionace glauca Bluefin tuna, Thunnus thynnus Dolphin fish, Coryphaena hippurus Oceanic whitetip shark, Carcharhinus longimanus..., Thunnus albacares Table 3 of Appendix A to Part 635-Demersal Species Atlantic sharpnose shark...

  16. 210Po Activity and concentrations of selected trace elements (As, Cd, Cu, Hg, Pb, Zn) in the muscle tissue of tunas Thunnus albacares and Katsuwonus pelamis from the Eastern Pacific Ocean.

    Science.gov (United States)

    Ruelas-Inzunza, Jorge; Soto-Jiménez, Martín Federico; Ruiz-Fernández, Ana Carolina; Bojórquez-Leyva, Humberto; Pérez-Bernal, Hascibe; Páez-Osuna, Federico

    2012-12-01

    Daily mineral intake (DMI) of Cu and Zn, percentage weekly intake (PWI) of As, Cd, Hg, Pb, and doses of (210)Po were estimated by using their elemental concentration in muscle of two tuna species and the average tuna consumption in Mexico. Skipjack tuna Katsuwonus pelamis had significantly (p tuna Thunnus albacares, whereas Pb concentrations (0.18 μg g(-1) dw) were significantly (p Cu > As > Hg > Pb > Cd. In T. albacares, concentrations of Cd and Pb in muscle tissue were positively correlated (p < 0.05) with weight of specimens, while Cu was negatively correlated. DMI values were below 10 %. PWI figures (<2 %) are not potentially harmful to human health. (210)Po concentration in T. albacares and K. pelamis accounts for 13.5 to 89.7 % of the median individual annual dose (7.1 μSv) from consumption of marine fish and shellfish for the world population.

  17. DRY SALTED AND SMOKED TUNA PRODUCTS. CHEMICAL, RHEOLOGICAL AND NUTRITIONAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    R. Mercogliano

    2013-02-01

    Full Text Available Since the presence of bluefin tuna (Thunnus thynnus is limited to some fishing areas and the species undergoes a high fishing pressure the commercial answers to this situation might be the diversification of the commercial offer. The commercial value of this species, especially in oriental market, has prompted researches aiming at fully exploiting the potential of this species through the production of innovative tuna based products. Sliceable dry salted and smoked tuna products were manufactured using whole muscles from fresh and frozen subjects. The shelf life was long enough to justify the industrial production (up to 3 months or more. No significant correlations were observed between sensory characteristics and physico-chemical parameters.

  18. Endogenous level of acetic acid in yellowfin tuna (Thunnus albacares): a pilot study about a possible controversy on its residue nature.

    Science.gov (United States)

    Chiesa, Luca Maria; Pasquale, Elisa; Panseri, Sara; Britti, Domenico; Malandra, Renato; Villa, Roberto; Arioli, Francesco

    2017-03-01

    A method based on headspace solid-phase microextraction (HS-SPME) followed by GC-MS analysis was developed for the determination of underivatised acetic acid in fresh tuna fish muscle. Parameters such as the fibre selected and the extraction time and temperature were optimised and the linearity, detection limits and precision of the whole analytical procedure were assessed. The method was then applied to determine the acetic acid concentration in fresh yellowfin tuna muscles (Thunnus albacares) in order to evaluate the endogenous level and its variations during the shelf life under different storage conditions. A qualitative comparison was also made with variations in histamine levels to evaluate the possibility of the joint monitoring of acetic acid and histamine to identify fish stored in poor conditions. The caudal area always had a lower content of acetic acid than the ventral area, independent of the storage time and temperature. A difference was found between the 6- and 3-day time points and day 0 at a storage temperature of 8°C and between the 6-day time point and day 0 at a storage temperature of 0°C, independent of the anatomical area of the sampled tissue. The evaluation of acetic acid could represent an important approach in the field of food safety to detect the illicit use of acetic acid as an antibacterial preservative treatment or to eliminate the unpleasant smell of trimethylamine.

  19. Spatial distribution of tuna larvae in the Gulf of Gabes (Eastern Mediterranean in relation with environmental parameters

    Directory of Open Access Journals (Sweden)

    W. KOCHED

    2013-03-01

    Full Text Available Spatial distribution and ecology of the larvae of three tuna species (Thunnus thynnus, Auxis rochei and Euthynnus alletteratus were studied during an ichthyoplankton survey carried out in the Gulf of Gabes (Tunisia in June and July 2009. A total of 80 stations, distributed on a regular sampling grid, were sampled. The main objectives of this survey were to provide information on tuna larvae distribution in the Gulf of Gabes in relation to the environmental parameters. Regarding small tunas, larvae of A. rochei (bullet tuna showed the more widespread distribution, being found at both inshore and offshore stations. E. alletteratus (Atlantic black skipjack larvae were mainly found at the inshore stations covering the wide continental shelf of this region. On the other hand, larvae of the large migratory tuna T. Thynnus (Atlantic bluefin tuna, were mainly recorded at offshore stations, suggesting that spawning possibly takes place mainly near the shelf break. Regarding the biological and physical parameters examined, our results indicate that tuna larvae were mainly collected in oligotrophic and mixed waters resulting from the confluence of surface water of recent Atlantic origin and resident surface Mediterranean waters, as shown by their preference for lower chlorophyll a concentrations (from 1.4 to 2.5 mg m-3 and moderate salinity values (between 37.35 and 37.75. Significantly, tuna larvae seemed to avoid the more eutrophic and saltier waters of the gulf situated very close to the coast and around Kerkennah and Djerba islands.

  20. Skin lesions on yellowfin tuna Thunnus albacares from Gulf of Mexico outer continental shelf: Morphological, molecular, and histological diagnosis of infection by a capsalid monogenoid.

    Science.gov (United States)

    Bullard, Stephen A; Womble, Matthew R; Maynard, Margaret K; Orélis-Ribeiro, Raphael; Arias, Cova R

    2015-12-01

    We characterize lesion-associated capsaline infections on yellowfin tuna, Thunnus albacares, in the Gulf of Mexico by comparing our specimens with published descriptions and museum specimens ascribed to Capsala biparasiticum and its synonyms: vouchers of C. biparasiticum from parasitic copepods; the holotype of Capsala neothunni; and vouchers of Capsala abidjani. Those from parasitic copepods differed by having a small, rounded body, large anterior attachment organs, closely spaced dorsomarginal body sclerites, small testes, and a short and wide testicular field. No morphometric feature in the holotype of C. neothunni ranged outside of that reported for the newly-collected specimens, indicating conspecificity of our specimens. The specimens of C. abidjani differed by having a large anterior attachment organ, few and dendritic testes, and a short, wide testicular field. Large subunit ribosomal DNA (28S) sequences grouped our specimens and Capsala sp. as sister taxa and indicated a phylogenetic affinity of Nasicola klawei. The haptoral attachment site comprised a crater-like depression surrounded by a blackish-colored halo of extensively rugose skin, with abundant pockmarked-like, irregularly-shaped oblong or semi-circular epidermal pits surrounding these attachment sites. Histology confirmed extensive folding of epidermis and underlying stratum laxum, likely epidermal hyperplasia, foci of weak cell-to-cell adhesions among apical malpighian cells as well as that between stratum germinativum and stratum laxum, myriad goblet cells in epidermis, rodlet cells in apical layer of epidermis, and lymphocytic infiltrates and melanin in dermis. The present study comprises (i) the first published report of this parasite from yellowfin tuna captured in the Gulf of Mexico-NW Atlantic Ocean Basin, (ii) confirmation of its infection on the skin (rather than on a parasitic copepod), (iii) the first molecular data for this capsaline, and (iv) the first observations of

  1. Trophic Ecology of Atlantic Bluefin Tuna (Thunnusthynnus) Larvae from the Gulf of Mexico and NW Mediterranean Spawning Grounds: A Comparative Stable Isotope Study

    Science.gov (United States)

    Malca, Estrella; Quintanilla, José María; Muhling, Barbara A.; Alemany, Francisco; Privoznik, Sarah L.; Shiroza, Akihiro; Lamkin, John T.; García, Alberto

    2015-01-01

    The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6–10 mm standard length) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlying microzooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages.These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton—zooplankton—larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvae. PMID:26225849

  2. Aeromonas hydrophila and Campylobacter jejuni isolated in fresh tuna (Thunnus spp.) sold in São Paulo, Brazil

    OpenAIRE

    Andréa Moura Costa; Aline Feola Carvalho; Rodrigo César Fredrigo; Patrícia Freitas Kobayashi; Eliana Scarcelli Pinheiro

    2016-01-01

    Aeromonas hydrophila e Campylobacter jejuni são bactérias de importância emergente em saúde pública, porém com escassos trabalhos publicados na área de pescado. O presente estudo investigou a presença de Aeromonas hydrophila e Campylobacter jejuni em amostras de atum (Thunnus spp.) fresco, capturados no litoral de Santa Catarina e distribuídos no comércio atacadista de São Paulo, SP. Foram colhidas 85 amostras de filé de atum e processadas por análises bacteriológicas e PCR. Do total, 11/85 (...

  3. [Tuna (Thunnus thynnus) glazed with hydrocolloids as alternative of edible coatings and storaged at -10 degrees C].

    Science.gov (United States)

    Mena, Sarahi; Rodriguez, Leonardo; Barrero, Marinela

    2010-09-01

    Numerous studies have been focused to natural ingredients to maintain the quality and shell life of foods. Edibles coating, biodegradable ingredients, such as hydrocolloids and proteins can be used for coating fish with the purpose to suppress changes of quality during frozen storage. At the present time several developing of edibles packing, like glaze using hydrocolloids, (gelatin, carrageen, starch), that besides acts as protective film for food, they are economic, can be ingested by the consumer without toxicity risk, help to preserve organoleptics and nutritional characteristics of the product and, being biodegradable they contribute to the conservation of the atmosphere. The objective of the present study was to evaluate the incorporation ofhydrocolloids in the glazing tuna process as alternative of packing, to enhance its physical and chemical characteristics. Samples of tuna was glazed incorporating to its solutions of carrageen at 0.05, 0,1 and 0.15%, and gelatin at 0.5, 1%. The samples were shaped as square (15 cm3), frozen al -30 degrees C and glazed incorporating hydrocolloids submerging the sample its solutions at 0 degrees C by 30 seconds and storage at -10 degrees C by 0, 15 and 30 days. Proximal analysis results, soluble proteins, TBA, and color showed that all the samples glazed with hydrocolloids decrease deterioration of the tuna products respect to samples glazed without hydrocolloids; concluding that glazing adding hydrocolloids protects tuna for loss humidity and delays degradation of proteins. Moreover, carrageen shows to a better performance at the concentrations of 0.05% compared with the gelatin and the starch.

  4. New Nuclear SNP Markers Unravel the Genetic Structure and Effective Population Size of Albacore Tuna (Thunnus alalunga.

    Directory of Open Access Journals (Sweden)

    Urtzi Laconcha

    Full Text Available In the present study we have investigated the population genetic structure of albacore (Thunnus alalunga, Bonnaterre 1788 and assessed the loss of genetic diversity, likely due to overfishing, of albacore population in the North Atlantic Ocean. For this purpose, 1,331 individuals from 26 worldwide locations were analyzed by genotyping 75 novel nuclear SNPs. Our results indicated the existence of four genetically homogeneous populations delimited within the Mediterranean Sea, the Atlantic Ocean, the Indian Ocean and the Pacific Ocean. Current definition of stocks allows the sustainable management of albacore since no stock includes more than one genetic entity. In addition, short- and long-term effective population sizes were estimated for the North Atlantic Ocean albacore population, and results showed no historical decline for this population. Therefore, the genetic diversity and, consequently, the adaptive potential of this population have not been significantly affected by overfishing.

  5. Physicochemical and sensory characterization of refined and deodorized tuna (Thunnus albacares) by-product oil obtained by enzymatic hydrolysis.

    Science.gov (United States)

    de Oliveira, Dayse A S B; Minozzo, Marcelo G; Licodiedoff, Silvana; Waszczynskyj, Nina

    2016-09-15

    In this study, the effects of chemical refining and deodorization on fatty acid profiles and physicochemical and sensory characteristics of the tuna by-product oil obtained by enzymatic hydrolysis were evaluated. Enzymatic extraction was conducted for 120 min at 60 °C and pH 6.5 using Alcalase at an enzyme-substrate ratio of 1:200 w/w. The chemical refining of crude oil consisted of degumming, neutralization, washing, drying, bleaching, and deodorization; deodorization was conducted at different temperatures and processing times. Although chemical refining was successful, temperature and chemical reagents favored the removal of polyunsaturated fatty acids (PUFA) from the oil. Aroma attributes of fishy odor, frying odor, and rancid odor predominantly contributed to the sensory evaluation of the product. Deodorization conditions of 160 °C for 1h and 200 °C for 1h were recommended for the tuna by-product oil, which is rich in PUFA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The real maccoyii: identifying tuna sushi with DNA barcodes--contrasting characteristic attributes and genetic distances.

    Directory of Open Access Journals (Sweden)

    Jacob H Lowenstein

    Full Text Available BACKGROUND: The use of DNA barcodes for the identification of described species is one of the least controversial and most promising applications of barcoding. There is no consensus, however, as to what constitutes an appropriate identification standard and most barcoding efforts simply attempt to pair a query sequence with reference sequences and deem identification successful if it falls within the bounds of some pre-established cutoffs using genetic distance. Since the Renaissance, however, most biological classification schemes have relied on the use of diagnostic characters to identify and place species. METHODOLOGY/PRINCIPAL FINDINGS: Here we developed a cytochrome c oxidase subunit I character-based key for the identification of all tuna species of the genus Thunnus, and compared its performance with distance-based measures for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City and Denver, Colorado. Both the character-based key and GenBank BLAST successfully identified 100% of the tuna samples, while the Barcode of Life Database (BOLD as well as genetic distance thresholds, and neighbor-joining phylogenetic tree building performed poorly in terms of species identification. A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of "white tuna" were not albacore (T. alalunga, but escolar (Lepidocybium flavorunneum, a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus or the critically endangered southern bluefin tuna (T. maccoyii, though nine restaurants that sold these species did not state these species on their menus. CONCLUSIONS/SIGNIFICANCE: The Convention on

  7. Aeromonas hydrophila and Campylobacter jejuni isolated in fresh tuna (Thunnus spp. sold in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Andréa Moura Costa

    2016-04-01

    Full Text Available Aeromonas hydrophila e Campylobacter jejuni são bactérias de importância emergente em saúde pública, porém com escassos trabalhos publicados na área de pescado. O presente estudo investigou a presença de Aeromonas hydrophila e Campylobacter jejuni em amostras de atum (Thunnus spp. fresco, capturados no litoral de Santa Catarina e distribuídos no comércio atacadista de São Paulo, SP. Foram colhidas 85 amostras de filé de atum e processadas por análises bacteriológicas e PCR. Do total, 11/85 (13% amostras foram positivas para Aeromonas spp., sendo 10/11 (90,9% confirmadas como Aeromonas hydrophila pela PCR. Para Campylobacter spp., 10/85 (11,7% foram positivas, sendo 10/10 (100% identificadas como Campylobacter jejuni pelas provas bioquímicas tradicionais e PCR ressaltando-se que duas (2/85 - 2,3% amostras de atum albergavam ambos os patógenos. Trata-se do primeiro relato no Brasil de contaminação de atum fresco por Campylobacter jejuni e Aeromonas hydrophila, indicando que este alimento ingerido in natura pode ser um veículo de transmissão de agentes patogênicos, ressaltando-se a importância de estudos adicionais que deem suporte ao controle desses microrganismos em pescado consumido cru.

  8. Development and validation of a spectrophotometry method for the determination of histamine in fresh tuna (Thunnus tunna)

    International Nuclear Information System (INIS)

    Chacon-Silva, Fainier; Barquero-Quiros, Miriam

    2002-01-01

    Histamine in foods can promote allergic reactions in sensitive persons. A colorimetric microscale method for histamine determination was developed and validated. Cu 2+ histamine chelation occurs at 9,5 ph. Dichloromethane extraction of the complex as the salt with tetrabromo phenolphthalein ethyl ester, allows photometric quantitation at 515 nm. The validation of micro method was accomplished trough its performance parameters, detection limit, quantitation limit, sensitivity, linearity, precision, recuperation. This methodology was applied to twenty raw tuna samples, collected in San Jose metropolitan area. It was found that 45% of analyzed samples had a histamine content in the range between 100-200 mg/kg. This finding indicates bacterial contamination, 15% of samples analyzed were over 500 mg/kg FDA level of sanitary risk. (Author) [es

  9. Preparation and characterization of protein isolate from Yellowfin tuna Thunnus albacares roe by isoelectric solubilization/precipitation process

    Directory of Open Access Journals (Sweden)

    Hyun Ji Lee

    2016-05-01

    Full Text Available Abstract Isoelectric solubilization/precipitation (ISP processing allows selective, pH-induced water solubility of proteins with concurrent separation of lipids and removal of materials not intended for human consumption such as bone, scales, skin, etc. Recovered proteins retain functional properties and nutritional value. Four roe protein isolates (RPIs from yellowfin tuna roe were prepared under different solubilization and precipitation condition (pH 11/4.5, pH 11/5.5, pH 12/4.5 and pH 12/5.5. RPIs contained 2.3–5.0 % moisture, 79.1–87.8 % protein, 5.6–7.4 % lipid and 3.0–3.8 % ash. Protein content of RPI-1 and RPI-2 precipitated at pH 4.5 and 5.5 after alkaline solubilization at pH 11, was higher than those of RPI-3 and RPI-4 after alkaline solubilization at pH 12 (P < 0.05. Lipid content (5.6–7.4 % of RPIs was lower than that of freeze-dried concentrate (10.6 %. And leucine and lysine of RPIs were the most abundant amino acids (8.8–9.4 and 8.5–8.9 g/100 g protein, respectively. S, Na, P, K as minerals were the major elements in RPIs. SDS-PAGE of RPIs showed bands at 100, 45, 25 and 15 K. Moisture and protein contents of process water as a 2’nd byproduct were 98.9–99.0 and 1.3–1.8 %, respectively. Therefore, yellowfin tuna roe isolate could be a promising source of valuable nutrients for human food and animal feeds.

  10. The Real maccoyii: Identifying Tuna Sushi with DNA Barcodes – Contrasting Characteristic Attributes and Genetic Distances

    Science.gov (United States)

    Lowenstein, Jacob H.; Amato, George; Kolokotronis, Sergios-Orestis

    2009-01-01

    Background The use of DNA barcodes for the identification of described species is one of the least controversial and most promising applications of barcoding. There is no consensus, however, as to what constitutes an appropriate identification standard and most barcoding efforts simply attempt to pair a query sequence with reference sequences and deem identification successful if it falls within the bounds of some pre-established cutoffs using genetic distance. Since the Renaissance, however, most biological classification schemes have relied on the use of diagnostic characters to identify and place species. Methodology/Principal Findings Here we developed a cytochrome c oxidase subunit I character-based key for the identification of all tuna species of the genus Thunnus, and compared its performance with distance-based measures for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City) and Denver, Colorado. Both the character-based key and GenBank BLAST successfully identified 100% of the tuna samples, while the Barcode of Life Database (BOLD) as well as genetic distance thresholds, and neighbor-joining phylogenetic tree building performed poorly in terms of species identification. A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of “white tuna” were not albacore (T. alalunga), but escolar (Lepidocybium flavorunneum), a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus) or the critically endangered southern bluefin tuna (T. maccoyii), though nine restaurants that sold these species did not state these species on their menus. Conclusions/Significance The Convention on International Trade

  11. Accounting for age uncertainty in growth modeling, the case study of yellowfin tuna (Thunnus albacares of the Indian Ocean.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Dortel

    Full Text Available Age estimates, typically determined by counting periodic growth increments in calcified structures of vertebrates, are the basis of population dynamics models used for managing exploited or threatened species. In fisheries research, the use of otolith growth rings as an indicator of fish age has increased considerably in recent decades. However, otolith readings include various sources of uncertainty. Current ageing methods, which converts an average count of rings into age, only provide periodic age estimates in which the range of uncertainty is fully ignored. In this study, we describe a hierarchical model for estimating individual ages from repeated otolith readings. The model was developed within a Bayesian framework to explicitly represent the sources of uncertainty associated with age estimation, to allow for individual variations and to include knowledge on parameters from expertise. The performance of the proposed model was examined through simulations, and then it was coupled to a two-stanza somatic growth model to evaluate the impact of the age estimation method on the age composition of commercial fisheries catches. We illustrate our approach using the sagittal otoliths of yellowfin tuna of the Indian Ocean collected through large-scale mark-recapture experiments. The simulation performance suggested that the ageing error model was able to estimate the ageing biases and provide accurate age estimates, regardless of the age of the fish. Coupled with the growth model, this approach appeared suitable for modeling the growth of Indian Ocean yellowfin and is consistent with findings of previous studies. The simulations showed that the choice of the ageing method can strongly affect growth estimates with subsequent implications for age-structured data used as inputs for population models. Finally, our modeling approach revealed particularly useful to reflect uncertainty around age estimates into the process of growth estimation and it can

  12. An Assessment of Near Surface Biological Volume Scattering off the Continental Shelf of Virginia.

    Science.gov (United States)

    1991-07-01

    species, bluefin tuna, Thunnus thynnus ; yellowfin tuna, Thunnus albacares; albacore, Thunnus alalunga; and swordfish, Xiphias gladius, are reported from...100 1000,’ 2000 370 37 1720 Figure 10. Distribution of longline by-catch of bluefin tuna, Thunnus thynnus during January to April 1987 - 1989. 19

  13. Dietary evidence of mesopelagic and pelagic foraging by Atlantic bluefin tuna (Thunnus thynnus L.) during autumn migrations to the Iceland Basin

    DEFF Research Database (Denmark)

    Olafsdottir, Droplaug; MacKenzie, Brian; Chosson-P, Valérie

    2016-01-01

    behavior, and bioenergetics of ABFT. Here, we report the dietary composition of ABFT during autumn migrations to the Iceland Basin south of the continental shelf of Iceland. A total of 36 prey species or higher taxa were observed in 421 stomach samples: 17 teleost fishes, 4 squid, 1 octopus, 12 crustaceans...

  14. Global habitat preferences of commercially valuable tuna

    KAUST Repository

    Arrizabalaga, Haritz

    2015-03-01

    In spite of its pivotal role in future implementations of the Ecosystem Approach to Fisheries Management, current knowledge about tuna habitat preferences remains fragmented and heterogeneous, because it relies mainly on regional or local studies that have used a variety of approaches making them difficult to combine. Therefore in this study we analyse data from six tuna species in the Pacific, Atlantic and Indian Oceans in order to provide a global, comparative perspective of habitat preferences. These data are longline catch per unit effort from 1958 to 2007 for albacore, Atlantic bluefin, southern bluefin, bigeye, yellowfin and skipjack tunas. Both quotient analysis and Generalised Additive Models were used to determine habitat preference with respect to eight biotic and abiotic variables. Results confirmed that, compared to temperate tunas, tropical tunas prefer warm, anoxic, stratified waters. Atlantic and southern bluefin tuna prefer higher concentrations of chlorophyll than the rest. The two species also tolerate most extreme sea surface height anomalies and highest mixed layer depths. In general, Atlantic bluefin tuna tolerates the widest range of environmental conditions. An assessment of the most important variables determining fish habitat is also provided. © 2014 Elsevier Ltd.

  15. Significant histamine formation in tuna ( Thunnus albacares ) at 2 degrees C - effect of vacuum- and modified atmosphere-packaging on psychrotolerant bacteria

    DEFF Research Database (Denmark)

    Emborg, Jette; Laursen, B. G.; Dalgaard, Paw

    2005-01-01

    tuna with 60% CO2/40% N-2 and formed > 5000 mg/kg of histamine after 24 days at 1.7 degrees C. These psychrotolerant bacteria were biochemically similar to M. morganii subsp. morganii and their 16S rDNA (1495 bp) showed > 98% sequence similarity to the type strain of this species. Toxic concentrations...... by both the psychrotolerant M morganii-like bacteria and P phosphoreum. In agreement with this, no formation of histamine was found in naturally contaminated fresh MAP tuna with 40% CO2/60% O-2 during 28 days of storage at 1.0 degrees C. To reduce current problems with histamine fish poisoning due to VP...... and sensory changes were evaluated during storage at 1-3 degrees C. To explain the results obtained with naturally contaminated tuna the effect of VP and MAP on biogenic amine formation by psychrotolerant bacteria was evaluated in challenge tests at 2 degrees C and 10 degrees C. The VP tuna that caused...

  16. Influence of carbon monoxide on the colour stability of defrosted yellowfin tuna (Thunnus albacares) muscle stored under aerobic and anaerobic conditions.

    Science.gov (United States)

    Neethling, Nikki E; Hoffman, Louwrens C; Britz, Trevor J; O'Neill, Bernadette

    2015-06-01

    The use of carbon monoxide (CO) and various packaging types has been suggested to improve/stabilise the colour and oxidative processes of red meats, thereby improving the retail value and revenue. The main aim of this study was to investigate the influence of packaging type and CO treatment on the colour and oxidative stability of tuna. The addition of CO significantly increased the redness (a(*) ) of the tuna steaks but the redness was not equally stable for all treatments. The aerobically packaged steaks showed a temporal decrease in redness while the redness of anaerobically packaged steaks remained relatively stable. The addition of CO did not significantly affect (P >0.05) the brownness (b(*) ) (with one exception) and lightness (L(*) ) of the steaks. The anaerobically packaged steaks showed a significant difference (P 0.05) in lipid or protein oxidation were observed between treatments. The aerobically packaged steaks had a significant temporal increase (P <0.05) in lipid oxidation while no such trend was apparent in the anaerobically packaged steaks. Protein oxidation remained relatively stable over time for both aerobically and anaerobically packaged steaks. Storing CO treated tuna steaks in anaerobic packaging can improve the oxidative and colour stability of tuna. Such treatment can reduce spoilage and wastage thereby potentially increasing revenue. © 2014 Society of Chemical Industry.

  17. Development of Formaldehyde Biosensor for Determination of Formalin in Fish Samples; Malabar Red Snapper (Lutjanus malabaricus and Longtail Tuna (Thunnus tonggol

    Directory of Open Access Journals (Sweden)

    Bohari Noor Aini

    2016-06-01

    Full Text Available Electrochemical biosensors are widely recognized in biosensing devices due to the fact that gives a direct, reliable, and reproducible measurement within a short period. During bio-interaction process and the generation of electrons, it produces electrochemical signals which can be measured using an electrochemical detector. A formaldehyde biosensor was successfully developed by depositing an ionic liquid (IL (e.g., 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][Otf], gold nanoparticles (AuNPs, and chitosan (CHIT, onto a glassy carbon electrode (GCE. The developed formaldehyde biosensor was analyzed for sensitivity, reproducibility, storage stability, and detection limits. Methylene blue was used as a redox indicator for increasing the electron transfer in the electrochemical cell. The developed biosensor measured the NADH electron from the NAD+ reduction at a potential of 0.4 V. Under optimal conditions, the differential pulse voltammetry (DPV method detected a wider linear range of formaldehyde concentrations from 0.01 to 10 ppm within 5 s, with a detection limit of 0.1 ppm. The proposed method was successfully detected with the presence of formalin in fish samples, Lutjanus malabaricus and Thunnus Tonggol. The proposed method is a simple, rapid, and highly accurate, compared to the existing technique.

  18. [Correlation of fat content and dioxins, total mercury and methyl mercury levels in tuna].

    Science.gov (United States)

    Kawakami, Hiroyuki; Amakura, Yoshiaki; Tsutsumi, Tomoaki; Sasaki, Kumiko; Iketsu, Ayumi; Inasaki, Mizue; Kubota, Emi; Toyoda, Masatake

    2010-01-01

    In this study, we analyzed the concentrations of mercury and dioxins in tuna with various fat contents (akami; the leaner meat, Chutoro; the belly area of the tuna along the side of the fish between the akami and the otoro. Otoro; the fattiest portion of the tuna) in wild and farmed bluefin tuna and farmed southern bluefin tuna. In the three kinds of tuna, average dioxins concentrations in Akami, chutoro and otoro were 1.7, 4.7 and 9.6 pg TEQ/g, respectively. The dioxins concentration in all three regions of tuna was in direct proportion to the fat content. In the farmed bluefin tuna, the dioxins concentration was almost the same as that of the wild tuna, but differed from that of the farmed southern bluefin tuna. Average total mercury concentration based on wet weight in akami was 0.42 µg/g, being higher than the values of 0.36 µg/g of chutoro and 0.31 µg/g of otoro, and in inverse proportion to the fat content. In all three regions, the total mercury concentration of the wild bluefin tuna was equal to that of the farmed tuna. The total mercury concentration in the latter was two to three times higher than that of the farmed southern bluefin tuna. If the Japanese intake is one fin of tuna (80 g) a day, the daily intake levels of dioxins and methyl mercury can be estimated as 0.48-37 pg TEQ/kg bw and 0.21-0.90 µg/kg bw, respectively.

  19. Multiple T state conformations in a fish hemoglobin. Carbon monoxide binding to hemoglobin of Thunnus thynnus.

    Science.gov (United States)

    Morris, R J; Neckameyer, W S; Gibson, Q H

    1981-05-10

    The blood of the Atlantic bluefin tuna (Thunnus thynnus) contains four hemoglobin components separable by chromatography on diethylaminoethylcellulose. These components are stable and functionally identical in their reactions with carbon monoxide. At low pH they remain in the T state even when liganded, and show two kinetic components in binding and in dissociation, with rates of 1) 1.2 microM-1 s-1 and 0.095 s-1 and 2) 0.013 microM-1 s-1 and 0.195 s-1, respectively, at pH 6, 20 degrees C, 0.1 m KPi. These components have difference spectra separated by more than 2 nm and are present in equal amounts. After CO has bound, there is a conformation change to an altered T state, in terms of the model of Monod et al. (Monod, J., Wyman, J., and Changeux, J. P. (1965) J. Mol. Biol. 12, 88-118), with a half-time of 65 s. At equilibrium, one-third of the slow kinetic component is changed into the new conformer, which binds CO at a rate of 0.14 microM-1 s-1.

  20. UTILITY OF FISHERY HIGH SCHOOL DATA IN EXAMINING SPATIAL AND TEMPORAL CATCH AND EFFORT TRENDS IN THE INDONESIAN LONGLINE TUNA FISHERY

    Directory of Open Access Journals (Sweden)

    Lilis Sadiyah

    2015-12-01

    Full Text Available One of the endeavours to address the shortage of catch per unit effort (CPUE information from the Indonesian Indian Ocean tuna fishery is the collation of a large amount of catch and effort data collected by Indonesian Fisheries High School students (“FHS data”. This paper attempts to investigate spatial-temporal patterns of catch and effort of the FHS data for the main tuna species caught by the fishery: bigeye tuna (Thunnus obesus - BET, yellowfin tuna (T. albacares - YFT, albacore (T. alalunga - ALB and southern bluefin tuna (T.maccoyii - SBT. Reported sets occurred in the Eastern Indian Ocean, north and south of 20°S. Recorded effort from the FHS data set was concentrated within the only known SBT spawning ground. However, within this data set, SBT were recorded in the lowest catch proportion relative to BET, YFT and ALB. The catch composition data suggested that YFT and ALB were predominantly targeted by the fishery, with ALB and SBT most predominantly recorded south of 20°S, whereas BET and YFT were mostly recorded north of 20°S. Unfortunately, there was no strong information on targeting practices reported by this data set, limiting any attempts to understand the factors that influenced those results. As the sampling predominantly occurred in between July and December, the data are not representative of fishing activities throughout the entire year, and any seasonal patterns from the FHS data set are biased. In addition, the FHS data set is prone to observation error and uncertainty in terms of fish identification and fishing location. Therefore, the FHS data set needs to be interpreted with caution.

  1. Direct ageing of Thunnus thynnus from the eastern Atlantic Ocean and western Mediterranean Sea using dorsal fin spines.

    Science.gov (United States)

    Luque, P L; Rodriguez-Marin, E; Landa, J; Ruiz, M; Quelle, P; Macias, D; Ortiz De Urbina, J M

    2014-06-01

    This study deals with important methodology issues that affect age estimates of eastern Atlantic bluefin tuna Thunnus thynnus using dorsal fin spines. Nearly 3800 spine sections were used from fish caught in the north-east Atlantic Ocean and western Mediterranean Sea over a 21 year period. Edge type and marginal increment analyses indicated a yearly periodicity of annulus formation with the translucent bands (50% of occurrence) appearing from October to May. Nucleus vascularization seriously affected specimens older than 6 years, with the disappearance of 40-50% of the presumed annuli by that age. An alternate sectioning location was a clear improvement and this finding is an important contribution to the methodology of using this structure for ageing the full-length range of eastern T. thynnus. Finally, there were no significant differences between the coefficients of von Bertalanffy growth model estimated from mean length at age data (L∞  = 327.4; k = 0.097; t0  = -0.838) and those estimated from the growth curves accepted for the eastern and western T. thynnus management units. © 2014 The Fisheries Society of the British Isles.

  2. OPTIMASI KONDISI PEMURNIAN ASAM LEMAK OMEGA-3 DARI MINYAK HASIL SAMPING PENEPUNGAN TUNA (Thunnus sp DENGAN KRISTALISASI UREA [Optimizing Conditions for the Purification of Omega-3 Fatty Acids from By-product of Tuna (Thunnus sp Meal Processing by Urea Crystallization

    Directory of Open Access Journals (Sweden)

    Teti Estiasih1*

    2009-12-01

    Full Text Available Omega-3 fatty acids (-3 are proven to have health beneficial effects. Some effort had been done to obtained oil high in -3 fatty acids. Among the methods developed, urea crystallization was preferred because it is simple, economic, and result in high purity of fatty acids. A source that had not been widely explored for -3 fatty acids production is the by-product of tuna meal processing. This research studied the optimization condition for separation and purification of -3 fatty acids from the by-product of tuna meal processing by urea crystallization. Crystallization reaction conditions of urea inclusion were optimized using the response surface methodology, and the model was developed.Optimization result showed a quadratic polynomial regression equation of Y= 140,52677X1 + 8,38203X2 – 19,85850X12 – 0,12173X22 – 0,74000X1X2 – 240,33546 with X1=urea to fatty acid ratio and X2=crystallization time. Maximum response was obtained at urea to fatty acid ratio of 3,07:1,crystallization time of 25,10 hours, and predicted response was 80,60%. Analysis of variance showed that urea to fatty acid ratio and crystallization time affected response. Under optimal conditions, the product was 3.89 times concentrated and the purity of -3 fatty acids was 81,98%. Verification result revealed that the predicted value from this model was reasonably close to the experimentally observed value. Urea crystallization process changed quality parameters that were oxidation level (peroxide value, anisidin value, and totox value, Fe and Cu content, P content, and water content. The changes were caused by adsorption of primary and secondary oxidation products, part of metals, and phosphoric compound onto unsaponifiable matters or soluble into water.

  3. Properties of protease and lipase from whole and individual organ of viscera from three tuna species

    Directory of Open Access Journals (Sweden)

    Thiraratana Prachumratana

    2008-04-01

    Full Text Available Properties of visceral enzymes from yellowfin tuna (Thunnus albacares, skipjack tuna (Katsuwonus pelamis and tonggol tuna (Thunnus albacares were studied. The crude enzymes from viscera of yellowfin tuna and skipjack tuna exhibited the highest activities at pH 10.0 whereas it was at pH 9.0 for those from viscera of tonggol tuna. The enzymes were the most stable at their optima pH after 120 min incubation. The optimum temperatures for protease and lipase activities were at 50oC and 60oC, respectively but the extracted enzymes were more stable in the temperature range of 37- 40oC. The protease and lipase from spleen were the most thermostable with the half-life of 120 and 90 min at 60oC incubation, respectively. Protease activity from spleen accounted for 45.6% of the total protease activity of the whole tuna viscera.

  4. Bluefin Tuna Life History (1972-1979)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Catch and size data for animals from which a collection of fish parts were done for life history studies. These samples will be used in comparison studies with more...

  5. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic): Atlantic Menhaden

    Science.gov (United States)

    1989-08-01

    saltatrix), striped bass (Morone and survival was poor at 6 ’C in saxatilis), bluefin tuna ( Thunnus freshwater (Lewis 1966). The effect thynnus ), and...Morone saxatilis), and bluefin tuna ( Thunnus thynnus ). The Atlantic menhaden is associated with estuarine and nearshore systems d--g- ll phases of its life

  6. STOMACH CONTENT OF THREE TUNA SPECIES IN THE EASTERN INDIAN OCEAN

    Directory of Open Access Journals (Sweden)

    Bram Setyadji

    2012-12-01

    Full Text Available Feeding habit of tuna in Indian Ocean has been described around Sri Lanka, Indian Waters, Andaman Sea, western Indian Ocean (Seychelles Islands, western equatorial Indian Ocean whereas the tunas feeding habit study in Eastern Indian Oceanis merely in existence. The purpose of this study is to investigate the stomach content of three tuna species (bigeye tuna, yellowfin tuna, and skipjack tuna, apex predator in the southern part of Eastern Indian Ocean. The study was conducted in March – April, 2010 on the basis of catches of commercial tuna longline vessel based in Port of Benoa. A total of 53 individual fishes were collected, consisting of bigeye tuna (Thunnus obesus, yellowfin tuna (Thunnus albacores, and skipjack tuna (Katsuwonus pelamis. Stomach specimens were collected and analyzed.Analysis was conducted on the basis of index of preponderance method. The diet of the three tuna species showed fishes as the main diet (56–82%, followed by cephalopods (squids as the complementary diet (0–8%, and crustaceans (shrimps as the additional diet (2–4%. Fish prey composed of 6 families i.e. Alepisauridae, Bramidae, Carangidae, Clupeidae, Engraulidae, and Scombridae.

  7. Bycatch in the Maldivian pole-and-line tuna fishery.

    Science.gov (United States)

    Miller, Kelsey I; Nadheeh, Ibrahim; Jauharee, A Riyaz; Anderson, R Charles; Adam, M Shiham

    2017-01-01

    Tropical tuna fisheries are among the largest worldwide, with some having significant bycatch issues. However, pole-and-line tuna fisheries are widely believed to have low bycatch rates, although these have rarely been quantified. The Maldives has an important pole-and-line fishery, targeting skipjack tuna (Katsuwonus pelamis). In the Maldives, 106 pole-and-line tuna fishing days were observed between August 2014 and November 2015. During 161 fishing events, tuna catches amounted to 147 t: 72% by weight was skipjack, 25% yellowfin tuna (Thunnus albacares) and 3% other tunas. Bycatch (all non-tuna species caught plus all tuna discards) amounted to 951 kg (0.65% of total tuna catch). Most of the bycatch (95%) was utilized, and some bycatch was released alive, so dead discards were particularly low (0.02% of total tuna catch, or 22 kg per 100 t). Rainbow runner (Elagatis bipinnulata) and dolphinfish (Coryphaena hippurus) together constituted 93% of the bycatch. Live releases included small numbers of silky sharks (Carcharhinus falciformis) and seabirds (noddies, Anous tenuirostris and A. stolidus). Pole-and-line tuna fishing was conducted on free schools and schools associated with various objects (Maldivian anchored fish aggregating devices [aFADs], drifting FADs from western Indian Ocean purse seine fisheries, other drifting objects and seamounts). Free school catches typically included a high proportion of large skipjack and significantly less bycatch. Associated schools produced more variable tuna catches and higher bycatch rates. Fishing trips in the south had significantly lower bycatch rates than those in the north. This study is the first to quantify bycatch rates in the Maldives pole-and-line tuna fishery and the influence of school association on catch composition. Ratio estimator methods suggest roughly 552.6 t of bycatch and 27.9 t of discards are caught annually in the fishery (based on 2015 national catch), much less than other Indian Ocean tuna

  8. Ocean Acoustic Waveguide Remote Sensing (OAWRS) of Marine Ecosystems

    Science.gov (United States)

    2009-12-03

    fish m–2 to a minimum detectable value of 0.003 fish m–2. Atlantic bluefin tuna Thunnus thynnus Atlantic bluefin tuna are large top-predators that...depth layers (adults: 60 to 90 m, packing density 0.5 fish m–2; juveniles: 60 to 90 m, density 0.3 fish m–2) Fig. 16. Thunnus thynnus . Modeled...sensing of submerged objects and 148 Fig. 17. Thunnus thynnus . Scattered intensity from bluefin tuna and seabottom modeled at 950 Hz. Tuna packing

  9. Projections of climate-driven changes in tuna vertical habitat based on species-specific differences in blood oxygen affinity.

    Science.gov (United States)

    Mislan, K A S; Deutsch, Curtis A; Brill, Richard W; Dunne, John P; Sarmiento, Jorge L

    2017-10-01

    Oxygen concentrations are hypothesized to decrease in many areas of the ocean as a result of anthropogenically driven climate change, resulting in habitat compression for pelagic animals. The oxygen partial pressure, pO 2 , at which blood is 50% saturated (P 50 ) is a measure of blood oxygen affinity and a gauge of the tolerance of animals for low ambient oxygen. Tuna species display a wide range of blood oxygen affinities (i.e., P 50 values) and therefore may be differentially impacted by habitat compression as they make extensive vertical movements to forage on subdaily time scales. To project the effects of end-of-the-century climate change on tuna habitat, we calculate tuna P 50 depths (i.e., the vertical position in the water column at which ambient pO 2 is equal to species-specific blood P 50 values) from 21st century Earth System Model (ESM) projections included in the fifth phase of the Climate Model Intercomparison Project (CMIP5). Overall, we project P 50 depths to shoal, indicating likely habitat compression for tuna species due to climate change. Tunas that will be most impacted by shoaling are Pacific and southern bluefin tunas-habitat compression is projected for the entire geographic range of Pacific bluefin tuna and for the spawning region of southern bluefin tuna. Vertical shifts in P 50 depths will potentially influence resource partitioning among Pacific bluefin, bigeye, yellowfin, and skipjack tunas in the northern subtropical and eastern tropical Pacific Ocean, the Arabian Sea, and the Bay of Bengal. By establishing linkages between tuna physiology and environmental conditions, we provide a mechanistic basis to project the effects of anthropogenic climate change on tuna habitats. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  10. The Effect of Clustered Scatterers on Volume Reverberation

    Science.gov (United States)

    2011-09-01

    aggregations of juvenile Atlantic bluefin tuna (ABT, Thunnus thynnus ) in order to create a realistic simulation of bioclutter. ABT represent a highly mobile...systematic of the tunas, GENUS THUNNUS , Fish. Bull. 66, 65-131, 1966. Love, R., Resonant acoustic scattering by swimbladder-bearing fish, J. Acoust. Soc...tuna, Thunnus albacores, Fish. Bull. 98, 364-374, 2000. Weber, T., A. Lyons, D. Bradley, Acoustic propagation through bubble clouds exhibiting

  11. Pelagic shark bycatch in the tuna- and swordfish-directed longline ...

    African Journals Online (AJOL)

    The capture of pelagic sharks as bycatch of the South African pelagic longline fleet targeting tuna Thunnus spp. and swordfish Xiphias gladius was investigated during the period 1998–2005. In all, 26 species were caught, of which six are listed by the International Union for Conservation of Nature (IUCN) as Vulnerable and ...

  12. A Review of the Aquatic Biological Resources of the Atlantic Coastal Area Off Virginia Beach, Virginia.

    Science.gov (United States)

    1984-02-01

    34anchoring, trawling, fishing and dragging." Fishing for bluefin tuna ( Thunnus thynnus ) occurs 10 to 30 miles offshore in June and July. King mackerel...bonita (Sarda sarda), blue marlin (Makaira nigricans), and yellowfin tuna ( Thunnus albacares) are caught in deeper waters, generally 30 to 50 miles

  13. SOME ANATOMIC AND MORPHOLOGIC CHARACTERISTICS OF CULTURED AND WILD TUNA

    Directory of Open Access Journals (Sweden)

    Ivana Miletić

    2008-04-01

    Full Text Available The main task of this paper is to describe digestive tract of bluefin tuna, with special focus on the liver. The samples for the research on tuna digestive tract where taken on the tuna farm »Sardina« d.d. Postira. The investigation were done on 22 samples (necropsy and photography of organs, Canon digital camera, 30 samples liver of unfatted tuna, 30 samples liver of fatted tuna and 20 histologic samples of liver before and after fattening. The quality of nutrition directly affects the differences of longitudinal and latitudinal values of the hepatosomatic index and the histology of liver of fatted and unfitted fish. Intensive, lipid–rich nutrition increases the quantity of the fat stored in liver therefore causing higher hepatosomatic index in fatted tuna. Histologic examination of fatted tuna indicates a beginning of hepatocytes degeneration with vacuolization of the cell and decentralized nuclei. Lack of eosinophilic granules in cytoplasm of hepatocytes indicates the cell’s inability of doing enzymatic activity, respectively its dysfunction.

  14. Bioenergetics, Trophic Ecology, and Niche Separation of Tunas.

    Science.gov (United States)

    Olson, R J; Young, J W; Ménard, F; Potier, M; Allain, V; Goñi, N; Logan, J M; Galván-Magaña, F

    Tunas are highly specialized predators that have evolved numerous adaptations for a lifestyle that requires large amounts of energy consumption. Here we review our understanding of the bioenergetics and feeding dynamics of tunas on a global scale, with an emphasis on yellowfin, bigeye, skipjack, albacore, and Atlantic bluefin tunas. Food consumption balances bioenergetics expenditures for respiration, growth (including gonad production), specific dynamic action, egestion, and excretion. Tunas feed across the micronekton and some large zooplankton. Some tunas appear to time their life history to take advantage of ephemeral aggregations of crustacean, fish, and molluscan prey. Ontogenetic and spatial diet differences are substantial, and significant interdecadal changes in prey composition have been observed. Diet shifts from larger to smaller prey taxa highlight ecosystem-wide changes in prey availability and diversity and provide implications for changing bioenergetics requirements into the future. Where tunas overlap, we show evidence of niche separation between them; resources are divided largely by differences in diet percentages and size ranges of prey taxa. The lack of long-term data limits the ability to predict impacts of climate change on tuna feeding behaviour. We note the need for systematic collection of feeding data as part of routine monitoring of these species, and we highlight the advantages of using biochemical techniques for broad-scale analyses of trophic relations. We support the continued development of ecosystem models, which all too often lack the regional-specific trophic data needed to adequately investigate climate and fishing impacts. © 2016 Elsevier Ltd. All rights reserved.

  15. [Otolith microchemistry of tuna species: research progress].

    Science.gov (United States)

    Zhu, Guo-ping

    2011-08-01

    Microchemistry analysis of trace elements and isotopes in fishes' calcified substances is an emerging approach to analyze the population structure, life history, and migration environmental history of fishes. With the increasing improvement of the researches and applications of otolith microchemistry, this approach has been a good tool for studying the ecology of tuna species. Currently, the research contents of tuna species' otolith microchemistry mainly include trace elements and isotopes, and the former is the emphasis and hotspot in applied research, playing a vital role in the researches of population partitioning, natal origin, migration environmental history, and life history of tuna species, especially bluefin tuna. However, most of the researches are focusing on the variation of otolith's Sr/Ca ratio, and there is no final conclusion on the relationships between the fractionation of isotopes C and O in otolith and the temperature. For the sake of exploiting the huge value of otolith microchemistry, it would be necessary to strengthen the researches on the deposition mechanisms of trace elements in otolith, and to analyze the spatio-temporal variations of various trace elements in otolith by comprehensive research methods.

  16. Halimeda tuna

    African Journals Online (AJOL)

    cas

    Full Length Research Paper. Evaluation of in vitro antimicrobial property of seaweed. (Halimeda tuna) from Tuticorin coast, Tamil Nadu,. Southeast coast of India. K. Indira*, S. Balakrishnan, M. Srinivasan, S. Bragadeeswaran and T. Balasubramanian. Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, ...

  17. Weight dependence of arsenic concentration in the Arabian Sea tuna fish

    Energy Technology Data Exchange (ETDEWEB)

    Ashraf, M.; Jaffar, M.

    1988-02-01

    The objective of the present investigation was to estimate the arsenic concentration in the edible muscle of Thunnus thynnus and Thunnus toggel (hereafter called tuna and longtail tune) as they have great commercial value. These fish are widely available along the coastal line of Pakistan and are consumed abundantly in large bulk. Thus, it was felt justifiable on the basis of safety of human health that data, in the first instance, be obtained on arsenic concentration in tuna as a function of weight to check whether the metal distribution was species-specific or it depended on individual mode of development. The data, the first of the kind so far presented on the Arabian Sea tuna, would thus provide the required baseline quantitative information needed in future studies on the physiological processes regulating the distribution and uptake of arsenic by these and other species of fish common to the region.

  18. Distribuição do metal mercúrio em atum (Thunnus albacares e pescada bicuda (Cynoscion microlepidotus capturados no litoral do Rio de Janeiro, Brasil Distribution of metal mercury in tuna (Thunnus albacares and weaker fish (Cynoscion microlepidotus captured in Rio de Janeiro coast, Brazil

    Directory of Open Access Journals (Sweden)

    R.J. Medeiros

    2008-06-01

    Full Text Available O presente estudo verificou a cinética mercurial em órgãos, tecido muscular e conteúdo estomacal de duas espécies de peixes marinhos predadores, identificando os locais de maior acumulação desse metal. Para o processo analítico, foi utilizada a técnica de espectrofotometria de absorção atômica por arraste de vapor a frio. A distribuição de Hg nas porções analisadas apresenta ampla dispersão. Para o atum, a variação foi de 0,004 µg.g-1 no fígado, nas brânquias e baço, e 0,172µg.g-1 no tecido muscular. Para a pescada bicuda, a variação foi entre 0,013µg.g-1 nas brânquias a 0,250µg.g-1 no tecido muscular. Este último demonstrou ser, nas duas espécies, a porção de maior concentração do metal, atum = 0,080±0,050µg.g-1 e pescada bicuda = 0,187±0,030µg.g-1. Os locais de menor concentração na pescada foram as brânquias 0,029±0,031µg.g-1, e no atum os olhos (0,013±0,008µg.g-1.The mercuric kinetic in organs, muscular tissue, and stomach contents of two species of marine fish predators was evaluated by the identification of the places showing higher accumulation of the metal. For the analytical process, the used technique was cold vapor atomic absorption spectrometry. The results demonstrated that the distribution of Hg in the analyzed portions presented wiede dispersion. For Thunnus albacares, the variation was of 0.004µg.g-1 in the liver, gills and spleen, and 0.172µg.g-1 in the muscular tissue. For Cynoscion microlepidotus, the variation was between 0.013µg.g-1 in gills and 0.250µg.g-1 in muscular tissue. The latter was the portion of higher concentration of this metal in both species, T. albacares = 0.080±0.050µg.g-1 and C. microlepidotus = 0.187±0.030µg.g-1, while less concentrations were found in the gills (0.029±0.031µg.g-1 in C. microlepidotus and in the eyes (0.013±0.008µg.g-1 in T. albacares.

  19. STRUKTUR UKURAN, HUBUNGAN PANJANG-BOBOT DAN FAKTOR KONDISI IKAN TUNA DI PERAIRAN PRIGI, JAWA TIMUR

    Directory of Open Access Journals (Sweden)

    Erfind Nurdin

    2016-03-01

    Full Text Available Penelitian tentang struktur ukuran dan faktor kondisi ikan tuna yang tertangkap di perairan sekitar rumpon di Selatan Prigi, Jawa Timur dilakukan pada bulan Juli 2010, Desember 2010 dan Januari 2011. Sampel ikan diperoleh di PPN Prigi, diidentifikasi menurut jenis dan diukur panjang cagak serta ditimbang bobotnya.  Tujuan penelitian ini adalah untuk mengetahui pola pertumbuhan dan faktor kondisi ikan tuna yang tertangkap di sekitar rumpon.  Hasil penelitian menunjukkan ikan cakalang (Katsuwonus pelamis yang diukur sebanyak 115 ekor dengan dominasi ukuran panjang berkisar antara 32–36 cmFL dan bobot antara 0,75–1,20 kg; tuna mata besar (Thunnus obesus sebanyak 114 ekor dengan dominasi panjang pada kisaran 40–44 cmFL dan bobot antara 0,75– 1,20 kg; dan tuna sirip kuning (Thunnus albacares 107 ekor dengan dominasi panjang berkisar antara 28–32 cmFL dengan bobot 0,30–0,75 kg. Hubungan panjang bobot ikan cakalang mengikuti persamaan W= 0,055FL2,733, tuna mata besar W= 0,014FL3,096 dan tuna sirip kuning W= 0,0006FL3,960.   Faktor kondisi (K ikan cakalang adalah 2, tuna mata besar 2,1 dan tuna sirip kuning 2,0.   Study on size structure and condition factor of tuna caught around FADs in the south of Prigi, East Java was conducted in July 2010, December 2010 and January 2011.  The objectives of this study are to investigate that the size distribution, L-W relationship and condition factor of dominant fish caught around of FADs.  The result showed that the size distribution of skipjack tuna dominated in range of  32–36 cmFL and 0.75–1.20 kg (body weight, bigeye tuna range of 40–44 cmFL and 0.75– 1.20 kg (body weight, yellowfin tuna range of 28–32 cmFL and 0.30–0.75 kg (body weight.  Length weight relationship of skipjack tuna can described as W= 0.055FL2.733, bigeye tuna W= 0.014FL3.096 and yellowfin W= 0.0006FL3.960.  The value of condition factor was 2.0 for skipjack tuna, mean while for bigeye tuna was 2.1 and for

  20. DAYA DUKUNG SUMBER DAYA PERIKANAN TUNA DI SAMUDERA HINDIA DALAM KAITANNYA DENGAN INDUSTRIALISASI PERIKANAN

    Directory of Open Access Journals (Sweden)

    Wijopriono Wijopriono

    2012-11-01

    Full Text Available Pemerintah berupaya untuk meningkatkan produksi dan ekspor hasil perikanan melalui program industrialisasi perikanan. Diantara komoditas utama perikanan yang ditetapkan menjadi target pertumbuhan ekspor adalah tuna dan cakalang. Salah satu area penangkapan penghasil komoditas tersebut adalah Samudera Hindia, yang menyumbang sekitar 17% dari seluruh produksi tuna dan cakalang Indonesia. Namun demikian, beberapa tahun terakhir ini produksi tuna dari perairan ini terus menurun. Peningkatan jumlah kapal yang lebih pada ukuran 10-30 GT belum mampu meningkatkan produksi secara berarti. Kajian stok global menunjukkan bahwa peluang untuk meningkatkan produksi dapat dilakukan untuk jenis tuna mata besar, madidihang dan cakalang. Untuk itu restrukturisasi armada penangkap tuna dan cakalang di Samudera Hindia diperlukan. Indonesian Government has been striving for increasing export of fish and fishery products through fisheries industrialization program. Among the commodities that has been targeted for the program are tuna and skipjack. One of the fishing areas for producing these commodities is Indian Ocean, which has contributed more than 17% to the total Indonesian tuna production. However, tuna production from this area has decreased during last couples of years. The increase of fleet number more on the size of 10-30 GT have not been able to increase tuna production sgnificantly. Global stock assessment suggested that there is an opportunity to increase tuna production, specifically yellowfin (Thunnus albacares, bigeye (T. obesus , and skipjack (Katsuwonus pelamis. To achieve this objective, restructurization of fishing fleet operated in Indian Ocean is needed.

  1. Keragaman Spesies Ikan Tuna di Pasar Ikan Kedonganan Bali dengan Analisis Sekuen Kontrol Daerah Mitokondria DNA (SPECIES DIVERSITY OF TUNA FISH USING MITOCHONDRIAL DNA CONTROL REGION SEQUENCE ANALYSIS AT KEDONGANAN FISH MARKET

    Directory of Open Access Journals (Sweden)

    Daud Steven Triyomi Hariyanto

    2015-10-01

    Full Text Available Tuna is an export commodity which has very high economic value. However, some tuna speciesare threatened with extinction. The purpose of this study was to identify the tuna species that aresold in Kedonganan Fish Market. The research method was polymerase chain reaction technique(PCR using the marker sequence mitochondrial DNA control region. Samples were obtained fromthe Fish Market tuna Kedonganan, Kuta, Badung, Bali. The total number of samples are 28specimens. Sequence from each sample was obtained through sequencing techniques. Sequencesobtained were run in BLAST (Basic Local Alignment Search Tool and subsequently analyzed withMEGA 5 for species confirmation. Three species of tuna that are identified in the Kedonganan FishMarket is: Thunnus albacares, T. obesus, and Katsuwonus pelamis. All three species have highgenetic variation HD = 1. This study needed to be continued with more number of samples todetermine the species of tuna sold in Kedonganan Fish Market.

  2. Report of species diagnosis of a tuna at Queens Products B.V. on 23 December 2009

    NARCIS (Netherlands)

    Couperus, A.S.

    2009-01-01

    According to a company in the same marketsegment as Queen Products B.V. part of the tuna filet sold by Queens Products B.V. does not consist of the species that is mentioned on the label. According to DNA analysis filets were not from the species on the label, Albacore (Thunnus alalunga), but from

  3. STATUS PEMANFAATAN DAN PENGELOLAAN SUMBERDAYA IKAN TUNA NERITIK DI SAMUDERA HINDIA WPP 572 DAN 573

    Directory of Open Access Journals (Sweden)

    Agustinus Anung Widodo

    2014-05-01

    Full Text Available Dalam rangka mendeskripsikan status pemanfaatan dan pengelolaan sumberdaya tuna neritik di perairan Samudera Hindia (WPP 572 dan 573 telah dilakukan analisis terhadap informasi tentang jenis dan produksi tuna neritik yang disajikan dalam Statistik Perikanan Tangkap di Laut Menurut WPP tahun 2005-2012 (DJPT, 2013 serta data hasil penelitian berbasis di PPS Cilacap dan PPN Sibolga tahun 2011. Rekomendasi ‘working party’ tentang tuna neritik dari IOTC dikaji sebagai langkah pengelolaan perikanan tuna neritik di Indonesia. Hasil analisis dan kajian menunjukkan bahwa sumberdaya ikan tuna neritik yang tertangkap nelayan Indonesia di perairan WPP 572 dan 573 meliputi tongkol lisong (Auxis rochei, tongkol krai (Auxis thazard, tongkol komo atau kawakawa (Euthynnus affinis dan tongkol abu-abu (Thunnus tonggol. Tuna neritik tertangkap sebagai by-product dari pukat cincin, jaring insang hanyut, pancing tonda, pancing ulur dan bagan. Tahun 2011 produksi neritik tuna di Samudera Hindia khususnya WPP 572 dan 573 mencapai 121.818 ton atau 29,4% dari total produksi tuna neritik nasional. Tuna neritik jenis tongkol lisong dan krai yang tertangkap jaring insang hanyut yang berbasis di Cilacap > 70% merupakan ikan yang telah dewasa. Adapun tongkol komo yang tertangkap pukat cincin yang berbasis di Sibolga sekitar 55,5% merupakan ikan dewasa. Belum ada langkah-langkah pengelolaan secara spesifik terhadap sumberdaya tuna neritik di Indonesia. Merujuk hasil Working Party on Neritic Tuna pertama dan kedua tahun 2011 dan 2012, Indian Ocean Tuna Commission (IOTC merekomendasikan adanya kerjasama antar negara anggota IOTC yang saling berdekatan didalam melakukan pengelolaan sumberdaya neritik tuna. Langkah pertama adalah dilakukan perelitian mengenai populasi melalui studi mtDNA untuk memastikan status stok dan populasinya.   The species of neritic tuna caught by fishers in the Indian Ocean particularly FMAs 572 and 573 consisted of frigate tuna (Auxis thazard

  4. Factors that determine the quality of bigeye tuna, caught in the western tropical Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    C.C. Nóbrega

    2014-06-01

    Full Text Available Tuna are highly prized in Oriental cuisine, and the bigeye tuna (Thunnus obesus is of great commercial importance. Quality is assessed by the tuna meat quality, freshness, texture and fat, which can be altered by factors inherent to capture, such as days of onboard storage, months of the year, whether the catch was living or dead, fish weight and year. These factors were correlated to identify those that affect quality. We obtained data from nine vessels, from January 2007 to April 2010, creating an information bank of 21,908 bigeye tuna. Fish quality and parameters were related using multiple linear regression analysis, in which the variables were included in the model by a stepwise procedure (F>4. We found that live catch, heavier fish and fewer days of storage positively affected the quality, and that there is a seasonality of quality related to biological factors, which are not amenable to control.

  5. STUKTUR UKURAN IKAN MADIDIHANG (Thunnus albacares YANG TERTANGKAP PANCING ULUR DI SEKITAR RUMPON SAMUDERA HINDIA SELATAN BALI DAN LOMBOK

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    Noor Muhammad

    2016-03-01

    Yellowfin tuna (Thunnus albacares are the main catches of hand line which fished in around of rumpon (FAD. Yellowfin tuna is one of fish that associated with rumpon. Rumpon is a device to generate plankton and other small fish, to attract the higher tropic level as part of it’s prey. The variation of distribution of tuna could determine the use of fishing gear will be operated.  A research conducted at the fish landing base  conducted at  Kedonganan-Bali during April to November 2009, to obtain data and information about the size stucsture, length and weight relationships, size of first capture of yellowfin tuna that caught in around fish aggregation devices. The results showed that yellowfin tuna caught in around of rumpon waters in the Indian Ocean have a range of lengths between 81-170 cmFL, the pattern of growth is positive allometric and length at first capture of yellowfin tuna caught by handline was 126,7 cmFL. Yellowfin tuna were caught in around of rumpon waters of the Indian Ocean are dominated by mature fish or fish had spawned.

  6. MASS SPECTROMETRIC ANALYSIS FOR THE IDENTIFICATION OF THUNNUS GENUS FOUR SPECIES

    Directory of Open Access Journals (Sweden)

    T. Pepe

    2011-01-01

    Full Text Available An accurate identification of similar fish species is necessary to prevent illegal substitution and is imposed by labeling regulations in UE countries (1. The genus Thunnus comprises many species of different quality and commercial value. The increasing trade of fish preparations of the species included in this genus and the consequent loss of the external anatomical and morphological features enables fraudulent substitutions. This study reports data relating to the proteomic analysis of four tuna species (T. thynnus, T. alalunga, T. albacares, T. obesus. Sarcoplasmic proteins were studied by mono and two dimensional electrophoresis. The most significant proteins for the characterization of the species were analyzed by mass spectrometric techniques. As reported in a previous study (2, an accurate identification of the species seems possible, owing to the polymorphism displayed by the species of the Thunnus genus.

  7. SEBARAN HASIL TANGKAPAN MADIDIHANG (Thunnus albacares Bonnaterre, 1788 DI SAMUDERA HINDIA BAGIAN TIMUR

    Directory of Open Access Journals (Sweden)

    Arief Wujdi

    2015-06-01

    Full Text Available Ikan Madidihang (Thunnus albacares Bobbaterre, 1788 merupakan salah satu komoditaspenting bagi industri perikanan di Indonesia dimana hasil tangkapannya merupakan yang tertinggi dibandingkan jenis tuna lainnya. Saat ini, kondisi stok madidihang berada dalam kondisi yang baik. Namun, untuk menjaga kelangsungan pemantaatan stok ikan tuna, diperlukan upaya pengelolaan sumber daya tuna. Penelitian ini bertujuan untuk mengetahui distribusi laju tangkap madidihang di Samudera Hindia Bagian Timur. Pengumpulan data dilakukan oleh pemantau ilmiah pada kapal rawai tuna komersial yang berbasis di Benoa, Pelabuhanratu dan Bungus dari Agustus 2005 sampai Desember 2013; serta program monitoring pendaratan tuna yang berbasis di Benoa tahun 2010-2013. Hasil penelitian menunjukkan bahwa laju pancing bervariasi secara bulanan dan tahunan. Rata-rata bulanan laju pancing tertinggi terjadi pada Mei (0,17 ekor/100 pancing dan terendah pada Februari (0,01 ekor/100 pancing, sedangkan rata-rata laju pancing tahunan tertinggi pada 2006 (0,11 ekor/100 pancing dan terendah pada 2011 (0,06 ekor/100 pancing. Rata-rata laju pancing tahunan cenderung mengalami penurunan sebesar 29,48%/ tahun. Ikan madidihang tertangkap oleh rawai tuna Indonesia tersebar dari 0°-34° LS dan 76°-134° BT. Sebaran spasial laju pancing tertinggi berada di sekitar Kepulauan Mentawai dan selatan Jawa Timur hingga Nusa Tenggara. Yellowfin tuna (Thunnus albacares Bobbaterre, 1788 is one of the important commodity for the fishing industry in Indonesia because it has the highest catches compared with other tunas. Nowadays, the yellowfin stock is currently in good condition (not overfished and not subject to overfishing. However, management measure was required to support sustainability of tuna fishery. This study aims to determine the hook rate distribution of yellowfin tuna in the Eastern Indian Ocean. Data was obtained by scientific observers on commercial tuna longline vessels

  8. Investigation of the Impact of Sonar Transmission on Fisheries and Habitat in the U.S. Navy’s USWTR: Summary of Stakeholder Concerns and Appropriate Research Areas

    Science.gov (United States)

    2007-09-01

    Thunnus thynnus (Block et al. 2001). This technology could potentially be applied to large-bodied fish species that occur in and around the...listed below. a. Sciaenidae spp. b. Caranigidae spp. c. Scombridae spp. d. Scleanidae spp. e. Bluefin and Yellowfin Tuna ( Thunnus spp.) f

  9. Trace elements in Thunnus thynnus from Mediterranean Sea and benefit-risk assessment for consumers.

    Science.gov (United States)

    Di Bella, Giuseppa; Potortì, Angela Giorgia; Lo Turco, Vincenzo; Bua, Daniel; Licata, Patrizia; Cicero, Nicola; Dugo, Giacomo

    2015-01-01

    Trace elemental levels were determined by inductively coupled plasma-mass spectrometry in muscle, eggs and sperm of 23 Thunnus thynnus fishes collected from May to August 2013 in the Mediterranean Sea. Zn, Mn, Fe, Cu, Cr, Ni and Se content was compared with Recommended Daily Allowances. Cd, Hg and Pb concentrations were below the maximum limits fixed by the European Legislation. Tuna food safety was evaluated considering Tolerable Weekly Intake (TWI) or Provisional Tolerable Weekly Intake for As, Hg, Cd and Pb. Only BMDL01 data for As and Pb were calculated as established by the Joint FAO/WHO Expert Committed on Food Additives. The daily consumption of fresh tuna ensures a good intake of these elements. None of the tested samples surpassed the European maximum limits. Cd, Hg and Pb remained within safety margins, while As is slightly higher than the provisional TWI.

  10. Mercury in tunas and blue marlin in the North Pacific Ocean.

    Science.gov (United States)

    Drevnick, Paul E; Brooks, Barbara A

    2017-05-01

    Models and data from the North Pacific Ocean indicate that mercury concentrations in water and biota are increasing in response to (global or hemispheric) anthropogenic mercury releases. In the present study, we provide an updated record of mercury in yellowfin tuna (Thunnus albacares) caught near Hawaii that confirms an earlier conclusion that mercury concentrations in these fish are increasing at a rate similar to that observed in waters shallower than 1000 m. We also compiled and reanalyzed data from bigeye tuna (Thunnus obesus) and blue marlin (Makaira nigricans) caught near Hawaii in the 1970s and 2000s. Increases in mercury concentrations in bigeye tuna are consistent with the trend found in yellowfin tuna, in both timing and magnitude. The data available for blue marlin do not allow for a fair comparison among years, because mercury concentrations differ between sexes for this species, and sex was identified (or reported) in only 3 of 7 studies. Also, mercury concentrations in blue marlin may be insensitive to modest changes in mercury exposure, because this species appears to have the ability to detoxify mercury. The North Pacific Ocean is a region of both relatively high rates of atmospheric mercury deposition and capture fisheries production. Other data sets that allow temporal comparisons in mercury concentrations, such as pacific cod (Gadus macrocephalus) in Alaskan waters and albacore tuna (Thunnus alalunga) off the US Pacific coast, should be explored further, to aid in understanding human health and ecological risks and to develop additional baseline knowledge for assessing changes in a region expected to respond strongly to reductions in anthropogenic mercury emissions. Environ Toxicol Chem 2017;36:1365-1374. © 2017 SETAC. © 2017 SETAC.

  11. 76 FR 13583 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Quotas and Atlantic Tuna Fisheries...

    Science.gov (United States)

    2011-03-14

    ...-mt TAC, reduced from 1,800 mt for 2010, is expected to allow for continued stock growth under both... methodology for compliance purposes. Nevertheless, the ICCAT- recommended TAC and U.S. quota are inclusive of... to the fishery, in the ] short term. In the long term, however, as stock growth is hindered, negative...

  12. 76 FR 39019 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Quotas and Atlantic Tuna Fisheries...

    Science.gov (United States)

    2011-07-05

    ..., and potential quota transfers, scientific research collection, and accounting for potential... previous fishing year and any accounting for estimated dead discards of BFT. At the time the proposed rule... categories (i.e., quota specifications), and its proposed methodology for handling dead discards. NMFS...

  13. ANALISIS EKSPOR IKAN TUNA INDONESIA

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    Indriana - Yudiarosa

    2012-05-01

    Full Text Available ABSTRACT   Facing the  free trade era, Indonesia needs to reorganize its export strategies with not mainly depending on oil and gas sector only. In relation to this, tuna as Indonesia’s export commodity has plate an important role but presently Indonesia can only contribute 7% of the world tuna supply. Being one of the country which have unused tunas potensial  up to 53,7%, Indonesia’s opportunity to supply world market is the large. This studied was aimed at analyzing; factors influencing Indonesia’s tunas export; factors  influencing domestic supply of tunas; predicting tunas export in the next 5 years (2000 –2005 and study marketing strategies that effect Indonesia’s export of tuna. To analyze factors that influenced tunas export and domestic supply of tunas, simultan equation in the form of double logarithma with two stage least square (2SLS methods were used. Meanwhile, export development were analyzed with trend analysis and tunas export strategies with SWOT analysis. Result of this study showed that, tunas export price,  tunas export  tax, exchange rate and tunas export the previous year effected tunas export.Factors that influenced domestic tuna supplies were domestic prices of tunas and domestic supplies of tunas the previous year.       Tunas export prediction from 2000 – 2005 drawn from the trend analysis; shows an increase in export by average of 1.06%. Hopefully this will be followed by increase in tunas production by an average of 1.27%. Increase in tunas export must be supported by marketing strategies.Marketing strategies that can be carried out based on the SWOT analysis are improving infrastucture, transfer of technology for fleet and catch material, improvement in the quality and quantity of the product , marketing research and upgrading cooperation with importing countries.   Keywords: tuna fish, export

  14. FLUKTUASI DAN KOMPOSISI HASIL TANGKAPAN TUNA NERITIK TERTANGKAP JARING INSANG DI PERAIRAN LAUT CINA SELATAN

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    Arief Wujdi

    2016-03-01

    Full Text Available Saat ini tuna neritik merupakan komoditas penting perikanan di Indonesia, namun ketersediaan data dan informasi hasil tangkapan jenis tuna ini masih tergolong kurang. Penelitian ini bertujuan untuk memperoleh informasi mengenai sebaran daerah penangkapan, fluktuasi hasil tangkapan tuna neritik yang tertangkap jaring insang yang beroperasi di Laut Cina Selatan. Pengumpulan data dilakukan melalui program enumerasi monitoring hasil tangkapan harian di Pemangkat pada tahun 2011-2012. Hasil menunjukkan daerah penangkapan tersebar di perairan Laut Cina Selatan pada koordinat 01°03’ LS-04°57’ LU; dan 104°65’-110°00’ BT. Hasil tangkapan jenis tuna neritik menunjukan variasi yang cenderung sama dimana puncak hasil tangkapan terjadi pada bulan Oktober dan November. Pola CPUE berfluktuasi dan cenderung mengalami peningkatan dan puncaknya terjadi pada bulan November 2011 dan 2012, yaitu 402,85 dan 444,57 kg/hari/trip. Secara statistik hasil tangkapan pada periode 2011-2012 tidak berbeda nyata (p<0,05. Komposisi hasil tangkapan bulanan jenis tuna neritik bervariasi berdasarkan atas spesies yang didominasi oleh Euthynnus affinis (49,7% diikuti dengan Thunnus tonggol (33,4%; Scomberomorus commerson (15,9%; dan Scomberomorus guttatus (1%. Kelimpahan Euthynnus affinis terjadi pada musim timur hingga musim peralihan 2 (Juni- November, sedangkan kelimpahan Thunnus tonggol terjadi pada musim barat (Januari-Februari. Nowadays, neritic tuna just become an important commodity Indonesia. However, the information about catch of tuna neritic species in Indonesia still quite lacks. This This study aims to obtain information about catch fluctuation, monthly catch per unit of effort, and catch composition of neritic tuna species caught by gill net operated in the South China Sea. Data was collected by daily catch monitoring program by enumerator in Pemangkat during period 2011-2012. The result showed that gillnetter fishing ground is scattered between 01°03

  15. Global trophic ecology of yellowfin, bigeye, and albacore tunas: Understanding predation on micronekton communities at ocean-basin scales

    Science.gov (United States)

    Duffy, Leanne M.; Kuhnert, Petra M.; Pethybridge, Heidi R.; Young, Jock W.; Olson, Robert J.; Logan, John M.; Goñi, Nicolas; Romanov, Evgeny; Allain, Valerie; Staudinger, Michelle D.; Abecassis, Melanie; Choy, C. Anela; Hobday, Alistair J.; Simier, Monique; Galván-Magaña, Felipe; Potier, Michel; Ménard, Frederic

    2017-06-01

    Predator-prey interactions for three commercially valuable tuna species: yellowfin (Thunnus albacares), bigeye (T. obesus), and albacore (T. alalunga), collected over a 40-year period from the Pacific, Indian, and Atlantic Oceans, were used to quantitatively assess broad, macro-scale trophic patterns in pelagic ecosystems. Analysis of over 14,000 tuna stomachs, using a modified classification tree approach, revealed for the first time the global expanse of pelagic predatory fish diet and global patterns of micronekton diversity. Ommastrephid squids were consistently one of the top prey groups by weight across all tuna species and in most ocean bodies. Interspecific differences in prey were apparent, with epipelagic scombrid and mesopelagic paralepidid fishes globally important for yellowfin and bigeye tunas, respectively, while vertically-migrating euphausiid crustaceans were important for albacore tuna in the Atlantic and Pacific Oceans. Diet diversity showed global and regional patterns among tuna species. In the central and western Pacific Ocean, characterized by low productivity, a high diversity of micronekton prey was detected while low prey diversity was evident in highly productive coastal waters where upwelling occurs. Spatial patterns of diet diversity were most variable in yellowfin and bigeye tunas while a latitudinal diversity gradient was observed with lower diversity in temperate regions for albacore tuna. Sea-surface temperature was a reasonable predictor of the diets of yellowfin and bigeye tunas, whereas chlorophyll-a was the best environmental predictor of albacore diet. These results suggest that the ongoing expansion of warmer, less productive waters in the world's oceans may alter foraging opportunities for tunas due to regional changes in prey abundances and compositions.

  16. RAD-seq derived genome-wide nuclear markers resolve the phylogeny of tunas

    KAUST Repository

    Díaz-Arce, Natalia

    2016-06-07

    Although species from the genus Thunnus include some of the most commercially important and most severely overexploited fishes, the phylogeny of this genus is still unresolved, hampering evolutionary and traceability studies that could help improve conservation and management strategies for these species. Previous attempts based on mitochondrial and nuclear markers were unsuccessful in inferring a congruent and reliable phylogeny, probably due to mitochondrial introgression events and lack of enough phylogenetically informative markers. Here we infer the first genome-wide nuclear marker-based phylogeny of tunas using restriction site associated DNA sequencing (RAD-seq) data. Our results, derived from phylogenomic inferences obtained from 128 nucleotide matrices constructed using alternative data assembly procedures, support a single Thunnus evolutionary history that challenges previous assumptions based on morphological and molecular data.

  17. Arsenic, cadmium and lead in fresh and processed tuna marketed in Galicia (NW Spain): Risk assessment of dietary exposure.

    Science.gov (United States)

    Núñez, Ricardo; García, M Ángeles; Alonso, Julián; Melgar, M Julia

    2018-01-29

    Currently, metal bioaccumulation in fish is increasing and is a cause of concern due to toxicity. Total arsenic, cadmium and lead concentrations in fresh and processed tuna (110 samples) marketed in Galicia (NW Spain) were determined by ICP-MS spectrometry. The average concentrations of As and Cd, 3.78 and 0.024 mg kg -1 w.w., respectively, in fresh tuna were statistically significantly higher than those in processed tuna (p  natural > pickled sauce. Of the two species studied in canned tuna, Thunnus alalunga showed statistically significant higher levels both for As 1.28 mg kg -1 (p < 0.001) and Pb 0.013 mg kg -1 (p = 0.0496) than Thunnus albacares. No samples surpassed the limits set by the EU for Cd and Pb. The limit for As in fish has not been established, but the arsenic contents in fresh tuna reported here are important, as they are among the highest reported in the literature. Considering public health in children and adults with respect to the investigated metals, the estimated daily intakes (EDIs) did not exceed the tolerable intakes. No chronic systemic risk was found since all the target hazard quotients (THQs-TTHQs) were far below 1 (critical value), and the carcinogenic risk (CR) for As did not exceed the acceptable value of 10 -5 . Thus, tuna consumption in the Galician diet does not pose a risk for different population groups in terms of these studied metals/metalloids. Copyright © 2018. Published by Elsevier B.V.

  18. Isolation and characterization of a new zinc-binding protein from albacore tuna plasma

    Energy Technology Data Exchange (ETDEWEB)

    Dyke, B.; Hegenauer, J.; Saltman, P.; Laurs, R.M.

    1987-06-02

    The protein responsible for sequestering high levels of zinc in the plasma of the albacore tuna (Thunnus alalunga) has been isolated by sequential chromatography. The glycoprotein has a molecular weight of 66,000. Approximately 8.2% of its amino acid residues are histidines. Equilibrium dialysis experiments show it to bind 3 mol of zinc/mol of protein. The stoichiometric constant for the association of zinc with a binding site containing three histidines was determined to be 10/sup 9.4/. This protein is different from albumin and represents a previously uncharacterized zinc transport protein.

  19. HUBUNGAN PANJANG BERAT, TINGKAT EKSPLOITASI DAN FLUKTUASI HASIL TANGKAPAN ALBAKORA (Thunnus alalunga, Bonnaterre DI SAMUDERA HINDIA

    Directory of Open Access Journals (Sweden)

    Setya Triharyuni

    2016-05-01

    Full Text Available Albakora (Thunnus alalunga, Bonnaterre merupakan salah satu jenis tuna yang ditangkap oleh nelayan dengan menggunakan pancing rawai dan jaring insang hanyut. Produksi Albakora yang didaratkan di Cilacap cenderung mengalami peningkatan sejak tahun 2002-2010, namun pada tahun 2004, 2007, dan 2009 mengalami penurunan. Penelitian sumberdaya albakora di Samudera Hindia telah dilakukan dengan tujuan untuk menentukan hubungan panjang dan berat, ukuran rata-rata tertangkap, tingkat eksploitasi albakora dan fluktuasi hasil tangkapan. Data yang digunakan adalah data sampling enumerator hasil tangkapan rawai tuna dan data statistik  perikanan PPS Cilacap tahun 2002-2010. Hasil penelitian menunjukkan bahwa hubungan panjang dan berat bersifat isometric dengan persamaan W= 3.10-6L3.42, ukuran rata-rata tertangkap ikan albakora adalah 99.7 cm, ukuran ini lebih besar dari setengah panjang infinitifnya (L∞. Tingkat eksploitasi albakora berdasarkan data tahun 2002-2010 telah berada pada taraf lebih langkap (Over fishing. Hasil tangkapan albakora yang didaratkan di PPS Cilacap pada bulan April-Mei lebih tinggi dibandingkan pada bulan November-Desember. Albacore (Thunnus alalunga, Bonnaterre is one of tuna species caught using longline and drift gill nets. Albacore production landed in Cilacap fishing port generally tend to increase from the year 2002 to 2010, except in years 2004, 2007, and 2009. The research on albacore resource in the Indian Ocean was conducted,   to investigate the length weight relationship, average size of fish caught, exploitation rate and catch fluctuation of albacore. Length and weight of albacore was analyzed using data from tuna longline catch and fishery statistic data from Cilacap fishing port in 2002-2010. The results showed that length and weight relation of albacore was isometric following the formula W= 3.10-6L3.42, the average length was 99.7cm higher than length infinitif (L∞. Based on production and effort of albacore

  20. Molecules infer origins of ectoparasite infrapopulations on tuna.

    Science.gov (United States)

    Bullard, Stephen A; Olivares-Fuster, Oscar; Benz, George W; Arias, Covadonga R

    2011-12-01

    Infrapopulation genetic variation of the oioxenous, hermaphroditic flatworm Nasicola klawei (Monogenea: Capsalidae) infecting the nasal cavities of nine yellowfin tuna, Thunnus albacares, from the Gulf of Mexico was analyzed using the first internal transcribed spacer (ITS1) single strand conformation polymorphism (SSCP), ITS1 sequencing, and amplified fragment length polymorphism (AFLP). Of a total of 32 worms, six had unique ITS1-SSCP types and the rest was grouped by three types. Two worms of the same infrapopulation shared an ITS1-SSCP type in nine instances but no infrapopulation was monophyletic by ITS1-SSCP analysis. ITS1 sequences (420 bp) varied by 1-11 (0.2-2.6%) nucleotides. Twenty-three AFLP profiles of 80-110 bands failed to support genomic monophyly of any N. klawei infrapopulation. 28S rDNA (990 bp) sequences from four worms representing four infrapopulations were identical and matched conspecific GenBank sequences. Concordant ITS1-SSCP and AFLP analyses indicated that these N. klawei infrapopulations principally resulted from tuna being repeatedly colonized by planktonic, infective larvae (oncomiracidia) rather than by a single host colonization followed by parasite maturation, self-fertilization, and production of auto-infecting progeny. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Discovery of Genome-Wide Microsatellite Markers in Scombridae: A Pilot Study on Albacore Tuna.

    Directory of Open Access Journals (Sweden)

    Natacha Nikolic

    Full Text Available Recent developments in sequencing technologies and bioinformatics analysis provide a greater amount of DNA sequencing reads at a low cost. Microsatellites are the markers of choice for a variety of population genetic studies, and high quality markers can be discovered in non-model organisms, such as tuna, with these recent developments. Here, we use a high-throughput method to isolate microsatellite markers in albacore tuna, Thunnus alalunga, based on coupling multiplex enrichment and next-generation sequencing on 454 GS-FLX Titanium pyrosequencing. The crucial minimum number of polymorphic markers to infer evolutionary and ecological processes for this species has been described for the first time. We provide 1670 microsatellite design primer pairs, and technical and molecular genetics selection resulting in 43 polymorphic microsatellite markers. On this panel, we characterized 34 random and selectively neutral markers («neutral» and 9 «non-neutral» markers. The variability of «neutral» markers was screened with 136 individuals of albacore tuna from southwest Indian Ocean (42, northwest Indian Ocean (31, South Africa (31, and southeast Atlantic Ocean (32. Power analysis demonstrated that the panel of genetic markers can be applied in diversity and population genetics studies. Global genetic diversity for albacore was high with a mean number of alleles at 16.94; observed heterozygosity 66% and expected heterozygosity 77%. The number of individuals was insufficient to provide accurate results on differentiation. Of the 9 «non-neutral» markers, 3 were linked to a sequence of known function. The one is located to a sequence having an immunity function (ThuAla-Tcell-01 and the other to a sequence having energy allocation function (ThuAla-Hki-01. These two markers were genotyped on the 136 individuals and presented different diversity levels. ThuAla-Tcell-01 has a high number of alleles (20, heterozygosity (87-90%, and assignment index. Thu

  2. Discovery of Genome-Wide Microsatellite Markers in Scombridae: A Pilot Study on Albacore Tuna.

    Science.gov (United States)

    Nikolic, Natacha; Duthoy, Stéphanie; Destombes, Antoine; Bodin, Nathalie; West, Wendy; Puech, Alexis; Bourjea, Jérôme

    2015-01-01

    Recent developments in sequencing technologies and bioinformatics analysis provide a greater amount of DNA sequencing reads at a low cost. Microsatellites are the markers of choice for a variety of population genetic studies, and high quality markers can be discovered in non-model organisms, such as tuna, with these recent developments. Here, we use a high-throughput method to isolate microsatellite markers in albacore tuna, Thunnus alalunga, based on coupling multiplex enrichment and next-generation sequencing on 454 GS-FLX Titanium pyrosequencing. The crucial minimum number of polymorphic markers to infer evolutionary and ecological processes for this species has been described for the first time. We provide 1670 microsatellite design primer pairs, and technical and molecular genetics selection resulting in 43 polymorphic microsatellite markers. On this panel, we characterized 34 random and selectively neutral markers («neutral») and 9 «non-neutral» markers. The variability of «neutral» markers was screened with 136 individuals of albacore tuna from southwest Indian Ocean (42), northwest Indian Ocean (31), South Africa (31), and southeast Atlantic Ocean (32). Power analysis demonstrated that the panel of genetic markers can be applied in diversity and population genetics studies. Global genetic diversity for albacore was high with a mean number of alleles at 16.94; observed heterozygosity 66% and expected heterozygosity 77%. The number of individuals was insufficient to provide accurate results on differentiation. Of the 9 «non-neutral» markers, 3 were linked to a sequence of known function. The one is located to a sequence having an immunity function (ThuAla-Tcell-01) and the other to a sequence having energy allocation function (ThuAla-Hki-01). These two markers were genotyped on the 136 individuals and presented different diversity levels. ThuAla-Tcell-01 has a high number of alleles (20), heterozygosity (87-90%), and assignment index. ThuAla-Hki-01

  3. Effect of tuna skin gelatin-based coating enriched with seaweed extracts on the quality of tuna fillets during storage at 4 °C

    Directory of Open Access Journals (Sweden)

    Milene Vala

    2017-10-01

    Full Text Available Nowadays, consumers demand high quality food products with an extended shelf-life without chemical additives. Edible coatings (EC containing natural compounds are a promising preservation technology for raw seafood without compromising fresh-like appeal and nutritional content.The aim of this work was to evaluate the effect of Thunnus obesus skin gelatin-based EC containing Codium spp. or Fucus vesiculosus extracts on raw tuna preservation. Three gelatin-based EC (gelatin (5 % + glycerol (25 %; gelatin (5 % + Codium spp. (1 % + glycerol (25 %; gelatin (5 % + Fucus vesiculosus (1 % + glycerol (25 % were applied directly on the surface of tuna fillets. Functional properties of gelatin and gelatin-based EC containing seaweed extracts were also studied. The gelatin was extracted by an acid-swelling process in the presence/absence of pepsin, followed by subsequent heating/refrigeration, after a pre-treatment with NaOH. The type of acid, temperature and concentration of NaOH greatly influence the process yield. The higher extraction yield was achieved using acetic acid in the presence of pepsin by subsequent refrigeration, especially when skins were previously treated with NaOH (0.2 M. Tuna quality was assessed over 12 days of storage at 4 ± 1 °C in terms of chemical and microbial indices. Results showed that tuna skin gelatin-based EC avoids tuna deterioration. Microbial growth, assessed by total viable counts, and total volatile basic nitrogen were maintained below the maximum limits recommended, contrarily to the control. Additionally, the use of EC increased the stability of red colour during storage. 

  4. Changesin Myoglobin of Big Eye Tuna During Chilling Storage

    Directory of Open Access Journals (Sweden)

    Stevi Imelda Murniati Wodi

    2015-01-01

    Full Text Available Big eye tuna (Thunnus obesus is one of the species of tuna which is have some value added such as have potential to improve animal protein sources, have high economic values as well as an export commodity.Mishandling and misapplication of high temparatures on the tuna handling at the tropics and sub tropics climate was significantly decreasing the value of myoglobin and affecting the solubility of protein. Myoglobin is a globular protein that have small molecular weight size and it was an important factor for determining the quality of meat and influencing factors of purchasing power by the consumer. The purpose of this experiments is to determining the changes of myoglobin content and the water soluble proteins content at some parts of big eye tuna in 9 days chilling temperatures. The portion which is analized was the ventral area, dorsal area and tail area. Myoglobin content in all portion above, both light and dark meat was analized. The results shows the decreased value of myoglobin content from first handling (day zero until day ninth (days 9th experiment. Each myoglobin contentfrom white meat at at ventral, dorsal and tail meat was decreased from 121.68 mg/100 into 41.35 mg/100, 148.2 mg/100g into 52.01 mg/100g, 105.16 mg/100g into 31.34 gr/100gram, after day ninth. The myoglobin content from dark meat at ventral, dorsal and tail meat, was decreased, too ; from 418.64 mg/100 gr into 121.01 mg/100 g, 446.21 mg/100 g into 58.34 mg/100 r and 145.65 mg/100 gr into 87.98 mg/100g after day ninth.Water soluble protein was derived into protein bands with molecular weight 15,4 kDa and 14 kDa. Its suspected as the myoglobin protein. The molecular weight difference was caused from degradation of protein during the storage.Keywords: Big eye tuna, meat, storage, myoglobin

  5. SEBARAN UKURAN PANJANG DAN NISBAH KELAMIN IKAN MADIDIHANG (Thunnus albacares DI SAMUDERA HINDIA BAGIAN TIMUR

    Directory of Open Access Journals (Sweden)

    Arief Wujdi

    2015-12-01

    Full Text Available Ikan madidihang atau tuna sirip kuning (Thunnus albacares merupakan salah satu komoditas penting bagi industri perikanan di Indonesia dengan hasil tangkapan tertinggi dibandingkan jenis tuna lainnya. Sebagai dasar pengelolaan sumberdaya ikan yang berkelanjutan, diperlukan data dan informasi tentang komposisi ukuran layak tangkap yaitu membandingkan proporsi rata-rata ikan tertangkap (Lc dan matang gonad (Lm, serta nisbah kelamin sebagai indikator pendugaan kemampuan memijah. Pengumpulan data dilakukanmelalui program observasi diatas kapal rawai tuna yang berbasis di Benoa, Pelabuhanratu dan Bungus dari bulan Agustus 2005 hingga November 2013. Penghitungan nisbah kelamin menggunakan uji Chi-Square (X2 dengan tingkat kepercayaan 95%. Hasil penelitian menunjukkan bahwa distribusi ukuran panjang cagak ikan madidihang berkisar antara 30-179 cm, modus ukuran 106-110 cm dan rata-rata 101,65 cm. Sebanyak 81,03% madidihang yang tertangkap berukuran lebih besar daripada Lm yang berarti telah layak tangkap. Nisbah kelamin betina:jantan adalah 1:1,45 mengindikasikan dominansi ikan jantan. Hubungan antara nisbah kelamin dengan panjang ikan menunjukkan signifikansi dimana ikan betina semakin berkurang pada ukuran 120-180 cm, serta tidak ditemukan lagi pada ukuran lebih dari 170 cm. Korelasi nisbah kelamin dan panjang cagak dapat dideskripsikan dengan persamaan regresi sebagai berikut: 1,8013 - 0,0099 FL dengan nilai R2=0,8058. Yellowfin tuna or YFT (Thunnus albacares is one of the important commodity for the fishing industry in Indonesia because it has the highest catches compared with other tunas. In order to fisheries resources management, it was necessary to monitor the size composition compared between proportion average size captured (Lc and maturity size (Lm to meets the size eligibility, as well as the sex ratio as an indicator to estimate the ability of spawn. Data collected by scientific observers program which was following tuna longline

  6. Abundance and Distribution Patterns of Thunnus albacares in Isla del Coco National Park through Predictive Habitat Suitability Models.

    Science.gov (United States)

    Gonzáles-Andrés, Cristina; F M Lopes, Priscila; Cortés, Jorge; Sánchez-Lizaso, José Luis; Pennino, Maria Grazia

    2016-01-01

    Information on the distribution and habitat preferences of ecologically and commercially important species is essential for their management and protection. This is especially important as climate change, pollution, and overfishing change the structure and functioning of pelagic ecosystems. In this study, we used Bayesian hierarchical spatial-temporal models to map the Essential Fish Habitats of the Yellowfin tuna (Thunnus albacares) in the waters around Isla del Coco National Park, Pacific Costa Rica, based on independent underwater observations from 1993 to 2013. We assessed if observed changes in the distribution and abundance of this species are related with habitat characteristics, fishing intensity or more extreme climatic events, including the El Niño Southern Oscillation, and changes on the average sea surface temperature. Yellowfin tuna showed a decreasing abundance trend in the sampled period, whereas higher abundances were found in shallow and warmer waters, with high concentration of chlorophyll-a, and in surrounding seamounts. In addition, El Niño Southern Oscillation events did not seem to affect Yellowfin tuna distribution and abundance. Understanding the habitat preferences of this species, using approaches as the one developed here, may help design integrated programs for more efficient management of vulnerable species.

  7. Abundance and Distribution Patterns of Thunnus albacares in Isla del Coco National Park through Predictive Habitat Suitability Models.

    Directory of Open Access Journals (Sweden)

    Cristina Gonzáles-Andrés

    Full Text Available Information on the distribution and habitat preferences of ecologically and commercially important species is essential for their management and protection. This is especially important as climate change, pollution, and overfishing change the structure and functioning of pelagic ecosystems. In this study, we used Bayesian hierarchical spatial-temporal models to map the Essential Fish Habitats of the Yellowfin tuna (Thunnus albacares in the waters around Isla del Coco National Park, Pacific Costa Rica, based on independent underwater observations from 1993 to 2013. We assessed if observed changes in the distribution and abundance of this species are related with habitat characteristics, fishing intensity or more extreme climatic events, including the El Niño Southern Oscillation, and changes on the average sea surface temperature. Yellowfin tuna showed a decreasing abundance trend in the sampled period, whereas higher abundances were found in shallow and warmer waters, with high concentration of chlorophyll-a, and in surrounding seamounts. In addition, El Niño Southern Oscillation events did not seem to affect Yellowfin tuna distribution and abundance. Understanding the habitat preferences of this species, using approaches as the one developed here, may help design integrated programs for more efficient management of vulnerable species.

  8. Comparative ecology of widely distributed pelagic fish species in the North Atlantic: Implications for modelling climate and fisheries impacts

    DEFF Research Database (Denmark)

    Trenkel, V.M.; Huse, G.; MacKenzie, Brian

    2014-01-01

    scombrus), capelin (Mallotus villosus), blue whiting (Micromesistius poutassou), and horse mackerel (Trachurus trachurus), which have distributions extending beyond the continental shelf and predominantly occur on both sides of the North Atlantic. We also include albacore (Thunnus alalunga), bluefin tuna...... (Thunnus thynnus), swordfish (Xiphias gladius), and blue marlin (Makaira nigricans), which, by contrast, show large-scale migrations at the basin scale. We focus on the links between life history processes and the environment, horizontal and vertical distribution, spatial structure and trophic role. Many...

  9. An Assessment of the Potential Impacts on Zooplankton and Fish of Ocean Dredged Material at the Norfolk Disposal Site.

    Science.gov (United States)

    1984-09-07

    shelf include hake, summer flounder, sand lance, mullets (Mugil sp.), mackerel, goosefish (Lophius americanus), menhaden, bluefin tuna ( Thunnus ... thynnus ), and many others. Species that spawn primarily in bays or ocean waters within 3 *miles of shore are weakfish, anchovy, Atlantic silverside (Menidia

  10. Preliminary forecasts of Pacific bigeye tuna population trends under the A2 IPCC scenario

    Science.gov (United States)

    Lehodey, P.; Senina, I.; Sibert, J.; Bopp, L.; Calmettes, B.; Hampton, J.; Murtugudde, R.

    2010-07-01

    An improved version of the spatial ecosystem and population dynamics model SEAPODYM was used to investigate the potential impacts of global warming on tuna populations. The model included an enhanced definition of habitat indices, movements, and accessibility of tuna predators to different vertically migrant and non-migrant micronekton functional groups. The simulations covered the Pacific basin (model domain) at a 2° × 2° geographic resolution. The structure of the model allows an evaluation from multiple data sources, and parameterization can be optimized by adjoint techniques and maximum likelihood using fishing data. A first such optimized parameterization was obtained for bigeye tuna ( Thunnus obesus) in the Pacific Ocean using historical catch data for the last 50 years and a hindcast from a coupled physical-biogeochemical model driven by the NCEP atmospheric reanalysis. The parameterization provided very plausible biological parameter values and a good fit to fishing data from the different fisheries, both within and outside the time period used for optimization. We then employed this model to forecast the future of bigeye tuna populations in the Pacific Ocean. The simulation was driven by the physical-biogeochemical fields predicted from a global marine biogeochemistry - climate simulation. This global simulation was performed with the IPSL climate model version 4 (IPSL-CM4) coupled to the oceanic biogeochemical model PISCES and forced by atmospheric CO 2, from historical records over 1860-2000, and under the SRES A2 IPCC scenario for the 21st century (i.e. atmospheric CO 2 concentration reaching 850 ppm in the year 2100). Potential future changes in distribution and abundance under the IPCC scenario are presented but without taking into account any fishing effort. The simulation showed an improvement in bigeye tuna spawning habitat both in subtropical latitudes and in the eastern tropical Pacific (ETP) where the surface temperature becomes optimal for

  11. Identification of parvalbumin and two new thermolabile major allergens of Thunnus tonggol using a proteomics approach.

    Science.gov (United States)

    Rosmilah, Misnan; Shahnaz, Murad; Meinir, Jones; Masita, Arip; Noormalin, Abdullah; Jamaluddin, Mohamed

    2013-01-01

    The longtail tuna (Thunnus tonggol) is widely consumed in Asia. Parvalbumin, the main major allergen of fish, has been well identified in multiple fish species, yet little is known about the allergenic proteins in T. tonggol. Thus, the aim of this study was to characterize the major allergens of T. tonggol using a proteomics approach. Raw and boiled extracts of the fish were prepared. Fish proteins were separated by means of SDS-PAGE and two-dimensional (2-DE) electrophoresis. 1-DE immunoblotting of raw extract was performed with sera from fish-allergic patients. Ten sera were further analysed by 2-DE immunoblotting. Selected major allergenic protein spots were excised, trypsin digested and analysed by means of mass spectrometry. SDS-PAGE of raw extract revealed 26 protein fractions, while boiled extract demonstrated fewer bands. The 2-DE gel profile of the raw extract further fractionated the protein bands to more than 100 distinct protein spots. 1-DE immunoblotting of raw extract exhibited two thermolabile protein fractions of 42 and 51 kDa as the major allergens, while the boiled extract only revealed a single IgE-binding band at 151 kDa. 2-DE immunoblotting of raw extract further detected numerous major IgE-reactive spots of 11-13, 42 and 51 kDa. Mass spectrometry analysis of the peptides generated from the 12, 42 and 51 kDa digested spots indicated that these spots were parvalbumin, creatine kinase and enolase, respectively. In addition to parvalbumin, two new thermolabile allergens were identified as major allergenic proteins of T. tonggol. This study proved that both thermostable and thermolabile proteins are important in local tuna allergy and should be included in diagnostic strategies.

  12. Governance innovation networks for sustainable tuna

    NARCIS (Netherlands)

    Miller, A.M.M.

    2014-01-01

    Governance Innovation Networks for Sustainable Tuna Alice M.M. Miller Tuna fisheries are among the most highly capitalised and valuable fisheries in the world and their exploitation will continue for the foreseeable future. This means the sustainability of tuna stocks is a pressing

  13. Governance innovation networks for sustainable tuna

    NARCIS (Netherlands)

    Miller, A.M.M.

    2014-01-01

    Governance Innovation Networks for Sustainable Tuna

    Alice M.M. Miller

    Tuna fisheries are among the most highly capitalised and valuable fisheries in the world and their exploitation will continue for the foreseeable future. This means the sustainability of tuna

  14. Mitochondrial DNA analysis reveals three stocks of yellowfin tuna Thunnus albacares (Bonnaterre, 1788) in Indian waters

    Digital Repository Service at National Institute of Oceanography (India)

    Kunal, S.P.; GirishKumar; Menezes, M.R.; Meena, R.M.

    DNA has proved to be useful in determining population stock of fish species due to its simple mode of transmission avoiding recombination, high mutation rate and predominantly maternal inheritance (Graves et al. 1984; Hoolihan et al. 2004). Most... homing of three YFT populations to identify potential spawning sites in the Indian Ocean. The genetic marker used in the present study is mtDNA which is maternally inherited. The genetic effect of male dispersal cannot be addressed by mtDNA. In addition...

  15. 77 FR 15712 - Atlantic Highly Migratory Species; 2012 Atlantic Bluefin Tuna Quota Specifications

    Science.gov (United States)

    2012-03-16

    ... meeting, ICCAT recommended a TAC of 1,750 mt annually for 2011 and for 2012, inclusive of dead discards... Rebuilding Program). This amount is expected to allow for continued stock growth under the both the low and... 868.6 mt, which is 175 mt less than the amount of quota (inclusive of dead discards) allowed under...

  16. 78 FR 21584 - Atlantic Highly Migratory Species; 2013 Atlantic Bluefin Tuna Quota Specifications

    Science.gov (United States)

    2013-04-11

    ... an active member of ICCAT, the United States implements binding ICCAT recommendations to comply with... be carried forward this year to 94.9 mt (10 percent of the 948.7-mt total U.S. quota). Accounting for... 2012 BFT quota specifications. Accounting for dead discards in the Longline category in this way may...

  17. 77 FR 44161 - Atlantic Highly Migratory Species; 2012 Atlantic Bluefin Tuna Quota Specifications

    Science.gov (United States)

    2012-07-27

    ... fighting among themselves while eastern Atlantic and Mediterranean BFT fishermen benefit. Some commenters... that assume the number of BFT yearlings (one-year- old fish) in 2011 would be reduced by 20 percent... conducted projections using the `MAST' model (Multistock Age-Structured Tag-Integrated assessment model...

  18. The oxidative stability of chilled and frozen pilchards used as feed for captive southern bluefin tuna

    DEFF Research Database (Denmark)

    Fitz-Gerald, C.H.; Bremner, Allan

    1998-01-01

    and flavour of cooked samples and by the chemical measures of peroxide value and levels of free fatty acids. There was considerable variability in fat content between individual fish with average content over all samples analysed in the trial being about 4 to 5%. In chilled storage, the pilchards exhibited...... obvious deterioration within two days. Substantial peroxide values were found and oxidised odours and flavours were clearly evident after 4 days' chilled storage. In frozen storage, oxidation occurred after only one month at a temperature of -20°C. This could be delayed if the fish were glazed with water....... Vacuum packaging in a film of low permeability to oxygen was less effective than glazing and is not recommended due to cost. Pilchards in which oxidation had commenced before freezing continued to oxidise in frozen storage irrespective of whether they were glazed or vacuum packed. It was thus thoroughly...

  19. 76 FR 74003 - Atlantic Highly Migratory Species; Adjustments to the Atlantic Bluefin Tuna General and Harpoon...

    Science.gov (United States)

    2011-11-30

    ... and comment process, NMFS has determined that keeping the proposed rule title at this stage would...'s quota. (ix) Review of dealer reports, daily landing trends, and the availability of the BFT on the.... Lowering of the minimum size could be achieved in a resource neutral fashion with a modest transfer...

  20. 78 FR 36685 - Atlantic Highly Migratory Species; 2013 Atlantic Bluefin Tuna Quota Specifications

    Science.gov (United States)

    2013-06-19

    ... deduction of half of the dead discard estimate from the Longline category as a transition from the method... possibility that deduction of half of the final estimate of dead discards from the baseline Longline category... adjustments, scientific research collection, potential overharvest in any category except the Purse Seine...

  1. The Southern Oscillation, Hypoxia, and the Eastern Pacific Tuna Fishery

    Science.gov (United States)

    Webster, D.; Kiefer, D.; Lam, C. H.; Harrison, D. P.; Armstrong, E. M.; Hinton, M.; Luo, L.

    2012-12-01

    The Eastern Pacific tuna fishery, which is one of the world's major fisheries, covers thousands of square kilometers. The vessels of this fishery are registered in more than 30 nations and largely target bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin (T. albacores) tuna. In both the Pelagic Habitat Analysis Module project, which is sponsored by NASA, and the Fishscape project, which is sponsored by NSF, we have attempted to define the habitat of the three species by matching a 50 year time series on fish catch and effort with oceanographic information obtained from satellite imagery and from a global circulation model. The fishery time series, which was provided by the Inter-American Tropical Tuna Commission, provided spatial maps of catch and effort at monthly time steps; the satellite imagery of the region consisted of sea surface temperature, chlorophyll, and height from GHRSST, SEAWiFS, and AVISO products, and the modeled flow field at selected depths was output from ECCO-92 simulations from 1992 to present. All information was integrated and analyzed within the EASy marine geographic information system. This GIS will also provides a home for the Fishscape spatial simulation model of the coupled dynamics of the ocean, fish, fleets, and markets. This model will then be applied to an assessment of the potential ecological and economic impacts of climate change, technological advances in fleet operations, and increases in fuel costs. We have determined by application of EOF analysis that the ECCO-2 simulation of sea surface height fits well with that of AVISO imagery; thus, if driven properly by predictions of future air-sea exchange, the model should provide good estimates of circulation patterns. We have also found that strong El Nino events lead to strong recruitment of all three species and strong La Nina events lead to weak recruitment. Finally, we have found that the general spatial distribution of the Eastern Pacific fishing grounds

  2. Aasta esimene Tuna / Vello Helk

    Index Scriptorium Estoniae

    Helk, Vello, 1923-2014

    2009-01-01

    ajakiri Tuna, 2009, nr. 1 sisust: Mait Kõivu Trooja sõja aineline essee, Tiina Kala Saare-Lääne piiskopi Johannes Kiveli ametissepühitsemine 1515. aastal, Jaan Rossi artikkel teadlaste panusest muusikasse, Riho Saardi Eesti Kirikute Nõukogu sünnilugu, Vello Salo 1924. aasta 1. detsembri lööksalkade juhtkonnast

  3. Tuna and dolphin associations in the North-east Atlantic: Evidence of different ecological niches from stable isotope and heavy metal measurements

    Energy Technology Data Exchange (ETDEWEB)

    Das, K.; Lepoint, G.; Loizeau, V.; Debacker, V.; Dauby, P.; Bouquegneau, J.M

    2000-02-01

    Associations of tunas and dolphins in the wild are quite frequent events and the question arises how predators requiring similar diet in the same habitat share their environmental resources. As isotopic composition of an animal is related to that of its preys, stable isotope ({sup 13}C/{sup 12}C and {sup 15}N/{sup 14}N) analyses were performed in three predator species from the North-east Atlantic: the striped dolphin, Stenella coeruleoalba, the common dolphin Delphinus delphis and the albacore tuna, Thunnus alalunga, and compared to their previously described stomach content. Heavy metals (Cd, Zn, Cu and Fe) are mainly transferred through the diet and so, have been determined in the tissues of the animals. Tuna muscles display higher {delta}{sup 15}N than in common and striped dolphins (mean: 11.4 vs. 10.3%o and 10.4%o, respectively) which reflects their higher trophic level nutrition. Higher {delta}{sup 13}C are found in common (-18.4%o) and striped dolphin (-18.1%o) muscles than in albacore tuna (-19.3%o) probably in relation with its migratory pattern. The most striking feature is the presence of two levels of cadmium concentrations in the livers of the tunas (32 mg kg{sup -1} dry weight (DW) vs. 5 mg kg{sup -1} DW). These two groups also differ by their iron concentrations and their {delta}{sup 15}N and {delta}{sup 13}C liver values. These results suggest that in the Biscay Bay, tunas occupy two different ecological niches probably based on different squid inputs in their diet.

  4. Tuna and dolphin associations in the North-east Atlantic: Evidence of different ecological niches from stable isotope and heavy metal measurements

    International Nuclear Information System (INIS)

    Das, K.; Lepoint, G.; Loizeau, V.; Debacker, V.; Dauby, P.; Bouquegneau, J.M.

    2000-01-01

    Associations of tunas and dolphins in the wild are quite frequent events and the question arises how predators requiring similar diet in the same habitat share their environmental resources. As isotopic composition of an animal is related to that of its preys, stable isotope ( 13 C/ 12 C and 15 N/ 14 N) analyses were performed in three predator species from the North-east Atlantic: the striped dolphin, Stenella coeruleoalba, the common dolphin Delphinus delphis and the albacore tuna, Thunnus alalunga, and compared to their previously described stomach content. Heavy metals (Cd, Zn, Cu and Fe) are mainly transferred through the diet and so, have been determined in the tissues of the animals. Tuna muscles display higher δ 15 N than in common and striped dolphins (mean: 11.4 vs. 10.3%o and 10.4%o, respectively) which reflects their higher trophic level nutrition. Higher δ 13 C are found in common (-18.4%o) and striped dolphin (-18.1%o) muscles than in albacore tuna (-19.3%o) probably in relation with its migratory pattern. The most striking feature is the presence of two levels of cadmium concentrations in the livers of the tunas (32 mg kg -1 dry weight (DW) vs. 5 mg kg -1 DW). These two groups also differ by their iron concentrations and their δ 15 N and δ 13 C liver values. These results suggest that in the Biscay Bay, tunas occupy two different ecological niches probably based on different squid inputs in their diet

  5. Value Chain Model Development of Tuna and Tuna Alike In Indonesia

    Directory of Open Access Journals (Sweden)

    Ateng Supriatna

    2014-11-01

    Full Text Available Sustainability of tuna and tuna alike fisheries depend on chain value system formed by stakeholders ranging from product fishing, processing/diversification, distribution, and marketing. The objective of this research was to create chain value system model of tuna and tuna alike fisheries, to predict the interaction pattern of stakeholders and to formulate the precise strategy to minimize the synergy resistance of chain value system development strategy of tuna and tuna alike fisheries. Structural Equation Modelling (SEM was applied to analyze the chain value model. The stakeholders/the players of tuna and tuna alike fisheries basically have positive interaction (CE>0.The negative interaction occured on retailers and consumers. Interaction of retailers with consumers is significant (p<0.05 0.01. Interaction pattern of fishermen, retailers, collectors, and exporters affected significantlly by pricing and the level of role played by the stakeholders. The strategy to minimize the sinergy resistance of chain value system development are respectivelly the strategy of involving the group of fishermen on products pricing (CE= 1,176 and P= 0,000, the strategy of involving the seller groups on products pricing (CE-PE=1,08, CE-PB= 0,766, CE EKS= 2,028 AND P= 0,000, and the strategy on guaranteeing flexible interaction between retailer and consumers (CE= 0,179 and p = 0,01.Keywords: tuna and tuna alike, interaction, tuna and tuna alike stakeholders, and value chain

  6. Mapping Risks of Indonesian Tuna Supply Chain

    Science.gov (United States)

    Karningsih, P. D.; Anggrahini, D.; Kurniati, N.; Suef, M.; Fachrur, A. R.; Syahroni, N.

    2018-04-01

    Due to its high economic value and is produced by many countries, Tuna is considered as one of the world’s popular fish. Demand for Tuna species are very high and it usually sells in three form: fresh, frozen or canned. Competition in Tuna trading is challengin with the potential risk of price and supply fluctuations. With recent focus of Indonesia government that see the future of Indonesia civilization depend on the oceans and as the three biggest Tuna producing country, Ministry of Marine Affairs and Fisheries should ensure sustainability and competitiveness of Indonesian tuna. Therefore, there is a great need to develop a proper and effective strategy to manage potential risks in Indonesian Tuna supply chain. This paper is aimed at identifying and mapping potential Tuna supply chain risks and its interrelationships that would assist government in determining proper strategies to manage Indonesian Tuna. A framework for identifying Tuna supply chain risks is proposed. Generic risk structure of Supply Chain Risk Identification System is adopted and modified to match with particular object, which is Indonesian Tuna. The proposed model consists of hierarchical and causal structure that encompass potential risks of Tuna supply chain operations from fishing, trading, processing and distribution. The causal structure consist of risk events and its risk agents which is the cause of risk events. To ensure the root cause of risk events are identified properly, five why’s analysis is utilized to obtain risk agents. This proposed model also captures risk interrelationship between internal and external environment of Tuna supply chain. Preliminary result of this study identifies 15 risk events and 13 risk factors on fishing and trading operations and maps their interrelationships.

  7. Relationships between tuna catch and variable frequency oceanographic conditions

    Directory of Open Access Journals (Sweden)

    F. I. Ormaza-González

    2016-08-01

    Full Text Available Skipjack (Katsuwunus pelamis, yellow fin (Thunnus albacares and albacore (Thunnus alulunga tunas landed in the Eastern Pacific Ocean (EPO countries and Ecuador were correlated to the Indexes Oceanic El Niño (ONI and Multivariate Enso Index (MEI. The temporal series 1983–2012, and 1977–1999 (warm Pacific Decadal Oscillation, PDO, and 2000–2012 (cold PDO were analyzed. Linear correlation showed that at least 11 % of the total landings were associated with the MEI, with a slightly negative gradient from cold to warm conditions. When non-linear regression (n  =  6, the R2 was higher up to 0.304 (MEI, r =  0.551. The correlation shows high spread from −0.5 to +0.5 for both MEI/ONI; the highest landings occurred at 0.34–0.45; both indexes suggested that at extreme values < −1.0 and > 1.1 total landings tend to decrease. Landings were associated up to 21.9 % (MEI in 2000–2012, 1983–1999 rendered lower R2 (< 0.09; i.e., during cold PDO periods there was a higher association between landings and oceanographic conditions. For the non-linear regression (n  =  6 a R2 of 0.374 (MEI and 0.408 (ONI were registered, for the 2000–2012, a higher R2 was observed in 1983–1999, 0.443 and 0.711 for MEI and ONI respectively, suggesting that is better to analyze split series (1983–1999, 2000–2012 than as a whole (1983–2012, due to noise produced by the transition from hot to cold PDOs. The highest landings were in the range −0.2 to 0.5 for MEI/ONI. The linear regression of skipjack landings in Ecuador gave an R2 of 0.140 (MEI and 0.066 (ONI and the non-linear were 0.440 and 0.183 respectively. Total landings in the EPO associated to oceanographic events of high and low frequencies could be used somehow as predictors of the high El Niño o La Niña. There is a clear evidence that tuna fish biomass are at higher levels when the PDO is on cold phase (2000–2030 and vice versa on warm phase (1980–1999. The

  8. PENGARUH PERBEDAAN UMPAN DAN WAKTU SETTING RAWAI TUNA TERHADAP HASIL TANGKAPAN TUNA DI SAMUDERA HINDIA

    Directory of Open Access Journals (Sweden)

    Abram Barata

    2016-06-01

    Full Text Available Rawai tuna merupakan alat tangkap yang efektif untuk menangkap tuna dan ikan pelagis besar lainnya di perairan laut dalam. Pengoperasian rawai tuna bersifat pasif, sehingga tertangkapnya tuna ditentukan oleh tertariknya ikan untuk memakan umpan. Jenis umpan yang sering digunakan adalah lemuru, layang, bandeng dan cumi. Adanya perbedaan waktu setting pada rawai tuna mempengaruhi jenis umpan yang akan digunakan. Penelitian ini bertujuan untuk mengetahui pengaruh jenis umpan yang digunakan pada rawai tuna terhadap hasil tangkapan tuna, pada saat setting pagi dan sore hari. Metode penelitian dengan ujicoba penangkapan selama 2 trip menggunakan KM Putra Jaya 05 di Samudera Hindia. Trip 1 pada tanggal 18 Maret sampai 29 April 2007, sedangkan trip 2 pada tanggal 15 Juli sampai 23 September 2008. Hasil penelitian menunjukkan bahwa penggunaan jenis umpan layang, lemuru dan cumi pada setting sore hari berpengaruh nyata terhadap hasil tangkapan tuna, sedangkan penggunaan jenis umpan bandeng, lemuru dan cumi pada setting pagi hari tidak berpengaruh nyata terhadap hasil tangkapan tuna. Umpan cumi adalah jenis umpan terbaik yang digunakan untuk setting sore hari pada rawai tuna di Samudera Hindia. Tuna longline is an effective fishing gear to catch tuna and other large pelagic fish in the ocean. As a passive gear, the capture of  tuna is depended on the attraction of fish to bait. The type of baits commonly used are sardine, milkfish, scad and squid. The different in setting time on tuna longline also influences the type of bait to be used. This research aims to determine the influence of bait used in the tuna longline on tuna catch, during setting in the morning and afternoon. Research methods to test the capture for 2 trips using the KM Putra Jaya 05 in Indian Ocean. First trip was on 18 March to 29 April 2007,and second trip was on 15 July to 23 September 2008. The results showed the use of bait type, i.e., scad, sardine and squid on the afternoon setting

  9. Towards better management of Coral Triangle tuna

    NARCIS (Netherlands)

    Bailey, M.L.; Flores, J.; Pokajam, S.; Rashid Sumaila, U.

    2012-01-01

    Indonesia, the Philippines, and Papua New Guinea, all part of a regional sub-group known as the Coral Triangle, have sizeable skipjack, yellowfin and bigeye tuna fisheries. Recent figures suggest that as much as a third of tuna catch from the western and central Pacific Ocean can be attributed to

  10. Elements in tissues and organs of an Antarctic fish, Champsocephalus gunnari

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Masafumi; Ishii, Toshiaki; Kitao, Kensuke (Div. of Marine Radioecology, National Inst. of Radiological Sciences, Isozaki, Ibaraki (Japan)); Nakamura, Keiji (Lab. of Environmental Sciences, Dept. of General Education, Ibaraki Univ., Mito (Japan)); Bassari, A. (Industrial Application Dept., Cekmece Nuclear Research and Training Centre, Istanbul (Turkey)); Kitao, Kensuke (Senshu Univ., Dept. of Biotechnology, Ishinomaki, Miyagi (Japan))

    1993-04-01

    Elements in the tissues and organs of the Antarctic fish Champsocephalus gunnari were analyzed by PIXE. A comparison was made with a migratory fish bluefin tuna, Thunnus thunnus, and morphologically similar fish, brown barracuda, Sphyraena pinguis. High levels of Mn were found in the gills and liver of bluefin tuna in the range of 4-10 ppm, while in the Champsocephalus gunnari, Mn was highest in the muscle (70 ppm). Fe was found in the spleen, kidney and liver of the bluefin tuna at levels of 300, 890 and 680 ppm. In Champsocephalus gunnari, however, levels in these organs were 40-80 ppm. A particularly higher level of 302 ppm was found in the muscle. Cu was the highest in the gall-bladder of a bluefin tuna (66 ppm), while it was 13 ppm in the Champsocephalus gunnari but it was 52 ppm in the muscle. Mn, Fe and Cu were particulary high in the muscle of the Champsocephalus gunnari. These elements may assist in oxygen fixation and transportation through cutaneous respiration. (orig.).

  11. A continuous time delay-difference type model (CTDDM) applied to stock assessment of the southern Atlantic albacore Thunnus alalunga

    Science.gov (United States)

    Liao, Baochao; Liu, Qun; Zhang, Kui; Baset, Abdul; Memon, Aamir Mahmood; Memon, Khadim Hussain; Han, Yanan

    2016-09-01

    A continuous time delay-diff erence model (CTDDM) has been established that considers continuous time delays of biological processes. The southern Atlantic albacore ( Thunnus alalunga) stock is the one of the commercially important tuna population in the marine world. The age structured production model (ASPM) and the surplus production model (SPM) have already been used to assess the albacore stock. However, the ASPM requires detailed biological information and the SPM lacks the biological realism. In this study, we focus on applying a CTDDM to the southern Atlantic albacore ( T. alalunga) species, which provides an alternative method to assess this fishery. It is the first time that CTDDM has been provided for assessing the Atlantic albacore ( T. alalunga) fishery. CTDDM obtained the 80% confidence interval of MSY (maximum sustainable yield) of (21 510 t, 23 118t). The catch in 2011 (24 100 t) is higher than the MSY values and the relative fishing mortality ratio ( F 2011/ F MSY) is higher than 1.0. The results of CTDDM were analyzed to verify the proposed methodology and provide reference information for the sustainable management of the southern Atlantic albacore stock. The CTDDM treats the recruitment, the growth, and the mortality rates as all varying continuously over time and fills gaps between ASPM and SPM in this stock assessment.

  12. Determination and quantification of PCBs, POCs and PAHs in Thunnus thynnus from the Straits of Messina (Italy).

    Science.gov (United States)

    Saija, Emanuele; Mangano, Valentina; Casale, Katia Ermina; La Torre, Giovanna Loredana; Dugo, Giacomo; Salvo, Andrea

    2016-06-01

    This data set is composed to assess the accumulation of persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) dioxin like (DL) and not dioxin like (NDL), organochlorine pesticides (POCs) and polycyclic aromatic hydrocarbons (PAHs) in Thunnus thynnus and to elucidate the suitability of this species as a bioindicator for monitoring contaminations of these compounds in the marine ecosystems of the Straits of Messina. This investigation was conducted on liver samples of 14 T. thynnus collected during April 2015. Quantitative determination of PCBs (DL and NDL), POCs and PAHs in the examined samples has been carried out by HRGC-MS/MS. Among the PCBs, high prevalence of DL was found while, generally, the values detected for PCBs-NDL were lower than the legal limits. Tuna samples analyzed for PAHs residues revealed that all the samples were contaminated with acenaphthalene, fluorene, phenanthrene and anthracene. Moreover, generally the residual levels of DDT and DDT metabolites were low. The total content of PCB-DL, in almost all the samples, showed higher concentration than the legal limit.

  13. Global integration of European tuna markets

    Science.gov (United States)

    Jiménez-Toribio, Ramòn; Guillotreau, Patrice; Mongruel, Rémi

    2010-07-01

    This paper evaluates the degree of integration between the world market and the major European marketplaces of frozen and canned tuna through both vertical and horizontal price relationships. Spatial linkages are investigated horizontally in order to estimate the connection between the European market and the world-wide market on the primary stage of the value chain. One of the key results is the high level of market integration at the ex-vessel stage, and the price leadership of yellowfin tuna over skipjack tuna. The same approach is applied at the ex-factory level. Basically, the European market for final goods appears to be segmented between the Northern countries consuming low-priced canned skipjack tuna imported from Asia (mainly Thailand) and the Southern countries (Italy, Spain) processing and importing yellowfin-based products sold at higher prices. France appears to be an intermediate market where both products are consumed. The former market is found to be well integrated to the world market and can be considered to be competitive, but there is a suspicion of market power being exercised on the latter. Price relationships are therefore tested vertically between the price of frozen tuna paid by the canneries and the price of canned fish in both Italy and France. The two species show an opposite pattern in prices transmission along the value chain: price changes along the chain are far better transmitted for the “global” skipjack tuna than for the more “European” yellowfin tuna. The results are discussed, along with their implications for the fishing industry.

  14. Dynamic optimal foraging theory explains vertical migrations of bigeye tuna

    DEFF Research Database (Denmark)

    Thygesen, Uffe Høgsbro; Sommer, Lene; Evans, Karen

    2016-01-01

    dynamic programming. With little calibration of model parameters, our results are consistent with observed data on vertical movement: we find that small tuna should display constant-depth strategies while large tuna should display vertical migrations. The analysis supports the hypothesis that the tuna...

  15. DISTRIBUTION PATTERNS OF KEY FISH SPECIES OF THE ...

    African Journals Online (AJOL)

    ... horse mackerel Trachurus trachurus capensis, lanternfish Lampanyctodes hectoris, lightfish Maurolicus muelleri, albacore Thunnus alalunga, bigeye tuna Thunnus obesus, yellowfin tuna Thunnus albacares, silver kob Argyrosomus inodorus, snoek Thyrsites atun, Cape hake Merluccius spp., kingklip Genypterus capensis ...

  16. U. S. Trade in Tuna for Canning, 1987

    OpenAIRE

    Parks , Wesley W.; Donley, Patricia J.; Herrick, Jr. , Samuel F.

    1990-01-01

    U.S. tuna fleet activity, canned tuna processing, ex-vessel, wholesale and retail prices and imports in 1987 are described and compared to their counterparts in previous years. Industry statistics gathered from government agencies and industry contacts are presented in 14 figures and 8 tables. In 1987, U.S. tuna fisheries delivered 253,136 short tons (tons) of tuna to U.S. canneries. Domestic deliveries of albacore (white-meat) tuna were 2,836 tons, down 20 percent from 1986 levels. Domest...

  17. The skinny on tuna fat: health implications.

    Science.gov (United States)

    Maqbool, Asim; Strandvik, Birgitta; Stallings, Virginia A

    2011-11-01

    Dietary n-3 (omega-3) and n-6 (omega-6) PUFA have significant implications in health and disease prevention. Marine life is rich in long-chain n-3 PUFA. Children and adults in North America are reluctant fish eaters; canned tuna is a common fish in children's diets. Although a multitude of tuna products are available, their respective PUFA contents have not been well described. The aim of the present study was to compare the fatty acid (FA) profiles of different commercially available US tuna products. Fat and FA composition of eight products randomly selected from two US suppliers were analysed with capillary GC after lipid extraction. Large north-eastern US grocery store chain. Canned tuna. Energy from fat varied from 3 to 33 % and the essential FA (EFA) linoleic acid (18 : 2n-6) and α-linolenic acid (18 : 3n-3) varied tenfold. DHA varied between 90 and 770 mg/serving. The n-6:n-3 ratio was 3:1-4:1 in oil-packaged products, 2:1-7:1 in packaged tuna salads and 1:3-1:7 in water-packaged products. A similar magnitude of differences was seen in the ratio between arachidonic acid (20 : 4n-6) and DHA. Light tuna canned in water may be a better choice of providing n-3 PUFA to individuals in a healthy population, whereas oil-packaged products may be preferable for those individuals with a need for increased EFA, such as for patients with cystic fibrosis. Awareness regarding PUFA content may aid in consumer product choices and health-care provider advice.

  18. Challenging the knowledge bio-based fisheries of tropical tuna stocks: assessing genomic population structure in yellowfin (Thunnus albacares

    Directory of Open Access Journals (Sweden)

    Carlo Pecoraro

    2014-06-01

    The YFT genetic population structure will be investigated at global scale (between- and within-ocean, using next-generation sequencing (2b-RAD method for genotyping by sequencing through examination of Single Nucleotide Polymorphisms (SNPs. This approach can represent a major advancement over classical techniques used until now (i.e. based on allozymes, DNA microsatellites and mitochondrial DNA in order to reveal the YFT stock structure between and within each ocean. The novel genomic data that will be generated can potentially reveal YFT population structure at a level not possible through classical latter approaches with significant implication for YFT stock assessment and management. In fact a carelessness of the proper genetic structure might lead to the over-exploitation and depletion of some populations with dramatic consequences for the long-term conservation and sustainable use of YFT stocks.

  19. 76 FR 18653 - Atlantic Highly Migratory Species; Bluefin Tuna Bycatch Reduction in the Gulf of Mexico Pelagic...

    Science.gov (United States)

    2011-04-05

    ... shown that the catch of adult-sized BFT in the GOM PLL fleet can be reduced by 56.5 percent with the use... charter/ party boats, 100 or fewer employees for wholesale dealers, or 500 or fewer employees for seafood...

  20. 76 FR 2313 - Atlantic Highly Migratory Species; Bluefin Tuna Bycatch Reduction in the Gulf of Mexico Pelagic...

    Science.gov (United States)

    2011-01-13

    ... Atlantic stock of BFT. This action would be consistent with the advice of the International Commission for..., are the lowest observed values in the time series. The Commission may wish to protect the 2003 year... sank approximately 50 miles southeast of Venice, LA. Oil flowed for 86 days into the GOM from a damaged...

  1. Direct quantification of energy intake in an apex marine predator suggests physiology is a key driver of migrations

    Science.gov (United States)

    Whitlock, Rebecca E.; Hazen, Elliott L.; Walli, Andreas; Farwell, Charles; Bograd, Steven J.; Foley, David G.; Castleton, Michael; Block, Barbara A.

    2015-01-01

    Pacific bluefin tuna (Thunnus orientalis) are highly migratory apex marine predators that inhabit a broad thermal niche. The energy needed for migration must be garnered by foraging, but measuring energy intake in the marine environment is challenging. We quantified the energy intake of Pacific bluefin tuna in the California Current using a laboratory-validated model, the first such measurement in a wild marine predator. Mean daily energy intake was highest off the coast of Baja California, Mexico in summer (mean ± SD, 1034 ± 669 kcal), followed by autumn when Pacific bluefin achieve their northernmost range in waters off northern California (944 ± 579 kcal). Movements were not always consistent with maximizing energy intake: the Pacific bluefin move out of energy rich waters both in late summer and winter, coincident with rising and falling water temperatures, respectively. We hypothesize that temperature-related physiological constraints drive migration and that Pacific bluefin tuna optimize energy intake within a range of optimal aerobic performance. PMID:26601248

  2. Kounis syndrome following canned tuna fish ingestion.

    Science.gov (United States)

    De Gennaro, Luisa; Brunetti, Natale Daniele; Locuratolo, Nicola; Ruggiero, Massimo; Resta, Manuela; Diaferia, Giuseppe; Rana, Michele; Caldarola, Pasquale

    2017-04-01

    Kounis syndrome (KS) is a complex of cardiovascular symptoms and signs following either allergy or hypersensitivity and anaphylactic or anaphylactoid insults. We report the case of 57-year-old man, with hypertension and history of allergy, referred for facial rash and palpitations appeared after consumption of canned tuna fish. Suddenly, the patient collapsed: electrocardiogram showed ST-elevation in inferior leads. The patient was transferred from the spoke emergency room for coronary angio, which did not show any sign of coronary atherosclerosis. A transient coronary spasm was therefore hypothesized and the final diagnosis was KS. To the best of our knowledge, this is one of the first cases of KS following the ingestion of tuna fish. KS secondary to food allergy has also been reported, and shellfish ingestion has been considered as one of the most active KS inducer foods. Canned tuna fish too is well known as an allergy inducer. Tuna fish allergy should be considered, however, within the context of scombroid food poisoning, also called histamine fish poisoning. Fish with high levels of free histidine, the enzyme substrate converted to histamine by bacterial histidine decarboxylase, are those most often implicated in scombroid poisoning. Inflammatory mediators such as histamine constitute the pathophysiologic basis of Kounis hypersensitivity-associated acute coronary syndrome. Patients with coronary risk factors, allergic reaction after food ingestion, and suspected scombroid poisoning should be therefore carefully monitored for a prompt diagnosis of possible coronary complications.

  3. Optimal condition to remove mercury in yellowfin tuna protein isolates and ACE-inhibitory property of peptide prepared using commercial proteases

    Directory of Open Access Journals (Sweden)

    Hathaigan Kokkaew

    2016-08-01

    Full Text Available Response surface methodology (RSM was performed to maximize the mercury (Hg reduction from yellowfin tuna (Thunnus albacare by products protein isolates (YBPI. The optimal condition of Hg reduction (89.3% was 10.5 mM CaCl 2 and a Water:YB of 12.9:1, while other variables were fixed at 5 mM citric acid, 60 min incubation, pH 11 and 8,000 x g for 15 min of centrifugation. At these conditions, the significant protein recovery (80.1% was obtained. Hydrolysates sequentially hydrolyzed with G6 followed by GN exhibited the highest angiotensin I-converting enzyme (ACE inhibitory activity than other enzyme preparations. Fractionated yellowfin tuna by products protein hydrolysate (YBPH increased in ACE-inhibitory activity when peptide size decreased. In-vitro gastrointestinal (GI digestion significantly increased bioactive property. ACEinhibitory activity of YBPH with and without simulated GI digestion significantly increased after incubating against ACE, demonstrating pro-drug type peptides.

  4. [Length growth of tunny (Thunnus thynnus) according to Sella's data].

    Science.gov (United States)

    Sager, G; Sammler, R

    1982-01-01

    The dates of Sella (1929) for the length of the mediterranean tunny (Thunnus thynnus) already treated by Krüger (1973) are taken as a basis for mathematical approximations by 19 growth functions. For this purpose some functions had to be modified to allow for a non-horizontal tangent at the beginning. As the available length values cease with 14 years of age, there is much room for the theoretical final length giving a good insight into the characteristics of the different approximations. Surprisingly the functions with final growth time yield values with only small deviations from each other except for one calculation thus hinting to a theoretical growth duration of about 25 +/- 2 years.

  5. Chemical contaminants (trace metals, persistent organic pollutants) in albacore tuna from western Indian and south-eastern Atlantic Oceans: Trophic influence and potential as tracers of populations.

    Science.gov (United States)

    Chouvelon, Tiphaine; Brach-Papa, Christophe; Auger, Dominique; Bodin, Nathalie; Bruzac, Sandrine; Crochet, Sylvette; Degroote, Maxime; Hollanda, Stephanie J; Hubert, Clarisse; Knoery, Joël; Munschy, Catherine; Puech, Alexis; Rozuel, Emmanuelle; Thomas, Bastien; West, Wendy; Bourjea, Jérôme; Nikolic, Natacha

    2017-10-15

    Albacore tuna (Thunnus alalunga) is a highly commercial fish species harvested in the world's Oceans. Identifying the potential links between populations is one of the key tools that can improve the current management across fisheries areas. In addition to characterising populations' contamination state, chemical compounds can help refine foraging areas, individual flows and populations' structure, especially when combined with other intrinsic biogeochemical (trophic) markers such as carbon and nitrogen stable isotopes. This study investigated the bioaccumulation of seven selected trace metals - chromium, nickel, copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg) and lead - in the muscle of 443 albacore tunas, collected over two seasons and/or years in the western Indian Ocean (WIO: Reunion Island and Seychelles) and in the south-eastern Atlantic Ocean (SEAO: South Africa). The main factor that explained metal concentration variability was the geographic origin of fish, rather than the size and the sex of individuals, or the season/year of sampling. The elements Cu, Zn, Cd and Hg indicated a segregation of the geographic groups most clearly. For similar sized-individuals, tunas from SEAO had significantly higher concentrations in Cu, Zn and Cd, but lower Hg concentrations than those from WIO. Information inferred from the analysis of trophic markers (δ 13 C, δ 15 N) and selected persistent organic pollutants, as well as information on stomach contents, corroborated the geographical differences obtained by trace metals. It also highlighted the influence of trophic ecology on metal bioaccumulation. Finally, this study evidenced the potential of metals and chemical contaminants in general as tracers, by segregating groups of individuals using different food webs or habitats, to better understand spatial connectivity at the population scale. Limited flows of individuals between the SEAO and the WIO are suggested. Albacore as predatory fish also provided some

  6. Proposed OTEC Punta Tuna Pilot Plant

    Science.gov (United States)

    Marina, J.; Perez, F.

    1981-12-01

    Siting features and the design of a 40 MWe prototype OTEC for installation at Punta Tuna, Puerto Rico are presented. An annual average temperature gradient of 40 F from surface to 3,000 ft depth, a sharp coastal drop-off, projected benign environmental effects, and expensive indigenous power supplies are seen as favorable for fixed, floating, or grazing OTEC plants. The Punta Tuna design is for a platform fitted with generators in 300 ft of water, submarine cable power transmission, fiberglass seawater pipes, NH3 as a working fluid, and heat exchangers at the 300 ft depth, below hurricane wind and wave action. Methods of installing the 3,000 ft cold water pipes are discussed, and the use of OTEC derived electricity for aluminum smelting in the Caribbean is indicated.

  7. PENANGKAPAN JUVENIL IKAN MADIDIHANG (Thunnus albacares Bonnatere 1788 DI PERAIRAN TELUK TOMINI

    Directory of Open Access Journals (Sweden)

    Siti Mardlijah

    2016-03-01

    The high intensity of juvenils yellowfin tuna (Thunuus albacares in Tomini bay has occurred after purse seine operated in this area. The aim of the research on “Exploitation of juvenile yellowfin tuna  in Tomini Bay”  was to give clear feature on yellowfin tuna juvenile exploitation by hand line and purse seine in Tomini Bay. The research was conducted in 2007 and 2010. All samples of yellow fin tuna were caught by hand line and purse seine which were operated in Tomini Bay. The result showed that juvenile yellowfin tuna were caught by hand line was about 88.11% from the total catch of hand line, while the juvenile yellowfin tuna caught by purse seine was 100%.  Length of first captune of yellowfin tuna by handline and purse seine was 31.6 cm FL and 30 cm. Fishing juvenile yellowfin tuna occurs every month.  Moreover, that condition was showing and giving the indication that the exploitation of juvenile yellowfin tuna was very high that may endanger their sustainability.

  8. KEBIJAKAN PENGELOLAAN HASIL TANGKAPAN SAMPINGAN TUNA LONGLINE DI SAMUDERA HINDIA

    Directory of Open Access Journals (Sweden)

    Budi Nugraha

    2013-11-01

    Full Text Available Tuna longline atau rawai tuna merupakan salah satu alat tangkap yang sangat efektif untuk menangkap tuna. Selain efektif alat tangkap ini juga merupakan alat tangkap yang selektif terhadap hasil tangkapannya. Namun demikian, alat tangkap ini masih menimbulkan suatu masalah dimana ikan hasil tangkapan yang diperoleh tidak semuanya merupakan hasil tangkapan utama (target species, ada sebagian yang merupakan hasil tangkapan sampingan (by-catch. Sebagian besar hasil tangkapan sampingan tuna longline memiliki nilai ekonomis, hanya jenis pari lumpur dan ikan naga yang tidak memiliki nilai ekonomis. Namun demikian, justru yang tidak memiliki nilai ekonomis mendominasi hasil tangkapan sampingan pada perikanan tuna longline. Oleh karena itu perlu adanya tindak lanjut dengan menyusun peraturan atau regulasi yang terkait dengan pengelolaan ikan hasil tangkapan sampingan dan pengelolaan yang benar terhadap hasil tangkapan tersebut beserta habitatnya agar terjaga kelestarian sumberdayanya dan juga tetap menjadi sumber pendapatan masyarakat.Tulisan ini membahas secara ringkas tentang isu hasil tangkapan sampingan pada perikanan tuna longline, komposisi jenisnya, pemanfaatannya dan kebijakannya. Tuna longline is one of the most effective fishing gears to catch tuna. In addition, this fishing gear is selective to catch tuna. However, this gear is still causing a problem where some species other than their target species were caught as by-catch. Most of by-catch species from the tuna longliners have an economic value, except pelagic stingrays and lancetfish. In fact, these by-catch species (non economical-valued species dominated the longline catch. Therefore, it is needed to develop rules or regulations related to the management of the fish by-products, and properly manage the fishing activities on these by-catch species and habitat preservation to preserve its resources and also remain as a source of income. This paper briefly discusses the issue of by

  9. Addition of different tuna meal levels to pizza dough

    Directory of Open Access Journals (Sweden)

    Daniel Abreu Vasconcelos Campelo

    Full Text Available Abstract The aim of this study was to develop pizza dough with different levels of tuna meal (Tunnus spp.. In order to produce tuna meal, tuna torsos without fins were used, cooked for 1 hour, pressed, milled and dehydrated for 24 hours at 60 °C. Pizza dough was produced without (0% or with the addition of 5, 10, 15 and 20% of tuna meal, calculated based on the quantity of wheat flour. The tuna meal and different pizza pastries were analyzed for moisture content, crude protein, total lipids, ash, carbohydrates, caloric value and fatty acid profiles. Microbiological and sensory analyses were also carried out on the pizza pastries. The increasing addition of tuna meal resulted in gains in the crude protein (10.89 to 18.94%, total lipid (4.63 to 5.89% and ash (2.54 to 3.54% contents of the pizza pastries, not influencing the moisture content or caloric value. The inclusion of tuna meal linearly increased the quantity of n-3 series fatty acids in the pizza pastry, from 1.56 to 5.93 g/kg with the addition of 20% tuna meal. The ratio between the polyunsaturated and saturated fatty acids in the tuna meal and pizza pastries varied from 1.21 to 1.85. The microbiological analyses showed that the pizza pastries were produced under proper hygiene conditions. It was also observed that the addition of 5 to 20% of tuna meal to the pizza pastry did not significantly (p>0.05 alter the parameters of aroma, flavor, overall impression and purchase intention. It was therefore concluded that the addition of 5 to 20% tuna meal is effective in improving the nutritional value and fatty acid profile of pizza pastry.

  10. Mercury in canned tuna: white versus light and temporal variation

    International Nuclear Information System (INIS)

    Burger, Joanna; Gochfeld, Michael

    2004-01-01

    There are abundant data and advisories for mercury levels in wild fish, but far fewer for commercial fish that compose a large majority of the fish most people eat. Until recently, relatively little attention has been devoted to examining mercury in canned tuna, despite its great importance in human diets. There is substantial media coverage of the benefits and risk from fish consumption, but few peer-reviewed data on canned tuna, the most commonly consumed fish in the United States. In this paper, we examine the levels of total mercury in canned tuna obtained from a New Jersey grocery store from 1998 to 2003, looking for temporal consistency within this data set and particularly for comparison with the Food and Drug Administration's 1991 study. We analyzed 168 cans individually for total mercury. All values are reported as parts per million (=μg/g) on a wet weight basis. In a subset of samples analyzed for total and inorganic mercury, the inorganic mercury was below detection levels; hence at least 89% of the mercury can be considered methylmercury. We found that white-style tuna had significantly more total mercury (mean 0.407 ppm) than light-style tuna (mean 0.118 ppm), presumably reflecting that 'white' tuna is albacore, a species relatively larger than the skipjack tuna, which is commonly available as 'light' or 'chunk light'. The maximum mercury in a can was 0.997 ppm, but 25% of white tuna samples exceeded 0.5 ppm. Data suggest a slight increase in levels since 1991, and mercury levels were significantly higher in 2001 than in other years. The mean level of mercury in white tuna (mean 0.407 ppm) was significantly higher than the mean value of 0.17 ppm currently used by the U.S. Food and Drug Administration (FDA) in its risk assessment and public information. There were no significant differences in mercury levels in tuna packed in oil compared to water. Draining contents had no effect on mercury levels, and the fluid, both oil and water, contained little

  11. 78 FR 65887 - International Fisheries; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the...

    Science.gov (United States)

    2013-11-04

    ... January 1, 2014. During the closure, a U.S. fishing vessel over 24 meters in overall length may not be... issued under Sec. 660.707 or Sec. 665.801. A fishing vessel of the United States over 24 meters, other... limit fishing mortality on bigeye tuna caused by [[Page 65888

  12. Tuna longline fishing around West and Central Pacific seamounts.

    Directory of Open Access Journals (Sweden)

    Telmo Morato

    Full Text Available BACKGROUND: Seamounts have been identified as aggregating locations for pelagic biodiversity including tuna; however the topography and prevailing oceanography differ between seamounts and not all are important for tuna. Although a relatively common feature in oceanic ecosystems, little information is available that identifies those that are biologically important. Improved knowledge offers opportunities for unique management of these areas, which may advance the sustainable management of oceanic resources. In this study, we evaluate the existence of an association between seamounts and tuna longline fisheries at the ocean basin scale, identify significant seamounts for tuna in the western and central Pacific Ocean, and quantify the seamount contribution to the tuna longline catch. METHODOLOGY/PRINCIPAL FINDINGS: We use data collected for the Western and Central Pacific Ocean for bigeye, yellowfin, and albacore tuna at the ocean basin scale. GLMs were applied to a coupled dataset of longline fisheries catch and effort, and seamount location information. The analyses show that seamounts may be associated with an annual longline combined catch of 35 thousand tonnes, with higher catch apparent for yellowfin, bigeye, and albacore tuna on 17%, 14%, and 14% of seamounts respectively. In contrast 14%, 18%, and 20% of seamounts had significantly lower catches for yellowfin, bigeye and albacore tuna respectively. Studying catch data in relation to seamount positions presents several challenges such as bias in location of seamounts, or lack of spatial resolution of fisheries data. Whilst we recognize these limitations the criteria used for detecting significant seamounts were conservative and the error in identification is likely to be low albeit unknown. CONCLUSIONS/SIGNIFICANCE: Seamounts throughout the study area were found to either enhance or reduce tuna catch. This indicates that management of seamounts is important Pacific-wide, but management

  13. Pathological manifestation of the Acanthocephalus dirus in Thunnus albacares

    Directory of Open Access Journals (Sweden)

    Alagarsamy Sakthivel

    2016-05-01

    Full Text Available Objective: To describe the pathological manifestation of the Acanthocephalus dirus (A. dirus infestation in Thunnus albacares (T. albacares from southeast coast of India. Methods: The parasite-infested fishes were collected from Nagapattinam landing centre of Tamil Nadu from southeast coast of India. The Acanthocephala morphology, gross pathology, histopathology and histochemistry were investigated. Results: T. albacares were severely infested with A. dirus, the group of Acanthocephala attached to the posterior region of the intestine. The adult worm proboscis was cylindrical and the length and width ranging between 2.7–6.4 mm and 0.8–1.3 mm, respectively. Histopathologically, the infested intestinal mucosal epithelium, stratum granulosum, lamina propria, muscular and serosa layers were highly degraded. The lesions were infiltrating with basophil-like inflammatory cells. The parasite-affected lesions were histochemically positive for alcian blue, azo dye, toluidine blue and oil red O. Conclusions: This is the new host for the parasite A. dirus in T. albacares. On the basis of histological and histochemical findings, the lesions were highly damaged due to the parasitic infestation. The high density of the parasite and severe penetration of the proboscis into the intestinal tissues are the main reason for the pathogenicity in the host.

  14. Exploring future scenarios for the global supply chain of tuna

    Science.gov (United States)

    Mullon, C.; Guillotreau, P.; Galbraith, E. D.; Fortilus, J.; Chaboud, C.; Bopp, L.; Aumont, O.; Kaplan, D.

    2017-06-01

    The abundance of tuna, an important top predator that ranges throughout tropical and subtropical oceans, is now largely determined by fishing activity. Fishing activity, in turn, is determined by the interaction of fish availability, fishing capacity, fishing costs and global markets for tuna products. In the face of overfishing, the continued sustainable supply of tuna is likely to require improved global governance, that would benefit from modeling frameworks capable of integrating market forces with the availability of fish in order to consider alternative future projections. Here we describe such a modeling framework, in which we develop several simple, contrasting scenarios for the development of the tuna supply chain in order to illustrate the utility of the approach for global evaluation of management strategies for tuna and other complex, stock-structured fisheries. The model includes multiple national and multi-national fishing fleets, canneries and fresh/frozen markets, and connects these to global consumers using a network of flows. The model is calibrated using recent data on fish catch, cannery and fresh/frozen production, and consumption. Scenarios explore the control on future outcomes in the global tuna fishery by representing, in a simple way, the effects of (1) climate change, (2) changes in the global demand for tuna, and (3) changes in the access to fishing grounds (marine reserves). The results emphasize the potential importance of increasing demand in provoking a global collapse, and suggest that controlling tuna production by limiting technical efficiency is a potential countermeasure. Finally we discuss the outcomes in terms of potential extensions of the scenario approach allowed by this global network model of the tuna supply chain.

  15. Modificaciones en la grasa del atún blanco (Thunnus alalunga debidas a la fabricación y almacenamiento de su conserva

    Directory of Open Access Journals (Sweden)

    Navarro, María P.

    1991-06-01

    Full Text Available Modifications in fatty acid composition in white tuna (Thunnus alalunga ocurring at each stage of the cannig process, boiling and sterilization in soybean oil, were studied. Boiling was performed in brine and two sterilization times (55 and 90 minutes as well as the effects of storage for one year were tested. Boiling had no effect on fatty acid composition or the n-3/n-6 ratio. However canned tuna absorbed soybean oil during sterilization, causing an increase of the percentage of C18:1, C18:2 and C18:3 and a decrease in C20:5 and C22:6. Therefore, unsaturated fatty acids to saturated fatty acids (PS/S ratio changed and the n-3/n-6 ratio declined from 7.03 to 0.59 compared with raw tuna. Due to the whole fat enrichment, canned fish showed a slight loss of PUFA (C20:5 and C22:6 and a increase of C18:1, C18:2 and C18:3. The latter effect was more marked in the preserves as a consequence of one year storage. The convenience of using for cannig an oil containing a lower amount of polyunsaturated fatty acid in order to remain the original n-3/n-6 ratio of the raw tuna is discussed.Se estudiaron los cambios que se producen en la grasa del atún blanco en cada una de las etapas que intervienen en el proceso de fabricación y almacenamiento de su conserva: cocción en salmuera y esterilización practicada en aceite de soja. Se estudiaron dos tiempos diferentes de esterilización (55 y 90 minutos y el almacenamiento por espacio de 1 año. La cocción en salmuera no afectó a la composición en ácidos grasos de los lípidos del pescado ni a la relación n-3/n-6. Sin embargo, durante la esterilización, el atún absorbió el aceite utilizado como cobertura, lo que produjo un aumento porcentual en el nivel de C18:1, C18:2, C18:3 y una disminución en C20:5 y C22:6. La relación ácidos grasos insaturados a saturados (PS/S cambió y la n-3/n-6 disminuyó desde 7,03 a 0,59 comparado con atún crudo. En el pescado en conserva, debido al enriquecimiento total

  16. Report of Didymocystis wedli Ariola, 1902 (Digenea; Didymozoidae from Thunnus albacares in Brazil

    Directory of Open Access Journals (Sweden)

    A Kohn

    2001-10-01

    Full Text Available Didymocystis wedli a parasite from the gills of Thunnus albacares from the coast of the State of Rio de Janeiro, is described by use of light and scanning electron microscopy. This is the first report of this species in Brazil and South America. New data are presented on the surface topography as demonstrated by scanning electron microscopy.

  17. Preparation of lasagnas with dried mix of tuna and tilapia

    Directory of Open Access Journals (Sweden)

    Katia Setsuko KIMURA

    Full Text Available Abstract The aim of this study was to develop a lasagna pasta enriched with dried mix of tuna (30% and tilapia (70% and formulate ready lasagna with enriched pasta. Lasagna pasta was elaborated with increasing levels (0, 5, 10 and 15% of dried mix. Moisture, lipids and calories were not different between the inclusion levels; crude protein and ash increased linearly, carbohydrates reduced linearly, according to increasing levels of inclusion. There was an increase in n-3 and n-6 fatty acids with the inclusion of mix in lasagna. Between lasagna prepared with different sauces (tuna, chicken and bolognese, and pasta with 15% mix, it was observed that tuna lasagna had lower moisture content and higher protein, lipids, ash, carbohydrates and calories. All lasagna showed optimal sensory acceptance, indicating that the inclusion of 15% dried mix of tilapia and tuna in the pasta is feasible to improve the nutritional composition of lasagna.

  18. Tuna Cannery Points, Tutuila AS, 2007, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — American Samoa's primary industry is tuna processing by the Samoa Packing Co., user of the "Chicken of the Sea" label, and StarKist Samoa. Canneries thrive in this...

  19. Massive consumption of gelatinous plankton by Mediterranean apex predators.

    Directory of Open Access Journals (Sweden)

    Luis Cardona

    Full Text Available Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus, little tunny (Euthynnus alletteratus, spearfish (Tetrapturus belone and swordfish (Xiphias gladius. Loggerhead sea turtles (Caretta caretta in the oceanic stage and ocean sunfish (Mola mola also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix, blue shark (Prionace glauca, leerfish (Lichia amia, bonito (Sarda sarda, striped dolphin (Stenella caerueloalba and loggerhead sea turtles (Caretta caretta in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga, amberjack (Seriola dumerili, blue butterfish (Stromaeus fiatola, bullet tuna (Auxis rochei, dolphinfish (Coryphaena hyppurus, horse mackerel (Trachurus trachurus, mackerel (Scomber scombrus and pompano (Trachinotus ovatus were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish, most of them with shrinking populations due to overfishing.

  20. Massive Consumption of Gelatinous Plankton by Mediterranean Apex Predators

    Science.gov (United States)

    Cardona, Luis; Álvarez de Quevedo, Irene; Borrell, Assumpció; Aguilar, Alex

    2012-01-01

    Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), spearfish (Tetrapturus belone) and swordfish (Xiphias gladius). Loggerhead sea turtles (Caretta caretta) in the oceanic stage and ocean sunfish (Mola mola) also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix), blue shark (Prionace glauca), leerfish (Lichia amia), bonito (Sarda sarda), striped dolphin (Stenella caerueloalba) and loggerhead sea turtles (Caretta caretta) in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus) were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga), amberjack (Seriola dumerili), blue butterfish (Stromaeus fiatola), bullet tuna (Auxis rochei), dolphinfish (Coryphaena hyppurus), horse mackerel (Trachurus trachurus), mackerel (Scomber scombrus) and pompano (Trachinotus ovatus) were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage) and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish), most of them with shrinking populations due to overfishing. PMID:22470416

  1. Etiologi Penyebab Malformasi Tunas Ranting Kakao di Kulonprogo, DIY dan Segayung, Jawa Tengah

    Directory of Open Access Journals (Sweden)

    Susamto Somowiyarjo

    2014-12-01

    insektisida hasilnya tunas muda yang tumbuh berikutnya tidak menunjukan adanya gejala malformasi. Diduga bahwa malformasi pada tunas dan ranting tersebut disebabkan oleh racun yang ditularkan oleh serangga. Penelitian lebih lanjut untuk karakterisasi penyebab penyakit secara molekuler saat ini sedang dilakukan.

  2. Vulnerability of teleosts caught by the pelagic tuna longline fleets in South Atlantic and Western Indian Oceans

    Science.gov (United States)

    Lucena-Frédou, Flávia; Kell, Laurie; Frédou, Thierry; Gaertner, Daniel; Potier, Michel; Bach, Pascal; Travassos, Paulo; Hazin, Fábio; Ménard, Frédéric

    2017-06-01

    Productivity and Susceptibility Analysis (PSA) is a methodology for evaluating the vulnerability of a stock based on its biological productivity and susceptibility to fishing. In this study, we evaluated the vulnerability of 60 stocks of tuna, billfishes and other teleosts caught by the tuna longline fleets operating in the South Atlantic and Indian Ocean using a semi-quantitative PSA. We (a) evaluated the vulnerability of the species in the study areas; (b) compared the vulnerability of target and non-target species and oceans; (c) analyzed the sensitivity of data entry; and (d) compared the results of the PSA to other fully quantitative assessment methods. Istiophoridae exhibited the highest scores for vulnerability. The top 10 species at risk were: Atlantic Istiophorus albicans; Indian Ocean Istiompax indica; Atlantic Makaira nigricans and Thunnus alalunga; Indian Ocean Xiphias gladius; Atlantic T. albacares, Gempylus serpens, Ranzania laevis and X. gladius; and Indian Ocean T. alalunga. All species considered at high risk were targeted or were commercialized bycatch, except for the Atlantic G. serpens and R. laevis which were discarded, and may be considered as a false positive. Those species and others at high risk should be prioritized for further assessment and/or data collection. Most species at moderate risk were bycatch species kept for sale. Conversely, species classified at low risk were mostly discarded. Overall, species at high risk were overfished and/or subjected to overfishing. Moreover, all species considered to be within extinction risk (Critically Endangered, Endangered and Vulnerable) were in the high-risk category. The good concordance between approaches corroborates the results of our analysis. PSA is not a replacement for traditional stock assessments, where a stock is assessed at regular intervals to provide management advice. It is of importance, however, where there is uncertainty about catches and life history parameters, since it can

  3. Spatial Patterns and Temperature Predictions of Tuna Fatty Acids: Tracing Essential Nutrients and Changes in Primary Producers.

    Directory of Open Access Journals (Sweden)

    Heidi R Pethybridge

    Full Text Available Fatty acids are among the least understood nutrients in marine environments, despite their profile as key energy components of food webs and that they are essential to all life forms. Presented here is a novel approach to predict the spatial-temporal distributions of fatty acids in marine resources using generalized additive mixed models. Fatty acid tracers (FAT of key primary producers, nutritional condition indices and concentrations of two essential long-chain (≥C20 omega-3 fatty acids (EFA measured in muscle of albacore tuna, Thunnus alalunga, sampled in the south-west Pacific Ocean were response variables. Predictive variables were: location, time, sea surface temperature (SST and chlorophyll-a (Chla, and phytoplankton biomass at time of catch and curved fork length. The best model fit for all fatty acid parameters included fish length and SST. The first oceanographic contour maps of EFA and FAT (FATscapes were produced and demonstrated clear geographical gradients in the study region. Predicted changes in all fatty acid parameters reflected shifts in the size-structure of dominant primary producers. Model projections show that the supply and availability of EFA are likely to be negatively affected by increases in SST especially in temperate waters where a 12% reduction in both total fatty acid content and EFA proportions are predicted. Such changes will have large implications for the availability of energy and associated health benefits to high-order consumers. Results convey new concerns on impacts of projected climate change on fish-derived EFA in marine systems.

  4. 76 FR 31351 - Safety Requirements and Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels

    Science.gov (United States)

    2011-05-31

    ... Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels AGENCY: Coast Guard, DHS. ACTION: Notice... Policy Letter 11-05 regarding Distant Water Tuna Fleet vessels manning exemption eligibility and safety requirements. This final policy clarifies the requirements to allow a distant water tuna fleet vessel to engage...

  5. Feeding Partitioning among Tuna Taken in Surface and Mid-water ...

    African Journals Online (AJOL)

    Crustaceans were the almost exclusive food source of surface-swimming bigeye tuna, with the stomatopod (Natosquilla investigatoris) being the sole prey item recorded in this category. The diet of deep-swimming yellowfin tuna was balanced between epipelagic fish, crustaceans and cephalopods. Bigeye tuna fed ...

  6. 50 CFR 216.95 - Official mark for “Dolphin-safe” tuna products.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Official mark for âDolphin-safeâ tuna... AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.95 Official mark for “Dolphin-safe... Department of Commerce that may be used to label tuna products that meet the “dolphin-safe” standards set...

  7. Studies on thermal processing of Tuna-A comparative study in tin ...

    African Journals Online (AJOL)

    Tin-free steel can is an ideal alternative to open top sanitary tin cans (OTS) for thermal processing of little tuna (Ethynnus affinis) in curry used as filling media. Effect of heat penetration on physical, biochemical and sensory characteristics of canned tuna product were studied. The chemical analysis of raw tuna fish showed a ...

  8. Universal PCR primers for ribosomal protein gene introns of fish

    Directory of Open Access Journals (Sweden)

    Seinen Chow

    2016-01-01

    Full Text Available Abstract Human ribosomal protein (RP gene sequences with respect to intron/exon structures and corresponding cDNA or genomic data of fish species were obtained from the GenBank database. Based on conserved exon sequences, 128 primer pairs for 41 genes were designed for exon-primed intron-crossing (EPIC polymerase chain reaction (PCR. In reference to the draft genome sequences of the Pacific bluefin tuna (Thunnus orientalis, 12 primer pairs expected to amplify introns of the bluefin tuna with lengths of 500–1000 bp were selected and applied to six distantly related fish species belonging to the Orders Clupeiformes, Tetraodontiformes, Pleuronectiformes, Perciformes, Scorpaeniformes, and Anguilliformes. PCR amplification was observed for at least four species in each primer pair, and all fragments were larger than those expected for intronless amplification. Single fragment amplification was observed for at least seven primer pairs per species. Fragment sizes of the bluefin tuna for nine primer pairs corresponded to those expected from the genomic data. Thus, our primer pairs are potentially applicable to a wide variety of fish species and serve as an initial step for isolating single-copy nuclear DNA sequences.

  9. DISCARDS OF THE INDONESIAN TUNA LONGLINE FISHERY IN INDIAN OCEAN

    Directory of Open Access Journals (Sweden)

    Bram Setyadji

    2013-06-01

    Full Text Available Incidental by-catch and associated discarding are difficult to estimate on the basis of logbook information because they are poorly reported by fishing masters and their importance varies with several interrelated factors. The purpose of this paper is to inform the commonly discarded fishes of the Indonesian tuna longline fishery in the Indian Ocean. The study was carried out during 2010 – 2011 following six commercial tuna longline vessels based in Port of Benoa. Discards composition was dominated by longnose lancetfish and pelagic stingrays which composed almost half of total discards. Almost half of total catch are discards and half of discards are disposed dead or dying.

  10. PENDUGAAN PARAMETER POPULASI DAN TINGKAT PEMANFAATAN IKAN MADIDIHANG (Thunnus albacares YANG DIDARATKAN DI BENOA, BALI

    Directory of Open Access Journals (Sweden)

    Hety Hartaty

    2016-03-01

    Full Text Available Parameter biologi seperti umur dan pertumbuhan sangat penting untuk pengkajian stok sumber daya ikan dan pengelolaan perikanan agar pemanfaatan sumber daya ikan dapat dilakukan secara berkelanjutan. Informasi mengenai parameter pertumbuhan dari ikan madidihang di Samudera Hindia khususnya di Indonesia masih sangat terbatas. Penelitian ini ditujukan untuk memberikan informasi mengenai parameter pertumbuhan ikan madidihang. Pengumpulan data dilakukan selama tahun 2011, dengan cara pengukuran dan pengamatan langsung terhadap hasil tangkapan rawai tuna yang didaratkan di Pelabuhan Benoa, Bali. Total sampel yang diamati berjumlah 3.092 ekor. Kisaran panjang cagak (FL; fork length ikan madidihang antara 75-179 cm dan kisaran bobot antara 8-101 kg. Dari hasil analisis data frekuensi panjang ikan madidihang diperoleh parameter pertumbuhan sebagai berikut: panjang asimtotik (L∞ 185,85 cm, koefisien  pertumbuhan (K 0,59 dan umur pada saat panjang 0 cm (t0 -0,22.  Estimasi umur ikan madidihang yang didaratkan di Benoa tahun 2011 berkisar antara 1-5 tahun dengan laju pertumbuhan sebesar 2,95 cm/tahun. Pola pertumbuhan madidihang bersifat allometrik negatif. Pertumbuhan madidihang tidak akan mencapai ukuran panjang maksimum karena laju eksploitasi (E = 0,75 yang melebihi laju eksploitasi optimum (E opt = 0,5. Biological parameters suchas age and growth are very important information for accuracy of stock assessments and management to ensure that fisheries develop sustainably. Growth parameter information of Indian Ocean yellowfin tuna in Indonesia is still very limited. This research was aimed to determine the age and growth rate of yellowfin tuna that landed at Benoa port, Bali. Data of fork length (FL and weight was collected during 2011. The data were measured and observed directly on the catch of tuna longline at Benoa Port, Bali. With numbers of fish samples was 3.092 fish. Age and growth rate was analyzed based on the FL using Von Bertalanffy

  11. DISKRIMINASI KELAMIN PADA IKAN TUNA SIRIP KUNING, Yellowfin tuna MENGGUNAKAN ANALISIS DOT BLOT DAN ELISA

    Directory of Open Access Journals (Sweden)

    Gusti Ngurah Permana

    2014-08-01

    Full Text Available Pemahaman tentang penentuan jenis kelamin dalam populasi induk merupakan hal yang sangat penting bagi keberhasilan program pembenihan. Pengukuran reaksi antibodi dan aktivitas hormon testosterone, serta estradiol adalah metode dengan potensi yang secara akurat dapat menentukan jenis kelamin ikan tanpa mematikan ikan. Tujuan penelitian ini adalah untuk mengetahui akurasi metode dot blot dan ELISA dengan 11-ketotestorsterone (11-KT yang tersedia secara komersial EIA-kit untuk membedakan jenis kelamin ikan tuna sirip kuning. Hasil analisis menunjukkan bahwa metode dot blot menghasilkan ekspresi vitelogenin tampak jelas pada individu betina dan efek plasma terlihat transparan, jika dibandingkan dengan individu jantan. Interpretasi dari metode ini memerlukan pengalaman dan keahlian dalam akurasi pembacaan hasil. Aktivitas hormon 11-KT dengan sampel klip sirip dan plasma memberikan hasil yang baik dengan aktivitas hormon terlihat jelas.

  12. Private provision of public information in tuna fisheries

    NARCIS (Netherlands)

    Bush, Simon R.; Bailey, Megan; Zwieten, van Paul; Kochen, Momo; Wiryawan, Budy; Doddema, Mandy; Mangunsong, Stephani C.

    2017-01-01

    Private enumeration of landings data and traceability is an emerging phenomena in developing world tuna fisheries. The general goal of these systems is to facilitate compliance with mandatory market requirements such as the European Union’s Illegal, Unreported and Unregulated fisheries regulation,

  13. Production of aspartic peptidases by Aspergillus spp. using tuna ...

    African Journals Online (AJOL)

    The production of extracellular aspartic peptidase by the fungi Aspergillus niger and Aspergillus awamori was carried out in a shake flask and in stirred tank submerged fermentations using tuna cooked wastewater, an industrial effluent, as nitrogen source for culture medium. In stirred tank fermentation, biomass production ...

  14. Genetic variation in Yellowfin Tuna Thunnus albacares (Bonnaterre, 1788) along Indian coast using PCR-RFLP analysis of mitochondrial DNA D–Loop region

    Digital Repository Service at National Institute of Oceanography (India)

    Kunal, S.P.; GirishKumar; Menezes, M.R.

    : Ward et al., 1994b; mtDNA: Me- nezes et al., 2006 and nDNA: Menezes et al., 2008). The mtDNA is haploid, maternally inherited and has a rapid evolution rate in comparison to nDNA and thus provides higher level of genetic resolution than allozyme...

  15. Conservation Status of Killer Whales, Orcinus orca, in the Strait of Gibraltar.

    Science.gov (United States)

    Esteban, R; Verborgh, P; Gauffier, P; Alarcón, D; Salazar-Sierra, J M; Giménez, J; Foote, A D; de Stephanis, R

    Killer whales (Orcinus orca) in the Mediterranean Sea are currently restricted to the Strait of Gibraltar and surrounding waters. Thirty-nine individuals were present in 2011, with a well-differentiated social structure, organized into five pods. Killer whale occurrence in the Strait is apparently related to the migration of their main prey, Atlantic bluefin tuna (Thunnus thynnus). In spring, whale distribution was restricted to shallow waters off the western coast of the Strait where all pods were observed actively hunting tuna. In summer, the whales were observed in the shallow central waters of the Strait. A relatively new feeding strategy has been observed among two of the five pods. These two pods interact with an artisanal drop-line fishery. Pods depredating the fishery had access to larger tuna in comparison with pods that were actively hunting. The Strait of Gibraltar killer whales are socially and ecologically different from individuals in the Canary Islands. Molecular genetic research has indicated that there is little or no female-mediated gene migration between these areas. Conservation threats include small population size, prey depletion, vessel traffic, and contaminants. We propose the declaration of the Strait of Gibraltar killer whales as an endangered subpopulation. A conservation plan to protect the Strait of Gibraltar killer whales is urgently needed, and we recommend implementation of a seasonal management area where activities producing underwater noise are restricted, and the promotion of bluefin tuna conservation. © 2016 Elsevier Ltd. All rights reserved.

  16. DINAMIKA PERIKANAN TUNA DI PERAIRAN PRIGI SELATAN JAWA TIMUR

    Directory of Open Access Journals (Sweden)

    Irwan Muripto

    2015-12-01

    Full Text Available Pelabuhan Perikanan Nusantara (PPN Prigi merupakan pelabuhan bagi kapal penangkap ikan tuna dan ikan pelagis lain berskala kecil. Terdapat 3 (tiga jenis alat penangkap ikan pelagis besar yaitu pancing tonda, pukat cincin dan jaring insang.Usaha perikanan tuna memiliki peranan penting dalam peningkatan ekonomi nelayan khususnya di perairan selatan Jawa, sehingga diperlukan upaya optimalisasi pendapatan nelayan khususnya tonda. Penelitian ini bertujuan untuk mengetahui dinamika perkembangan armada, alat tangkap, produksi, daerah penangkapan, laju tangkap (CPUE dan indeks musim penangkapan (IMP ikan tuna. Data statistik dianalisis dari PPN Prigi pada periode 2005-2013 dan hasil pengamatan langsung di lapangan. Kontribusi hasil tangkapan untuk masing-masing jenis alat tangkap selama 9 tahun terakhir adalah  pancing tonda sebesar 27,17%, pukat cincin: 57,67% dan gillnet: 15,16%.  Hasil tangkapan tuna di perairan Samudera Hindia selatan Prigi relatif berfluktuasi, tertinggi terjadi peride 2005 dan terendah periode 2007. Daerah Penangkapan Ikan (DPI bagi nelayan mengoperasikan pukat cincin  di area 08º-09ºLS dan 111º-113ºBT, sedang  DPI  tonda di area 08º-10ºLS dan 110º-113ºBT. Indeks musim penangkapan (IMP ikan tuna di perairan Prigi tercatat tinggi (nilai ideks di atas 100% terjadi pada April sampai Oktober berkisar antara 113,28% dan 128,93%. Prigi Fishing Port is a harbour for landing artisanal fishing boats. There are 3 types of fishing gear for catching tuna such as trolling, purse seiner and gill nets. Tuna fisheries had been an economical role of business for the local fishermen, therefore, should have optimization to trolling fishermen’s especially at southern coast of Java. These study to investigate development of fleets, kind of fishing gears, fishing ground, the Catch per Unit of Effort (CPUE and the fishing season indexes of tuna.  Statistically data collected from The Prigi Fishing Port in period of 2005-2013 and also

  17. Penanganan penyu yang tertangkap rawai tuna di Samudera Hindia

    Directory of Open Access Journals (Sweden)

    Budi Nugraha

    2017-03-01

    Full Text Available Turtle is one of the vulnerable of megafauna and as a by-catch in tuna longline fisheries, however, management practices have not been done yet. This paper described the efforts to avoid the capture of turtles on the tuna longline fishery and its handling recommendation. It has been written based on the research results and observer programs of activities that have been implemented since 2005. It’s also including a literature review rules and regulations regarding the management of sea turtles. The record results during 2005 - 2014 conducted by an independent scientific board on tuna longline in the Indian Ocean with 72 times number of setting and 89,441number of hooks. There are 105 turtles caught, which are leatherback, olive ridley turtles, hawksbill, loggerhead sea turtles as well as the unknown green turtle where the current status of turtles in the Indian Ocean is in a state of vulnerable, endangered, critically even endangered. The olive ridley turtle, loggerhead and leatherback turtles are in a vulnerable status. While, the green turtles are in a state endangered and even hawksbill in a state extremely endangered. Policy measures for handling of turtles in tuna longline fishery needs to be taken in order to be implemented include the socialization of the use of intensified circle hooks and if necessary the government issued regulations regarding the use of circle hooks, the implementation of the placement of fishing monitoring (observer aboard the tuna longline in order to assist the skippers monitoring the catch of turtles and turtle handling training for the skippers and crew in order to hold the caught turtles can be handled directly on the boat to reduce the mortality turtles which can be released back into the sea alive. Penyu merupakan salah satu biota yang rawan punah dan sebagai hasil tangkapan sampingan pada perikanan rawai tuna dimana pengelolaannya belum banyak dilakukan. Makalah ini membahas tentang upaya bagaimana

  18. Hubungan Antara Body Image Dan Self-esteem Pada Dewasa Awal Tuna Daksa

    OpenAIRE

    Sari, Dahlia Nur Permata

    2012-01-01

    Penelitian ini meneliti mengenai pengaruh body image terhadap selfesteem pada dewasa awal tuna daksa. Hipotesis pada penelitian ini adalah adanya hubungan positif antara body image dan self-esteem pada dewasa awal tuna daksa. Semakin positif body image maka semakin tinggi self-esteem yang dimiliki, begitu juga sebaliknya, semakin negatif body image maka semakin rendah self-esteem yang dimiliki. Sampel penelitian sebanyak 30 dewasa awal tuna daksa yang memiliki cacat tubuh seteleh kelahiran. D...

  19. Size-dependent behavior of tuna in an array of fish aggregating devices (FADs)

    OpenAIRE

    Robert, Marianne; Dagorn, Laurent; Deneubourg, J. L.; Itano, D.; Holland, K.

    2012-01-01

    Several lines of evidence indicate that aggregations of yellowfin tuna associated with floating objects are more frequently composed of small animals than larger ones. Also, the diet of small yellowfin tuna caught at anchored fish aggregating devices (FADs) around Oahu, Hawaii, was found to shift quite rapidly when these fish reached approximately 50 cm FL. In order to test for ontogenetic changes in aggregation behavior, we tagged and released two distinct size classes of yellowfin tuna in a...

  20. Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu in Captivity: Sound Structure, Context and Vocal Activity.

    Directory of Open Access Journals (Sweden)

    Craig A Radford

    Full Text Available Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish-1 h-1 with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas.

  1. Indian Ocean tuna fisheries: Data summary for 1991-2000

    OpenAIRE

    Anon

    2002-01-01

    Catch statistics and fishing craft statistics are presented for the Indian Ocean tuna fisheries for the period 1991-2000. The former are presented by species, country, year and by gear. Details are also given of the number of fisheries crafts in the national fleets, in order to provide information on the economic and technical development of the fisheries and to provide an approximate idea of fluctuations in fishing effort.

  2. Indian Ocean tuna fisheries: Data summary for 1990-1999

    OpenAIRE

    Anon

    2003-01-01

    Catch statistics and fishing craft statistics are presented for the Indian Ocean tuna fisheries for the period 1990-1999. The former are presented by species, country, year and by gear. Details are also given of the number of fisheries crafts in the national fleets, in order to provide information on the economic and technical development of the fisheries and to provide an approximate idea of fluctuations in fishing effort.

  3. Optimization of enzymatic hydrolysis of skipjack tuna by-product ...

    African Journals Online (AJOL)

    The goal of this study was to optimize enzymatic hydrolysis of the dark flesh of skipjack tuna (Katsuwonus pelamis). Protamex® was used as the hydrolytic enzyme at various concentrations (1%, 1.5%, 2%, 2.5% and 3% w/w) at pHs from 6.5 to 8.5, temperatures from 40 to 60 oC and times of 2 to 6 h. The experiment was ...

  4. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a) U.S...

  5. 76 FR 3646 - Safety Requirements and Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels

    Science.gov (United States)

    2011-01-20

    ... Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels AGENCY: Coast Guard, DHS. ACTION: Notice... fleet vessels manning exemption eligibility and safety requirements. We request your comments on the Safety Requirements and Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels. DATES...

  6. Low-temperature transitions in cod and tuna determined by differential scanning calorimetry

    DEFF Research Database (Denmark)

    Jensen, Kristina Nedenskov; Jørgensen, Bo; Nielsen, Jette

    2003-01-01

    Differential scanning calorimetry measurements have revealed different thermal transitions in cod and tuna samples. Transition temperatures detected Lit -11degreesC, -15degreesC and -21degreesC were highly dependent on the annealing temperature. In tuna muscle an additional transition was observed...

  7. Implications of new economic policy instruments for tuna management in the Western and Central Pacific

    NARCIS (Netherlands)

    Yeeting, A.D.; Bush, S.R.; Ram-Bidesi, V.; Bailey, M.L.

    2016-01-01

    Tuna management in the Western and Central Pacific is complicated by the conflicting interests of countries and agents exploiting tuna resources in the region. Historically, regulatory attempts by Pacific Island Countries to control fishing effort within their Exclusive Economic Zones (EEZs) have

  8. Can Cooperative Management of Tuna Fisheries in the Western Pacific Solve the Growth Overfishing Problem?

    NARCIS (Netherlands)

    Bailey, M.L.; Rashid Sumaila, U.; Martell, S.J.D.

    2013-01-01

    Tuna fisheries in the western and central Pacific Ocean are important globally for both food and economic security. Yellowfin and bigeye tuna stocks in this region are declining, in part due to the juvenile bycatch of these species by the purse seine fishery using floating objects and fish

  9. 77 FR 24669 - Atlantic Highly Migratory Species; Public Conference Call Regarding Recreational Yellowfin Tuna...

    Science.gov (United States)

    2012-04-25

    ... collection in the U.S. recreational yellowfin tuna fishery and the relationship to international yellowfin...-XB162 Atlantic Highly Migratory Species; Public Conference Call Regarding Recreational Yellowfin Tuna... Administration (NOAA), Commerce. ACTION: Notice of public conference call. SUMMARY: In order to better inform the...

  10. Perilaku Tuna Fungsi Auditor: Pengujian atas Karakteristik Personal dan Penilai Kinerja Auditor

    Directory of Open Access Journals (Sweden)

    Aprina Nugrahesthy Sulistya Hapsari

    2016-12-01

      Fenomena perilaku tuna fungsi yang dilakukan oleh auditor makin dianggap lazim di lingkup audit. Hubungan antara karakteristik personal, karakteristik non personal dan perilaku tuna fungsi menjadi sesuatu hal yang menarik untuk diteliti. Penelitian ini menguji hubungan antara karakteristik personal berupa locus of control, tingkat kinerja pribadi karyawan, komitmen organisasi dan turnover intention dan penilai kinerja auditor sebagai faktor diluar karakteristik personal terhadap penerimaan perilaku tuna fungsi dalam lingkup audit. Pengumpulan data dilakukan melalui kuisioner dari responden yaitu auditor di KAP Kota Semarang dan Surakarta dengan metode convenience sampling karena populasi auditor yang bekerja tidak diketahui dengan pasti. Analisis data dengan menggunakan Model Persamaan Struktural. Hasil dari pengujian hipotesis mengindikasikan bahwa tidak ada hubungan antara karakteristik personal dengan penerimaan perilaku tuna fungsi dalam ruang lingkup audit. Sementara itu di lain sisi terdapat hubungan antara penilai kinerja auditor dengan penerimaan perilaku tuna fungsi dalam ruang lingkup audit.

  11. Studi Laju Umpan pada Proses Biokonversi Limbah Pengolahan Tuna menggunakan Larva Hermetia illucens

    Directory of Open Access Journals (Sweden)

    Arif Rahman Hakim

    2017-12-01

    Full Text Available Seiring dengan berkembangnya industri tuna, limbah pengolahan yang dihasilkan semakin meningkat. Namun demikian pemanfaatan limbah tersebut belum optimal. Biokonversi bahan organik limbah tuna menjadi biomassa larva sebagai bahan pakan diharapkan mampu mengatasi permasalahan tersebut. Biokonversi menggunakan larva Hermetia illucens atau Black Soldier Fly (BSF memiliki keunggulan dibandingkan proses konversi lain; di antaranya larva BSF mampu mengkonversi berbagai macam bahan organik, memiliki kandungan nutrisi tinggi serta bukan vektor penyakit. Tujuan penelitian ini ialah mempelajari laju umpan larva BSF dalam mengkonversi limbah tuna menjadi biomassa larva. Limbah tuna yang digunakan sebagai umpan larva BSF adalah kepala dan jeroan. Larva dipelihara selama 19 hari dengan pemberian umpan bervariasi (60, 80, 100 mg/larva/hari. Analisa dilakukan terhadap konsumsi umpan, indeks pengurangan limbah (waste reduction index/WRI, efisiensi konversi umpan tercerna (efficiency of conversion of digested-feed/ECD, tingkat kelulusan hidup (survival rates /SR, bobot larva, kandungan protein dan lemak larva. Hasil penelitian menunjukkan kepala dan jeroan tuna dapat digunakan sebagai pakan BSF, dengan nilai SR 41,33 – 98,33%. Laju umpan yang menghasilkan proses biokonversi paling optimum adalah umpan berupa kepala tuna sebesar 60 mg/larva/hari (K60. Nilai parameter pada perlakuan K60 adalah konsumsi umpan 77,09 %, WRI 4,06 % per hari, ECD 8,32 %, bobot larva 72,59 mg dan SR 98,33 %. Limbah berupa kepala tuna menghasilkan konsumsi umpan, WRI, ECD, bobot larva dan SR yang lebih tinggi dibandingkan limbah jeroan tuna. Penggunaan limbah kepala tuna dapat dimanfaatkan untuk mereduksi limbah sekaligus menghasilkan bahan pakan yang potensial. Kandungan larva BSF dengan umpan kepala tuna 60 mg/larva/hari meliputi protein 25,38 %, lemak 6,85 % dan air 62,81 %.

  12. Symposium on World tuna fisheries: commemorating the 50th anniversary of the establishment of the Inter-American Tropical Tuna Commission

    OpenAIRE

    2001-01-01

    The Inter-American Tropical Tuna Commission (lA TTC) came into existence in 1950, after its convention, signed by representatives ofCosta Rica and the United States in 1949, was ratified. It was the first international tuna organization, and only the third international fisheries organization, whose staff has had the responsibility for performing scientific research, the others being the International Pacific Halibut Commission, established in 1923, and the International Pacific Salmon Fis...

  13. QUANTIFICATION AND REPRESENTATION OF POTENTIAL ...

    African Journals Online (AJOL)

    ... kingklip Genypterus capensis, Cape hake Merluccius spp., silver kob Argyrosomus inodorus, snoek Thyrsites atun, albacore Thunnus alalunga, bigeye tuna Thunnus obesus and yellowfin tuna Thunnus albacares. It is based on distribution maps per species after combining available commercial and research databases.

  14. An evaluation of management strategies for Atlantic tuna stocks

    Directory of Open Access Journals (Sweden)

    L. T. Kell

    2003-04-01

    Full Text Available International agreements for the International Commission for the Conservation of Atlantic Tunas (ICCAT convention area imply that Atlantic tuna stocks should be managed by strategies based on maximum sustainable yield (MSY; however, there is concern whether this will actually ensure sustainability with sufficiently high probability consistent with the principals of the precautionary approach. Therefore, the performance of MSY management strategies based on current assessment procedures was evaluated using a computer simulation framework. The framework includes the data collection, assessment, prediction, and management processes, as well as the implementation of management regulations. It therefore provides an integrated way to evaluate the relative importance of and the interactions between each component of the system with regard to the overall success of the management strategy. The study elucidates guidelines about assessment and management that are general enough to be applied to all tunas in the Atlantic Ocean. It does so by comparing different hypotheses about management and assessment for three stocks (North Atlantic albacore, Atlantic bigeye and East Atlantic skipjack, which are representative of the variety encountered (i.e. from data rich to poor and tropical to temperate waters in ICCAT stocks. Management performance was especially sensitive to the carrying capacity of the stock. The type of proxy used for MSY was more important to the success of the procedure than the frequency of assessment or the number of indices used in the assessment. Whilst the procedure was successful at achieving the management objectives for albacore, it was only partially successful for bigeye and was too conservative for skipjack.

  15. Predicting the Distribution of Yellowfin Tuna in Philippine Waters

    Science.gov (United States)

    Perez, G. J. P.; Leonardo, E. M.

    2015-12-01

    The Philippines is considered as a major tuna producer in the Western and Central Pacific Ocean, both for domestic consumption and on industrial scale. However, with the ever-increasing demand of growing population, it has always been a challenge to achieve sustainable fishing. The creation of satellite-derived potential fishing zone maps is a technology that has been adopted by advanced countries for almost three decades already and has led to reduction in search times by up to 40%. In this study, a Generalized Additive Model (GAM) is developed to predict the distribution of the Yellowfin tuna species in seas surrounding the Philippines based on the Catch-Per-Unit-Effort (CPUE) index. Level 3 gridded chlorophyll-a and sea surface temperature from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite of the National Aeronautics and Space Administration (NASA) are the main input parameters of the model. Chlorophyll-a is linked with the presence of phytoplankton, which indicates primary productivity and suggests potential regions of fish aggregation. Fish also prefers to stay in regions where the temperature is stable, thus the sea surface temperature fronts serve as a guide to locate concentrations of fish school. Historical monthly tuna catch data from Western and Central Pacific Commissions (WCPFC) is used to train the model. The resulting predictions are converted to potential fishing zone maps and are evaluated within and beyond the historical time range of the training data used. Diagnostic tests involving adjusted R2 value, GAM residual plots and root mean square error value are used to assess the accuracy of the model. The generated maps were able to confirm locations of known tuna fishing grounds in Mindanao and other parts of the country, as well us detect their seasonality and interannual variability. To improve the performance of the model, ancillary data such as surface winds reanalysis from National Centers for

  16. Global pollution monitoring of butyltin compounds using skipjack tuna as a bioindicator

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, D.; Inoue, S.; Takahashi, S.; Ikeda, K.; Tanaka, H.; Subramanian, A.N.; Fillmann, G.; Lam, P.K.S.; Zheng, J.; Muchtar, M.; Prudente, M.; Chung, K.; Tanabe, S

    2004-01-01

    Global pollution monitoring of butyltin in offshore water and open sea were conducted using skipjack tuna as a bioindicator. - Butyltin compounds (BTs) including mono- (MBT), di- (DBT), tri-butyltin (TBT) and total tin ({sigma}Sn), were determined in the liver of skipjack tuna (Katsuwonus pelamis) collected from Asian offshore waters (off-Japan, the Japan Sea, off-Taiwan, the East China Sea, the South China Sea, off-Philippines, off-Indonesia, the Bay of Bengal), off-Seychelles, off-Brazil and open seas (the North Pacific). BTs were detected in all the skipjack tuna collected, suggesting widespread contamination of BTs even in offshore waters and open seas on a global scale. Considering specific accumulation, Sex-, body length- differences and migration of skipjack tuna did not seem to affect BT concentrations, indicating rapid reflection of the pollution levels in seawater where and when they were collected. Skipjack tuna is a suitable bioindicator for monitoring the global distribution of BTs in offshore waters and open seas. High concentrations of BTs were observed in skipjack tuna from offshore waters around Japan, a highly developed and industrialized region (up to 400 ng/g wet weight). Moreover skipjack tuna collected from offshore waters around Asian developing countries also revealed the levels comparable to those in Japan (up to 270 ng/g wet weight) which may be due to the recent improvement in economic status in Asian developing countries. High percentages (almost 90%) of BTs in total tin ({sigma}Sn: sum of inorganic tin+organic tin) were found in the liver of skipjack tuna from offshore waters around Asian developing countries. This finding suggests that the anthropogenic BTs represent the major source of Sn accumulation in skipjack tuna from these regions.

  17. PRODUKTIVITAS DAN MUSIM PENANGKAPAN IKAN MADIDIHANG (Thunnus albacares Bonnaterre, 1788 PADA PERIKANAN SKALA KECIL DI PALABUHANRATU, JAWA BARAT

    Directory of Open Access Journals (Sweden)

    Erfind Nurdin

    2015-09-01

    Full Text Available Pemanfaatan sumber daya perikanan tuna skala kecil di Pelabuhan Perikanan Nusantara (PPN Palabuhanratu menggunakan armada pancing tonda (troll liners dengan mengoperasikan lima macam jenis pancing. Penelitian perikanan tuna skala kecil dilakukan di PPN Pelabuhanratu pada April – Juli 2015, dengan tujuan untuk menganalisa produktivitas (laju tangkap, faktor yang mempengaruhi hasil tangkapan dan musim penangkapan madidihang (yellowfin tuna. Laju tangkap (hasil tangkapan per trip digunakan sebagai indikator produktivitas, moving average persentage digunakan untuk mengetahui pola musim penangkapan, dan fungsi produksi (Cobb Douglas untuk mengidentifikasi faktor-faktor teknis yang mempengaruhi hasil tangkapan tuna pada perikanan pancing tonda. Hasil penelitian menunjukkan bahwa madidihang merupakan hasil tangkapan paling dominan armada pancing tonda dengan laju tangkap sebanyak 339,93 kg/trip dengan musim penangkapan terjadi pada Mei hingga Oktober. Analisa Cobb Douglas menunjukkan secara simultan 84% hasil produksi (dependent variable yang diperoleh, dipengaruhi secara bersama oleh variabel independen yang digunakan (BBM, kekuatan mesin, GT dan jumlah ABK. The utilization of tuna resources on small scale (artisanal fishery in Palabuhanratu is using trolling fishing fleets (trolling liners characterized by five types of fishing lines during their operation. Research on small scale tuna fishery was conducted at Pelabuhanratu fishing port on April to July 2015 with the aims to analyze the productivity (catch rate, variable effects on the catch and fishing season for yellowfin tuna. The catch rate (the catch per trip is used as productivity indicator, while the moving average percentage is used to determine the pattern of fishing season, and Cobb Douglas production function to identify the technical factors that influence to the catch of yellowfin tuna. Analysis result showed that the catch rate of yellowfin tuna by trolling liners

  18. Treatment of tuna cooking juices by nano filtration

    International Nuclear Information System (INIS)

    Walha, K. a.; Ben Amar, R.; Bourseau, P.; Jaouen, P.

    2009-01-01

    Canned tuna is among the largest commercial canned fishery product in Tunisia. This industry rejects many aqueous effluents (washing, thawing, rinsing and cooking waters). Cooking juice represents 50 pour cent of the total effluent volume. It has a high organic load and a very high salt content. For consequence, discarding directly the effluent in the environment is not possible and need further treatment. However, the juice seems to contain interesting flavour compounds. In this work, a membrane process system consisting in nano filtration was used to reduce the pollution load and to concentrate flavour compounds of tuna cooking juice. The NF membrane tested in this work concentrate the organic matter since the retentions are high, starting at 74 pour cent for total circulation and increasing up to 85 pour cent for volume reduction factor (VRF) of 5. The membrane undergoes severe fouling, it can be effectively cleaned through a complete basic-acid washing cycle. The effect of three chemical reagents was studied for the regeneration of the fouled membrane. In the future, we will focus on the concentrates obtained by NF: sensory analysis with a panel of trained tasters and analysis of aromatic molecules should allow to value the quality of the flavouring concentrates.

  19. Maneuvering and stability performance of a robotic tuna.

    Science.gov (United States)

    Anderson, Jamie M; Chhabra, Narender K

    2002-02-01

    The Draper Laboratory Vorticity Control Unmanned Undersea Vehicle (VCUUV) is the first mission-scale, autonomous underwater vehicle that uses vorticity control propulsion and maneuvering. Built as a research platform with which to study the energetics and maneuvering performance of fish-swimming propulsion, the VCUUV is a self-contained free swimming research vehicle which follows the morphology and kinematics of a yellowfin tuna. The forward half of the vehicle is comprised of a rigid hull which houses batteries, electronics, ballast and hydraulic power unit. The aft section is a freely flooded articulated robot tail which is terminated with a lunate caudal fin. Utilizing experimentally optimized body and tail kinematics from the MIT RoboTuna, the VCUUV has demonstrated stable steady swimming speeds up to 1.2 m/sec and aggressive maneuvering trajectories with turning rates up to 75 degrees per second. This paper summarizes the vehicle maneuvering and stability performance observed in field trials and compares the results to predicted performance using theoretical and empirical techniques.

  20. KAPASITAS PENANGKAPAN PANCING ULUR TUNA DI KEPULAUAN BANDA NEIRA

    Directory of Open Access Journals (Sweden)

    Baihaqi Baihaqi

    2016-04-01

    Fishing capacity is an approach to fishery management relating to restrictions on fishing effort capacity. The effort capacity is determined by several variables such as vessel  and engine sizes, the size of the nets, and fishing tool technology. Study of fishing capacity based fisheries management is an alternative approach to control the input factors that are not efficiently used in fishing effort. Through the research capacity, it is expected to know the level of technical efficiency of fishing tuna fishing fleet in the Banda Sea. Fishing capacity was examined using analysis technique Data Envelopment Analysis (DEA using a linear programming. The results show that the tuna line fisheries in the Banda Neira with single output approach (catch weight, was generally at the level of efficiency that is far under from the optimal level with the current input has exceeded the optimal capacity. To achieve the production potential of the third fishing grounds, reductions of the capacity of 33%, 42% and 45% for Hatta Island, Manukang Island and Rhum Island, respectively should be done.

  1. ESTABLISHMENT OF THE PENTECOSTALISM IN VICTORY OF LAS TUNAS CITY / ASENTAMIENTO DEL PENTECOSTALISMO EN VICTORIA DE LAS TUNAS

    Directory of Open Access Journals (Sweden)

    Enrique Antonio Lalana Torres

    2012-09-01

    Full Text Available The socioreligious studies are a topic that they have not been very managed at present. During the search of the information for this investigation, verified that in the word of investigations of the religious phenomenon that form the socio-religious specter in the country the approach to certain variants of the pentecostalism and its influence into the national cultural identity has been a topic not blown for the main investigating sociologists, ethnologists, and even the theologians have not blown the topic for considering it a little delicate. Therefore, in the environment of the religious investigations in our country, is the first time makes a study of this nature. In this work it makes, after a theoretical dissertation on the pentecostal movement, an approach to his settling in the territory of Las Tunas, by contributing a compendium of historiographical data that guarantees with an endorsement this prosecute developed in the decade of the 50´s of the XX century and the importance that has generated in the popular culture in the belonging territory to the then municipality of Victoria de Las Tunas.

  2. SWFSC/MMTD/ETP: Dolphin-Tuna Tracking Studies (DTTS) 1992-1993

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This research was designed to better understand the nature of the dolphin-tuna bond in the eastern tropical Pacific Ocean. In this study, researchers attempted to...

  3. STATUS STOK, EKSPLOITASI DAN OPSI PENGELOLAAN SUMBERDAYA IKAN TUNA DI LAUT BANDA

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    Agustinus Anung Widodo

    2015-05-01

    Full Text Available Laut Banda merupakan salah satu daerah penangkapan tuna yang potensial di Indonesia, Jenis alat tangkap yang digunakan terdiri dari pukat cincin, huhate, rawai tuna, pancing ulur dan pancing tonda. Hasil tangkapan tuna di Laut Banda meliputi cakalang, madidihang dan tuna mata besar. Sumberdaya tuna di Laut Banda diduga masih merupakan sub stok sumberdaya tuna di perairan Pasifik Tengah dan Barat. Hasil kajian stok tuna oleh Western and Central Pacific Fisheries Commission (WCPFC pada 2012 melaporkan bahwa stok cakalang dan madidihang tidak mengalami overfishing dan overfished, sedangkan tuna mata besar telah mengalami overfishing dan overfished. Hasil penelitian Pusat Penelitian Pengelolaan Perikanan dan Konservasi Sumber Daya Ikan (P4KSI pada 2012 menunjukkan madidihang dan tuna mata besar tertangkap pukat cincin, huhate serta kombinasi pancing ulur permukaan dan pancing tonda pada stadium yuwana, dengan indikasi nilai LcFmsy while YFT and SKJ are not in overfishing or overfished state. It was also reported by RCFMC that the size of catch of those species by various fishing gear indicating that value of Lctuna resource and market preference, so that to the best fishing practice for resource sustainability it is suggestted for tuna management in Banda sea should be not to develop and increase the effort for purse seine and may shift to pole line, hand line and/or troll line are still openated.

  4. The western Indian Ocean tuna fishery from 1980 to 1985: a summary of data collected by coastal states

    OpenAIRE

    Lawson, T.A.; Lablache, G.; Simões, F.

    1987-01-01

    Longliner and purse-seiner catch/effort statistics for tuna fisheries in the western Indian Ocean collected by Mozambique, Seychelles and Somalia are summarized. Although the data are not considered sufficient to indicate trends for the western Indian Ocean as a whole, an examination of data from the Seychelles EEZ shows that catch rates for yellowfin tuna declined consistently from 1982 to 1985, to about half their former levels. The data were processed by the FAO/Indo Pacific Tuna Developme...

  5. DAYA SAING EKSPOR TUNA KALENG INDONESIA DI UNI EROPA TAHUN 2003-2013

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    Umar Wahono

    2017-06-01

    Full Text Available Perbedaan tarif yang diberikan antara Indonesia yang lebih tinggi sebesar 20.5% dibandingkan dengan negara pesaing utamanya yang tergabung dalang Africa, Caribbean, Pasific (ACP Countries dengan pelayanan tarif impor hingga 0% ke pasar Uni Eropa (UE. Keadaan ini mampu menyebabkan menghilangnya distorsi perbedaan harga sesungguhnya yang seharusnya menjadi keuntungan lebih atas keunggulan komparatif yang dimiliki. Hal ini mampu melemahkan daya saing komoditi ekspor akibat dampak kenaikan harga terhadap tarif. Penelitian ini bertujuan untuk gambaran daya saing komoditas tuna kaleng Indonesia terhadap negara pesaingnya dipasar UE pada periode 2003-2013. Metode yang digunakan dalam penelitin ini adalah metode Revealed Comparative Advantage (RCA yang kemudian nilai RCA dikomparasikan tiap-tiap negara pengekspor utama tuna kaleng di pasar UE untuk melihat posisi daya saing relatifnya. Sedangkan untuk mendekomposisikan determinan pertumbuhan ekspor tuna kaleng Indonesia ke UE digunankan metode Constant Market Share (CMS. Hasil perhitungan nilai RCA tuna kaleng Indonesia periode 2003-2013 di pasar UE memiliki daya saing dengan rata-rata nilai RCA 4.27. Namun masih dibawah rata-rata nilai RCA negara ACP Countries. Perbedaan pelayanan tarif impor oleh UE untuk komoditas tuna kaleng Indonesia tidak berdampak terhadap penurunan daya saing. The difference between the rates given Indonesia which is higher by 20.5% compared to its main competitor countries that joined the mastermind Africa, Caribbean, Pacific (ACP Countries with service import tariffs to 0% to the European Union (EU. This situation is capable of causing the disappearance of the distortion of the true price difference should be more advantages over comparative advantage. It is capable of undermining the competitiveness of export commodities due to the impact of price increases on tariffs. This study aims to illustrate the competitiveness of commodities Indonesian canned tuna to the EU market of

  6. JENIS, UKURAN DAN DAERAH PENANGKAPAN HIU THRESHER (FAMILI ALOPIIDAE YANG TERTANGKAP RAWAI TUNA DI SAMUDERA HINDIA

    Directory of Open Access Journals (Sweden)

    Agustinus Anung Widodo

    2016-03-01

    Full Text Available Sebagai anggota Indian Ocean Tuna Commision (IOTC Indonesia wajib mengadopsi isi Resolusi IOTC 10/12 yang mengatur pengelolaan sumberdaya ikan hiu thresher (famili Alopiidae. Secara spesifik Indonesia belum melaksanakan pengelolaan sumberdaya hiu thresher karena spesies tersebut belum mendapatkan perhatian serius. Tulisan ini bermaksud menyampaikan hasil penelitian tentang ikan hiu thresher (Famili Alopiidae yang tertangkap rawai tuna di Samudera Hindia berbasis di Cilacap. Data diperoleh dari kegiatan pengambilan contoh di pelabuhan tahun 2010, kegiatan observasi di atas kapal rawai tuna bulan Januari 2010 dan laporan statistik PPS Cilacap tahun 2006-2010. Hasil kajian menunjukkan bahwa: (a di perairan Indonesia ada dua spesies dari tiga spesies hiu thresher yang ada di dunia, yaitu hiu monyet atau pelagic thresher (Alopias pelagicus Nakamura 1935 dan hiu paitan atau bigeye thresher (A. superciliosus Lowe 1840. Satu spesies lainnya yang belum pernah ditemukan adalah thinfin thresher (A.vulpinus Bonnaterre1788.  Dilihat dari teknologi rawai tuna yang digunakan, daerah sebaran hiu thresher sama dengan tuna di Samudera Hindia, sehingga sulit untuk menghindari tidak tertangkapnya hiu thresher oleh rawai tuna. Jumlah dari jenis hiu monyet yang tertangkap rawai tuna di Samudera Hindia berkisar 0,1-0,6 % dan hiu paitan berkisar 0,1-1,3 % dari total tangkapan. Ukuran hiu thresher yang tertangkap rawai tuna umumnya ikan yang telah dewasa (berkisar 54-74% dan diduga telah mengalami pemijahan. Hampir semua bagian hiu thresher dimanfaatkan sebagai bahan pangan dan farmasi. Selain dipasarkan di dalam negeri, ikan hiu thresher juga diekspor terutama siripnya ke manca negara dan terbanyak ke China.   As a member of IOTC, Indonesia is obliged to implement all IOTC’s resolutions including resolution 10/12 on the conservation of thresher sharks (Family Alopiidae caught in association with fisheries in the IOTC area of competence. Indonsia has not

  7. Modelling the spatial behaviour of a tropical tuna purse seine fleet.

    Science.gov (United States)

    Davies, Tim K; Mees, Chris C; Milner-Gulland, E J

    2014-01-01

    Industrial tuna fisheries operate in the Indian, Atlantic and Pacific Oceans, but concerns over sustainability and environmental impacts of these fisheries have resulted in increased scrutiny of how they are managed. An important but often overlooked factor in the success or failure of tuna fisheries management is the behaviour of fishers and fishing fleets. Uncertainty in how a fishing fleet will respond to management or other influences can be reduced by anticipating fleet behaviour, although to date there has been little research directed at understanding and anticipating the human dimension of tuna fisheries. The aim of this study was to address gaps in knowledge of the behaviour of tuna fleets, using the Indian Ocean tropical tuna purse seine fishery as a case study. We use statistical modelling to examine the factors that influence the spatial behaviour of the purse seine fleet at broad spatiotemporal scales. This analysis reveals very high consistency between years in the use of seasonal fishing grounds by the fleet, as well as a forcing influence of biophysical ocean conditions on the distribution of fishing effort. These findings suggest strong inertia in the spatial behaviour of the fleet, which has important implications for predicting the response of the fleet to natural events or management measures (e.g., spatial closures).

  8. El Nino Southern Oscillation (ENSO) impact on tuna fisheries in Indian Ocean.

    Science.gov (United States)

    Kumar, Palanisamy Satheesh; Pillai, Gopalakrishna N; Manjusha, Ushadevi

    2014-01-01

    El Nino Southern Oscillation (ENSO) is an important driver of interannual variations in climate and ecosystem productivity in tropical regions. However, detailed information about this important phenomenon of the Indian Ocean is scarce. Consequently, the objective of this study is to improve understanding of the impact of warm event El Nino and cool event La Nina on annual tuna landings from the Indian Ocean from 1980 to 2010. In this study, maximum tuna landings were recorded during a weak El Nino year (1456054 t in 2006) and during a weak La Nina year (1243562 t in 2000), although the lowest tuna catch was followed during the strong El Nino year (1204119 t in 2009) and during a strong La Nina year (706546 t in 1988). Validation of predicted tuna landings and SST were showing a significant positive correlation (p Ocean tend to be optimum SST 25 to 26°C in ENSO event. Our results confirm the ENSO impact on climate, tuna abundance and production in the Indian Ocean. However, among the oceanic variables SST explained the highest deviance in generalized additive models and therefore considered the best habitat predictor in the Indian Ocean followed by sea level pressure and Winds (U, V, W).

  9. DYNAMICS OF GEARS, FLEETS, CATCH AND FISHING SEASON OF SMALLSCALE TUNA FISHERIES IN LABUHAN LOMBOK, WEST NUSA TENGGARA

    Directory of Open Access Journals (Sweden)

    Bram Setyadji

    2015-12-01

    Full Text Available In Indonesia, about 80% of fishing activities are small-scale and play major role both economically and socially. Previous studies mostly concentrated in Java, while in eastern part of Indonesia the information still scarce and limited. The study was conducted from January to December 2013, describes in detail the gears, fleets and catch dynamics of the small-scale tuna fisheries operating based in Labuhan Lombok Coastal Fishing Port (PPP. Labuhan Lombok. Small-scale tuna fishery in Labuhan Lombok are characterized by the small boats less than 10 GT, operating both troll line and hand line simultaneously, targeting large tuna, skipjack tuna and small tuna. Fishing season starts from April to August and influence by southwest monsoon wind and the presence of middleman as the connector between fishers and the market are the main character of the small-scale fisheries business in this area.

  10. The incidental capture of seabirds by Spanish drifting longline fisheries in the western Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Julio Valeiras

    2003-07-01

    Full Text Available The western Mediterranean Sea is an important fishing area for the Spanish drifting longline fleet, targeting swordfish (Xiphias gladius, bluefin tuna (Thunnus thynnus and albacore (T. alalunga. Some seabird species can be captured incidentally as bycatch marine fauna. From July 1999 to August 2000 information on 554 surface longline sets was collected by onboard observers of the Spanish Oceanographic Institute (IEO on 18 longline fishing boats working within the Spanish Mediterranean fishing area. Eleven yellow-legged gulls (Larus cachinnans, 9 Cory´s shearwaters (Calonectris diomedea and 1 Northern gannet (Morus bassanus were captured incidentally. Bycatch rates ranged from 0.002 to 0.023 birds/1000 hooks.

  11. Modeling the Spatial Dynamics of International Tuna Fleets.

    Directory of Open Access Journals (Sweden)

    Jenny Sun

    Full Text Available We developed an iterative sequential random utility model to investigate the social and environmental determinants of the spatiotemporal decision process of tuna purse-seine fishery fishing effort in the eastern Pacific Ocean. Operations of the fishing gear mark checkpoints in a continuous complex decision-making process. Individual fisher behavior is modeled by identifying diversified choices over decision-space for an entire fishing trip, which allows inclusion of prior and current vessel locations and conditions among the explanatory variables. Among these factors are vessel capacity; departure and arrival port; duration of the fishing trip; daily and cumulative distance travelled, which provides a proxy for operation costs; expected revenue; oceanographic conditions; and tons of fish on board. The model uses a two-step decision process to capture the probability of a vessel choosing a specific fishing region for the first set and the probability of switching to (or staying in a specific region to fish before returning to its landing port. The model provides a means to anticipate the success of marine resource management, and it can be used to evaluate fleet diversity in fisher behavior, the impact of climate variability, and the stability and resilience of complex coupled human and natural systems.

  12. Leaching of Oil from Tuna Fish Liver by Using Solvent of Methyl-Ethyl Ketone

    Directory of Open Access Journals (Sweden)

    Mirna Rahmah Lubis

    2013-12-01

    Full Text Available Research of oil leaching from Tuna Fish Liver has been carried out by extracting of tuna fish liver in soxhlet by using methyl-ethyl ketone as solvent. Liver of fresh tuna fish is blended, put into soxhlet, and extracted at temperatures of 60oC, 65oC, 70oC, 75oC, and 80oC. After obtaining the oil, separation between solvent and oil is carried out by distillation. Oil obtained is analyzed by testing the yield, acid number, Iodine value, viscosity, and its impurities content. Yield obtained is influenced by temperature and time of leaching. Both variables indicates that the higher the variables, the more fish liver oil obtained. Maximum yield obtained is 25.552% at operating condition of leaching temperature 80oC, and leaching duration of 5 hours.

  13. Performance variation due to stiffness in a tuna-inspired flexible foil model.

    Science.gov (United States)

    Rosic, Mariel-Luisa N; Thornycroft, Patrick J M; Feilich, Kara L; Lucas, Kelsey N; Lauder, George V

    2017-01-17

    Tuna are fast, economical swimmers in part due to their stiff, high aspect ratio caudal fins and streamlined bodies. Previous studies using passive caudal fin models have suggested that while high aspect ratio tail shapes such as a tuna's generally perform well, tail performance cannot be determined from shape alone. In this study, we analyzed the swimming performance of tuna-tail-shaped hydrofoils of a wide range of stiffnesses, heave amplitudes, and frequencies to determine how stiffness and kinematics affect multiple swimming performance parameters for a single foil shape. We then compared the foil models' kinematics with published data from a live swimming tuna to determine how well the hydrofoil models could mimic fish kinematics. Foil kinematics over a wide range of motion programs generally showed a minimum lateral displacement at the narrowest part of the foil, and, immediately anterior to that, a local area of large lateral body displacement. These two kinematic patterns may enhance thrust in foils of intermediate stiffness. Stiffness and kinematics exhibited subtle interacting effects on hydrodynamic efficiency, with no one stiffness maximizing both thrust and efficiency. Foils of intermediate stiffnesses typically had the greatest coefficients of thrust at the highest heave amplitudes and frequencies. The comparison of foil kinematics with tuna kinematics showed that tuna motion is better approximated by a zero angle of attack foil motion program than by programs that do not incorporate pitch. These results indicate that open questions in biomechanics may be well served by foil models, given appropriate choice of model characteristics and control programs. Accurate replication of biological movements will require refinement of motion control programs and physical models, including the creation of models of variable stiffness.

  14. U.S. Tuna Fisheries: a trifecta of sustainable practices at odds with climate change mitigation

    Science.gov (United States)

    McKuin, B.; Campbell, J. E.

    2016-12-01

    Environmental concerns have given rise to eco-label initiatives in the seafood industry and a shift to more sustainable fishing practices in the U.S. Currently, the greenhouse gas emissions of fisheries are being considered in the sustainability criteria of the consumer advocacy group Seafood Watch. We looked at sustainable practices employed by U.S. tuna fisheries and find the term "sustainably sourced" changes when climate forcing is added to the criteria. Specifically, there are three sustainable practices at odds with climate change mitigation: 1) the use of selective fishing gear reduces bycatch but increases fuel use; 2) fishing within exclusive economic zones is more equitable to coastal fishermen, and allows the high seas to serve as an ecological bank, but fishing within these regions means fisheries are subject to more stringent fuel sulfur laws thereby diminishing the cooling effects of sulfate aerosols and increasing climate forcing; and 3) removing sulfur from fuels improves air quality but there are added emissions from the refinery process. We used ship registry data, historical sulfur levels in fuels, gear-specific fishery fuel use data collected from the literature, historical gear-specific tuna landings data, and a range of global warming potentials to estimate the climate forcing of U.S. tuna fisheries over the last fifteen years. We found that for tuna caught within exclusive economic zones, the net fuel-related climate forcing has more than doubled over the last fifteen years. We also normalized the fuel-related climate forcing results to a unit of tuna protein and compared these results to other farmed sources of protein. We found that tuna caught within exclusive economic zones has the highest climate impact of all land-based protein sources considered, with the exception of beef. Our results can inform policy makers and consumer advocacy groups which is an important step in communicating the climate impact of dietary choices to consumers.

  15. Environmental radioecological study of beaches of Las Tunas and Holguin provinces, Cuba

    International Nuclear Information System (INIS)

    Brigido, F.O.; Peres Tamayo, L.; Barrerras Caballero, A.; Batista Mateo, R.; Hernandez Perez, A.; Parra Valdes, D.; Bravo Lopez, R.; Freeman, D.A.; Zerquera, J.T.

    1999-01-01

    The survey of radioactivity levels in beaches of Las Tunas and Holguin was undertaken as a programme aimed at studying the environmental radioactivity in Cuba. Concentrations of radionuclides were determined by In Situ gamma ray spectrometry. The average concentrations of Ra 226 , Th 232 and K 40 in the surveyed soils of Las Tunas beaches (Covarrubia, Real de Covarrubia and Corella) were 3, < 1 and 14.3 Bq.Kg 1 - , respectively. In surveyed soils of Holguin beaches (Guardalavaca, Pesquero and Don Lino) were 6.0, < 1 and 25.0 Bq.Kg 1 - , respectively. Radiological measurements carried out with a portable scintillometer revealed an average outdoor absorbed dose rate in air of 34.2 n Gy.h 1 - for Las Tunas beaches and 37.3 n Gy.h 1 - for Holguin one. For assessing the ionizing component of cosmic rays, measurements were performed on board a wood and plastic boat in the middle of two deep artificial basins and in two bays. The readings averaged 33.5 n Gy.h 1 - . Measurements of gross beta activity in outdoor air revealed 0.3 and 0.5 Bq.m 3 - for Las Tunas and Holguin beaches, respectively, and indoor values averaged 3.5 and 4.3 Bq.m 3 - , respectively. Taking into account the results of measurements was possible to assess effective doses due to external and internal exposure. For the first one were estimated 230 Sv.year 1 - for Las Tunas beaches and 250 Sv.year 1 - for Holguin beaches. The assessing of internal component of exposure revealed 236 and 292 Sv.year 1 - for Las Tunas and Holguin beaches, respectively, due to exposure to radon daughter. The results of our survey show that studied beaches are characterized by low environmental radioactive background

  16. Differential loggerhead by-catch and direct mortality due to surface longlines according to boat strata and gear type

    Directory of Open Access Journals (Sweden)

    Juan A. Camiñas

    2006-12-01

    Full Text Available Surface longline gears are used to fish different species, mainly albacore Thunnus alalunga (Bonnaterre, 1788, bluefin tuna Thunnus thynnus (Linnaeus, 1758, and swordfish Xiphias gladius Linnaeus, 1758, and are considered highly dangerous for threatened marine turtles. Loggerheads Caretta caretta (Linnaeus, 1758 can be incidentally captured by surface longlines. A number of captured individuals die during the fishing operation, which we consider direct mortality due to fishing. We analysed the relative loggerhead by-catch and direct mortality associated with each type of boat and gear from April to December during the period 1999-2004 in the Spanish surface longline fleet that fishes in the western Mediterranean Sea, an important fishing area for this fleet. We used different indices to compute the catch per unit effort (CPUE according to the number of hooks and to the number of fishing operations for each type of boat and gear. Both by-catch and direct mortality differed significantly according to the type of boat and gear. With respect to the number of hooks, boats longer than 12 m not using a roller and targeting bluefin tuna captured the highest number of loggerheads, whereas boats longer than 12 m with a roller that targeted swordfish caused the highest direct mortality. With respect to the number of fishing operations, boats longer than 12 m without a roller that targeted albacore captured the highest number of loggerheads; the highest direct mortality was caused by this type of boat and by boats longer than 12 m using a roller and targeting swordfish.

  17. The concentration and variability of selenium and mercury measured in vacuum-packed tuna fish

    International Nuclear Information System (INIS)

    Brockman, J.D.; Sharp, N.; Ngwenyama, R.A.; Shelnutt, L.D.; McElroy, J.A.

    2009-01-01

    Methylmercury (meHg) is a known toxin commonly found in fish. Fish is also a rich source of the trace nutrient selenium which has been hypothesized to modify the toxicity of meHg. We analyzed 28 samples of commercially packaged albacore and light tuna fish for selenium and mercury using standard comparator instrumental neutron activation analysis. Significant differences in the concentration of mercury and selenium were associated with the type of fish, brand and batch. Fish consumers should vary the brand of tuna fish to avoid routine consumption of a brand high in mercury. (author)

  18. Rent-Maximization versus Competition in the Western and Central Pacific Tuna Fishery

    OpenAIRE

    Hannesson, Rognvaldur; Kennedy, John O.S.

    2007-01-01

    Where a fish stock straddles or migrates between country A's exclusive economic zone (EEZ) and country B's EEZ, or the high seas, vesting ownership rights in the stock with A does not ensure efficient harvesting of the stock. This problem arises in the case of migratory tuna stocks in the Western and Central Pacific Ocean (WCPO). Four species of tuna reside for only part of the year in the EEZs of coastal states, many of which are Pacific Island Countries (PICs). Most of the harvesting of the...

  19. Notes on helminth parasites of tuna fishes (Scombridae in Brazil Notas sobre los helmintos parásitos del atún (Scombridae en Brasil

    Directory of Open Access Journals (Sweden)

    Márcia Cristina Nascimento-Justo

    2012-03-01

    Full Text Available Four species of Scombridae from the coast of Rio de Janeiro, southwest Atlantic Ocean were found to be parasitized with species of Didymozoidae (Digenea: Thunnus atlanticus (Lesson a new host record for Nephrodidymotrema ahi Yamaguti, 1970, Didymocystis neothunni (Yamaguti, 1970, and Didymozoon longicolle (Yamaguti, 1970; Thunnus obesus (Lowe parasitized by Didymozoon longicolle and reported as a new host for Nephrodidymotrema ahi; Thunnus albacares (Bonaterre parasitized by Nephrodidymotrema ahi, and Katsuwonus pelamis (Linnaeus by Didymozoon longicolle. Measurements, figures, and parameters of infection are presented.Cuatro especies de Scombridae de la costa de Río de Janeiro, suroeste del océano Atlántico, se reportan parasitados con diferentes especies de Didymozoidae (Digenea: Thunnus atlanticus (Lesson un registro de nuevo huésped para Nephrodidymotrema ahi Yamaguti, 1970, Didymocystis neothunni (Yamaguti, 1970 y para Didymozoon longicolle (Yamaguti, 1970; Thunnus obesus (Lowe parasitado por Didymozoon longicolle, se indica como nuevo huésped para Nephrodidymotrema ahi; Thunnus albacares (Bonaterre parasitados por Nephrodidymotrema ahi y Katsuwonus pelamis (Linnaeus por Didymozoon longicolle. Se presentan las mediciones, las figuras y los parámetros de la infección.

  20. Trophic position increases with thermocline depth in yellowfin and bigeye tuna across the Western and Central Pacific Ocean

    Science.gov (United States)

    Houssard, Patrick; Lorrain, Anne; Tremblay-Boyer, Laura; Allain, Valérie; Graham, Brittany S.; Menkes, Christophe E.; Pethybridge, Heidi; Couturier, Lydie I. E.; Point, David; Leroy, Bruno; Receveur, Aurore; Hunt, Brian P. V.; Vourey, Elodie; Bonnet, Sophie; Rodier, Martine; Raimbault, Patrick; Feunteun, Eric; Kuhnert, Petra M.; Munaron, Jean-Marie; Lebreton, Benoit; Otake, Tsuguo; Letourneur, Yves

    2017-05-01

    Estimates of trophic position are used to validate ecosystem models and understand food web structure. A consumer's trophic position can be estimated by the stable nitrogen isotope values (δ15N) of its tissue, once the baseline isotopic variability has been accounted for. Our study established the first data-driven baseline δ15N isoscape for the Western and Central Pacific Ocean using particulate organic matter. Bulk δ15N analysis on 1039 muscle tissue of bigeye and yellowfin tuna were conducted together with amino acid compound-specific δ15N analysis (AA-CSIA) on a subset of 21 samples. Both particulate organic matter and tuna bulk δ15N values varied by more than 10‰ across the study area. Fine-scaled trophic position maps were constructed and revealed higher tuna trophic position (by ∼1) in the southern latitudes compared to the equator. AA-CSIA confirmed these spatial patterns for bigeye and, to a lesser extent, yellowfin tuna. Using generalized additive models, spatial variations of tuna trophic positions were mainly related to the depth of the 20°C isotherm, a proxy for the thermocline behavior, with higher tuna trophic position estimates at greater thermocline depths. We hypothesized that a deeper thermocline would increase tuna vertical habitat and access to mesopelagic prey of higher trophic position. Archival tagging data further suggested that the vertical habitat of bigeye tuna was deeper in the southern latitudes than at the equator. These results suggest the importance of thermocline depth in influencing tropical tuna diet, which affects their vulnerability to fisheries, and may be altered by climate change.

  1. Quantitative analysis on dose to humans as a result of consuming tuna fish contaminated by cesium radionuclides

    International Nuclear Information System (INIS)

    Khani, J.; Donev, J.M.K.C.

    2014-01-01

    Quantitative empirical data is presented on the dose exposure to North Americans consuming tuna fish that have accumulated concentrations of radioactive isotopes. The two particular radioactive isotopes of interest are cesium-137 and cesium-134. Though biological effects of radiation are a widely debatable topic, the consumption of tuna fish does not support significant increased risk of cancer to humans. An important comparison is made between the elevated levels of radioactive cesium concentrations to naturally occurring radionuclides, namely potassium-40 and polonium-210. It is calculated that naturally occurring radioactive isotopes are in the orders of magnitude greater than the cesium radionuclides in tuna fish. (author)

  2. Age and growth of bullet tuna, Auxis rochei (Risso), from the Turkish ...

    African Journals Online (AJOL)

    The study aims to identify the age and growth parameters of bullet tuna (Auxis rochei) in Turkish waters. The fish were caught from the Turkish Mediterranean coasts between December 2008 and December 2009. A total of 186 dorsal fin spines obtained from the specimens were analyzed for ageing and growth studies.

  3. Uncertainty in catch and effort data of small- and medium-scale tuna fisheries in Indonesia

    NARCIS (Netherlands)

    Yuniarta, Shinta; Zwieten, van Paul A.M.; Groeneveld, Rolf A.; Wisudo, Sugeng Hari; Ierland, van E.C.

    2017-01-01

    This study aims to identify the sources and magnitude of uncertainty in the collection and processing of catch and effort data of small- and medium-scale tuna fisheries in Indonesia, as well as the causes of uncertainty on an operational level. We identified possible sources of uncertainty

  4. Closing the Incentive Gap: The Role of Public and Private Actors in Governing Indonesia's Tuna Fisheries

    NARCIS (Netherlands)

    Bailey, M.L.; Miller, A.M.M.; Bush, S.R.; Zwieten, van P.A.M.; Wiryawan, B.

    2016-01-01

    Indonesia is one of the world's largest tuna producing countries, yet regulatory oversight remains weak and management is poor. Incentive-based approaches are a way to improve state-based resource management, but they often require strong government regulation. In this paper, we use principal–agent

  5. Commentary: BESTTuna: Benefiting from Equitable and Sustainable Trans-boundary Tuna fisheries in the Western Pacific

    NARCIS (Netherlands)

    Bush, S.R.; Zwieten, van P.A.M.; Bailey, M.L.

    2013-01-01

    In this commentary we introduce the BESTTuna research programme which addresses the challenges of governing sustainable and equitable tuna fisheries in the Western Pacific. The research in this programme attempts to build an inter-disciplinary understanding of the complex social-ecological

  6. Synthesis of Monoacylglycerol Rich in Polyunsaturated Fatty Acids from Tuna Oil with Immobilized Lipase AK

    DEFF Research Database (Denmark)

    Pawongrat, Ratchapol; Xu, Xuebing; H-Kittikun, Aran

    2007-01-01

    -Butyl methyl ether (MTBE) was the most suitable organic solvent after screening a list of different solvents and their mixtures. The optimum conditions for MAG production were: 10% w/v of tuna oil in MTBE; mole ratio of glycerol to tuna oil 3:1, water added 4 wt% in glycerol; the amount of IM-AK 30 wt%, based......The aim of this study was to produce monoacylglycerols (MAG) rich in polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), by glycerolysis of tuna oil with lipase AK from Pseudomonas fluorescence immobilized on Accurel EP-100 (IM-AK). tert...... on tuna oil. The temperature was controlled at 45 degrees C. Under these conditions, with a 24 h reaction, the yield of MAG was 24.6%, but containing 56.0 wt% PUFA (EPA and DHA). Stability of the IM-AK was also studied. The hydrolytic activity of the enzyme remained at 88% and 80% of initial activity...

  7. Seasonal change of lipid and fatty acid composition of little tuna Euthynnus alletteratus-by-products.

    Science.gov (United States)

    Selmi, Salah; Mbarki, Raouf; Sadok, Saloua

    2008-01-01

    Little tuna (Euthynnus alletteratus) is an important Mediterranean commercial fish species. In this study, the lipids of tuna filet, head, viscera, liver, and gonads fished in Tunisian waters were examined in summer and winter. Total lipid content in most organs showed a significant variation due to seasonal change. The highest lipid content was found in head in little tuna fished in winter and summer (14.2%). The lowest levels were attributed to gonads (1.5%). The major fatty acids classes were polyunsaturated fatty acids (PUFA) followed by saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA). The lowest percentage of (MUFA) was recorded in winter season (9.77%). In summer, the proportion of PUFA decreased while that of SFA increased. The major contributing factor to the seasonal change of PUFA was n-3 fatty acids especially eicosapentaenoic acid (EPA) and docosahexaenoic (DHA). The lowest levels of PUFA/SFA were registered in summer. Little tuna by-products are an adequate raw material for fish oil production and excellent sources of n-3 fatty acids, the highest levels of PUFA were found during winter.

  8. Reducing the Bitterness of Tuna (Euthynnus pelamis Dark Meat with Lactobacillus casei subsp. casei ATCC 393

    Directory of Open Access Journals (Sweden)

    Ernani S. Sant’Anna

    2004-01-01

    Full Text Available During the process of canning tuna fish, considerable amounts of dark tuna meat are left over because of its bitterness, which are then used in the production of animal food. Fermentation with Lactobacillus casei subsp. casei ATCC 393 was used as an alternative to reduce this bitter taste. Samples of meat were prepared, vacuum packed and then stored at –18 °C. The frozen dark meat was used immediately after defrosting and the experiment was carried out with 2 and 4 % of NaCl with the addition of 2 and 4 % of glucose, respectively. The dark tuna meat was inoculated with lactic acid bacteria (LAB and fermented at 10 °C for 30 days. The fermentation process was monitored through bacteriological and chemical analyses, when an increase of acidity and the corresponding decrease of pH were observed due to the prevalence of LAB. Sensorial analysis, using a test of multiple comparison, was carried out with pastes of fermented dark tuna meat and presented a significant difference when compared to the paste control, indicating the reduction of bitter taste.

  9. Gender Transformations and Colonial Displacements in Laura Antillano's "Tuna de mar"

    Science.gov (United States)

    Reid, Alana

    2015-01-01

    This paper examines the trajectories of two characters in Laura Antillano's short story, "Tuna de mar" (1991), as they navigate interrelated systems of power and attempt to position themselves closer to, or further away from, the margins. Set in the late eighteenth century, the tale features a female protagonist who escapes prostitution…

  10. CONCENTRATION AND RECOVERY OF PROTEIN FROM TUNA COOKING JUICE BY FORWARD OSMOSIS

    Directory of Open Access Journals (Sweden)

    KHONGNAKORN W.

    2016-07-01

    Full Text Available Tuna cooking processing plants generate large amount of cooking juice containing a significant content of protein. Recovery and concentrating process of this valuable compound together with a low energy consumption process are of interest regarding full utilization concept and green process approach. Forward osmosis (FO was employed in this work to recover and concentrate tuna cooking juice. FO process could increase the protein concentration up to 9% with an average permeate flux of 2.54 L/m2h. The permeate flux however tended to decrease as protein concentration increased due to the impact of osmotic pressure of the feed and fouling on the membrane surface. Since tuna cooking juice consists of protein and minerals, membrane analyses indicated that fouling was more severe compared to the fouling caused by standard bovine serum albumin pure protein. However, the presence of minerals rendered it a quicker and lower energy process by comparison. These results indicated that FO is a promising technique in the recovery and concentration of tuna cooking juice protein.

  11. V ITER chrání zimu tuna stříbra

    Czech Academy of Sciences Publication Activity Database

    Řípa, Milan

    Říjen (2016) ISSN 2464-7888 Institutional support: RVO:61389021 Keywords : fusion * tokamak * ITER * thermal shield * silver * superconductivity Subject RIV: BL - Plasma and Gas Discharge Physics http://www.3pol.cz/cz/rubriky/jaderna-fyzika-a-energetika/1922-v-iter-chrani-zimu-tuna-stribra

  12. Visualizing the Food-Web Effects of Fishing for Tunas in the Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Jefferson T. Hinke

    2004-06-01

    Full Text Available We use food-web models to develop visualizations to compare and evaluate the interactions of tuna fisheries with their supporting food webs in the eastern tropical Pacific (ETP and the central north Pacific (CNP Oceans. In the ETP and CNP models, individual fisheries use slightly different food webs that are defined by the assemblage of targeted tuna species. Distinct energy pathways are required to support different tuna species and, consequently, the specific fisheries that target different tuna assemblages. These simulations suggest that catches of tunas, sharks, and billfishes have lowered the biomass of the upper trophic levels in both systems, whereas increases in intermediate and lower trophic level animals have accompanied the decline of top predators. Trade-offs between fishing and predation mortality rates that occur when multiple fisheries interact with their respective food webs may lead to smaller changes in biomass than if only the effect of a single fishery is considered. Historical simulations and hypothetical management scenarios further demonstrate that the effects of longline and purse seine fisheries have been strongest in upper trophic levels, but that lower trophic levels may respond more strongly to purse-seine fisheries. The apex predator guild has responded most strongly to longlining. Simulations of alternative management strategies that attempt to rebuild shark and billfish populations in each ecosystem reveal that (1 changes in longlining more effectively recover top predator populations than do changes in purse seining and (2 restrictions on both shallow-set longline gear and shark finning may do more to recover top predators than do simple reductions in fishing effort.

  13. Mercury poisoning in a fisherman working on a pelagic fishing vessel due to excessive tuna consumption.

    Science.gov (United States)

    Ahn, Ji-Sung; Kang, Kyung Wook; Kang, Won-Yang; Lim, Hyeong-Min; Cho, Seunghyeon; Moon, Jai-Dong; Park, Won-Ju

    2018-01-25

    To report the case of a fisherman who developed chronic mercury poisoning due to excessive consumption of tuna while working on a pelagic fishing vessel. A 48-year-old male deep-sea fisherman developed paresthesia and pain in both legs while working at sea. He continued working for over 4 months on a pelagic fishing vessel but was eventually unable to function normally as his condition deteriorated. Upon arrival on land, he received specialist treatment, including imaging studies, for 2 months; however, the cause of the symptoms was not identified. An examination of his occupational history revealed that he had worked as a crew member on a pelagic fishing vessel catching tuna for the last 2 years and consumed tuna for two or more meals per day, every day. Two months after discontinuation of tuna consumption, he was tested for mercury. The result showed an elevated blood mercury level (BML) of 21.79 μg/l. Based on the half-life of mercury, the BML was evaluated as 38.70-53.20 μg/l when he was on board. Four months after discontinuing tuna consumption, his BML decreased to 14.18 μg/l, and the symptoms were almost ameliorated. The person responsible for preparing meals on a pelagic fishing ship should be aware that fish may contain high levels of heavy metals and should prepare meals for crew members according to the recommended levels. Crew members should also be aware that fish and shellfish may contain mercury, and hence, they should consume only an appropriate amount.

  14. Predicting Interactions between Common Dolphins and the Pole-and-Line Tuna Fishery in the Azores.

    Science.gov (United States)

    Cruz, Maria João; Menezes, Gui; Machete, Miguel; Silva, Mónica A

    2016-01-01

    Common dolphins (Delphinus delphis) are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998-2012) collected by observers placed aboard tuna fishing vessels. Dolphins interacted in less than 3% of the fishing events observed during the study period. The probability of dolphin interaction varied significantly between years with no evident trend over time. Generalized additive modeling results suggest that fishing duration, sea surface temperature and prey abundance in the region were the most important factors explaining common dolphin interaction. Dolphin interaction had no impact on the catches of albacore, skipjack and yellowfin tuna but resulted in significantly lower catches of bigeye tuna, with a predicted median annual loss of 13.5% in the number of fish captured. However, impact on bigeye catches varied considerably both by year and fishing area. Our work shows that rates of common dolphin interaction with the pole-and-line tuna fishery in the Azores are low and showed no signs of increase over the study period. Although overall economic impact was low, the interaction may lead to significant losses in some years. These findings emphasize the need for continued monitoring and for further research into the consequences and economic viability of potential mitigation measures.

  15. Predicting Interactions between Common Dolphins and the Pole-and-Line Tuna Fishery in the Azores.

    Directory of Open Access Journals (Sweden)

    Maria João Cruz

    Full Text Available Common dolphins (Delphinus delphis are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998-2012 collected by observers placed aboard tuna fishing vessels. Dolphins interacted in less than 3% of the fishing events observed during the study period. The probability of dolphin interaction varied significantly between years with no evident trend over time. Generalized additive modeling results suggest that fishing duration, sea surface temperature and prey abundance in the region were the most important factors explaining common dolphin interaction. Dolphin interaction had no impact on the catches of albacore, skipjack and yellowfin tuna but resulted in significantly lower catches of bigeye tuna, with a predicted median annual loss of 13.5% in the number of fish captured. However, impact on bigeye catches varied considerably both by year and fishing area. Our work shows that rates of common dolphin interaction with the pole-and-line tuna fishery in the Azores are low and showed no signs of increase over the study period. Although overall economic impact was low, the interaction may lead to significant losses in some years. These findings emphasize the need for continued monitoring and for further research into the consequences and economic viability of potential mitigation measures.

  16. Predicting Interactions between Common Dolphins and the Pole-and-Line Tuna Fishery in the Azores

    Science.gov (United States)

    Cruz, Maria João; Menezes, Gui; Machete, Miguel; Silva, Mónica A.

    2016-01-01

    Common dolphins (Delphinus delphis) are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998–2012) collected by observers placed aboard tuna fishing vessels. Dolphins interacted in less than 3% of the fishing events observed during the study period. The probability of dolphin interaction varied significantly between years with no evident trend over time. Generalized additive modeling results suggest that fishing duration, sea surface temperature and prey abundance in the region were the most important factors explaining common dolphin interaction. Dolphin interaction had no impact on the catches of albacore, skipjack and yellowfin tuna but resulted in significantly lower catches of bigeye tuna, with a predicted median annual loss of 13.5% in the number of fish captured. However, impact on bigeye catches varied considerably both by year and fishing area. Our work shows that rates of common dolphin interaction with the pole-and-line tuna fishery in the Azores are low and showed no signs of increase over the study period. Although overall economic impact was low, the interaction may lead to significant losses in some years. These findings emphasize the need for continued monitoring and for further research into the consequences and economic viability of potential mitigation measures. PMID:27851763

  17. Keragaman Spesies dan Genetik Bakteri Staphylococcus pada Ikan Tuna dengan Analisis Sekuen 16s rRNA (SPECIES DIVERSITY AND GENETIC OF STAPHYLOCOCCUS BACTERIA IN TUNA FISH BY USING 16S rRNA SEQUENCE ANALYSIS)

    OpenAIRE

    Putu Mei Purnama Dewi; I Nengah Kerta Besung; I Gusti Ngurah Kade Mahardika

    2015-01-01

    Tuna industry belongs to high economic value fish of marine fisheries commodity. Bacteria found intuna might have impact on consumer health. The purpose of this research was to determine the geneticvariation of Staphylococcus in Kedonganan fish market, Kuta, Badung, Bali by sequence analysis of 16SrRNA. Staphylococcus bacteria was isolated from feces samples of 30 tuna. After identification with Gramstaining, Staphylococcus colonies were transferred to the medium chelex 10% for DNA extraction...

  18. Influence of physical damage and freezing on histamine concentration and microbiological quality of yellowfin tuna during processing

    Directory of Open Access Journals (Sweden)

    Gonzalo García-Tapia

    2013-09-01

    Full Text Available Yellowfin tuna has a high level of free histidine in their muscle, which can lead to histamine formation by microorganisms if temperature abuse occurs during handling and further processing. The objective of this study was to measure levels of histamine in damaged and undamaged thawed muscle to determine the effect of physical damage on the microbial count and histamine formation during the initial steps of canning processing and to isolate and identify the main histamine-forming microorganisms present in the flesh of yellowfin tuna. Total mesophilic and psicrophilic microorganisms were determined using the standard plate method. The presence of histamine-forming microorganisms was determined in a modified Niven's agar. Strains were further identified using the API 20E kit for enterobacteriaceae and Gram-negative bacilli. Physically damaged tuna did not show higher microbiological contamination than that of undamaged muscle tuna. The most active histamine-forming microorganism present in tuna flesh was Morganella morganii. Other decarboxylating microorganisms present were Enterobacter agglomerans and Enterobacter cloacae. Physical damage of tune during catching and handling did not increase the level of histamine or the amount of microorganisms present in tuna meat during frozen transportation, but they showed a higher risk of histamine-forming microorganism growth during processing.

  19. Are Consumers Willing to Pay More for Sustainable Products? A Study of Eco-Labeled Tuna Steak

    Directory of Open Access Journals (Sweden)

    Guzhen Zhou

    2016-05-01

    Full Text Available A high demand for seafood leads to overfishing, harms the long-term health of seafood stocks, and threatens environmental sustainability in oceans. Sustainability certification is one of the major sustainability movements and is known as eco-labeling. For instance, in the tuna industry, leading tuna brands have committed to protecting sea turtles by allowing the tracing of the source of their tuna “from catch to can.” This paper relies on an Internet survey on consumers from Kentucky conducted in July 2010. The survey investigates household-level tuna steak (sashimi grade consumption and examines consumer preferences for eco-labeling (“Certified Turtle Safe” (CTS in this study while mimicking individuals’ seafood procurement processes. A random parameter logit model is utilized, and willingness-to-pay measures are calculated based on model estimation results. It was found that respondents on average preferred turtle-safe-labeled tuna steak and were likely to pay more for it; however, they were less likely to purchase wild-caught species, and insignificant results were found for pre-frozen. Moreover, significant heterogeneities were found across individuals regarding tuna steak purchases. The findings indicate evidence of public support for environmental friendliness, particularly with regard to eco-labeling.

  20. Oligonucleotide indexing of DNA barcodes: identification of tuna and other scombrid species in food products

    Directory of Open Access Journals (Sweden)

    Botti Sara

    2010-08-01

    Full Text Available Abstract Background DNA barcodes are a global standard for species identification and have countless applications in the medical, forensic and alimentary fields, but few barcoding methods work efficiently in samples in which DNA is degraded, e.g. foods and archival specimens. This limits the choice of target regions harbouring a sufficient number of diagnostic polymorphisms. The method described here uses existing PCR and sequencing methodologies to detect mitochondrial DNA polymorphisms in complex matrices such as foods. The reported application allowed the discrimination among 17 fish species of the Scombridae family with high commercial interest such as mackerels, bonitos and tunas which are often present in processed seafood. The approach can be easily upgraded with the release of new genetic diversity information to increase the range of detected species. Results Cocktail of primers are designed for PCR using publicly available sequences of the target sequence. They are composed of a fixed 5' region and of variable 3' cocktail portions that allow amplification of any member of a group of species of interest. The population of short amplicons is directly sequenced and indexed using primers containing a longer 5' region and the non polymorphic portion of the cocktail portion. A 226 bp region of CytB was selected as target after collection and screening of 148 online sequences; 85 SNPs were found, of which 75 were present in at least two sequences. Primers were also designed for two shorter sub-fragments that could be amplified from highly degraded samples. The test was used on 103 samples of seafood (canned tuna and scomber, tuna salad, tuna sauce and could successfully detect the presence of different or additional species that were not identified on the labelling of canned tuna, tuna salad and sauce samples. Conclusions The described method is largely independent of the degree of degradation of DNA source and can thus be applied to

  1. Improving the safety and quality of raw tuna fillets by x-ray irradiation

    Science.gov (United States)

    In this study, raw tuna fillet (25 g) samples were inoculated by immersing in 0.1% peptone water that contained 108-9 CFU ml-1 of a three-strain mixture of Salmonella enterica for 1 min. The samples were then air dried at 22 oC for 30 min and were packaged separately in sterilized bags prior to X-ra...

  2. CHARACTERIZATION OF ARTIFICIAL RICE PAPUA SAGU WITH ADDITION GELATIN FROM TUNA FISH BONE

    OpenAIRE

    Tina Fransiskha Carolyn Panjaitan

    2017-01-01

    Artificial rice sago Papua is one alternative to reduce dependence on rice. The existence of a significant difference in the chemical composition of sago Papua is a high amylose and low amylopectin contentto cause the texture of the rice produced is not good, that is necessary for a binder to improve the texture of artificial rice sago Papua. Binding agent (binder) used is gelatin originating from bones of tuna. Characterization of Papua sago artificial riceconducted to determine the texture ...

  3. Incidental spawning of some scombrids in Adriatic or not?

    Directory of Open Access Journals (Sweden)

    Vanja Cikes Kec

    2015-10-01

    Full Text Available During routine monitoring of commercial purse seine catches in 2011, 87 fingerling specimens of scombrids were collected in the southern Adriatic Sea. Sequencing of mitochondrial control region locus inferred that specimens belonged to the Atlantic bluefin tuna, Thunnus thynnus (Linnaeus, 1758 (N=29, bullet tuna, Auxis rochei (Risso, 1810 (N=30 and little tunny, Euthynnus alletteratus, Rafinesque, 1810 (N=28. Due to previously published growth parameters, age of collected specimens was estimated to be approximately 30 days. In order to determine possible location of the spawning event coupled modelling system ROMS-ICHTHYOP was run. Realistic ROMS simulations were made to provide current and density fields for the ICHTHYOP model. ROMS model was forced with realistic surface air-sea fluxes calculated from fine resolution ALADIN model, river inflows, tides and external dynamics. ICHTHYOP was run in the backward mode for 30 days using published investigations on the studied species and its early stage dynamics, such as their growth and developmental stage thermal dependence, lethal temperatures, etc. Apart simulations with coupled modelling system, detailed analysis of prevailing meteorological and oceanographic conditions was made using all available data. Comparison to climatology of the area approved that 2011 had unusually prolonged warm and dry summer season. Occasional inflows of hot and dry air from the northern Africa additionally warm up Adriatic atmosphere. Under these conditions sea surface temperature was up to 2 standard deviations above normal. In the deeper layers, high temperature and salinity were recorded. According to performed simulations it seems that tuna species spawn within the commercial tuna cages (this is not the first evidence of natural spawning within commercial tuna farming facility in the Adriatic, while the other two species most probably opportunistically use positive environmental (abiotic and biotic conditions and

  4. Isolation of 137-Cs in tuna fish by ammonium phosphomolybdate (AMP)

    International Nuclear Information System (INIS)

    Yumiarti; Surtipanti, S.

    1988-01-01

    The isolation of 137-Cs in tuna fish (Neithunnus macroptenus) has been carried out using AMP. The energy of 137-Cs was measure using NaI(T1) detector connected to a Multi Channel Analyzer (MCA). In standard solution of 137-Cs with activity 160.74 and 80.37 pCi, the addition of 120 mg AMP and 7 hours of absorption time, caused 97% of 137-Cs in the solution was absorbed. The destruction of tuna fish was carried out using two methods namely by wet destruction with sulfuric acid, nitrit acid and hydrogen peroxid mixture and by wet destruction with hydrogen peroxide. The applications of this technique of tuna fish was carried out by spiking 137-Cs standard into the fish before being destructed. The recovery obtained from wet destruction with H2O2 was about 80%, while from destruction with acid mixtures and H2O2 was only about 47%. (authors). 3 refs, 3 tabs

  5. Economic Impacts of Climate Change on Tuna Fisheries in Fiji Islands and Kiribati

    Energy Technology Data Exchange (ETDEWEB)

    Aaheim, Asbjoern; Sygna, Linda

    2000-06-01

    This paper discusses the possible economic consequences of a change in the tuna fisheries in the Pacific Ocean resulting from climate change. On the background of Lehodey's (2000) study of potential changes in the tuna fisheries, we survey possible economic impacts in terms of quantities and values and give examples of macroeconomic impacts. The two main effects of climate change on tuna fishing are likely to be a decline in the total stock and a migration of the stock westwards. This will lead to various changes in the catch in different countries. The price of the fish in the export market may also change as a result. The Pacific islands are generally dependent on fisheries, and may therefore be vulnerable to these changes, although some will probably gain while others will lose. Based on a very simple macroeconomic model, it is shown that the resulting effects for the national economy in general may diverge substantially from the expected. This applies, in particular, if the national economies are inflexible and a large part of the population relies on subsistence production, which is the case for many developing countries. (author)

  6. Aplikasi Sistem Informasi Geografis (SIG dan Penginderaan Jauh untuk Pemetaan Daerah Penangkapan Ikan Tuna Mata Besar di Selatan Jawa dan Bali

    Directory of Open Access Journals (Sweden)

    Kadek Bagus Padmaningrat

    2017-02-01

    Full Text Available Bigeye tuna is the dominant species of tuna caught in the territorial waters of the Indian Ocean and a productive tropical species which accounts for more than 10% of the total catch in the whole world. Distribution of bigeye tuna can be predicted through optimum temperature associated with the presence of bigeye tuna and distribution of chlorophyll-a is associated with the presence of small pelagic fish. The distribution of sea surface temperature and chlorophyll-a can be detected through remote sensing systems. The purpose of this study was to determine the relationship between sea surface temperature and chlorophyll-a by the number of bigeye tuna catches in the waters south of Java and Bali, and mapped the area catching bigeye tuna in the waters south of Java and Bali. The method used is a second order polynomial regression analysis to determine the effect of sea surface temperature and chlorophyll-a by the number of bigeye tuna catches as well as correlation analysis to determine the relationship of sea surface temperature and chlorophyll-a by the number of bigeye tuna catches. Sea surface temperature and chlorophyll-a is related to the number of bigeye tuna catches.  The results of the analysis showed a strong relationship between sea surface temperature and chlorophyll-a by the number of bigeye tuna catches. Bigeye tuna fishing grounds in the waters south of Java and Bali are in a position 12oS-15oS and 106°E-118°E.

  7. Baja visión en la población pediátrica de Las Tunas Low vision of the pediatric population in Las Tunas province

    Directory of Open Access Journals (Sweden)

    Yunia Herbania Labrada Rodríguez

    2006-12-01

    Full Text Available Se presentan los resultados de un estudio descriptivo en 35 pacientes ciegos y débiles visuales matriculados en la Escuela de Ciegos de la provincia Las Tunas. Los pacientes fueron agrupados según categoría visual, sexo, y etiología de baja visión. El sexo masculino fue el más afectado, el mayor número de pacientes eran débiles visuales y las etiologías más frecuentes de baja visión fueron la catarata congénita y la retinopatía de la prematuridadThe results of a descriptive study of 35 blind and impaired vision patients, who study at the School for Blind People in Las Tunas province were presented in this paper. The patients were grouped according to their visual category, sex and etiology of low vision. Males were the most affected, the highest number of patients had impaired vision and the most common causes of low vision were congenital cataract and prematurity retinopathy

  8. Comportamiento de la retinopatía de la prematuridad en la provincia Las Tunas Performance of retinopathy of prematurity in Las Tunas province

    Directory of Open Access Journals (Sweden)

    Yunia Herbania Labrada Rodríguez

    2006-06-01

    Full Text Available Se realizó un estudio observacional de tipo transversal en la provincia de Las Tunas en el período comprendido desde enero de 2002 a diciembre de 2004. El universo estuvo constituido por 14 503 nacidos vivos, la muestra la integraron 227 recién nacidos prematuros a los cuales se les realizó oftalmoscopia indirecta. La tasa de incidencia de retinopatía de la prematuridad fue de 0,10. Los factores de riesgo más relevantes fueron la prematuridad y el bajo peso al nacer. La retinopatía de la prematuridad fue más frecuente en recién nacidos de peso menor o igual a 1 500 g y la edad gestacional entre 30 y 34 semanas. La retinopatía de la prematuridad estadio I predominó en la serieAn observational cross-sectional study was conducted in Las Tunas province from January 2002 to December 2004. The universe of study was made up of 14 503 live births and the sample was composed by 227 premature newborns, who were performed indirect ophtalmoscopy. The incidence rate was 0,10. The most relevant risk factors were prematurity and low birthweight. Retinopathy of prematurity was more frequent in newborns weighing 1 500 g or less at birth and in gestational age of 30-34 weeks. Retinopathy of prematurity stage 1 predominated

  9. Fish and robot dancing together: bluefin killifish females respond differently to the courtship of a robot with varying color morphs

    International Nuclear Information System (INIS)

    Phamduy, P; Polverino, G; Porfiri, M; Fuller, R C

    2014-01-01

    The experimental integration of bioinspired robots in groups of social animals has become a valuable tool to understand the basis of social behavior and uncover the fundamental determinants of animal communication. In this study, we measured the preference of fertile female bluefin killifish (Lucania goodei) for robotic replicas whose aspect ratio, body size, motion pattern, and color morph were inspired by adult male killifish. The motion of the fish replica was controlled via a robotic platform, which simulated the typical courtship behavior observed in killifish males. The positional preferences of females were measured for three different color morphs (red, yellow, and blue). While variation in preference was high among females, females tend to spend more time in the vicinity of the yellow painted robot replicas. This preference may have emerged because the yellow robot replicas were very bright, particularly in the longer wavelengths (550–700 nm) compared to the red and blue replicas. These findings are in agreement with previous observations in mosquitofish and zebrafish on fish preference for artificially enhanced yellow pigmentation. (paper)

  10. A comparative study of thermal calcination and an alkaline hydrolysis method in the isolation of hydroxyapatite from Thunnus obesus bone

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesan, Jayachandran; Ryu, BoMi; Thomas, Noel Vinay; Kim, Se Kwon [Department of Chemistry, Pukyong National University, Busan 608-737 (Korea, Republic of); Qian Zhongji, E-mail: sknkim@pknu.ac.kr [Marine Bioprocess Research Center, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2011-06-15

    In the present study, hydroxyapatite (HAp) was isolated from Thunnus obesus bone using alkaline hydrolysis and thermal calcination methods. The obtained ceramic has been characterized by thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), powder x-ray diffraction analysis (XRD), field-emission scanning electron microscopy, energy-dispersive x-ray analysis, transmission electron microscopy (TEM), selected area diffraction analysis, cytotoxic analysis and cell proliferation analysis. The results indicate that there are significant differences between the ceramics and T. obesus bone. FT-IR and TGA results affirmed that the collagen and organic moieties have been eliminated by both the proposed methods. XRD results were in agreement with JCPDS data. TEM and selective area diffraction images have signified that the thermal calcination method produces good crystallinity with dimensions 0.3-1.0 {mu}m, whereas the alkaline hydrolysis method produces nanostructured HAp crystals with 17-71 nm length and 5-10 nm width. Biocompatibility of HAp crystals was evaluated by cytotoxicity and cell proliferation with human osteoblast-like cell MG-63.

  11. Utilization of tuna roe and using inulin as oil replacer for producing value added omega-3 mayonnaise product

    Directory of Open Access Journals (Sweden)

    Kanrawee Hunsakul

    2016-03-01

    Full Text Available Background: The fishery industry has been important for Thailand’s economy for more than 30 years. For example, Thailand isthe world’s largest canned tuna producer and exporter. However, onlyordinary meat or white meatis usedfor raw materialin canned tuna products. Whileroe, viscera, head and dark meataresold at cheap prices,with theseby-products being usedto feed plant or local human food,its nutritive values withfat,protein and minerals arestill high. It is well known that tuna is a good source of polyunsaturated fatty acid (PUFA, including Eicosapentaenoicacid (EPA and Docosahexanoic acid (DHA.People around the world pay more attention to eatingsaladsconsisting of fruits and vegetables, in addition todressing. Generally, mayonnaise, a kind of salad dressing, consists of chicken egg yolk(12-15% and soybean oil (30-65%. Both of these ingredients contain very high saturated fatty acid contents. Therefore, because normal mayonnaise is high in fat content and low in polyunsaturated fatty acid, this product is not ideal for people on a diet or those who are trying to control their weight. Objective: To increase omega-3 through tuna roe substitution and to replace fat content using inulin gel. Methods: Tuna roe was prepared by soaking in galangalsolutionextracted with 95% ethanol for removal fishy/rancidity odor. Inulin powder 45 g was suspended in 55 ml of water before being brought to heat at temperature 80oC for 30min to form a gel and stored at 4oC. Treatment ofmakingomega-3 mayonnaise product was started using 100% tuna roe substitution for egg yolk. Thereafter, inulin gel was added to replace vegetable oil at 0, 25, 50, 75 and 100%. Basic mayonnaise containing egg yolk and 0% inulin gel (100% soy bean oil was used asthecontrol sample. Color and emulsion stability testswere monitored for physical quality. pH value, peroxide value (PV and thiobarbituric acid reactive substances (TBARS were used for chemical qualityanalyses. Total viable

  12. The efficacy of x-ray doses on murine norovirus-1 (MNV-1) in pure culture, half-shell oyster, salmon sushi, and tuna salad

    Science.gov (United States)

    n this investigation, we determined the efficacy of X-ray doses on reducing a human norovirus (HuNoV) surrogate [murine norovirus-1 (MNV-1)] in pure culture, half-shell oyster, salmon sushi and tuna salad. The pure culture (phosphate-buffer saline, pH 7.4), half-shell oyster, salmon