Sample records for sardina sardinops sagax

  1. Anchovy Engraulis capensis and sardine Sardinops sagax currently ...

    African Journals Online (AJOL)


    crossing the jet current off the Cape Peninsula was conducted from August 1995 to July 1996 as part of the third phase of the South African Sardine and Anchovy Recruitment Programme, designed to investigate within-season variability in factors affecting sardine Sardinops sagax and anchovy Engraulis capensis.

  2. Although South African sardine (or pilchard, Sardinops sagax) were ...

    African Journals Online (AJOL)


    The South African sardine Sardinops sagax resource is subjected to both directed fishing that targets adult fish, and bycatch of both juvenile and adult ... South African Journal of Marine Science 19. 1998. Fig. 1: Map of Southern Africa with ...... numbers-at-age matrix can be reconstructed back- wards in time by applying the ...

  3. Incorporating parasite data in population structure studies of South African sardine Sardinops sagax. (United States)

    Van Der Lingen, Carl David; Weston, Laura Frances; Ssempa, Nurudean Norman; Reed, Cecile Catharine


    A multidisciplinary approach has been applied to examine the population structure of sardine Sardinops sagax off South Africa, where this species supports significant fisheries and is also of ecological and eco-tourism importance. Observations of discontinuous sardine distribution patterns, discrete spawning grounds and significant spatial differences in a variety of phenotypic characteristics have suggested the existence of discrete western, southern and eastern sardine sub-populations or stocks. The use of parasites as biological tags to elucidate sardine population structure has recently been investigated, and strong spatial gradients around South Africa in the prevalence, mean infection intensity and mean abundance of a digenean 'tetracotyle' type metacercarial endoparasite considered to be of the genus Cardiocephaloides and found in the humours of fish eyes support and have proved particularly convincing evidence for the sardine multiple stock hypothesis. A discontinuous distribution in the occurrence of another parasite, the coccidean Eimeria sardinae found in fish testes, has provided additional but weaker evidence of discrete stocks. These results have contributed to a changed understanding of the population structure of South African sardine and have significant implications for management of the fisheries for this species.

  4. Comparative trophodynamics of anchovy Engraulis encrasicolus and sardine Sardinops sagax in the southern Benguela: are species alternations between small pelagic fish trophodynamically mediated?

    National Research Council Canada - National Science Library

    van der Lingen, CD; Hutchings, L; Field, JG


    The results of detailed morphological, experimental, field and modelling studies on various aspects of the trophic ecology of sardine Sardinops sagax and anchovy Engraulis encrasicolus in the Benguela...

  5. Population structure of three species of Anisakis nematodes recovered from Pacific sardines (Sardinops sagax) distributed throughout the California Current system. (United States)

    Baldwin, Rebecca E; Rew, Mary Beth; Johansson, Mattias L; Banks, Michael A; Jacobson, Kym C


    Members of the Anisakidae are known to infect over 200 pelagic fish species and have been frequently used as biological tags to identify fish populations. Despite information on the global distribution of Anisakis species, there is little information on the genetic diversity and population structure of this genus, which could be useful in assessing the stock structure of their fish hosts. From 2005 through 2008, 148 larval anisakids were recovered from Pacific sardine (Sardinops sagax) in the California Current upwelling zone and were genetically sequenced. Sardines were captured off Vancouver Island, British Columbia in the north to San Diego, California in the south. Three species, Anisakis pegreffii, Anisakis simplex 'C', and Anisakis simplex s.s., were identified with the use of sequences from the internal transcribed spacers (ITS1 and ITS2) and the 5.8s subunit of the nuclear ribosomal DNA. The degree of nematode population structure was assessed with the use of the cytochrome c oxidase 2 (cox2) mitochondrial DNA gene. All 3 Anisakis species were distributed throughout the study region from 32°N to 50°N latitude. There was no association between sardine length and either nematode infection intensity or Anisakis species recovered. Larval Anisakis species and mitochondrial haplotype distributions from both parsimony networks and analyses of molecular variance revealed a panmictic distribution of these parasites, which infect sardines throughout the California Current ecosystem. Panmictic distribution of the larval Anisakis spp. populations may be a result of the presumed migratory pathways of the intermediate host (the Pacific sardine), moving into the northern portion of the California Current in summer and returning to the southern portion to overwinter and spawn in spring. However, the wider geographic range of paratenic (large piscine predators), and final hosts (cetaceans) can also explain the observed distribution pattern. As a result, the recovery of 3

  6. Effects of environmental variability on recruitment and bioeconomic modelling in the Pacific sardine (Sardinops sagax caerulea fishery from Magdalena Bay, Baja California Sur, Mexico

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    Juan Antonio de Anda-Montañez


    Full Text Available Ricker's stock-recruitment equation, including the multivariate ENSO index (MEI as an environmental variable, was fitted to data of the Pacific sardine (Sardinops sagax caerulea fishery from Magdalena Bay, Baja California Sur, Mexico. The equation was then incorporated into an age-structured, bioeconomic model. Uncertainty was incorporated by using environmental fluctuations; seven-year projections, equivalent to one sardine generation, were computed. Five management options were considered in the projections: open access, effort at maximum sustainable economic yield (fMSE, catch at maximum sustainable yield (CMSY, equivalent effort level applied in the year 2004 (f2004, and an arbitrary catch quota of 40000 tons (CQ40000. Projection results were summarised by the indicator Net Present Value (NPV of the fishery for the modelled period. The strategies that involved some regulation in the effort level (fMSE and f2004 yielded the largest NPV. On the other hand, the strategies that involved regulation of the catch predicted—in addition to a lower NPV—a substantial increase in the effort to achieve the desired catch level. This study is the first bioeconomic approach for a sardine fishery management plan in this region.

  7. Abundance patterns of early stages of the Pacific sardine (Sardinops sagax during a cooling period in a coastal lagoon south of the California Current

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    René Funes-Rodríguez


    Full Text Available Abundance patterns of eggs and larvae of the Pacific sardine, Sardinops sagax (Jenyns, 1842, in Bahía Magdalena, Baja California Sur, were analysed during a cooling period south of the California Current from 2005 to 2009. The thermohaline characteristics and zooplankton abundance were good descriptors of the potential spawning habitat. Individual quotient analyses showed a predominance of eggs and larvae within a SST range of 16 to 18°C, at low salinities (33.9-34.1 and at low density gradient variability (0.009-0.029, associated with deeper waters (25-40 m near the main entrance, where the transparency was intermediate (6-8 m and zooplankton abundance was relatively high ( > 316 ml/1000 m3. Increments within different class intervals meant that neither dissolved inorganic nitrogen (DIN, phosphates nor chlorophyll a predominated. The large interannual fluctuations in sardine spawning activity and preferential temperatures observed in historical and recent data suggest that two sardine stocks spawn in Bahia Magdalena: one stock spawned in the period 1981-1989 and one stock spawned in the period 1997-2009. The influence of cooling and warming periods as additional components of the regional environmental framework is analysed and discussed.

  8. Efecto de la variabilidad ambiental en el reclutamiento y modelación bioeconómica en la pesquería de sardina del Pacífico (Sardinopssagax caerulea) de Bahía Magdalena, Baja California Sur, México


    de Anda-Montañez, Juan Antonio; Ramos-Rodríguez, Alejandro; Martínez-Aguilar, Susana


    La ecuación stock-reclutamiento de Ricker incorporándole el índice multivariado del ENSO(IME) como variable ambiental fue ajustada a datos de la pesquería de sardina (Sardinops sagax caerulea) de Bahía Magdalena, Baja California Sur, México. Esta ecuación fue incorporada a un modelo bioeconómico estructurado por edad. La incertidumbre fue considerada al incorporar la variabilidad ambiental, y se realizaron proyecciones de siete años de duración, que equivalen a una generación de sardina. En l...

  9. Indicators of sustainable fishing for South African sardine Sardinops ...

    African Journals Online (AJOL)

    Six indicators were investigated for South African sardine Sardinops sagax and anchovy Engraulis encrasicolus: mean length of catch, length-at-50% maturity, total mortality, exploitation rate, ratio of bycatch, and centre of gravity of commercial catches. Sardine length-at-50% maturity is the most promising as a descriptive ...

  10. The southern African sardine Sardinops sagax supports major purse ...

    African Journals Online (AJOL)


    sampling shallower than about 25 m, two large floats were attached to the upper sweeps near the wings of the trawl. Temperature, salinity and oxygen were measured at six CTD stations in the bay, and ADCP current profiles were recorded at the last three stations. Sizing of schools. The primary task, from the point of view of ...

  11. The southern African sardine Sardinops sagax (also known as ...

    African Journals Online (AJOL)


    bined with poor recruitment, led to a crash in biomass in the late 1960s, to <2 million tons by 1970. Then, in 1972, a ..... length 20–21 cm, whereas in 1998 and 1999 the fish were larger, 21–23.5 cm. The distribution of the catches ..... garia), and Ms J. C. Coetzee. Drs P. Fréon (IRD, France) and C. L. Moloney (MCM) are ...

  12. Anchovy Engraulis capensis, sardine Sardinops sagax and round ...

    African Journals Online (AJOL)


    Formerly Marine Biology Research Institute, Department of Zoology, University of Cape Town; now Department of Mathematics and. Applied ..... material) in female anchovy, estimated from histo- logical studies of anchovy gonads (Fig. 5) were used as an index of reproductive condition. Previous studies. (Hunter and ...

  13. Traditionally, sardine Sardinops sagax has been the backbone of ...

    African Journals Online (AJOL)


    0.2 year-1. Changes in fish stock abundance have resulted in alterations in biological parameters of several fish ..... Age determination of fish showed fish up to 10 years of age during the 1950s and 1960s (Le Clus et al. .... mented a change in the sex ratio of sardine catches from 1:1.8 in the 1950s to 1:1.2 during the 1970s.

  14. The South African sardine Sardinops sagax popu- lation partially ...

    African Journals Online (AJOL)


    plane, polished with 0.05-µm aluminia powder and etched with 0.1M ethylene diamine-tetra-acetic acid. (EDTA). They were then mounted on stubs and sputter- coated with gold and examined with a SEM at. 600–1000× magnification. All otoliths that showed a clear sequence of daily increments in >90% of the longitudinal ...

  15. 2012 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) and Pacific Sardine (Sardinops sagax) (SH1204, EK60) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC), the Fishery Resources...

  16. The 2012 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake (Merluccius productus) and Pacific Sardine (Sardinops sagax) (SH1204, ME70) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists from the Fishery Resource Analysis and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center (NWFSC), the Fishery Resources...

  17. Comparative molecular analysis of evolutionarily distant glyceraldehyde-3-phosphate dehydrogenase from Sardina pilchardus and Octopus vulgaris. (United States)

    Baibai, Tarik; Oukhattar, Laila; Mountassif, Driss; Assobhei, Omar; Serrano, Aurelio; Soukri, Abdelaziz


    The NAD(+)-dependent cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC, which is recognized as a key to central carbon metabolism in glycolysis and gluconeogenesis and as an important allozymic polymorphic biomarker, was purified from muscles of two marine species: the skeletal muscle of Sardina pilchardus Walbaum (Teleost, Clupeida) and the incompressible arm muscle of Octopus vulgaris (Mollusca, Cephalopoda). Comparative biochemical studies have revealed that they differ in their subunit molecular masses and in pI values. Partial cDNA sequences corresponding to an internal region of the GapC genes from Sardina and Octopus were obtained by polymerase chain reaction using degenerate primers designed from highly conserved protein motifs. Alignments of the deduced amino acid sequences were used to establish the 3D structures of the active site of two enzymes as well as the phylogenetic relationships of the sardine and octopus enzymes. These two enzymes are the first two GAPDHs characterized so far from teleost fish and cephalopod, respectively. Interestingly, phylogenetic analyses indicated that the sardina GAPDH is in a cluster with the archetypical enzymes from other vertebrates, while the octopus GAPDH comes together with other molluscan sequences in a distant basal assembly closer to bacterial and fungal orthologs, thus suggesting their different evolutionary scenarios.

  18. Assessment of fish coproducts Sardina pilchardus as the source of lactic acid bacteria

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    Hamza Belkhodja


    Full Text Available Objective: To recover the waste (edges, heads and guts of a species of pelagic fish Sardina pilchardus as a source of lactic bacteria. Methods: The microbiological control of the fish waste was carried out. Then, the fish waste was assessed as a source of bacteria of industrial interest among other lactic bacteria. The standard protocol for researches of these microorganisms was adopted which comprised enrichment, isolation, identification, purification and conservation. Results: The results of the microbiological control indicated the presence of some species as part of the normal flora of the fish. The physiological and biochemical characterization has presented 2 different groups of lactic bacteria: Lactobacillus fermentum and Lactobacillus spp. Conclusions: The assessment of fish waste can give us the opportunity to obtain different species of useful bacteria.

  19. Reconstrucción de las conexiones tróficas entre el plancton y la sardina del norte de la península Ibérica (Sardina Pilchardus) a través del análisis de las distribuciones de frecuencia de la abundancia natural de isótopos estables


    Antonio Bode; María Teresa Alvarez-Ossorio; Pablo Carrera; Jorge Lorenzo


    A partir de las medidas de la abundancia natural de isótopos estables de carbono y nitrógeno se reconstruyó la alimentación de juveniles (< 1 año de edad) y adultos de sardina (Sardina pilchardus) a partir de fito- y zooplancton en el noroeste de la península Ibérica. Las muestras de plancton y sardinas fueron tomadas al comienzo de la época de afloramiento y durante el máximo de freza de la sardina. Previamente a las determinaciones isotópicas, el plancton fue fraccionado por tamaños a travé...

  20. Constant harvest rate for the Pacific sardine (Sardinops caeruleus) fishery in the Gulf of California based on catchability-at-length estimations


    Martínez Aguilar, Susana; de Anda Montañez, Juan Antonio; Arreguín Sánchez, Francisco; Cisneros Mara, Miguel Angel


    Constant harvest rate as a management strategy for the Pacific sardine (Sardinops caeruleus) fishery in the Gulf of California is supported by an analysis of variations in the catchability coefficient (q), stock abundance and commercial catch. Catchability was analyzed based on population length-structured data standard length (SL), expressed as CPUE, for 26 fishing seasons (1972-1973 to 1997-1998). We used a deterministic model of catchability to estimate the catchability-at-length assuming ...

  1. Effects of chitosan on the shelf life of marinated sardine (Sardina pilchardus fillets during refrigerated storage

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    Aygül Küçükgülmez


    Full Text Available This study was carried out to evaluate the effect of chitosan on chemical, colour, sensory and microbial changes of marinated sardine (Sardina pilchardus fillets. Marination solution consisted of 10% sodium chloride + 1% chitosan (dissolved in 3% acetic acid for the chitosan group, and 10% sodium chloride + 3% acetic acid solution for the control group. After the marination process, sardine fillets were packed and stored at 4ºC for 60 days. Thiobarbituric acid (TBA values were found to be lower in the chitosan group than the control group (PL*, a*, or b* values of marinated sardine fillets. According to sensory analysis, shelf life of the chitosan group was found to be ten days longer than that of the control group. Total bacteria count of two marinated groups was found to be less than 1 log CFU/g. This study concluded that sardine marination with the addition of chitosan can delay undesirable chemical changes, retard lipid oxidation, improve sensory attributes and extend the shelf life of the product during refrigerated storage.

  2. Identificación de rasgos morfológicos para una rápida diferenciación de sardina austral (Sprattus fuegensis y sardina común (Strangomera bentincki

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    Antonio Aranis


    Full Text Available La pesquería artesanal de cerco multiespecífica que opera en aguas interiores de Chiloé captura sardina común (Strangomera bentincki y sardina austral (Sprattus fuegensis al mismo tiempo y en la misma área. Debido a la gran similitud morfológica externa que presentan estas dos especies de peces óseos, la identificación específica en terreno es difícil, aún para observadores científicos experimentados. Por lo tanto, el objetivo de este trabajo es proponer cual o cuales rasgos morfométricos externos debiesen ser considerados para una rápida identificación de estas especies en terreno. Se analizaron 60 ejemplares de sardina común y 79 de sardina austral. Se identificaron los ejemplares a nivel de especie y se registraron las siguientes medidas: longitud total, longitud de la cabeza, preórbita, órbita y posórbita. Todas las medidas morfométricas fueron estandarizadas para evitar colinealidad. Las diferencias en las medidas morfométricas entre especies fueron probadas mediante métodos estadísticos multivariados que incluyen el análisis de componentes principales, análisis de varianza y covarianza (ANOVA y ANCOVA, análisis multivariado de covarianza (MANOVA y análisis lineal discriminante. La medida posórbita fue el rasgo morfométrico que presentó mayor diferenciación entre especies. Se concluye que la medida de posórbita es por sí sola un carácter morfométrico externo que permitiría una rápida identificación de estas especies en terreno. Los resultados de esta investigación pueden ser tomados como línea base para la generación de guías de campo que apoyen el trabajo de identificación de especies de los observadores científicos.

  3. Reconstruction of trophic pathways between plankton and the North Iberian sardine (Sardina pilchardus using stable isotopes

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    Antonio Bode


    Full Text Available Feeding on phyto- and zooplankton by juvenile (< 1 year old and adult sardines (Sardina pilchardus was inferred from analyses of natural abundance of stable carbon and nitrogen isotopes in samples from the northwestern Iberian Peninsula (Spain collected at the beginning of the upwelling season and peak spawning period of sardine. Plankton samples were fractionated through nets of 20, 200, 500, 1000 and 2000 ?m mesh-size and the muscle protein of individual sardines was isolated before isotopic determinations. Up to six planktonic components and two sardine feeding types were identified from the modes in the frequency distributions of isotope abundance values. Also, the most probable pathways for carbon and nitrogen flows between compartments were analysed. The resulting food web revealed a relatively large degree of omnivory, both in plankton and sardine components, which confirms that complex trophic interactions could also occur in pelagic upwelling ecosystems. Young sardines had isotope abundance values clustered around a single mode in the frequency distribution, while adult sardines displayed two main modes. These modes are interpreted as representative of two extreme feeding types: one related to the individual capture of zooplankton prey and the other to unselective filter-feeding. Although both types of feeding could include micro- (20-200 ?m and mesozooplankton (200-2000 ?m prey, phytoplankton appears to be ingested mainly by filter-feeding. However, even adult sardines must be mainly zoophagous to achieve the observed isotopic abundance values, taking into account current assumptions on stable isotope enrichment through trophic levels. From the differences in the resulting pathways using either carbon or nitrogen isotopes, we interpreted that sardines acquire most of the protein nitrogen from zooplankton while a substantial fraction of their carbon would derive from phytoplankton. These interpretations agree with the information

  4. Stomach Chitinase from Japanese Sardine Sardinops melanostictus: Purification, Characterization, and Molecular Cloning of Chitinase Isozymes with a Long Linker. (United States)

    Kawashima, Satoshi; Ikehata, Hiroki; Tada, Chihiro; Ogino, Tomohiro; Kakizaki, Hiromi; Ikeda, Mana; Fukushima, Hideto; Matsumiya, Masahiro


    Fish express two different chitinases, acidic fish chitinase-1 (AFCase-1) and acidic fish chitinase-2 (AFCase-2), in the stomach. AFCase-1 and AFCase-2 have different degradation patterns, as fish efficiently degrade chitin ingested as food. For a comparison with the enzymatic properties and the primary structures of chitinase isozymes obtained previously from the stomach of demersal fish, in this study, we purified chitinase isozymes from the stomach of Japanese sardine Sardinops melanostictus, a surface fish that feeds on plankton, characterized the properties of these isozymes, and cloned the cDNAs encoding chitinases. We also predicted 3D structure models using the primary structures of S. melanostictus stomach chitinases. Two chitinase isozymes, SmeChiA (45 kDa) and SmeChiB (56 kDa), were purified from the stomach of S. melanostictus. Moreover, two cDNAs, SmeChi-1 encoding SmeChiA, and SmeChi-2 encoding SmeChiB were cloned. The linker regions of the deduced amino acid sequences of SmeChi-1 and SmeChi-2 (SmeChi-1 and SmeChi-2) are the longest among the fish stomach chitinases. In the cleavage pattern groups toward short substrates and the phylogenetic tree analysis, SmeChi-1 and SmeChi-2 were classified into AFCase-1 and AFCase-2, respectively. SmeChi-1 and SmeChi-2 had catalytic domains that consisted of a TIM-barrel (β/α)₈-fold structure and a deep substrate-binding cleft. This is the first study showing the 3D structure models of fish stomach chitinases.

  5. Evaluating fishermen's conservation attitudes and local ecological knowledge of the European sardine (Sardina pilchardus), Peniche, Portugal. (United States)

    Braga, Heitor O; Azeiteiro, Ulisses M; Oliveira, Henrique M F; Pardal, Miguel A


    European sardines are an important fishing resource in the North Atlantic. Recognized for its great commercial and economic value in southern Europe, this resource currently has low stock indices. From this perspective, fishers' local ecological knowledge (LEK) is appreciated as an auxiliary tool in the management of sardines in this region. Our goal is to evaluate the LEK and attitudes towards the conservation of Sardina pilchardus in the typical fishing village of Peniche, Portugal. From June to September 2016, we carried out 87 semi-structured interviews. The four main points of the interviews were interviewee profile, fishing structure, fishermen's LEK and attitudes towards sardine conservation. The interviews were qualitatively and quantitatively analyzed using a 3-point Likert scale. An LEK index and an attitude index were generated. Comparison analyses and correlations were made between the indices and variables of the interviewee profile and the fishing structure. The mean LEK index was 0.55 and was classified as moderate. The attitudes index in relation to conservation was 0.76 and was classified as positive. This index had a positive and significant correlation with the LEK index and a significant negative correlation with the fishermen's age. When the LEK index was compared with the educational level, significant differences were observed only between class A and class C. The result showed that the differences in the attitudes index were statistically significant when the three educational classes were compared. The fishermen of Peniche in Portugal present moderate informal knowledge about the biology and ecology of sardines. Attitudes towards conservation were predominantly positive. Fishermen with greater LEK, with a higher educational level and at a younger age presented more positive attitudes in relation to environmental conservation issues in the present case of the sardine population. The LEK is not necessarily related to the educational level of

  6. Optimization of a chemical method for skinning of sardines (Sardina pilchardus during canning processing

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    Manuela Vaz Velho


    Full Text Available Most of sardine (Sardina pilchardus catches is used for canning purposes. The most common product presentation is a beheaded sardine with skin and bones packed in a tin can. Canned sardines can also be presented skinless and boneless. For this last type of product, after beheading and evisceration, sardines are placed in trays, cooked and then skinned by hand, one by one, and placed in the tins, a process involving high labour costs. The aim of this work was to develop a chemical process for peeling raw sardines and its subsequent application in a canning industry processing line just after the beheading and evisceration step and before cooking. Potassium hydroxide treatments (pellets a.r. 85% KOH were applied at concentrations of 2, 3 and 4% (v/v, distilled water. Frozen sardines were beheaded and eviscerated after thawing and immersed in the different potassium hydroxide solutions at 93ºC (pH respectively 13, 13 and 13.02 for 3 min and further washed with distilled water at 100°C. In this first set of experiments, fat sardines were used (average of 9.86% of fat, w/w. The best performance, with respect to skin removal, was achieved with the 2% potassium hydroxide immersion (pH 13. With this treatment the skin was totally removed after immersion. With the other tested concentrations portions of skin were always visible and in some cases changes in texture with breakdown of muscle structure and changes of colour occurred. It was decided to perform a second set of experiments using the 2% KOH treatment, but this time applied to low fat sardines (average of 4.77% of fat, w/w, following the same subsequent procedures. The results showed that the lower fat sardines are more prone to surface changes of colour and major muscle breaks than fat sardines after the potassium hydroxide treatment. In the canning industry for this type of product (skinless and boneless only fat sardines are used to assure the total removal of skin. This treatment of 2% KOH

  7. Relative role of life-history traits and historical factors in shaping genetic population structure of sardines (Sardina pilchardus

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    Zardoya Rafael


    Full Text Available Abstract Background Marine pelagic fishes exhibit rather complex patterns of genetic differentiation, which are the result of both historical processes and present day gene flow. Comparative multi-locus analyses based on both nuclear and mitochondrial genetic markers are probably the most efficient and informative approach to discerning the relative role of historical events and life-history traits in shaping genetic heterogeneity. The European sardine (Sardina pilchardus is a small pelagic fish with a relatively high migratory capability that is expected to show low levels of genetic differentiation among populations. Previous genetic studies based on meristic and mitochondrial control region haplotype frequency data supported the existence of two sardine subspecies (S. p. pilchardus and S. p. sardina. Results We investigated genetic structure of sardine among nine locations in the Atlantic Ocean and Mediterranean Sea using allelic size variation of eight specific microsatellite loci. Bayesian clustering and assignment tests, maximum likelihood estimates of migration rates, as well as classical genetic-variance-based methods (hierarchical AMOVA test and RST pairwise comparisons supported a single evolutionary unit for sardines. These analyses only detected weak but significant genetic differentiation, which followed an isolation-by-distance pattern according to Mantel test. Conclusion We suggest that the discordant genetic structuring patterns inferred based on mitochondrial and microsatellite data might indicate that the two different classes of molecular markers may be reflecting different and complementary aspects of the evolutionary history of sardine. Mitochondrial data might be reflecting past isolation of sardine populations into two distinct groupings during Pleistocene whereas microsatellite data reveal the existence of present day gene flow among populations, and a pattern of isolation by distance.

  8. Comparative trophodynamics of anchovy Engraulis encrasicolus ...

    African Journals Online (AJOL)

    Comparative trophodynamics of anchovy Engraulis encrasicolus and sardine Sardinops sagax in the southern Benguela: are species alternations between small pelagic fish trophodynamically mediated? CD van der Lingen, L Hutchings, JG Field ...

  9. Food safety considerations in relation to Anisakis pegreffii in anchovies (Engraulis encrasicolus) and sardines (Sardina pilchardus) fished off the Ligurian Coast (Cinque Terre National Park, NW Mediterranean). (United States)

    Serracca, Laura; Battistini, Roberta; Rossini, Irene; Carducci, Annalaura; Verani, Marco; Prearo, Marino; Tomei, Laura; De Montis, Gabriella; Ercolini, Carlo


    Engraulis encrasicolus and Sardina pilchardus are pelagic fishes of notable economic and gastronomic importance in the northwest Mediterranean (Ligurian Sea, Italy). The consumption of thermally unprocessed or lightly processed, marinated or salted anchovies and sardines presents a potential risk to acquire anisakiasis, a fish-borne parasitic disease in humans. Prevalence and abundance of Anisakis larvae in Engraulis encrasicolus and Sardina pilchardus from the Monterosso fishing grounds (Cinque Terre National Park, Ligurian Sea, Italy) were assessed, and the larvae were identified by morphological and PCR-RFLP methods. Anisakis larvae, all belonging to Anisakis pegreffii spp. were found in the visceral mass of 1050 anchovies (0.8% overall prevalence), whereas no Anisakis larvae were found in the 750 sardines examined. According to these data, the risk of acquiring anisakiasis from the consumption of raw or undercooked anchovies and sardines caught in the fishing area we investigated is very low. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Assessment of the sardine (Sardina pilchardus Walbaum, 1792 fishery in the eastern Mediterranean basin (North Aegean Sea

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    Full Text Available The aim of this study was to describe the biometric characteristics of the European sardine (Sardina pilchardus catches and assess the current status of sardine stock in North Aegean Sea based on population characteristics and abundance trends. The stock was dominated by age groups 1 and 2, not exceeding age group 4. The sardine stock in this area was assessed through an Integrated Catch-at-Age model which implements a separable Virtual Population Analysis on catch at age data with weighted tuning indices. Sardine landings data derived from the commercial purse seine fishery over the period 2000-2008 were combined with the age structure of the stock as resulted from fisheries independent acoustic surveys. Sensitivity analysis of the impact of natural mortality values on stock assessment results was applied. Additionally forecast of the sardine population parameters and catches under different exploitation scenarios was implemented in a medium term basis. Results indicated that the North Aegean Sea sardine stock is considered fully exploited with the fishery operating close but over the empirical exploitation level for sustainability. Finally, the status of the sardine stock in N. Aegean Sea is discussed in relation to the sardine stocks from the western and the central Mediterranean basin.

  11. Biochemical and physiological modifications in tissues of Sardina pilchardus: spatial and temporal patterns as a baseline for biomonitoring studies

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    Bruno Silva Nunes


    Full Text Available Sardina pilchardus is a marine species common in the North Atlantic Ocean, and is subjected to diffuse anthropogenic chemical contamination and seasonal fluctuations in biotic and abiotic parameters that may alter its physiology and condition. Biological material is easily available through commercial fisheries, which could facilitate its use as a bioindicator species. The aim of the present work was to address its potential inclusion in biomonitoring studies, considering a combinatory approach through the use of enzymatic biomarkers and somatic indices, by assessing spatial and temporal patterns in a metapopulation along the west coast of Portugal. Our results showed significant variability of the biochemical and physiological profile of the fish, mainly concordant between sampling sites. Large differences for most markers were found across periods of the year, showing the importance of seasonality, which was mostly related to the reproductive cycle. Hence, environmental scientists should acknowledge seasonality as a strong driving force for physiological adaptations, influencing biochemical markers that are normally used to identify effects of chemical contamination. The here-obtained set of data suggests that S. pilchardus may be successfully included in oceanic biomonitoring studies, when one considers that the contribution of seasonal factors may exceed the influence of eventual anthropogenic contamination.

  12. Culture viability of Sardina pilchardus (Fish, Teleost: Preliminary results of growth in captivity up to 18 months

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    José Iglesias


    Full Text Available Larvae of Sardina pilchardus were obtained in captivity from fertilized eggs captured in the wild and grown in a 10000-L tank. Isochrysis galbana, Artemia franciscana nauplii and live zooplankton were used as prey during the first two weeks; afterwards, the animals were fed on Artemia metanauplii enriched with Isochrysis galbana. A dry feed (Gemma 0.4 and 0.8 from Skretting S.A. (Burgos, España was supplied from the 3rd to the 18th month. The total length reached by sardines at one year of life was 162.02±9.49 mm, corresponding to a wet weight of 36.12±10.82 g. Total length of the last survivor individual at 18 months was 182.37 mm. An 18-month experiment of sardine culture is described for the first time, and the growth data reported can help to determine its potential as a candidate for marine aquaculture.

  13. La pesca de sardina, Sardinella aurita (Teleostei: Clupeidae) asociada con la variabilidad ambiental del ecosistema de surgencia costera de Nueva Esparta, Venezuela


    Leo W. González; Jorge Euán; Nora Eslava; Jesús Suniaga


    Se comparó la pesca de sardina (Sardinella aurita) con algunos parámetros climáticos y meteorológicos del ecosistema de surgencia costera de El Morro, Nueva Esparta, Venezuela. Para el período 1996-2000, se aplicaron los modelos de regresión lineal simple y múltiple a los datos de captura en función de la velocidad del viento, temperatura superficial del mar, temperatura del aire y pluviosidad. Hubo una correlación positiva de la captura con la velocidad del viento, y una negativa con tempera...

  14. Reproducción de la sardina, Sardinella aurita (Cupleiformes: Clupeidae del sureste de la Isla de Margarita, Venezuela

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    Juan Gassman


    Full Text Available Se determinó la proporción y madurez sexual, fecundidad y época de desove de la sardina, Sardinella aurita Valenciennes, 1847 del sureste de la Isla de Margarita, Venezuela; a través de muestreos mensuales provenientes de la pesca comercial desde enero 2004 hasta abril 2005, examinándose un total de 3 736 individuos. La composición global por sexos fue de 55.06% hembras y 44.19% machos, siendo la proporción sexual 1:1.25 (χ² = 44.454, p Reproduction of the Spanish sardine, Sardinella aurita (Clupeiformes: Clupeidae from the south-eastern area of Margarita Island, Venezuela. Sex ratio, sexual maturity, fecundity and time of spawning of the Spanish sardine (Sardinella aurita from the south-eastern area of Margarita Island were determined through monthly samplings of commercial fisheries, from January 2004 to April 2005. A total of 3 736 individuals were examined. Sex ratio was 55.47% females and 44.53% males, with a 1:1.25 sexual proportion (χ2 = 44.454, p < 0.05. Length at first sexual maturity (L50 was 20 cm. Spawning of the species was confirmed to be partial and continuous throughout the year, with two peaks of intensity during the first and last quarters. Absolute fecundity ranged from 10 530 to 83 779 oocytes and it was proportional to body length (F = - 100 900 + 6 696.2 * L and to body weight (F = 13 327 + 5 666.3 * P. Relative fecundity ranged from 149 to 1 020 oocytes/g and also was proportional to body length and weight. We concluded that the Spanish sardine exhibits two peaks of spawning activity per year with a very fluctuating partial fecundity which could possibly be explained by environmental variability. Rev. Biol. Trop. 56 (4: 1813-1824. Epub 2008 December 12.

  15. Fishing area and fish size as risk factors of Anisakis infection in sardines (Sardina pilchardus) from Iberian waters, southwestern Europe. (United States)

    Molina-Fernández, Dolores; Malagón, David; Gómez-Mateos, Magdalena; Benítez, Rocío; Martín-Sánchez, Joaquina; Adroher, Francisco Javier


    The sardine (Sardina pilchardus) is a fish commonly consumed and appreciated in many countries, although they are more likely to be eaten fresh in western Mediterranean countries such as Spain, Portugal, France or Italy. A molecular epidemiological survey of sardines from 5 fishing areas of the Spanish Mediterranean (Málaga, southern Spain) and Atlantic coasts (southern: Cádiz and Isla Cristina; northern: A Coruña and Ondarroa) was carried out to determine the presence of Anisakis spp. larvae. The highest prevalence of these larvae was observed in fish from A Coruña (28.3%), followed by Ondarroa (5%) and Cádiz (2.5%). No Anisakis larvae were found in fish from Málaga and Isla Cristina. Three Anisakis genotypes were identified: Anisakis simplex sensu stricto, Anisakis pegreffii and a hybrid genotype between these two species. A. pegreffii was the most prevalent species in A Coruña (71% of larvae). Only three Anisakis larvae (9% collected larvae) were located in the musculature of sardines: two were identified as A. pegreffii while the other was a hybrid genotype. Sardine infection was associated with fishing area and fish length/weight (length and weight were strongly correlated; Pearson's correlation 0.82; pAnisakis through consumption of sardines is generally low due to the low epidemiological parameter values (prevalence 10%, mean intensity 1.7 (range 1-5) and mean abundance 0.17), as larger fish are more heavily parasitized, there is an increased risk of infection by Anisakis through consumption of large sardines which are raw or have undergone insufficient treatment (undercooked, smoked, marinated, salted, pickled, freezing,…). Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Distribution and abundance of early life stages of Sardina pilchardus in the Gulf of Tunis (Central Mediterranean Sea in relation to environmental and biological factors

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    Rafik Zarrad


    Full Text Available Four seasonal surveys were carried out in the Gulf of Tunis between summer 2002 and spring 2003 to study the abundance and distribution of Sardina pilchardus eggs and larvae in relation to environmental parameters. In the Gulf of Tunis, Sardina pilchardus begins spawning in autumn (23 eggs/10 m² and attains its peak in winter (257 eggs/10 m² when the mean SST is lowest (13.4°C. Sardine reproduction seems to be triggered by the decrease in the SST. In winter, the main spawning areas were located to the south of Zembra Island and the north of Cape Bon. Larvae were more abundant in winter (38 larvae/10 m², while lower densities were collected in autumn and spring (1 larva/10 m². The highest abundance of larvae (288 larvae/10 m² was recorded southwest of Zembra Island. Eggs and larvae were mainly concentrated in the relatively warmer and saltier waters with high zooplankton abundance and, inversely, with a low concentration of nitrate and chlorophyll a and a low diatom abundance.

  17. Effect of different types of coatings on texture and nutritional properties of canned Portuguese sardines (Sardina pilchardus

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    Rita Pinheiro


    Full Text Available Canned foods have a long history of success and are likely to remain popular for the foreseeable future owing to their convenience, long shelf life and economy. Interest in fish consumption has increased in recent years due to the wide range of its health benefits. In addition to fresh product, canned fish enables a delayed consumption of this appreciated kind of food. Among the different types of fish, in Portugal, the most used in canning manufacture are sardines, tuna, anchovies, mackerels. Vegetable oils and tomato sauce are usually adopted as coatings (liquid medium. In fact, oil has a preserving effect and contributes to make the product more palatable. Its protective action lies in the ability to insulate products from air, rather than having an active bacteriostatic or bactericidal action. Among the different types of coatings the most commonly used in canning are: olive oil, seed oils and different sauces, such as tomato sauce. Tomato sauce has also vegetable oil on its formulation. The amount of coating substance can affect the nutritional composition as well as texture properties of the sardines. The aim of this work was to investigate the effect of different types of coatings on texture and nutritional properties of whole, skinless and boneless canned Portuguese Sardines (Sardina pilchardus. An experimental investigation was carried out to assess the protein, lipid, carbohydrates and ash content, texture and colour profile of canned sardine with different kinds of coatings: olive oil, sunflower oil and tomato sauce. The obtained results showed that protein and carbohydrates content were not significantly influenced by the coating used, varying between 5%-8% and13%-18%, respectively. For the moisture content it was found that the samples with tomato sauce were 2.2-fold higher than the samples with sunflower oil, and 1.3-fold higher than the samples with olive oil, independently of being whole, skinless or boneless sardine. As

  18. Formación de compuestos fluorescentes durante el almacenamiento refrigerado de sardina (Sardina pilchardus: comparación con índices de alteración lipídica

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    Aubourg, S. P.


    Full Text Available Sardine was stored at 0°C on ice during 16 days. During this time the fluorescent compounds formation was studied at different wavelength maxima in order to assert quality changes; fluorescence analyses were undergone on the aqueous and organic (lipids phases resulting from the lipid extraction. Quality measures of lipid hydrolysis (free fatty acids content, FFA and oxidation (conjugated diene formation and thiobarbituric acid, TBA, test were also carried out. Traditional indexes of lipid damage did not assert deterioration in the case of advanced damage. Diene content reflected and increasing value till the day 9 of storage, and then a continuous decrease. Further, FFA content and TBA test showed the highest values on the day 13 of storage, followed by a slight decrease. An increase in fluorescence content was observed in most of the excitation/emission maxima studied (393/463 nm, 446/490 nm and 479/516 nm, at the time that others decreased (327/415 nm, specially; as an overall result, a relative increase in the maxima of higher wavelength was observed in comparison with the lower ones. The ratio between two of the fluorescence maxima analyzed (393/463 nm and 327/415 nm exhibited an overall increase respect to the time of chilled storage. The study of this ratio in the aqueous extract showed a better correlation (r= 0,8533 than in the case of the organic one (r= 0,7457. From the present results, it is concluded that the interaction compounds determination by mean of their fluorescent properties is useful as a damage measure during the chilled storage.

    Durante 16 días se almacenaron sardinas en hielo. A lo largo de este tiempo se estudió la formación de compuestos fluorescentes a distintos máximos de longitud de onda de excitación/emisión con el fin de seguir las posibles variaciones de estos compuestos producidas al aumentar el tiempo de almacenamiento; las medidas de fluorescencia se realizaron sobre las fases acuosa y org

  19. Chemical Profile, Antibacterial and Antioxidant Activity of Algerian Citrus Essential Oils and Their Application in Sardina pilchardus

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    Djamel Djenane


    Full Text Available Stored fish are frequently contaminated by foodborne pathogens. Lipid oxidation and microbial growth during storage are also important factors in the shelf-life of fresh fish. In order to ensure the safety of fish items, there is a need for control measures which are effective through natural inhibitory antimicrobials. It is also necessary to determine the efficacy of these products for fish protection against oxidative damage, to avoid deleterious changes and loss of commercial and nutritional value. Some synthetic chemicals used as preservatives have been reported to cause harmful effects to the environment and the consumers. The present investigation reports on the extraction by hydrodistillation and the chemical composition of three citrus peel essential oils (EOs: orange (Citrus sinensis L., lemon (Citrus limonum L. and bergamot (Citrus aurantium L. from Algeria. Yields for EOs were between 0.50% and 0.70%. The chemical composition of these EOs was determined by gas chromatography coupled with mass spectrometry (GC/MS. The results showed that the studied oils are made up mainly of limonene (77.37% for orange essential oil (EO; linalyl acetate (37.28%, linalool (23.36%, for bergamot EO; and finally limonene (51.39%, β-pinene (17.04% and γ-terpinene (13.46% for lemon EO. The in vitro antimicrobial activity of the EOs was evaluated against Staphylococcus aureus (S. aureus using the agar diffusion technique. Results revealed that lemon EO had more antibacterial effects than that from other EOs. Minimal inhibitory concentrations (MICs showed a range of 0.25–0.40 μL/mL. Lemon and bergamot citrus peel EOs were added at 1 × MIC and 4 × MIC values to Sardina pilchardus (S. pilchardus experimentally inoculated with S. aureus at a level of 3.5 log10 CFU/g and stored at 8 ± 1 °C. The results obtained revealed that the 4 × MIC value of bergamot reduced completely the growth of S. aureus from day 2 until the end of storage. The presence of EOs

  20. Análisis socioeconómico e interrelación de las pesquerías de sardina y atún aleta azul en la región noroeste de México

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    Raúl Jesús del Moral-Simanek


    Full Text Available El establecimiento de las engordas de atún aleta azul en las costas de Baja California cambió el destino de las capturas de sardina, ya que antes se destinaban al mercado de congelados y a la elaboración de harina de pescado, y en la actualidad se utilizan como alimento para el atún aleta azul. Esto generó un efecto socioeconómico positivo para los armadores y pescadores de pelágicos menores, ya que la llegada de grandes capitales foráneos para el desarrollo de las engordas de atún mejoró los precios de la sardina, e hizo más rentable su pesquería.

  1. Trophic ecology of European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus in the Bay of Biscay (north-east Atlantic) inferred from delta C-13 and delta N-15 values of fish and identified mesozooplanktonic organisms


    Chouvelon, Tiphaine; Chappuis, A.; Bustamante, Paco; Lefebvre, Sebastien; Mornet, Francoise; Guillou, G.; Violamer, L.; Dupuy, Christine


    European sardine (Sardina pilchardus) and European anchovy (Engraulis encrasicolus) are two species of economical and ecological significance in the Bay of Biscay (north-east Atlantic). However, the trophic ecology of both species is still poorly known in the area, and more generally, few studies have considered the potential trophic overlap between sardines and anchovies worldwide. This study aims to highlight the trophic links between the mesozooplankton and adults of these two pelagic fish...

  2. Small pelagic fish feeding patterns in relation to food resource variability: an isotopic investigation for Sardina pilchardus and Engraulis encrasicolus from the Bay of Biscay (north-east Atlantic)


    Chouvelon, Tiphaine; Violamer, Laurie; Dessier, Aurélie; Bustamante, Paco; Mornet, Françoise; Pignon‑Mussaud, Cécilia; Christine, Dupuy


    International audience; Small pelagic fish represent an essential link between lower and upper trophic levels in marine pelagic ecosystems and often support important fisheries. In the Bay of Biscay in the north-east Atlantic, no obvious controlling factors have yet been described that explain observed fluctuations in European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus stocks, in contrast to other systems. The aim of this study was therefore to investigate to which...

  3. Coupling between the environment and the pelagic resources exploited off northern Chile: ecosystem indicators and a conceptual model Acoplamiento entre el ambiente y los recursos pelágicos explotados en el norte de Chile: un modelo conceptual

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    Eleuterio Yáñez


    pesquería de anchoveta (Engraulis ringens; en tanto, desde mediado de los 70's los desembarques de sardina (Sardinops sagax aumentan notablemente. Un segundo cambio de régimen se observa a finales de los 80's, representado principalmente por la notable recuperación de anchovy y disminución de sardina. Se presenta un modelo conceptual integrador de los diferentes fenómenos locales y de gran escala que afectan el ambiente marino del norte de Chile, y la distribución y abundancia de recursos pelágicos. El modelo considera análisis de datos ambientales y bio-pesqueros a distintas escalas, y describe como las fluctuaciones interdecadales (asociadas a cambios de régimen e interanuales (asociadas a los eventos El Niño del Pacífico Ecuatorial se manifiestan en el Pacífico Sur Oriental y por tanto en la zona norte de Chile, afectando el ciclo anual, la dinámica de las ondas atrapadas a la costa y la surgencia costera. En este marco, las fluctuaciones interdecadales estarían jugando un rol importante en la secuencia del reemplazo anchoveta-sardina-anchoveta.

  4. The 2004 re-assessment of the South African sardine and anchovy ...

    African Journals Online (AJOL)

    Hydroacoustic surveys off the coast of South Africa over the early years of the 21st century indicated that both the sardine Sardinops sagax and anchovy Engraulis encrasicolus populations had simultaneously reached record abundances. The South African pelagic fishery is regulated using an Operational Management ...

  5. Fine-scale spatial variability of different stages of pelagic fish eggs ...

    African Journals Online (AJOL)

    Stage-dependent spatial distributions of anchovy Engraulis encrasicolus, sardine Sardinops sagax and round herring Etrumeus whiteheadi eggs over the western Agulhas Bank South Africa were examined from samples collected at a fine-scale (1.8 km) resolution using a continuous underway fish egg sampler (CUFES).

  6. Vertical distribution of small pelagic fish eggs and larvae on the ...

    African Journals Online (AJOL)

    Vertical distributions of anchovy Engraulis encrasicolus and sardine Sardinops sagax eggs and larvae within the upper 50 m of the water column on the eastern Agulhas Bank, South Africa, were examined using discrete depth samples collected with a multiple, opening/closing plankton net. Eggs and larvae of sardine and ...

  7. Comparing trophic flows in the southern Benguela to those in other ...

    African Journals Online (AJOL)

    Small pelagic fish other than anchovy Engraulis capensis and sardine. Sardinops sagax, mainly round herring Etrumeus whiteheadi and mesopelagic fish, were important components of the food web in the southern Benguela. Severe balancing difficulties were encountered with respect to the semi-pelagic resources (hake ...

  8. Biological characteristics of sardine caught by the beach-seine ...

    African Journals Online (AJOL)

    Catches of sardine Sardinops sagax made by the beach-seine fishery off the KwaZulu-Natal (KZN) coast during the annual winter sardine run have been sampled intermittently since 1951, and a substantial amount of data on various biological characteristics of sardine caught off KZN now exists. Information on length ...

  9. Revised estimates of abundance of South African sardine and ...

    African Journals Online (AJOL)

    Hydro-acoustic surveys have been used to provide annual estimates of May recruitment and November spawner biomass of the South African sardine Sardinops sagax and anchovy Engraulis encrasicolus resources since 1984. These time-series of abundance estimates form the backbone of the assessment of these ...

  10. Download this PDF file

    African Journals Online (AJOL)


    DEDUCED FROM ACOUSTIC SURVEYS. M. BARANGE*, I. HAMPTON† and B. A. ROEL‡. The South African pelagic resources have been monitored acoustically since 1983. The results of these surveys are currently used to determine catch limits for anchovy Engraulis capensis and sardine Sardinops sagax. Two.

  11. Refined estimates of South African pelagic fish biomass from hydro ...

    African Journals Online (AJOL)

    The biomass of small pelagic fish species off the coast of South Africa has been monitored since 1984 using hydro-acoustic survey techniques. These time-series of spawner biomass and recruitment estimates form the basis for management of both the South African sardine Sardinops sagax and anchovy Engraulis ...

  12. Breeding success of African penguins Spheniscus demersus at ...

    African Journals Online (AJOL)

    The reproductive success of African penguins Spheniscus demersus at Dassen Island from 1994 to 2000 was variable, but much higher than previously reported figures for the species. Breeding success was positively related to the abundance of anchovy Engraulis encrasicolus and sardine Sardinops sagax, and the high ...

  13. Influences of the abundance and distribution of prey on African ...

    African Journals Online (AJOL)

    Off South Africa, anchovy Engraulis encrasicolus and sardine Sardinops sagax are the main prey of African penguins Spheniscus demersus. The combined spawner biomass of these fish increased from less than one million t in 1996 to more than nine million t in 2001 and then decreased to four million t in 2005.

  14. Implications for seabirds off South Africa of a long-term change in ...

    African Journals Online (AJOL)

    From 1997 to 2005, the distribution of sardine Sardinops sagax, an important prey item for four seabirds off South Africa, shifted 400 km to the south and east, influencing its availability to breeding birds. It became progressively less available to seabirds in the Western Cape Province, where the number of African penguins ...

  15. Responses of African penguins to regime changes of sardine and ...

    African Journals Online (AJOL)

    Regional trends in numbers of African penguins Spheniscus demersus conform with an altered distribution of sardine Sardinops sagax and anchovy Engraulis capensis prey. In the 1950s, sardine dominated the pelagic fish component of the Benguela system. Abundance of this fish decreased in the 1960s and early 1970s ...

  16. Foraging effort and prey choice in cape gannets | Adams | African ...

    African Journals Online (AJOL)

    In order to test the hypothesis that sardine Sardinops sagax are the preferred prey of Cape gannets Morus capensis, the link between foraging effort and prey choice was evaluated by simultaneously monitoring the activity and the diet of adult birds attending chicks at Bird Island, Algoa Bay, South Africa. Foraging trip ...

  17. Influence of oceanographic fronts and low oxygen on the distribution ...

    African Journals Online (AJOL)

    The horizontal and vertical distributions of eggs and larvae of sardine Sardinops sagax, anchovy Engraulis encrasicolus and horse mackerel Trachurus trachurus capensis were examined in relation to distribution patterns of temperature, salinity and dissolved oxygen. Samples were collected during February–March 2002 ...

  18. accounting for food requirements of seabirds in fisheries management

    African Journals Online (AJOL)

    In South Africa, four of the seabirds that feed mainly on sardine Sardinops sagax and anchovy Engraulis encrasicolus have an unfavourable conservation status or a small population: African penguin Spheniscus demersus, Cape gannet Morus capensis, Cape cormorant Phalacrocorax capensis and swift tern Sterna bergii.

  19. Investigations into the diet and feeding ecology of the bearded goby ...

    African Journals Online (AJOL)

    The bearded goby Sufflogobius bibarbatus has come to replace sardine Sardinops sagax in the diets of many top predators within the marine environment off Namibia, ... The results indicate that the species has a fairly generalised diet, feeding mostly on benthic and pelagic animals (phytoplankton was rare), in a way that ...

  20. The importance of lipid-rich fish prey for Cape gannet chick growth : are fishery discards an alternative?

    NARCIS (Netherlands)

    Mullers, Ralf H. E.; Navarro, Rene A.; Crawford, Robert J. M.; Underhill, Les G.


    A recent decline in population numbers of Cape gannets (Morus capensis) breeding off the west coast of South Africa coincided with decreased availability of lipid-rich fish prey: anchovy (Engraulis encrasicolus) and sardine (Sardinops sagax). Seabirds can use fishery discards as an alternative, but

  1. Broad-scale distribution patterns of sardine and their predators in ...

    African Journals Online (AJOL)

    The annual movement of South African sardine Sardinops sagax up the east coast of South Africa, known as the 'sardine run', was investigated using data from aerial surveys for the period 1988–2005 and compared with remotely sensed sea surface temperature (SST) and chlorophyll a data. Sardine sighting rates were ...

  2. Comparison of trends in abundance of guano-producing seabirds in ...

    African Journals Online (AJOL)

    The abundant guano-producing seabirds in Peru and southern Africa feed mainly on the large populations of anchovy Engraulis spp. and sardine Sardinops sagax supported by the Humboldt and Benguela upwelling systems. Numbers of guanay cormorants Phalacrocorax bougainvillii in Peru and the breeding population ...

  3. Ecosystem considerations of the KwaZulu-Natal sardine run ...

    African Journals Online (AJOL)

    The annual winter sardine run along the South African east coast impacts the KwaZulu-Natal (KZN) coastal system in a variety of ways. These include ecological impacts, such as enrichment of a largely oligotrophic environment, competition between migrant sardine Sardinops sagax, other migrant and resident small ...

  4. Fritura de filetes de sardinas congeladas en aceite de oliva. Influencia de diferentes métodos de descongelación sobre el contenido graso y la composición en ácidos grasos

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    Álvsarez-Pontes, M. E.


    Full Text Available To study the effect of freezing and different thawing methods on the moisture, fat an fatty acid content of fried sardines, fresh sardine fillets were first frozen and then some were thawed either in a refrigerator at 4°C or in a microwave over prior to frying. These fillets were then analyzed both before and after being fried in olive oil. Frying increased the fat content of the fillets, mainly due to water losses, especially in those thawed in the refrigerator. Mono-unsaturated fatty acid (MUFA content increased in fresh and frozen fillets after frying from 21% to 55% and 56%, respectively. However, thawing prior to frying had a different effect depending on the method because oleic acid absorption was facilitated by refrigerator-thawing, the MUFA content increased to 61,8%, whereas after microwave-thawing the MUFA content reached 47%. Saturated and polyunsaturated fatty acids decreased in fried fillets compared to uncooked ones as a consequence of the increase in MUFA. Frying decreased the C22:6/C16:0 ratio with respect to fresh fillets in frozen fillets and in those thawed in the refrigerator but not in those thawed in a microwave.

    Filetes de sardinas frescas, congeladas y descongeladas en frigorífico a 4°C o en microondas se analizaron en crudo y después de freírlos en aceite de oliva, con objeto de conocer si la congelación y descongelación, previa a la fritura, alteraba los cambios en humedad, grasa y composición en ácidos grasos que introdujera la fritura. El contenido graso (g/100g de filetes de sardinas se incrementó durante el proceso de fritura, debido, sobre todo, a las pérdidas de agua. Dicho efecto aumentó principalmente en la descongelación en frigorífico. Con la fritura, la sardina fresca y la congelada sin previa descongelación se enriquecieron en ácido oleico, ascendiendo el contenido de ácidos grasos monoinsaturados en (AGM del 21 al 55-56%. La descongelación, anterior a la fritura, influyó de forma

  5. Bases conceptuales para la aplicación de una evaluación de estrategias de manejo (EEM en sardina común (Strangomera bentincki y anchoveta (Engraulis ringens en la zona centro-sur de Chile

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    Marcos Arteaga


    Full Text Available Se identifican los factores claves a considerar en el desarrollo de una evaluación de estrategias de manejo (EEM para los recursos pequeños pelágicos en la zona de centro-sur de Chile, sardina común (Strangomera bentincki y anchoveta (Engraulis ringens. En Chile, la EEM no ha sido aplicada al manejo de estas pesquerías y la asesoría científica se ha desarrollado sobre la evaluación de estrategias de explotación utilizando modelos de evaluación mono-específicos. Para ambas especies se analizan los siguientes tópicos: i alternancia en la abundancia poblacional asociada a los pulsos de reclutamientos y capturas, ii variabilidad temporal en la fuerza del reclutamiento, iii estacionalidad del crecimiento cohorte y especie-específico, y iv relación ambiente-recurso. Los resultados evidencian que los tópicos analizados debieran ser considerados en la construcción de un modelo operativo y/o en la regla de cosecha, dado el carácter mixto de ambas pesquerías, su marcada alternancia y la influencia de las condiciones ambientales. Por lo tanto, se propone que el diseño e implementación de una EEM para sardina común y anchoveta, incluya los elementos señalados en un marco de evaluación multi-especifico y de manejo de carácter mixto.

  6. Medidas de conservación y ordenación pesquera del jurel Trachurus murphyien el Perú

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    Jorge Zuzunaga


    Full Text Available Las pesquerías peruanas como actividades realizadas sobre recursos naturales renovables son reguladas por un marco jurídico, cuyo objetivo es asegurar su conservación y uso sostenible. La Ley General de Pesca (DL N°. 25977 señala que para cada tipo de pesquería y según la situación del recurso explotado debe establecerse un sistema de ordenamiento que concilie el principio de sostenibilidad de los recursos pesqueros o conservación en el largo plazo, con la obtención de los mayores beneficios económicos y sociales. En el ordenamiento pesquero del jurel Trachurus murphyi, las medidas incluyen entre otras, el régimen de acceso constituido por las autorizaciones de incremento de flota y permisos de pesca, que se otorgan solo a los buques cuyas capturas son destinadas únicamente para el consumo humano directo, de acuerdo a lo dispuesto en el Reglamento de Ordenamiento Pesquero (DS N.° 011-2007-PRODUCE. La obligación de destinar los recursos sardina Sardinops sagax, jurel T. murphyiy caballa Scomber japonicus al consumo humano directo rige desde septiembre 2002 (DS N°. 001-2002-PRODUCE. Otras medidas vigentes restringen el tamaño mínimo de malla de las redes, prohíben la captura de ejemplares menores de 31 cm de longitud total, determinan el inicio y cierre de las temporadas de pesca, los límites de captura o cuotas anuales. Estas disposiciones son complementadas por medidas de seguimiento, control y vigilancia para la efectiva conservación y uso sostenido del recurso.

  7. anchovy Engraulis capensis, sardine Sardinops sa

    African Journals Online (AJOL)


    gain through prolonged bouts of low-cost filter-feeding. (Van der Lingen ... 3 000-l fibreglass tank supplied with a continuous flow of 5-µm-filtered ... A sample of 20 fish was taken from each trawl to provide data on stomach contents at t = 0. Fish in the tank were observed to ensure that there was no feeding, and dead or ...

  8. Trophic ecology of European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus in the Bay of Biscay (north-east Atlantic) inferred from δ13C and δ15N values of fish and identified mesozooplanktonic organisms (United States)

    Chouvelon, T.; Chappuis, A.; Bustamante, P.; Lefebvre, S.; Mornet, F.; Guillou, G.; Violamer, L.; Dupuy, C.


    European sardine (Sardina pilchardus) and European anchovy (Engraulis encrasicolus) are two species of economical and ecological significance in the Bay of Biscay (north-east Atlantic). However, the trophic ecology of both species is still poorly known in the area, and more generally, few studies have considered the potential trophic overlap between sardines and anchovies worldwide. This study aims to highlight the trophic links between the mesozooplankton and adults of these two pelagic fish in the Bay of Biscay, through carbon and nitrogen stable isotope analysis (SIA). Mesozooplankton and individuals of sardines and anchovies were collected during one season (spring 2010), over spatially contrasted stations within the study area. First, the potential effect of preservation (ethanol vs. freezing) and of delipidation (by cyclohexane) on mesozooplankton δ13C and δ15N values was assessed. Results demonstrated the necessity to correct for the preservation effect and for lipid contents in mesozooplankton for further analyses of sardines' and anchovies' diet through SIA. Next, this study highlighted the interest of working on identified mesozooplanktonic organisms instead of undetermined assemblages when unravelling food sources of planktivorous fish using stable isotopes. The inter-specific variability of isotope values within a planktonic assemblage was effectively high, probably depending on the various feeding behaviours that can occur among mesozooplankton species. Intra-specific variability was also significant and related to the spatial variations of baseline signatures in the area. To investigate the foraging areas and potential diet overlap of S. pilchardus and E. encrasicolus, mixing models (SIAR) were applied. Both fish species appeared to feed mainly in the neritic waters of the Bay of Biscay in spring and to select mainly small- to medium-sized copepods (e.g. Acartia sp., Temora sp.). However, E. encrasicolus showed a greater trophic plasticity by

  9. Trends in spatio-temporal distribution of Peruvian anchovy and other small pelagic fish biomass from 1966-2009 Tendencias espacio-temporales en la distribución de la biomasa de anchoveta peruana y de otros peces pelágicos pequenos entre 1966 y 2009

    Directory of Open Access Journals (Sweden)

    Mariano Gutiérrez


    de pequenos peces pelágicos de la región norte del Sistema de la Corriente de Humboldt (NHCS son el producto de la variación de forzantes ambientales en diferentes escalas de tiempo y espacio que influyen entre el ecosistema 'frío' costero y el oceánico 'cálido'. La información para estudiar estas fluctuaciones provienen mayormente de las pesquerías, y muestran que la anchoveta (Engraulis ringens incrementa su abundancia cuando la de sardina (Sardinops sagax declina y viceversa. Sin embargo, utilizando datos acústicos de biomasa latitudinal se muestra que otras especies como la caballa (Scomber japonicus y el jurel (Trachurus murphyi también siguen la misma tendencia opuesta a anchoveta, lo que en principio indica que los datos pesqueros disponibles no indican la verdadera dimensión del balance de abundancia entre especies. Utilizando diagramas de Hovmoller se analizan los cambios en la biomasa acústica latitudinal, capturas e influencia de eventos El Nino ocurridos entre 1966 y 2009 con el objetivo de describir: 1 cómo el patrón de distribución decadal de anchoveta se movió de sur a norte desde la década de 1960, 2 cómo se han producido cambios concomitantes en la abundancia latitudinal de otras especies tales como sardina, caballa y jurel antes, durante y después de eventos El Nino, y 3 cuál fue el efecto general de la sucesión de eventos El Nino sobre todas estas especies. Se concluye que: a cada evento El Nino ha tenido un efecto en la expansión o contracción de la distribución de especies pelágicas, con diferente gradiente latitudinal, y b El Nino 1997-98 no disparó sino aceleró la fase declinante de la abundancia de sardina, caballa y jurel al reducirse el tamano de su hábitat ideal debido a una expansión del hábitat costero que presentó además un acercamiento a la superficie del límite superior de la Zona Mínima de Oxígeno (MOZ. Las observaciones logradas con datos acústicos podrían ser tomadas en consideración para el

  10. Worldwide, where anchovies Engraulis spp. and sardine Sardinops ...

    African Journals Online (AJOL)


    1987). The spawner biomass of sardine was then 0.03 million tons, but it increased steadily to 0.62 million. Benguela Dynamics. Pillar, S. C., Moloney, C. L., Payne, A. I. L. and F. A. Shillington (Eds). S. Afr. J. mar. Sci. 19: 355–364. 1998. 355 ..... tate their ability to cope is the facility of first-time breeders to emigrate from natal ...

  11. Clasificación acústica de anchoveta (Engraulis ringens y sardina común (Strangomera bentincki mediante máquinas de vectores soporte en la zona centro-sur de Chile: efecto de la calibración de los parámetros en la matriz de confusión Acoustic classification of anchovy (Engraulis ringens and sardine (Strangomera bentincki using support vector machines in central-southern Chile: effect of parameter calibration on the confusion matrix

    Directory of Open Access Journals (Sweden)

    Hugo Robotham


    Full Text Available Se clasificó la anchoveta (Engraulis ringens y sardina común (Strangomera bentincki detectadas mediante equipos acústicos en la zona centro-sur de Chile, mediante el método de Máquinas de Vectores Soporte (SVM. Para esto se utilizaron descriptores de cardúmenes extraídos desde ecogramas, que fueron clasificados como morfológicos, batimétricos, energéticos y posicional espacial. Para lograr clasificaciones precisas mediante la utilización de esta metodología, fue necesario optimizar parámetros correspondientes al Kernel-Gaussiano, γ y de penalización del modelo C, mediante el análisis del efecto de la calibración sobre las matrices de confusión resultantes de la clasificación de las especies analizadas. El método SVM ajustó correctamente el 95,3% de los cardúmenes de anchoveta y sardina común. Los parámetros óptimos del Kernel-Gaussiano γ y de penalización C obtenidos mediante la metodología propuesta fueron γ = 450 y C = 0,95, respectivamente. Los parámetros mencionados incidieron de manera importante en la matriz de confusión y los porcentajes de clasificación final, por lo que se sugiere establecer, en aplicaciones futuras de este método, un protocolo experimental de calibración. La sardina común fue la especie con menor error de clasificación en el conjunto de las matrices de confusión. El descriptor correspondiente a profundidad del fondo fue el más sensible al SVM, la segunda variable en importancia es el descriptor distancia a la costa.The support vector machines (SVM method was used to classify the anchovy (Engraulis ringens and common sardine (Strangomera bentincki species detected in south-central Chile by means of acoustic equipment. For this, descriptors of fish schools (morphology, bathymetry, energy, spatial position extracted from ecograms were used. In order to obtain precise classifications using this methodology, it was necessary to optimize the parameters Gaussian-Kernel γ and penalty term

  12. Preservación y abundancia de escamas de peces en sedimentos del margen continental de Chile (21-36° S Fish scale preservation and abundance in sediments from the continental margin off Chile (21-36° S

    Directory of Open Access Journals (Sweden)



    Full Text Available Con el objetivo de evaluar la relación entre la preservación de escamas de peces y las variaciones en las condiciones redox en sedimentos del margen continental de Chile, este trabajo presenta recuentos de escamas de peces y concentraciones normalizadas de elementos redox sensibles (Mo/Al, S/Al, Fe/Al en ocho testigos de sedimento recolectados en la zona de minimo oxígeno frente a Chile (Iquique: 20°15' S, bahía de Mejillones: 23° S y Concepción: 36° S. En el norte de Chile (Iquique y Mejillones predominan las escamas de anchoveta (Engraulis ringens y de peces de la familia Myctophidae (media = 90 y 120 escamas 1.000 cm-3, respectivamente mientras que en Chile centro-sur (Concepción son más abundantes las escamas de jurel (Trachurus murphy; media = 140 escamas 1.000 cm-3. La abundancia de escamas de merluza común (Merluccius gayi gayi y de sardina (Sardinops sagax es aproximadamente un orden de magnitud más baja que la de anchoveta o jurel. En general, los valores más altos y los rangos más amplios de variación en las razones Mo/Al, S/Al y Fe/Al se encuentran en Mejillones (Mo/Al ~0,8-12 mg g-1, S/Al 0,2-4,6 g g-1, Fe/Al 0,3-0,7 g g-1 seguidos por Iquique (Mo/Al -0,2-1,8; S/Al 0,2-0,7, Fe/Al 0,5-0,8, mientras que Concepción revela valores más bajos y poco variables (Mo/Al ~0,07, S/Al ~0,15 y Fe/Al ~0,5. La razón Mo/Al, utilizada como indicador de paleo-oxigenación, permite inferir condiciones reductoras relativamente más intensas en los sedimentos de la Bahía de Mejillones e Iquique que en Concepción. En las tres localidades de muestreo se evidencia una asociación estadísticamente significativa entre la abundancia de escamas de anchoveta y el logaritmo de la razón Mo/Al (r²= 0,46; P 1 mg g-1.The relationship between fish scale preservation and variations in the sediment redox conditions on Chile's continental shelf are evaluated herein through fish scale counts and normalized concentrations of redox sensitive elements

  13. Freshness assessments of Moroccan sardine (Sardina pilchardus): comparison of overall sensory changes to instrumentally determined volatiles. (United States)

    Triqui, Réda; Bouchriti, Nourredine


    Freshness of ice-stored sardine was assessed by two sensory methods, the quality index method (QIM) and the European Union freshness grading system, and by instrumental means using the method of aroma extract dilution analysis. Screening of sardine potent volatiles was carried out at three freshness stages. In the very fresh state, the plant-like fresh volatiles dominated the odor pattern, with the exception of methional. Overall odor changes in sardine throughout storage correlated with changes in the concentration of some potent volatiles: after 2 days of ice storage, (Z)-4-heptenal, (Z)-1,5-octadien-3-one, and methional imparted an overall "fishy" odor character to sardine, whereas at a lower sensory grade (B), the compounds (E)-2-nonenal and (E,Z)-2,6-nonadienal could be, in part, associated with the slightly rancid aroma top notes. Trimethylamine was detected as a highly volatile odorant using solid-phase microextraction (SPME) headspace analysis of refrigerator-stored sardine. Intensity and sensory characteristics of some SPME determined volatiles, for example, 3-methylnonane-2,4-dione, were closely related to overall odor changes. SPME headspace analysis may be useful in the characterization of off-flavors in fish.

  14. Temporal genetic variation as revealed by a microsatellite analysis of European sardine ( Sardina pilchardus) archived samples

    DEFF Research Database (Denmark)

    Ruggeri, Paolo; Splendiani, Andrea; Bonanomi, Sara


    ) that explain the genetic diversity variation, while the same parameters turned out to be more stable in the southern samples. In addition, we detected the presence of a genetic bottleneck and low effective population size ( Ne) values in several northern samples. Even if the northern and southern Adriatic...... of otoliths and scales from sampling locations of northern (Chioggia) and southern (Vieste) Adriatic Sea, with the aim to investigate the genetic effects of these stock biomass fluctuations. The northern samples showed significant reduction in observed heterozygosity ( HO) and mean number of alleles ( Na...... sardine samples belong to the same genetic stock, the more pronounced decrease in genetic variability recorded in the northern sample led us to speculate that a more intensive fishing pressure and a more pronounced oceanographic isolation of this area could have accentuated the effects of the genetic...

  15. Proteolysis of Sardine (Sardina pilchardus and Anchovy (Stolephorus commersonii by Commercial Enzymes in Saline Solutions

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    Chau Minh Le


    Full Text Available Fish sauce production is a very long process and there is a great interest in shortening it. Among the different strategies to speed up this process, the addition of external proteases could be a solution. This study focuses on the eff ect of two commercial enzymes (Protamex and Protex 51FP on the proteolysis of two fish species traditionally converted into fish sauce: sardine and anchovy, by comparison with classical autolysis. Hydrolysis reactions were conducted with fresh fish at a temperature of 30 °C and under different saline conditions (from 0 to 30 % NaCl. Hydrolysis degree and liquefaction of the raw material were used to follow the process. As expected, the proteolysis decreased with increasing amount of salt. Regarding the fi sh species, higher rate of liquefaction and higher hydrolysis degree were obtained with anchovy. Between the two proteases, Protex 51FP gave better results with both fi sh types. This study demonstrates that the addition of commercial proteases could be helpful for the liquefaction of fi sh and cleavage of peptide bonds that occur during fi sh sauce production and thus speed up the production process.

  16. Feeding of European pilchard (Sardina pilchardus in the northwestern Mediterranean: from late larvae to adults

    Directory of Open Access Journals (Sweden)

    David Costalago


    Full Text Available We assessed the relative importance of different prey types of the European pilchard (European sardine from the late larval to the adult stage. Two different methodologies for analysing stomach contents were used to describe the trophic dynamics of sardine and the relationship of sardine feeding behaviour with the ontogenetic development of body structures used for feeding, such as gill rakers and pyloric caeca. This information is essential to accurately depict the use of the planktonic resources in the area by sardine and to discuss the extent to which the sardine population could be affected by environmental changes in the Mediterranean Sea. We showed that cladocerans in summer and diatoms in winter were numerically the most important prey types for both juveniles and adults. However, decapod larvae were the most important prey during all seasons in terms of carbon content. Accordingly, differences in methodology should be considered in the analysis of sardine diets. An analysis of the composition of the plankton showed that small copepods were strongly selected by sardines at all ages and in both seasons. We also observed that the pyloric caeca began to grow when the sardines were approximately 4-5 cm standard length (SL and ended their development when the sardines reached approximately 8 cm SL, whereas the gill rakers appeared to be completely functional when the sardines reached 7 cm SL. Therefore, filter feeding of small particles could be performed with total efficacy beginning at 7-8 cm SL. In view of the energetic advantage of filter feeding in a well-adapted filter-feeding species such as sardine, the prospective limited availability of small particles hypothesized by certain authors for the Mediterranean could have negative consequences for sardine. This study demonstrates that sardine populations, given their extremely high dependence on the lower marine trophic levels, could be strongly affected by alterations in the environment and in the planktonic community.

  17. Effect of natural antioxidants on the quality of frozen sardine fillets (Sardina pilchardus

    Directory of Open Access Journals (Sweden)

    Rui Manuel Maneta Ganhão


    Full Text Available The use of new technologies / processes provides different benefits on seafood sector, namely by enhanced the shelf-life of fish products with high polyunsaturated fatty acid composition. This is particularly critical during some months of the year when fish (e.g. sardines are larger supply than demand by consumers. The aim of this study was to performed the optimization process of adding natural antioxidants on frozen sardine fillets and evaluated the effect of addition of two natural antioxidants on the lipid oxidation process during storage at -200C. To evaluate the effect of the addition of antioxidants in sardine fillets, the product matrix was chemical characterized, including by the evaluation of the fatty acid profile. The lipid oxidation process was followed by the primary products (peroxide value and secondary products (TBARS quantification, and also by the analysis of the sensory changes (instrumental assessment of color. Finally, it was done a hedonic preference test to know the opinion of consumers about the frozen fillets with and without antioxidant. The natural antioxidants used, tocopherol (54 mg/fillet and tocopherols (15 mg/fillet with rosemary extract (6.5 mg/fillet inhibited or retarded the oxidation over time of storage when compared with the control samples, that had advanced oxidation process. There was not statistically differences among the fillets treated with tocopherol in the presence and absence of rosemary extract. However, our laboratorial results shown slight tendency for the view that the antioxidant tocopherols and rosemary extract had a greater effect on the oxidative stability of fillets. This observation is in line with results of the hedonic test consumer preference. The use of natural antioxidants is an inexpensive solution which allows the complete use of products with less waste of fish products and with a great need for disposal. At the same time meets the consumer´s requirements.

  18. Fish larvae retention linked to abrupt bathymetry at Mejillones Bay (northern Chile during coastal upwelling events

    Directory of Open Access Journals (Sweden)

    Pablo M Rojas


    Full Text Available The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax, associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus, associated with the thermocline (12°C, and finally, larvae of the families Myctophidae (Diogenichthys atlanticus and Bathylagidae (Bathylagus nigrigenys, associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.

  19. Metals and metalloids in Little Penguin (Eudyptula minor) prey, blood and faeces. (United States)

    Finger, Annett; Lavers, Jennifer L; Dann, Peter; Kowalczyk, Nicole D; Scarpaci, Carol; Nugegoda, Dayanthi; Orbell, John D


    Piscivorous species like the Little Penguin (Eudyptula minor) are particularly at risk of being negatively impacted by pollution due to their heightened exposure through aquatic food chains. Therefore, determining the concentration of heavy metals in the fish prey of seabirds is an essential component of assessing such risk. In this study, we report on arsenic, cadmium, mercury, lead and selenium concentrations in three fish species, which are known to comprise a substantial part of the diet of Little Penguins at the urban colony of St Kilda, Melbourne, Australia. Metal concentrations in the fish sampled were generally within the expected limits, however, arsenic and mercury were higher than reported elsewhere. Anchovy (Engraulis australis) and sandy sprat (Hyperlophus vittatus) contained higher Hg concentrations than pilchard (Sardinops sagax), while sandy sprat and pilchard contained more selenium. We present these findings together with metal concentrations in Little Penguin blood and faeces, sampled within weeks of the fish collection. Mercury concentrations were highest in the blood, while faeces and fish prey species contained similar concentrations of arsenic and lead, suggesting faeces as a primary route of detoxification for these elements. We also investigated paired blood - faecal samples and found a correlation for selenium only. Preliminary data from stable isotope ratios in penguin blood indicate that changes in penguin blood mercury concentrations cannot be explained by trophic changes in their diet alone, suggesting a variation of bioavailable Hg within this semi-enclosed bay. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Larval fish variability in response to oceanographic features in a nearshore nursery area. (United States)

    Pattrick, P; Strydom, N A


    The influence of oceanographic features on ichthyoplankton assemblages in the warm temperate nearshore region of Algoa Bay, South Africa, was assessed. The nearshore ichthyoplankton comprised 88 taxa from 34 families. Samples were collected at six stations between August 2010 and July 2012 using a plankton ring net of 750 mm diameter and 500 µm mesh aperture. The majority of larvae collected were in a preflexion stage, indicating the potential importance of the nearshore for newly hatched larvae. Engraulidae dominated the catch (38·4%), followed by Cynoglossidae (28·1%) and Sparidae (8·4%). Larval fish abundance was highest during austral spring and summer (September to February). Unique patterns in responses of each dominant fish species to oceanographic features in the nearshore indicate the sensitivity of the early developmental stage to environmental variables. Using generalized linear models, ichthyoplankton abundance responded positively to upwelling and when warm water plumes originating from an Agulhas Current meander entered Algoa Bay. Highest abundances of Engraulis encrasicolus and Sardinops sagax were observed during Agulhas Plume intrusions into Algoa Bay. When a mixed and stratified water column persisted in the nearshore region of Algoa Bay, larval fish abundance decreased. The nearshore region of Algoa Bay appears to serve as a favourable environment for the accumulation of ichthyoplankton. © 2014 The Fisheries Society of the British Isles.

  1. An Empty Donut Hole: the Great Collapse of a North American Fishery

    Directory of Open Access Journals (Sweden)

    Kevin M. Bailey


    Full Text Available Walleye pollock (Theragra chalcogramma is North America's most abundant and lucrative natural fishery, and is the world's largest fishery for human food. The little-known demise of the "Donut Hole" stock of pollock in the Aleutian Basin of the central Bering Sea during the 1980s is the most spectacular fishery collapse in North American history, dwarfing the famous crashes of the northern cod and Pacific sardine (Sardinops sagax. This collapse has received scant recognition and became evident only in 1993 when fishing was banned by an international moratorium; nearly 20 years later it has not recovered. The history of fishing in the North Pacific Ocean after World War II offers some insights into how the Donut Hole pollock fishery developed, and the societal and economic pressures behind it that so influenced the stock's fate. Overfishing was, without a doubt, the greatest contributor to the collapse of the Aleutian Basin pollock fishery, but a lack of knowledge about population biocomplexity added to the confusion of how to best manage the harvest. Unfortunately, the big scientific questions regarding the relationship of Donut Hole fish to other stocks are still unanswered.

  2. Macro-Scale Patterns in Upwelling/Downwelling Activity at North American West Coast.

    Directory of Open Access Journals (Sweden)

    Romeo Saldívar-Lucio

    Full Text Available The seasonal and interannual variability of vertical transport (upwelling/downwelling has been relatively well studied, mainly for the California Current System, including low-frequency changes and latitudinal heterogeneity. The aim of this work was to identify potentially predictable patterns in upwelling/downwelling activity along the North American west coast and discuss their plausible mechanisms. To this purpose we applied the min/max Autocorrelation Factor technique and time series analysis. We found that spatial co-variation of seawater vertical movements present three dominant low-frequency signals in the range of 33, 19 and 11 years, resembling periodicities of: atmospheric circulation, nodal moon tides and solar activity. Those periodicities might be related to the variability of vertical transport through their influence on dominant wind patterns, the position/intensity of pressure centers and the strength of atmospheric circulation cells (wind stress. The low-frequency signals identified in upwelling/downwelling are coherent with temporal patterns previously reported at the study region: sea surface temperature along the Pacific coast of North America, catch fluctuations of anchovy Engraulis mordax and sardine Sardinops sagax, the Pacific Decadal Oscillation, changes in abundance and distribution of salmon populations, and variations in the position and intensity of the Aleutian low. Since the vertical transport is an oceanographic process with strong biological relevance, the recognition of their spatio-temporal patterns might allow for some reasonable forecasting capacity, potentially useful for marine resources management of the region.

  3. Comparison of three molecular methods for the detection of pilchard herpesvirus in archived paraffin-embedded tissue and frozen tissue. (United States)

    Crockford, Melanie; Jones, J Brian; McColl, Kenneth; Whittington, Richard J


    Two epizootics affecting pilchards Sardinops sagax neopilchardus have been observed over their entire geographical range off the Australian coastline. The first occurred in 1995, involving high mortality (at least 10%) that devastated the pilchard population. The second occurred in 1998 and involved even higher mortality (70%). Both epizootics moved rapidly against the prevailing Leeuwin and East Australian currents from a defined point of origin. A herpesvirus, pilchard herpesvirus (PHV), was determined to be the cause of the epizootics, but the source of the virus remains unknown. In this research, in situ hybridization (ISH), polymerase chain reaction (PCR), and real-time PCR were compared for the detection of PHV in archived paraffin-embedded tissue and frozen tissue collected before, during, and after the 1995 epizootic. Results show that the conventional PCR failed to detect PHV in archived paraffin-embedded tissue, and that real-time PCR was the most sensitive of the 3 techniques and the best method for the detection of PHV.

  4. Macro-Scale Patterns in Upwelling/Downwelling Activity at North American West Coast (United States)

    Saldívar-Lucio, Romeo; Di Lorenzo, Emanuele; Nakamura, Miguel; Villalobos, Héctor; Lluch-Cota, Daniel; Del Monte-Luna, Pablo


    The seasonal and interannual variability of vertical transport (upwelling/downwelling) has been relatively well studied, mainly for the California Current System, including low-frequency changes and latitudinal heterogeneity. The aim of this work was to identify potentially predictable patterns in upwelling/downwelling activity along the North American west coast and discuss their plausible mechanisms. To this purpose we applied the min/max Autocorrelation Factor technique and time series analysis. We found that spatial co-variation of seawater vertical movements present three dominant low-frequency signals in the range of 33, 19 and 11 years, resembling periodicities of: atmospheric circulation, nodal moon tides and solar activity. Those periodicities might be related to the variability of vertical transport through their influence on dominant wind patterns, the position/intensity of pressure centers and the strength of atmospheric circulation cells (wind stress). The low-frequency signals identified in upwelling/downwelling are coherent with temporal patterns previously reported at the study region: sea surface temperature along the Pacific coast of North America, catch fluctuations of anchovy Engraulis mordax and sardine Sardinops sagax, the Pacific Decadal Oscillation, changes in abundance and distribution of salmon populations, and variations in the position and intensity of the Aleutian low. Since the vertical transport is an oceanographic process with strong biological relevance, the recognition of their spatio-temporal patterns might allow for some reasonable forecasting capacity, potentially useful for marine resources management of the region. PMID:27893826

  5. A cold oceanographic regime with high exploitation rates in the Northeast Pacific forecasts a collapse of the sardine stock. (United States)

    Zwolinski, Juan P; Demer, David A


    The oceanographic conditions in the north Pacific have shifted to a colder period, Pacific sardine (Sardinops sagax) biomass has declined precipitously in the California Current, the international sardine fishery is collapsing, and mackerel (Trachurus symmetricus and Scomber japonicus) are thriving. This situation occurred in the mid-1900s, but indices of current oceanographic conditions and the results of our acoustic-trawl surveys indicate it likely is recurring now, perhaps with similar socioeconomic and ecological consequences. Also alarming is the repetition of the fishery's response to a declining sardine stock-progressively higher exploitation rates targeting the oldest, largest, and most fecund fish. Furthermore, our data indicate the recent reproductive condition of sardine is poor, and their productivity is below modeled estimates used to derive the current fishery-exploitation rates. Consequently, the sardine population has been reduced to two cohorts that are unlikely to produce an appreciable new cohort. Thus, a near-term recovery of this important stock is unlikely, depending on the return of warmer oceanographic conditions, reduced pressure from mackerel species, and perhaps the adoption of a more precautionary strategy for managing the residual sardine population.

  6. National aquatic animal health plans: the Australian experience. (United States)

    Bernoth, E M; Ernst, I; Wright, B


    Following a major pilchard (Sardinops sagax) mortality event in 1995, Australia recognised the need for a national approach to aquatic animal health, particularly with respectto disease response. Cooperation between industry and government led to the development of AQUAPLAN, Australia's National Strategic Plan for Aquatic Animal Health. Under AQUAPLAN, institutional arrangements for the national technical response to aquatic animal health emergencies were developed based on existing arrangements for terrestrial animal health. The number and range of Australian Aquatic Veterinary Emergency Plan (AQUAVETPLAN) manuals are rising steadily; these are manuals that outline Australia's approach to national disease preparedness and propose the technical response and control strategies to be activated. Additional resources include standard diagnostic techniques and a disease field identification guide. Simulation exercises provide training to respond to aquatic emergency animal disease events. While resource issues and addressing governance remain priorities for the further implementation of AQUAPLAN, the highest priority is the development of a formal arrangement between governments and private sectors on the response to an aquatic emergency animal disease event.

  7. Sharing fishers´ ethnoecological knowledge of the European pilchard (Sardina pilchardus) in the westernmost fishing community in Europe. (United States)

    Braga, Heitor de Oliveira; Pardal, Miguel Ângelo; Azeiteiro, Ulisses Miranda


    With the present difficulties in the conservation of sardines in the North Atlantic, it is important to investigate the local ecological knowledge (LEK) of fishermen about the biology and ecology of these fish. The ethnoecological data of European pilchard provided by local fishermen can be of importance for the management and conservation of this fishery resource. Thus, the present study recorded the ethnoecological knowledge of S. pilchardus in the traditional fishing community of Peniche, Portugal. This study was based on 87 semi-structured interviews conducted randomly from June to September 2016 in Peniche. The interview script contained two main points: Profile of fishermen and LEK on European pilchard. The ethnoecological data of sardines were compared with the scientific literature following an emic-etic approach. Data collected also were also analysed following the union model of the different individual competences and carefully explored to guarantee the objectivity of the study. The profile of the fishermen was investigated and measured. Respondents provided detailed informal data on the taxonomy, habitat, behaviour, migration, development, spawning and fat accumulation season of sardines that showed agreements with the biological data already published on the species. The main uses of sardines by fishermen, as well as beliefs and food taboos have also been mentioned by the local community. The generated ethnoecological data can be used to improve the management of this fishery resource through an adaptive framework among the actors involved, in addition to providing data that can be tested in further ecological studies. Therefore, this local knowledge may have the capacity to contribute to more effective conservation actions for sardines in Portugal.

  8. Patterns of Distribution and Spatial Indicators of Ecosystem Change Based on Key Species in the Southern Benguela.

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    Katherine E Watermeyer

    Full Text Available Several commercially and ecologically important species in the southern Benguela have undergone southward and eastward shifts in their distributions over previous decades, most notably the small pelagic fish sardine Sardinops sagax and anchovy Engraulis encrasicolus. Understanding these changes and their implications is essential in implementing an ecosystem approach to fisheries in the southern Benguela and attempting to appreciate the potential impacts of future environmental change. To investigate possible impacts of these shifts at an ecosystem level, distribution maps for before (1985-1991, during (1997-2000 and after (2003-2008 the shift in small pelagic fish were constructed for 14 key species from catch and survey data, and used to calculate spatial indicators including proportion east and west of Cape Agulhas, relative overlap in biomass and area, index of diversity, connectivity. Potential interactions on the south and west coasts were also compared. For several species (redeye; chub mackerel; kingklip; chokka squid; yellowtail, previously unidentified increases in the proportion of biomass east of Cape Agulhas were shown to have occurred over the same period as that of small pelagic fish, although none to the same degree. On average, overlap with small pelagic fish increased over time and overall system connectivity was lowest in the intermediate period, possibly indicating a system under transition. Connectivity declined over time on the west coast while increasing on the east coast. Distributions of other species have changed over time, with the region east of Cape Agulhas becoming increasingly important in terms of potential trophic interaction. Variations in distribution of biomass and structural complexity affect the trophic structure and hence functioning of the system, and implications should be considered when attempting to identify the possible ecosystem impacts of current and future system-level change.

  9. Anchovies to Whales: tracking vertebrate biodiversity in Monterey Bay by metabarcoding environmental DNA (eDNA) (United States)

    Closek, C. J.; Starks, H.; Walz, K.; Boehm, A. B.; Chavez, F.


    The oscillation between the dominance of Sardinops sagax (pacific sardine) and Engraulis mordax (northern anchovy) has been documented in the California Coastal Ecosystem for more than 100 years. These two species are strong drivers of trophic interactions in the region. As part of the Marine Biodiversity Observational Network (MBON) initiative, we used archived filtered seawater samples collected late-summer to mid-fall over a span of 8 years from Monterey Bay, CA to examine the change in marine vertebrate environmental DNA (eDNA). Water samples were collected from a nearshore location in Monterey Bay (C1) during the years of 2008-15. The water was then filtered, and the filter was archived at -80°C. DNA was extracted from the filters, and the 12S rRNA gene present in mitochondrial DNA was PCR amplification using primers designed to amplify 12s rRNA genes from marine vertebrates. The amplicons were subsequently sequenced with an Illumina MiSeq and the data processed using an analysis pipeline for sequence annotation. More than 20 fish genera were noted in the sequences from 2008-12, with Engraulis the dominant fish genus from 2013-15. Anchovy and Megaptera novaeangliae (humpback whale) were present in temporal patterns similar to those noted during visual observations where anchovy and humpback whale were more abundant during the years of 2013-2015 than the other years. This study demonstrates our ability to detect megafauna and fish species that are important to the Monterey Bay ecosystem from coastal water samples and determine community structural differences over time.

  10. Managing small-scale commercial fisheries for adaptive capacity: insights from dynamic social-ecological drivers of change in Monterey Bay. (United States)

    Aguilera, Stacy E; Cole, Jennifer; Finkbeiner, Elena M; Le Cornu, Elodie; Ban, Natalie C; Carr, Mark H; Cinner, Joshua E; Crowder, Larry B; Gelcich, Stefan; Hicks, Christina C; Kittinger, John N; Martone, Rebecca; Malone, Daniel; Pomeroy, Carrie; Starr, Richard M; Seram, Sanah; Zuercher, Rachel; Broad, Kenneth


    Globally, small-scale fisheries are influenced by dynamic climate, governance, and market drivers, which present social and ecological challenges and opportunities. It is difficult to manage fisheries adaptively for fluctuating drivers, except to allow participants to shift effort among multiple fisheries. Adapting to changing conditions allows small-scale fishery participants to survive economic and environmental disturbances and benefit from optimal conditions. This study explores the relative influence of large-scale drivers on shifts in effort and outcomes among three closely linked fisheries in Monterey Bay since the Magnuson-Stevens Fisheries Conservation and Management Act of 1976. In this region, Pacific sardine (Sardinops sagax), northern anchovy (Engraulis mordax), and market squid (Loligo opalescens) fisheries comprise a tightly linked system where shifting focus among fisheries is a key element to adaptive capacity and reduced social and ecological vulnerability. Using a cluster analysis of landings, we identify four modes from 1974 to 2012 that are dominated (i.e., a given species accounting for the plurality of landings) by squid, sardine, anchovy, or lack any dominance, and seven points of transition among these periods. This approach enables us to determine which drivers are associated with each mode and each transition. Overall, we show that market and climate drivers are predominantly attributed to dominance transitions. Model selection of external drivers indicates that governance phases, reflected as perceived abundance, dictate long-term outcomes. Our findings suggest that globally, small-scale fishery managers should consider enabling shifts in effort among fisheries and retaining existing flexibility, as adaptive capacity is a critical determinant for social and ecological resilience.

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

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    Sae Yun Kwon


    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.

  12. Different Levels of Hypoxia Tolerance during Early Life History Stages of Key Fish Species from the Northern Benguela Upwelling Ecosystem Inferred from the Comparison of Eco-Physiological Traits (United States)

    Geist, S. J.; Imam, R. M.; Kunzmann, A.; Ekau, W.


    Global change factors such as a pronounced Oxygen Minimum Zone and the shoaling of hypoxic waters are assumed to play a major role in controlling the recruitment of fish stocks in Upwelling Systems by affecting the planktonic early life history stages. Ecological and ecophysiological traits in the larval stages of five key fish species in the Northern Benguela Upwelling System (Sardine, Sardinops sagax; Anchovy, Engraulis encrasicolus; Cape horse mackerel, Trachurus capensis; Cape hake, Merluccius sp.; Pelagic goby, Sufflogobobius bibarbatus) were investigated during the GENUS (Geochemistry and Ecology of the Namibian Upwelling Ecosystem) research project . Analysis of vertical larval distributions in relation to the depth of hypoxic water layers showed gradual interspecific differences, suggesting lower hypoxia tolerance levels of the small pelagics Sardine and Anchovy. Cape horse mackerel juveniles and larvae exhibited very high tolerance levels to short-term hypoxia in respirometry stress experiments, close to the levels of the extremely hypoxia-tolerant Pelagic goby. In the latter two species, we also measured the highest activities of anaerobic enzymes (pyruvate kinase and lactate dehydrogenase) in early and late larval stages, compared to very low activities in Sardine larvae. A higher amount of anaerobic enzymatic activity is related to a higher capacity to break down metabolites that build up during phases of oxygen debt and thus help the larvae to quickly recover from hypoxia exposure. In consequence, a high hypoxia tolerance during their early life stages allows Cape horse mackerel and Pelagic goby to successfully reproduce in an environment characterized by frequent hypoxic events. The low hypoxia tolerance of Sardine larvae, eventually resulting in higher mortality rates, is likely to be an important factor to understand the poor reproductive success and continuing recruitment failures of this formerly dominant fish species of the NBUS during the last

  13. Daily food intake of Kajikia audax (Philippi, 1887 off Cabo San Lucas, Gulf of California, Mexico Tasa de consumo diario de alimento de Kajikia audax (Philippi, 1887 frente a Cabo San Lucas, golfo de California, México

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    Leonardo A Abitia-Cárdenas


    Full Text Available The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae, were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus, California pilchard (Sardinops caeruleus, and jumbo squid (Dosidicus gigas; together these represented ~55% of the striped marlin diet. The daily food consumption was estimated to be 2 kg per day, or ~3.6% of the mean body weight of K. audax. The total biomass of the prey consumed by the striped marlin during the 27 months of sampling around Los Cabos was estimated at 24.8 ton, of which the chub mackerel represented ~29% (7.2 ton, California pilchard just under 16% (3.9 ton, and jumbo squid ~10% (2.5 ton. The feeding habits of K. audax are discussed in terms of the distribution of the epipelagic (neritic and oceanic zones, demersal, and benthic prey, confirming that striped marlin migrate vertically and horizontally in search of their food.Se estimó la tasa de consumo diario de alimento del marlín rayado Kajikia audax (Perciformes: Istiophoridae, sobre la base de análisis cualitativos y cuantitativos de su espectro trófico. Se analizó el contenido estomacal de 505 ejemplares capturados por la flota deportiva frente a Cabo San Lucas, Baja California Sur, México muestreados de octubre 1987 a diciembre 1989. Las presas más importantes fueron la macarela del Pacífico (Scomber japonicus, sardina monterrey (Sardinops caeruleus y calamar gigante (Dosidicus gigas, que en conjunto representaron aproximadamente el 55% de la dieta. La tasa de consumo de alimento fue estimado en 2 kg diarios, lo cual representó aproximadamente el 3,6% del peso corporal de K. audax. La biomasa total de presas consumidas por el marlín rayado

  14. Geographic and host size variations as indicators of Anisakis pegreffii infection in European pilchard (Sardina pilchardus) from the Mediterranean Sea: Food safety implications. (United States)

    Bušelić, Ivana; Botić, Antonela; Hrabar, Jerko; Stagličić, Nika; Cipriani, Paolo; Mattiucci, Simonetta; Mladineo, Ivona


    European pilchards are traditionally eaten marinated or salted in the Mediterranean countries often without thermal processing or gutting due to small size. Since ingestion of live third stage Anisakis larvae represents a causing agent in the onset of anisakiasis, the aim of our study was to assess prevalence and intensity of Anisakis infection in European pilchards originating from different Mediterranean regions in a three-year sampling period (2013-2015). A total of 1564 specimens of European pilchard collected from two geographically distinct sampling regions (western Mediterranean and Adriatic Sea) were examined using the UV-Press method, which utilises the fluorescence of frozen anisakids in flattened and subsequently frozen fillets and viscera. A subsample of 67 isolated larvae was identified as A. pegreffii by diagnostic allozyme markers and sequence analyses of the mtDNA cox2 locus. The overall prevalence in pilchards was 12.2% (range 0-44.9% for different sampling points) and mean intensity 1.8. More importantly, we have observed an overall larval prevalence of 1.5% in fillets. The highest prevalence (44.9%) was recorded in pilchards caught in western parts of the Mediterranean. As fish host size was a significant predictor of parasite abundance, it should be highlighted that these pilchards were also the largest (mean total length 173.2mm); on average >2cm larger than the rest of the samples. Other isolated nematode species included Hysterothylacium sp. in viscera, showing almost a double of A. pegreffii prevalence, 20.1%. In summary, our study demonstrates that the presence of A. pegreffii in European pilchards from the Mediterranean Sea is highly influenced by both geographic and host size variation. This implies that, before future risk management measures are developed, these variables should be assessed in order to minimize public health concerns. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Exploring fidelity of Sardines (Sardina pilchardus to feeding grounds in the Atlantic Moroccan waters using stable isotope analyses (C, N and otolith microchemistry

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    Hicham Masski


    Sardine individuals from the different sites showed significantly different trophic position for both C and N isotopes. The northern individuals were depleted in d15N (1‰ difference, suggesting that phytoplankton is more important in their diet. The d13C values showed greater differences (~3‰ for both Sardines and zooplankton between the two sites, pointing high fidelity for sardine individuals towards the feeding grounds. While Anchovy and Horse Mackerel showed a similar pattern with sardine for δ13C, chub mackerel showed no significant differences between the two areas suggesting a higher seasonal migratory behavior for this species. Sardine Microelements profiles reinforced the sedentary behavior hypothesis for sardine. The Barium (Ba profiles were the most discriminant: the concentration range was 7× higher for the southern area where upwelling intensity is higher [4].

  16. Searching for a stock structure in Sardina pilchardus from the Adriatic and Ionian seas using a microsatellite DNA-based approach

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    Ruggeri, Paolo; Splendiani, Andrea; Bonanomi, Sara


    of homozygote individuals higher than expected at Hardy-Weinberg equilibrium. The inter-population differentiation level estimated by AMOVA, qST and rRST and Bayesian descriptors detected no signs of population differentiation between the samples analysed. These results are consistent with previous studies...

  17. Searching for a stock structure in Sardina pilchardus from the Adriatic and Ionian seas using a microsatellite DNA-based approach

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    Paolo Ruggeri


    Full Text Available In the present study the genetic variability of European sardine from Adriatic and Ionian seas was investigated in order to detect the occurrence of genetic structure within and between these basins. In several samples the analysis of genetic variability at eight microsatellite loci showed a number of homozygote individuals higher than expected at Hardy-Weinberg equilibrium. The inter-population differentiation level estimated by AMOVA, qST and rRST and Bayesian descriptors detected no signs of population differentiation between the samples analysed. These results are consistent with previous studies based on allozymes and several mitochondrial DNA markers and add further evidence contradicting the early identification, based on morphological and reproductive data, of two sub-populations in the Adriatic Sea.

  18. Effect of baking of sardine (Sardina pilchardus) and frying of anchovy (Engraulis encrasicholus) in olive and sunflower oil on their quality. (United States)

    Zotos, Anastasios; Kotaras, Akylas; Mikras, Emmanouil


    Quality changes due to oven-baking of sardine for 20, 40, 50 and 60 min and due to deep frying of anchovy for 2, 3, 4 and 5 min in olive and sunflower oil were studied. Linear increase in total losses with the time of processing was observed. A linear inverse relationship was observed between moisture/lipid and moisture/protein due to time of baking of sardines and time of frying of anchovies (wet matter). However, no changes were detected in sardine samples due to time of baking (dry matter), while a reduction in proteins and ash followed by an increase in lipids was detected in fried anchovies due to time of frying (dry matter). The fatty acid profiles indicated that a rich in EPA + DHA (33.16%) and in ω-3/ω-6 ratio (9.40) baked sardines can be produced in 20 min at 200 °C. The fatty acid profiles of fried anchovies tremendously changed, indicating entirely different products. Olive oil is probably a better medium to fry fish products, since either the two beneficial fatty acids (EPA and DHA) detected at higher concentrations in anchovies fried in olive oil or the ω-3/ω-6 ratio remained at higher values (0.71-2.56). An increase of cholesterol and squalene content with increasing the time of baking was detected in sardine samples, probably due to decline of moisture content. On the contrary, cholesterol significantly reduced due to frying of anchovy in olive oil. Simultaneously squalene concentration significantly and linearly increased, from 3.87 mg/100 g in the unprocessed anchovies to 73.25 mg/100 g in the samples fried for 5 min, indicating its existence at beneficial levels, besides low cholesterol concentration detected in fried olive oil and squalene concentration gradually and linearly decreased, confirming the absorption from the anchovy samples. Similar was the changes of cholesterol and squalene in anchovies samples fried in sunflower oil.

  19. A shift in the dominant toxin-producing algal species in central California alters phycotoxins in food webs (United States)

    Jester, R.; Lefebvre, K.; Langlois, G.; Vigilant, V.; Baugh, K.; Silver, M.W.


    In California, the toxic algal species of primary concern are the dinoflagellate Alexandrium catenella and members of the pennate diatom genus Pseudo-nitzschia, both producers of potent neurotoxins that are capable of sickening and killing marine life and humans. During the summer of 2004 in Monterey Bay, we observed a change in the taxonomic structure of the phytoplankton community-the typically diatom-dominated community shifted to a red tide, dinoflagellate-dominated community. Here we use a 6-year time series (2000-2006) to show how the abundance of the dominant harmful algal bloom (HAB) species in the Bay up to that point, Pseudo-nitzschia, significantly declined during the dinoflagellate-dominated interval, while two genera of toxic dinoflagellates, Alexandrium and Dinophysis, became the predominant toxin producers. This change represents a shift from a genus of toxin producers that typically dominates the community during a toxic bloom, to HAB taxa that are generally only minor components of the community in a toxic event. This change in the local HAB species was also reflected in the toxins present in higher trophic levels. Despite the small contribution of A. catenella to the overall phytoplankton community, the increase in the presence of this species in Monterey Bay was associated with an increase in the presence of paralytic shellfish poisoning (PSP) toxins in sentinel shellfish and clupeoid fish. This report provides the first evidence that PSP toxins are present in California's pelagic food web, as PSP toxins were detected in both northern anchovies (Engraulis mordax) and Pacific sardines (Sardinops sagax). Another interesting observation from our data is the co-occurrence of DA and PSP toxins in both planktivorous fish and sentinel shellfish. We also provide evidence, based on the statewide biotoxin monitoring program, that this increase in the frequency and abundance of PSP events related to A. catenella occurred not just in Monterey Bay, but also

  20. Regime Change in the Pacific Ocean and the Relative Intensities of Multi-Decadal and Quasi-Centennial Variability (United States)

    Heavens, N. G.; Yung, Y. L.


    Fish scales deposited in varves in the Santa Barbara Basin off the coast of California suggest that both Pacific Sardine (Sardinops sagax) and Northern Anchovy (Engraulis mordax) populations vary with common characteristic periodicities of 58, 72-77, and 102-106 years [Baumgartner et al., 1992]. Variability of sardine populations on 30-70 year scales also has been observed since the mid 17th century off the coast of Japan [Yasuda, 1997]. These periodicities in population are thought to be climatically driven. While the 58 year and possibly the 72-77 year "multi-decadal" cycles are observable in modern instrument- derived records of the Pacific Decadal Oscillation (PDO) index, the 102-106 year "quasi-centennial" cycle is less apparent. Recently, Shen et al. [2006] presented a reconstruction of the PDO index since 1470 based on eastern China rainfall in which the quasi-centennial periodicity was more apparent before 1850. Using empirical mode decomposition (EMD, Huang et al., 1998) of the PDO reconstruction, we confirm this result. We then use EMD to analyze a white spruce (Picea glauca) tree ring record from Kobuk/Noatak, Alaska, which correlates with the April PDO index. The results show that multidecadal and quasi-centennial variability in this proxy record were similar in magnitude during the Little Ice Age but that multi-decadal variability dominated during both the Medieval Warm Period and since 1850. Based on this limited analysis, we suggest the possibility that multi-decadal variability in the Pacific Ocean could be enhanced by anthropogenic climate change. Changes in ocean circulation of this type are a major unknown in future climate forecasts. Additionally, we propose that these changes in the dominant periodicities of decadal to centennial variability over time may represent significant changes in Pacific Ocean circulation. Indeed, these regime changes may explain the multi-centennial variability in the covariance of particular Pacific fish populations

  1. Impact of El Niño events on pelagic fisheries in Peruvian waters (United States)

    Ñiquen, Miguel; Bouchon, Marilú


    Using data from stock assesment surveys on pelagic resources during El Niño events of 1972/73, 1982/83, 1997/98, we analyze biological changes on pelagic ecosystems and pelagic fisheries during different stages of development of El Niño phenomenon: emergence, full, final and post-Niño. Results indicate changes in spatial distribution of resources, their concentration and size structure. In anchovy (Engraulis ringens) a decrease in biomass was observed, which was estimated at 1.2 million tons in September 1998, the lowest throughout the 1990s. This resource showed an asymmetric distribution towards the south of Peru. Other pelagic resources increased their biomass during or after Niño events, primarily sardine (Sardinops sagax), jack mackerel (Trachurus murphyi), pacific mackerel (Scomber japonicus), and longnose anchovy (Anchoa nasus). At the end of the El Niño phenomenon we found less productivity but more diversity in the pelagic ecosystem. During the 1997/98 El Niño, the diversity index (Manual de Ecologia, 1a Edition, Editorial Trillas, Mexico, 267pp) increased from 0.87 to 1.23-1.70. In both the emergence stage and fully developed stages of El Niño we found large numbers of sardine and longnose anchovy present simultaneously. Size structure of sardine, jack mackerel, and pacific mackerel showed an increase in juveniles. Anchovy during El Niño showed a single modal group composed of adults, but the post-Niño phase indicated an increase in juveniles with an average length of 6-7 cm. In El Niño conditions spawning among anchovy was low, but among sardine and pacific mackerel it was high. We observed, for the first time during full spawning, juvenile sardines with a total length of 18-20 cm. The anchovy spawning season during the post-Niño phase was considerably lengthened, from April to December 1998. Drastic change occurred in fisheries when monospecific fisheries, based on anchovy before El Niño, became multispecific fisheries based on sardine, jack

  2. Características hidro-planctónicas y su relación con las distribuciones de sardina y anchoa en la plataforma francesa del Golfo de Vizcaya


    Pierre Petitgas; Jacques Masse; Paul. Bourriau; Pierre Beillois; Daniel Delmas; Alain Herbland; Noussithe Koueta; Jean Maire Froidefond; Maria Santos


    The spatial pattern in hydro-plankton and fish distributions and their relationship were analysed based on the spring 2000 fisheries acoustic survey. The importance of this survey was that it was a multi-disciplinary platform which collected an extensive set of parameters in the hydro-plankton leading to a potentially finer description of hydro-plankton conditions and fish habitats. More than 50 variables were measured on a grid of stations, in four compartments of the ecosystem: hydrology, n...

  3. Biogeochemical and ecological impacts of boundary currents in the Indian Ocean (United States)

    Hood, Raleigh R.; Beckley, Lynnath E.; Wiggert, Jerry D.


    , though local wind forcing can lead to transient near shore current reversals and localized coastal upwelling. The poleward direction of this eastern boundary current is unique. Due to its high kinetic energy the Leeuwin Current sheds anomalous, relatively high chlorophyll, warm-core, downwelling eddies that transport coastal diatom communities westward into open ocean waters. Variations in the Leeuwin transport and eddy generation impact many higher trophic level species including the recruitment and fate of rock lobster (Panulirus cygnus) larvae. In contrast, the transport of the Agulhas Current is very large, with sources derived from the Mozambique Channel, the East Madagascar Current and the southwest Indian Ocean sub-gyre. Dynamically, the Agulhas Current is upwelling favorable; however, the spatial distribution of prominent surface manifestations of upwelling is controlled by local wind and topographic forcing. Meanders and eddies in the Agulhas Current propagate alongshore and interact with seasonal changes in the winds and topographic features. These give rise to seasonally variable localized upwelling and downwelling circulations with commensurate changes in primary production and higher trophic level responses. Due to the strong influence of the Agulhas Current, many neritic fish species in southeast Africa coastal waters have evolved highly selective behaviors and reproductive patterns for successful retention of planktonic eggs and larvae. For example, part of the Southern African sardine (Sardinops sagax) stock undergoes a remarkable northward migration enhanced by transient cyclonic eddies in the shoreward boundary of the Agulhas Current. There is evidence from the paleoceanographic record that these currents and their biogeochemical and ecological impacts have changed significantly over glacial to interglacial timescales. These changes are explored as a means of providing insight into the potential impacts of climate change in the Indian Ocean.

  4. Can small pelagic fish landings be used as predictors of high-frequency oceanographic fluctuations in the 1–2 El Niño region?

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    F. I. Ormaza-González


    Full Text Available A group of small pelagic fish captured between 1981 and 2012 within El Niño area 1–2 by the Ecuadorian fleet was correlated with the oceanographic Multivariate ENSO Index (MEI, and the Oceanographic El Niño Index (ONI referred to El Niño region 3–4. For the period 1981–2012, total landings correlated poorly with the indexes, but during 2000–2012 (cold PDO they proved to have a 14–29 % association with both indexes; the negative slope of the curves suggested higher landing during cold events (La Niña and also indicated a tendency to decrease at extreme values ( >  0.5 and  < −1.0. Round herring (Etrumeus teres fourth-quarter (Q4 landings were related to the MEI in a nonlinear analysis by up to 80 %. During moderate or strong La Niña events landings noticeably increased. Bullet tuna (Auxis spp. catches showed a negative gradient from cold to warm episodes with an R2 of 0.149. For Chilean jack mackerel (Trachurus murphyi irregular landings between 2003 and 2007 were observed and were poorly correlated (R2 < 0.1 with ONI or MEI. Anchovy (Engraulis ringens captured in Ecuadorian waters since 2000 had an R2 of 0.302 and 0.156 for MEI and ONI, respectively, but showed a higher correlation with the cold Pacific Decadal Oscillation (PDO. South American pilchard (Sardinops sagax was higher than −0.5 for the ONI and MEI, and landings dramatically decreased; however, Q4 landings correlated with ONI and MEI, with R2 of 0.109 and 0.225, respectively (n = 3. Linear correlation of Q4 indexes against the following year's Q1 landings had a linkage of up to 22 %; this species could therefore be considered a predictor of El Niño. Chub mackerel (Scomber japonicus landings did not have a significant linear correlation with the indexes for 1981–2012 and therefore could not be considered a valid predictor. Chuhueco (Cetengraulis mysticetus is a local species with high landings during El Niño years and, conversely

  5. Effects of Climate Change on Sardine Productivity in the California Current System (United States)

    Baumgartner, T. R.; Auad, G.; Miller, A. J.


    The Pacific sardine (Sardinops sagax caeruleus) is one of several coastal pelagic, planktivorous species of fish that provide important trophic links within the ecosystems of the major eastern and western boundary currents. Significant and persistent change in sardine productivity has occurred in the California Current over interdecadal periods in response to reorganization of basin-wide, ocean-atmosphere circulation. Less extreme, but still significant changes in sardine productivity are associated with interannual to decadal-scale climate variability. A precipitous decline of the sardine population began in the mid-1940s with a shift in climate leading to cooling of the California Current system. While the decline, and ultimately the collapse of the population, was exacerbated by intensive fishing, the sardine also suffered a severe reduction in productivity with the southward contraction of favorable thermal habitat that led to restriction of the population to the waters off Southern California and Baja California. This southward displacement resulted in geographic separation of the population from the region off central and northern California that is characterized by significantly higher concentrations of zooplankton that supported the previous levels of success in spawning and larval development. The climate shift in 1976-77 led to the recovery of the population and extension of its range of distribution northwards into the waters off British Columbia. The relation of reproductive success of the sardine population to interannual and decadal climate change was examined for the period 1982-2005 using a suite of seasonal indices representing climate processes and habitat conditions (including zooplankton food levels) occurring through the different stages in the sardine life cycle. We used both stepwise regression and EOF analyses to determine the association between levels of recruitment success and seasonal indices of the Pacific Decadal Oscillation, Ekman

  6. Trophic ecology of small pelagic fish in the northwestern Mediterranean / Ecología trófica de peces pelágicos pequeños en el Mediterráneo noroccidental


    Costalago, D.


    [spa] En el Mediterráneo noroccidental, anchoa, Engraulis encrasicolus, y sardina, Sardina pilchardus, son las especies más importantes en términos de biomasa y de toneladas capturadas. La anchoa y la sardina son especies planctívoras que consumen, durante todas sus fases de desarrollo, un amplio rango de especies, lo que podría esperarse que se tradujera en un posible solapamiento de sus nichos tróficos. Sin embargo, las interacciones tróficas entre las dos especies habían sido, hasta el...

  7. The southern Benguela ecosystem supports a large and highly ...

    African Journals Online (AJOL)


    The southern Benguela ecosystem supports a large and highly productive assemblage of epipelagic fish, including anchovy Engraulis capensis, sardine Sardi- nops sagax and round herring Etrumeus whiteheadi. These clupeoids support a valuable purse-seine fishery, which has been dominated over the last 20 years or ...

  8. make up.contents pg

    African Journals Online (AJOL)


    systems from which Sardinops are absent, for example, Brazil, where they and Sardinella are segregated vertically in the water column. 1 Scripps Institution ..... Kushiro Fisheries Experimental Station. Fig. 4: Annual changes in (a) ...... discrete spawning areas, which are consistent in space and time, but the products of these ...

  9. Download this PDF file

    African Journals Online (AJOL)


    There is a similarity in the marine avifaunas of the. Humboldt upwelling system off western South. America and the Benguela upwelling system off western southern Africa. Each system has an abun- dant, endemic cormorant, sulid and penguin, each of which feeds primarily on the large populations of sardine. Sardinops ...

  10. The southern Benguela ecosystem supports a large and highly ...

    African Journals Online (AJOL)


    Dr M. Castillo-Rivera of the Universidad Autonoma. Metropolitana, Mexico, are thanked for their valuable reviews of the manuscript. LITERATURE CITED. ARMSTRONG, M. J., CHAPMAN, P., DUDLEY, S. F. J., HAMP-. TON, I. and P. E. MALAN 1991 — Occurrence and popu- lation structure of pilchard Sardinops ocellatus, ...

  11. Colombian dry moist forest transitions in the Llanos Orientales - A comparison of model and pollen-based biome reconstructions

    NARCIS (Netherlands)

    Marchant, R.A.; Berrio, J.C.; Behling, H.; Boom, A.; Hooghiemstra, H.


    Abstract Colombian vegetation, at the ecological level of the biome, is reconstructed at six sites using pollen data assigned a priori to plant functional types and biomes. The chosen sites incorporate four savanna sites (Laguna Sardinas, Laguna Angel, El Piñal and Laguna Carimagua), a site on the

  12. African Journal of Biotechnology - Vol 12, No 24 (2013)

    African Journals Online (AJOL)

    Salvatore Mastrangelo, Marco Tolone, Maria Teresa Sardina, Rosalia Di Gerlando, Baldassare Portolano ... Gustavo Veloso, Deonir Secco, Helton Aparecido Rosa, Reginaldo Ferreira Santos, Samuel Nelson Melegari de Souza, Aracéli Ciotti de Marins, Willian Tenfen Wazilewski, Tiago Roque Benetoli da Silva ...

  13. On the dynamics of the Mauritanian small-pelagic fishery, North ...

    African Journals Online (AJOL)

    Catches are influenced by region and by seasonal hydrographic conditions. Yields of carangids (Trachurus trachurus, T. trecae and Decapterus rhonchus) are significantly higher (p < 0.05) in the southern part of the fishing zone than in the north, whereas the reverse is observed for Sardina pilchardus. Carangids are caught ...

  14. Juan Ruiz, un hombre de nuestro tiempo

    Directory of Open Access Journals (Sweden)

    Matías Escalera Cordero


    Full Text Available Alguien. Cual.quiera. Nos cuenta una historia. Es la historia del rico emperador de las viandas. Es la historia de una escuálida hembra, adusta como el tiempo que anuncia. De un reto. Son ejércitos de chuletas y de pechugas. Son sardinas, boquerones y arenques. Trabados en confusa reyerta. En batalla encarnizada.

  15. Spatial and seasonal patterns of European short-snouted seahorse ...

    African Journals Online (AJOL)

    Melenara Bay (mean sighting rate = 0.44 individuals VFC–1; SD 0.72) offered protected environments where seahorse distribution varied with substratum type, irrespective of season. Strong hydrodynamic forces in winter affected abundance and size at exposed locations in Sardina del Norte Bay (mean sighting rate = 0.21 ...

  16. Influencia de la topografía submarina sobre la distribución horizontal de las comunidades de ictioplancton en el entorno de la reserva marina de cabo de Palos - islas Hormigas (sudeste ibérico)


    Vidal Peñas, I.; López Castejón, F.; Mas-Hernández, J. (Julio)


    The present study examines the relationships between the horizontal distribution of ichthyoplankton populations and submarine topography, in both neritic and oceanic waters of Cape Palos - Hormigas Islands Marine Reserve (southeast Spain). Larvae from self-spawners (Sardina pilchardus, Walbaum, 1792; Gobiidae and Sparidae) constituted the shallow community which dominated neritic waters, whereas larvae of Myctophidae (Benthosema glaciale, Reinhardt, 1837, and Lampanyctinae) constituted anothe...

  17. Chemical composition and antioxidant activity of seven cultivars of guava (Psidium guajava) fruits. (United States)

    Flores, Gema; Wu, Shi-Biao; Negrin, Adam; Kennelly, Edward J


    The antioxidant activity and identification of phenolic compounds of seven edible guava (Psidium guajava) cultivars that varied in colour from white to pink were examined. In the DPPH assay all four pink-pulp guavas (Barbie Pink, Homestead, Sardina 1, Sardina 2) included in the study showed higher activity than the white pulp cultivars (Yen 2 and Sayla) and less than the red pulp guava cultivar (Thai Maroon). In the ABTS(+) assay this trend was the same up to 20 min, but from 20 to 40 min Barbie Pink showed lower activity than the white guavas. Twenty-one compounds were characterised in the cultivars, and ten of them are reported for the first time in this fruit. Principle component analysis was performed to identify differences in chemistry among these cultivars. Our results suggest that the antioxidant activity and phytochemical composition of P. guajava vary significantly according to the cultivar and pulp colour. Copyright © 2014. Published by Elsevier Ltd.


    African Journals Online (AJOL)


    Pour une meilleure compréhension des effets du stockage à l'état congelé de la sardine (Sardina pilchardus), principale espèce de ... Mots-clés : conservabilité, sardine, congélation, altération chimique, acides gras omega-3, EPA, DHA, ABVT ... Cependant, la qualité des produits congelés dépend entre autres de la ...

  19. Population changes in small pelagic fish of the Gulf of Lions : a bottom-up control?


    Van Beveren, Elisabeth


    Knowledge on population dynamics is key to the improvement of management and the understanding of ecosystem functioning. Since 2007, the size of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Gulf of Lions (NW Mediterranean) has severely decreased, which has strongly affected the fisheries. Simultaneously, the commercially uninteresting sprat population increased remarkably. As the economic and ecological stakes are high, the EcoPelGol project of which this PhD is pa...





    Este estudio abordó la variabilidad en la calidad de alimento, entendida como la composición de macromoléculas y de sustancias esenciales (e.g. vitaminas), y su disponibilidad, en distintos aspectos de la reproducción/fisiología de las poblaciones de peces pelágicos pequeños (Strangomera bentincki, sardina común y Engraulis ringens, anchoveta) endémicos del Sistema de Corrientes de Humboldt. Para ello, se determinó la composición bioquímica (proteínas, aminoácidos libres, lípid...

  1. Born small, die young: Intrinsic, size-selective mortality in marine larval fish


    Garrido, S.; R. Ben-Hamadou; Santos, A. M. P.; Ferreira, S.; Teodósio, M. A.; U. Cotano; Irigoien, X.; Peck, M A; Saiz, E.; Ré, P.


    Mortality during the early stages is a major cause of the natural variations in the size and recruitment strength of marine fish populations. In this study, the relation between the size-at-hatch and early survival was assessed using laboratory experiments and on field-caught larvae of the European sardine (Sardina pilchardus). Larval size-at-hatch was not related to the egg size but was significantly, positively related to the diameter of the otolith-at-hatch. Otolith diameter-at-hatch was a...

  2. La pesquería de peces pelágicos pequeños en Ecuador durante 2008


    De Prado, M


    Se realizó el seguimiento a los desembarques de peces pelágicos pequeños en la costa ecuatoriana durante el 2008, los cuales se incrementaron en un 11 % con relación al 2007. Las especies que aumentaron fueron chuhueco (Cetengraulis ringens), sardina redonda (Etrumeus teres), y pinchagua (Opisthonema spp) en un 96 %, 80 % y 56 %, respectivamente, mientras disminuyeron los desembarques de macarela (Scomber japonicus) en un 50 % y anchoveta (Engraulis ringens) en un 25 %, mientras que botell...

  3. Tissue effect on RNA:DNA ratios of marine fish larvae


    M. Pilar Olivar; Marina V. Diaz; M. Alexandra Chícharo


    [ES] Efecto del tipo de tejido sobre los cocientes ARN:ADN en larvas de peces marinos. – En estudios de condición nutricional larvaria basados en la relación ARN:ADN, las cabezas y/o tubos digestivos suelen diseccionarse para posteriores estudios de edad o alimentación. Además, durante la captura algunas larvas pierden los ojos. En este trabajo analizamos el efecto de diferentes tejidos (músculo, cabeza, ojos y tubo digestivo) sobre la relación ARN:ADN en Sardina pilchardus, Engraulis encrasi...

  4. Ants (Hymenoptera:Fonnicidae) from Atlantlc rainforest at Santa Catarina Island, Brazil: two years of sampling


    da Silva, Rogério Rosa; Córtes Lopes, Benedito


    Se muestreó las hormigas diurnas y nocturnas durante el período 1992/1994, en una región de selva atlantica ("mata atlantica"), en cerro de "Lagoa da Conceicao", Florianópolis, Santa Catarina, Brasil, con cebos de sardina distribuidos sobre el suelo y en la vegetación arbustiva y arbórea para las especies diurnas, y embudo de BerleseTullgren para las nocturnas. Se identificó 74 especies diurnas (d) y 49 nocturnas (n) en las subfaruilias: Dolichoderinae (7d, 3n), Ecitoninae (Id), Formicinae (l...

  5. Quimeras. Presentación

    Directory of Open Access Journals (Sweden)

    Julio Premat


    Full Text Available Si a una cabeza humana,muy peinada a la moda y muy galana,le añadiera un pintor plumas de galloy un pescuezo de burro o de caballo ;si juntando las piezas desigualesde varios animalespor último en el lienzo retratarauna mujer de lindo talle y caracon alas de avestruz o de gallinay cola de merluza o de sardina,¿quién, amigos Pisones,dejara de reírse a borbotones ?Pues a este lienzo semejante fuera,el poema o quimera,cuyas partes sin tino colocadas,no fuesen a una forma conspiradas [...]Félix...

  6. Dinámica poblacional de Opisthonema medirastre (Pisces: Clupeidae en la Costa Pacífica de Costa Rica.

    Directory of Open Access Journals (Sweden)

    Rosa Lidia Soto Rojas


    Full Text Available Se analizaron la curva de crecimiento y la talla de la primera madurez  de la sardina Opisthonema medirastre en el Golfo de Nicoya. Los resultados muestran que esta especie presenta una L∞ de 30,6 cm para las hembras y de 28,0 cm para los machos. Los valores de la tasa de crecimiento (K fueron bajos en concordancia con lo esperado para especies de vida corta. La talla de primera madurez de esta especie es de 17,0 cm.

  7. Efectos del fenómeno "El Niño 1997-98" sobre los principales recursos pelágicos en la costa peruana

    Directory of Open Access Journals (Sweden)

    Miguel Ñiquen


    Full Text Available En el período abril 1997 setiembre 1998 fueron realizados 5 cruceros de evaluación de los recursos pelágicos en la costa peruana, éstos permitieron observar cambios en la composición por especies, distribución, estructura por tamaño, reproducción y niveles poblacionales de los principales recursos pelágicos. Estos cambios guardan similitud con los observados en los eventos El Niño 1972-73 y 1982-83, especialmente en cuanto a la disminución de la biomasa de anchoveta y el incremento de otras especies pelágicas. En el período post-Niño se observó cambios notables en la estructura por tallas de anchoveta, mientras que la sardina, samas a y caballa coincidieron en mostrar buenos reclutamientos. La actividad reproductiva también se incrementó, inclusive en tallas juveniles, destacando la incidencia de sardinas sexualmente maduras con longitudes de 18-20 cm, situación que no había sido antes registrada.

  8. Effects of Storage Temperatures on the Quality of Frozen Sardine, Mackerel, and Saury (United States)

    Kozima, Tsuneo; Ohataka, Tateo

    The three Japanese coastal fish species, sardine (Sardinops melanosticta), mackerel (Scomber japonicus) and saury (Cololabis saira) was frozen under commercial condition and stored at -18, -23, -30 and -40°C for 12 months. During frozen storage the quality was measured by determining the K value (freshness index), peroxide value (POV) of fat, a mount of free drip, water-holding capacity of muscle, weight ratio of cooking loss, histological feature of frozen and thawed muscle, and organoleptic test at regular intervals (each 2 months). Storage life of frozen sardine was 6 months at -18°C and 12 months at below -23°C. On frozen mackerel it was 6 months at -18°C. 8 months at -23°C and 12 months at below -30°C. On saury it was 6 months at 18°C and 12 months at below -23°C.

  9. Functional and antioxidant properties of hydrolysates of sardine (S. pilchardus) and horse mackerel (T. mediterraneus) for the microencapsulation of fish oil by spray-drying. (United States)

    Morales-Medina, R; Tamm, F; Guadix, A M; Guadix, E M; Drusch, S


    The functionality of fish protein hydrolysates (FPH) for the microencapsulation of fish oil was investigated. Muscle protein from sardine (Sardina pilchardus) and horse mackerel (Trachurus mediterraneus) was hydrolysed using Alcalase or trypsin. Physically stable emulsions suitable for spray-drying were obtained when using FPH with a degree of hydrolysis of 5%. Microencapsulation efficiency amounted to 98±0.1% and oxidative stability of the encapsulated oil over a period of twelve weeks was in a similar range as it is reported for other matrix systems. Therefore, the suitability of FPH for use in spray-dried emulsions has been shown for the first time. Since no clear correlation between the antioxidative activity of the FPH and the course of lipid oxidation could be established future research is required to more specifically characterise the molecular structure of the peptides and its impact on protein alteration and role in lipid oxidation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Detection of a diverse marine fish fauna using environmental DNA from seawater samples

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Kielgast, Jos; Iversen, Lars Lønsmann


    eDNA from 15 different fish species, including both important consumption species, as well as species rarely or never recorded by conventional monitoring. We also detect eDNA from a rare vagrant species in the area; European pilchard (Sardina pilchardus). Additionally, we detect four bird species......Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation. This is greatly impacting global biodiversity, economy and human health. Intriguingly, marine fish are largely surveyed using selective and invasive methods, which are mostly...... for marine fish biodiversity. This eDNA approach has recently been used successfully in freshwater environments, but never in marine settings. We isolate eDNA from 1/2-litre seawater samples collected in a temperate marine ecosystem in Denmark. Using next-generation DNA sequencing of PCR amplicons, we obtain...

  11. Physical and Oxidative Stability of Fish Oil-In-Water Emulsions Stabilized with Fish Protein Hydrolysates

    DEFF Research Database (Denmark)

    García Moreno, Pedro Jesús; Guadix, Antonio; Guadix, Emilia M.


    The emulsifying and antioxidant properties of fish protein hydrolysates (FPH) for the physical and oxidative stabilization of 5% (by weight) fish oil-in-water emulsions were investigated. Muscle proteins from sardine (Sardina pilchardus) and small-spotted catshark (Scyliorhinus canicula) were...... hydrolyzed to degrees of hydrolysis (DH) of 3-4-5-6% with subtilisin. Sardine hydrolysates with low DH, 3% and 4%, presented the most effective peptides to physically stabilize emulsions with smaller droplet size. This implied more protein adsorbed at the interface to act as physical barrier against...... prooxidants. This fact might also be responsible for the higher oxidative stability of these emulsions, as shown by their lowest peroxide value and concentration of volatiles such as 1-penten-3-one and 1-penten-3-ol. Among the hydrolysates prepared from small-spotted catshark only the hydrolysate with DH 3...

  12. Glycerolysis of sardine oil catalyzed by a water dependent lipase in different tert-alcohols as reaction medium

    Directory of Open Access Journals (Sweden)

    Solaesa, Á. G.


    Full Text Available The production of monoacylglycerol rich in polyunsaturated fatty acids (PUFA via enzymatic glycerolysis of sardine oil in a homogeneous system was evaluated. Reactions were conducted in two different tert-alcohols. Based on the phase equilibrium data, the amount of solvent added to create a homogeneous system has been calculated and optimized. The immobilized lipase used in this work was Lipozyme RM IM from Rhizomucor miehei, a water dependent lipase. The amount of water added as well as other reaction parameters were studied to evaluate the optimum conditions for monoacylglycerol obtencion. An initial reactant mole ratio glycerol to sardine oil 3:1, 12 wt% of water based on glycerol content and 10 wt% of lipase loading (based on weight of reactants, achieved a MAG yield of around 70%, with nearly 28 wt% PUFA, with low free fatty acid content (lower than 18 wt%.En este trabajo se ha estudiado la producción de monoacilglicéridos, ricos en ácidos grasos poliinsaturados (AGPI, mediante glicerolisis enzimática de aceite de sardina. La reacción se ha llevado a cabo en dos tert-alcoholes para conseguir de esta forma un medio homogéneo de reacción. La cantidad de disolvente añadida al medio de reacción se ha optimizado y calculado en base al equilibrio de fases de los componentes del sistema. La lipasa empleada como biocatalizador ha sido la enzima inmovilizada Lipozyme RM IM de Rhizomucor miehei, una lipasa dependiente de agua. Se ha estudiado el efecto de distintos parámetros cinéticos, así como de la cantidad de agua añadida al medio de reacción, en la producción de monoacilglicéridos. De los resultados obtenidos, se puede concluir que, para una relación molar inicial de reactantes glicerol:aceite de sardina de 3:1, un 12 % en peso de agua en base al glicerol y un 10 % en peso de lipasa, en base al peso de reactantes; se puede llegar a conseguir un rendimiento en monoacilglicéridos alrededor del 70 % en peso, con casi un 28 % en

  13. Optimization of α-tocopherol and ascorbyl palmitate addition for the stabilization of sardine oil

    Directory of Open Access Journals (Sweden)

    Morales-Medina, R.


    Full Text Available The purpose of the present work was to optimize the addition of natural antioxidants (α- tocopherol and ascorbyl palmitate for the stabilization of sardine oil rich in omega-3 PUFA. The optimal values for peroxide value (PV, which minimizes primary oxidation products, were obtained at low concentrations of α-tocopherol (50–207 ppm, high content of ascorbyl palmitate (450 ppm and 50 ppm citric acid. On the other hand, optimal values for p-anisidine value (AV, which minimizes secondary oxidation products, were found at medium concentrations of α-tocopherol (478–493 ppm, high contents of ascorbyl palmitate (390–450 ppm and 50 ppm citric acid. The conflicting effect of α-tocopherol on the individual optimization of PV and AV motivated the generation of a Pareto front (set of non inferior solutions employing the weighted-sum multi-objective optimization technique.El objetivo de este trabajo fue optimizar la adición de antioxidantes naturales (α-tocoferol y palmitato de ascorbilo para la estabilización de aceite de sardina rico en omega-3 PUFA. Bajas concentraciones de α-tocoferol (50–207 ppm combinadas con la adicción de antioxidantes secundarios como palmitato de ascorbilo (450 ppm y ácido cítrico (50 ppm, minimizaron la formación de hidroperóxidos en el aceite de sardina estudiado. Sin embargo, los productos secundarios de oxidación se redujeron para concentraciones medias de α-tocoferol (478–493 ppm, altas de palmitato de ascorbilo (390–450 ppm y 50 ppm de ácido cítrico. El efecto contradictorio de la concentración de α-tocoferol en la optimización individual del índice de peróxidos e índice de p-anisidina motivó la realización de una optimización simultánea que permite satisfacer la optimización de cada una de las variables individuales en el grado deseado.

  14. A review of Kudoa-induced myoliquefaction of marine fish species in South Africa and other countries

    Directory of Open Access Journals (Sweden)

    Sun S. Henning


    Full Text Available Myoliquefaction of fish musculature results in customer quality complaints and in huge economic losses, especially with regard to Pacific hake (Merluccius productus, farm-reared Atlantic salmon (Salmo salar, South African pilchards (Sardinops ocellatus and Cape snoek (Thyrsites atun. Myoliquefaction, or jelly flesh, is caused by proteolytic enzymes released by the marine myxosporean parasite,Kudoa thyrsites, after the death of the fish. Currently there are no fast methods of detection for this microscopic parasite, and because myoliquefaction is evident only after 38-56 h post-mortem, infected fish inevitably reach the processor and/or consumer. Several methods of detection have been investigated, but most of these methods are time-consuming and/or result in destruction of the fish, and are thus impractical for fishing vessels and fish processors. Limited research is available on possible means of destroying or inhibiting the post-mortem activity of the parasitic proteolytic enzyme. Means such as manipulating post-mortem pH and temperature control have been suggested; leaving opportunities for research into food technology applications such as cold-chain management and ionising radiation.

  15. Fish larvae from the Gulf of California

    Directory of Open Access Journals (Sweden)

    Gerardo Aceves-Medina


    Full Text Available Taxonomic composition of fish larvae was analysed from 464 plankton samples obtained during 10 oceanographic surveys in the Gulf of California between 1984 and 1988. We identified 283 taxa: 173 species, 57 genera, and 53 families. Tropical and subtropical species predominated except during the winter, when temperate-subarctic species were dominant. The most abundant species were the mesopelagic Benthosema panamense, Triphoturus mexicanus and Vinciguerria lucetia, but the coastal pelagic species Engraulis mordax, Opisthonema spp., Sardinops caeruleus and Scomber japonicus were also prominent. The taxonomic composition of the ichthyoplankton shows the seasonality of the Gulf as well as environmental changes that occurred between the 1984-1987 warm period and the 1956-1957 cool period previously reported. The presence of E. mordax larvae as one of the most abundant species in the Gulf provides evidence of the reproduction of this species two years before the development of the northern anchovy fishery and the decline of the sardine fishery in the Gulf of California.

  16. Comparison of PCR-DGGE and PCR-SSCP analysis for bacterial flora of Japanese traditional fermented fish products, aji-narezushi and iwashi-nukazuke. (United States)

    An, Choa; Takahashi, Hajime; Kimura, Bon; Kuda, Takashi


    The bacterial flora of two Japanese traditional fermented fish products, aji-narezushi (salted and long-fermented horse mackerel (Trachurus japonicas) with rice) and iwashi-nukazuke (salted and long-fermented sardine (Sardinops melanostica) with rice bran), was analysed using non-culture-based polymerase chain reaction (PCR) denaturing gradient gel electrophoresis (DGGE) and culture-based PCR single-strand conformation polymorphism (SSCP) methods. Viable plate counts in aji-narezushi and iwashi-nukazuke were about 6.3-6.6 and 5.7-6.9 log colony-forming units g(-1) respectively. In the PCR-DGGE analysis, Lactobacillus acidipiscis was detected as the predominant bacterium in two of three aji-narezushi samples, while Lactobacillus versmoldensis was predominant in the third sample. By the PCR-SSCP method, Lb. acidipiscis and Lactobacillus plantarum were isolated as the predominant bacteria, while Lb. versmoldensis was not detected. The predominant bacterium in two of three iwashi-nukazuke samples was Tetragenococcus muriaticus, while Tetragenococcus halophilus was predominant in the third sample. The results suggest that the detection of some predominant lactic acid bacteria species in fermented fish by cultivation methods is difficult. Copyright (c) 2010 Society of Chemical Industry.

  17. Volatile compounds of some popular Mediterranean seafood species

    Directory of Open Access Journals (Sweden)



    Full Text Available The volatile compounds of highly commercialised fresh Mediterranean seafood species, including seven fish (sand-smelt Atherina boyeri, picarel Spicara smaris, hake Merluccius merluccius, pilchard Sardina pilchardus, bogue Boobps boops, anchovy Engraulis encrasicolus and striped-mullet Mullus barbatus, squid (Loligo vulgaris, shrimp (Parapenaeus longirostris and mussel (Mytilus galloprovincialis, were evaluated by simultaneous steam distillation-extraction and subsequent GC-MS analysis. A total of 298 volatile compounds were detected. The mussels contained the highest total concentration of volatile compounds, while pilchard among fish species contained the highest number and concentrations of volatile compounds. Individual patterns of volatile compounds have been distinguished. The fish species when compared to the shellfish species studied, contained 6 to 30 times more 1-penten-3-ol, higher quantities of 2-ethylfuran, and 2,3-pentanedione, which was absent from the shellfish species. Pilchard is characterized by a high concentration of alcohols, shrimps by the high presence of amines and S-compounds, while mussels by high amounts of aldehydes, furans, and N-containing compounds (pyridine, pyrazines and pyrrols. The fatty acid-originating carbonyl compounds in fish seem to be related to the species’ fat content.

  18. Born small, die young: Intrinsic, size-selective mortality in marine larval fish

    KAUST Repository

    Garrido, S.


    Mortality during the early stages is a major cause of the natural variations in the size and recruitment strength of marine fish populations. In this study, the relation between the size-at-hatch and early survival was assessed using laboratory experiments and on field-caught larvae of the European sardine (Sardina pilchardus). Larval size-at-hatch was not related to the egg size but was significantly, positively related to the diameter of the otolith-at-hatch. Otolith diameter-at-hatch was also significantly correlated with survival-at-age in fed and unfed larvae in the laboratory. For sardine larvae collected in the Bay of Biscay during the spring of 2008, otolith radius-at-hatch was also significantly related to viability. Larval mortality has frequently been related to adverse environmental conditions and intrinsic factors affecting feeding ability and vulnerability to predators. Our study offers evidence indicating that a significant portion of fish mortality occurs during the endogenous (yolk) and mixed (yolk /prey) feeding period in the absence of predators, revealing that marine fish with high fecundity, such as small pelagics, can spawn a relatively large amount of eggs resulting in small larvae with no chances to survive. Our findings help to better understand the mass mortalities occurring at early stages of marine fish.

  19. Species identification of small pelagic fish schools by means of hydroacoustics in the Eastern Mediterranean Sea

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    Full Text Available Reliable biomass estimates by means of hydroacoustics largely depend on the correct identification of acoustic targets. Data collected during five summer acoustic surveys (2004-2008 in the North Aegean Sea (Greece were analyzed to explore effective discrimination of small pelagic fish schools according to the species they belong. Discriminant Function Analyses (DFA using bathymetric, energetic and morphometric school descriptors as explanatory variables were applied per research cruise as well as to pooled data from all surveys. Results revealed that the schools can be successfully classified into the five species considered (anchovy Engraulis encrasicolus, sardine Sardina pilchardus, round sardinella Sardinella aurita, blue whiting Micromessistius poutassou, and Atlantic mackerel Scomber scombrus. The percentage of correct classifications in terms of number of schools was higher in the analyses of the annual cruises (75.6%-95.36% than in the analysis of pooled data (≈72%. This is because of (i the lower number of species, as well as (ii the reduced intraspecific variability, occurring in each separate cruise. Significant differences were detected among school descriptors for the different species, revealing discrete aspects of schooling behaviour for each species. The benefit of the specific approach is that the classification functions of the DFAs can be used to classify a larger set of schools, which has not been possible to assign to specific species. Overall the approach constitutes an objective, more automated and less time consuming procedure for the analysis of acoustic data and can contribute to the improvement of biomass estimates in the area.

  20. Distribution of mercury in the organs and tissues of five toothed-whale species of the Mediterranean. (United States)

    Frodello, J P; Roméo, M; Viale, D


    Mercury levels were determined in the tissues and organs (lung, liver, kidney, skin, muscle, bone) of five toothed-whales stranded along the Corsican coast between November 1993 and February 1996. The species taken into consideration were the bottlenose dolphin Tursiops truncatus, the common dolphin Delphinus delphis, the striped dolphin Stenella coeruleoalba, the pilot whale Globicephala melas and the Risso's dolphin Grampus griseus. The variation in mercury levels between the different tissues and organs (lung, liver, kidney, skin, muscle, bone) of the cetacean species are discussed as regards storage, biotransformation and elimination. In all cases, the liver appears to be the preferential organ for mercury accumulation (with concentrations as high as 4250 microg Hg/g dw and 3298 microg Hg/g in the livers of Tursiops truncatus and Grampus griseus, respectively). The kidney and lung are the next organs in terms of mercury uptake followed by the muscle, bone and skin. The stomach contents of Grampus griseus and D. delphis were determined and consisted of cephalopods for Grampus griseus, and of sardines Sardina pilchardus and mackerels Trachurus sp. for D. delphis. Cephalopods had higher mercury concentrations (25.4 microg Hg/g dw) than fish (ca 1 microg Hg/g). These contents represent only one meal and mercury levels found in livers may integrate mercury uptake having occurred during the whole life span of animals.

  1. A real-time PCR assay to estimate invertebrate and fish predation on anchovy eggs in the Bay of Biscay

    KAUST Repository

    Albaina, A.


    In order to investigate the role of predation on eggs and larvae in the recruitment of anchovy (Engraulis encrasicolus), sardine (Sardina pilchardus), sprat (Sprattus sprattus) and 52 macrozooplankton taxa were assayed for anchovy remains in the gut during the 2010 spawning season using a molecular method. This real-time PCR based assay was capable of detecting 0.005. ng of anchovy DNA (roughly 1/100 of a single egg assay) in a reliable way and allowed detecting predation events up to 6. h after ingestion by small zooplankton taxa. A total of 1069 macrozooplankton individuals, 237 sardines and 213 sprats were tested. Both fish species and 32 macrozooplankton taxa showed remains of anchovy DNA within their stomach contents. The two main findings are (1) that the previously neglected macrozooplankton impact in anchovy eggs/larvae mortality is in the same order of magnitude of that due to planktivorous fishes and that, (2) the predation pressure was notably different in the two main spawning centers of Bay of Biscay anchovy. While relatively low mortality rates were recorded at the shelf-break spawning center, a higher predation pressure from both fish and macrozooplankton was exerted at the shelf one.

  2. Diet of bottlenose dolphins (Tursiops truncatus) from the Gulf of Cadiz: Insights from stomach content and stable isotope analyses. (United States)

    Giménez, Joan; Marçalo, Ana; Ramírez, Francisco; Verborgh, Philippe; Gauffier, Pauline; Esteban, Ruth; Nicolau, Lídia; González-Ortegón, Enrique; Baldó, Francisco; Vilas, César; Vingada, José; G Forero, Manuela; de Stephanis, Renaud


    The ecological role of species can vary among populations depending on local and regional differences in diet. This is particularly true for top predators such as the bottlenose dolphin (Tursiops truncatus), which exhibits a highly varied diet throughout its distribution range. Local dietary assessments are therefore critical to fully understand the role of this species within marine ecosystems, as well as its interaction with important ecosystem services such as fisheries. Here, we combined stomach content analyses (SCA) and stable isotope analyses (SIA) to describe bottlenose dolphins diet in the Gulf of Cadiz (North Atlantic Ocean). Prey items identified using SCA included European conger (Conger conger) and European hake (Merluccius merluccius) as the most important ingested prey. However, mass-balance isotopic mixing model (MixSIAR), using δ13C and δ15N, indicated that the assimilated diet consisted mainly on Sparidae species (e.g. seabream, Diplodus annularis and D. bellottii, rubberlip grunt, Plectorhinchus mediterraneus, and common pandora, Pagellus erythrinus) and a mixture of other species including European hake, mackerels (Scomber colias, S. japonicus and S. scombrus), European conger, red bandfish (Cepola macrophthalma) and European pilchard (Sardina pilchardus). These contrasting results highlight differences in the temporal and taxonomic resolution of each approach, but also point to potential differences between ingested (SCA) and assimilated (SIA) diets. Both approaches provide different insights, e.g. determination of consumed fish biomass for the management of fish stocks (SCA) or identification of important assimilated prey species to the consumer (SIA).

  3. Diet of bottlenose dolphins (Tursiops truncatus from the Gulf of Cadiz: Insights from stomach content and stable isotope analyses.

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    Joan Giménez

    Full Text Available The ecological role of species can vary among populations depending on local and regional differences in diet. This is particularly true for top predators such as the bottlenose dolphin (Tursiops truncatus, which exhibits a highly varied diet throughout its distribution range. Local dietary assessments are therefore critical to fully understand the role of this species within marine ecosystems, as well as its interaction with important ecosystem services such as fisheries. Here, we combined stomach content analyses (SCA and stable isotope analyses (SIA to describe bottlenose dolphins diet in the Gulf of Cadiz (North Atlantic Ocean. Prey items identified using SCA included European conger (Conger conger and European hake (Merluccius merluccius as the most important ingested prey. However, mass-balance isotopic mixing model (MixSIAR, using δ13C and δ15N, indicated that the assimilated diet consisted mainly on Sparidae species (e.g. seabream, Diplodus annularis and D. bellottii, rubberlip grunt, Plectorhinchus mediterraneus, and common pandora, Pagellus erythrinus and a mixture of other species including European hake, mackerels (Scomber colias, S. japonicus and S. scombrus, European conger, red bandfish (Cepola macrophthalma and European pilchard (Sardina pilchardus. These contrasting results highlight differences in the temporal and taxonomic resolution of each approach, but also point to potential differences between ingested (SCA and assimilated (SIA diets. Both approaches provide different insights, e.g. determination of consumed fish biomass for the management of fish stocks (SCA or identification of important assimilated prey species to the consumer (SIA.


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    Camilo Bernardo García Ramírez


    Full Text Available The rainbow runner (Elagatis bipinnulata scores high in trophic level (4.24 but it is not a voracious fish (Q/B = 10.8. Its diet is dominated by the dwarf herring (Jenkinsia lamprotaenia, eats more in the dry season, than in the rainy season and significantly more in the afternoon that in the morning suggesting preference for daylight feeding. Primera aproximación a la ecología trófica del salmón, Elagatis bipinnulata (Quoy y Gaimard, 1825 (Pisces: Carangidae, en el Caribe central colombianoEl salmón (Elagatis bipinnulata marca alto en nivel trófico (4,24 pero no es un pez voraz (Q/B = 10,8. Su dieta está dominada por la sardina enana (Jenkinsia lamprotaenia, come más en la época seca que en la época de lluvia y come significativamente más en la tarde que en la mañana, lo cual sugiere preferencia por la alimentación diurna. 

  5. Contents of cadmium, mercury and lead in fish from the Atlantic sea (Morocco) determined by atomic absorption spectrometry. (United States)

    Chahid, Adil; Hilali, Mustapha; Benlhachimi, Abdeljalil; Bouzid, Taoufiq


    As a part of a specific monitoring program, lead (Pb) cadmium (Cd) and mercury (Hg) concentrations in important species of fish from various fishing ports of the southern Kingdom of Morocco (Sardina pilchardus, Scomber scombrus, Plectorhinchus mediterraneus, Trachurus trachurus, Octopus vulgaris, Boops boops, Sarda sarda, Trisopterus capelanus, and Conger conger) were investigated by the Moroccan Reference Laboratory (NRL) for trace elements in foodstuffs of animal origin. The samples were analysed for lead and cadmium by a graphite furnace atomic absorption spectrometry (GFAAS); and for mercury by cold vapour atomic absorption spectrometry (CVAAS). The results were expressed as μg/g of wet weight (w/w). The levels of Cd, Pb and Hg in muscles of fish were 0.009-0.036, 0.013-0.114 and 0.049-0.194 μg/g, respectively. The present study showed that different metals were present in the sample at different levels but within the maximum residual levels prescribed by the EU for the fish and shellfish from these areas, in general, should cause no health problems for consumers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. ¿Criaríamos leones en granjas? Uso de pruebas y conocimiento conceptual en un problema de acuicultura

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    Beatriz Bravo Torija


    Full Text Available El objetivo es analizar la influencia de la tarea en el uso de pruebas y modelos conceptuales al resolver un problema sobre la sustentabilidad de la acuicultura. Los participantes son 134 estudiantes universitarios de biología de tres cursos. La tarea solicitaba comparar desde el punto de vista de la eficiencia ecológica alimentarse de arenques y sardinas o de salmones. Se comparan resultados de un curso en el que habían realizado un mapa conceptual sobre la eficiencia ecológica con los de dos en los que no se había hecho. Los resultados muestran diferencias sustanciales tanto en el uso de modelos de flujo de energía y pirámide trófica como de pruebas. Estas diferencias ponen de manifiesto la necesidad de prestar atención al papel de los conceptos al diseñar actividades para desarrollar la competencia de uso de pruebas.

  7. [Effects of an obesogenic diet enriched in sardine by-products on pro-atherogenic markers in Wistar rats]. (United States)

    Affane, F; Boukhari Benahmed Daidj, N; Louala, S; Munezero, A N; Lamri-Senhadji, M Y


    The effects of an obesogenic diet enriched in sardine by-products (Sardina pilchardus) on blood pressure, glycemic control and some cardiovascular risk factors, in particular pro-atherogenic were studied on an experimental model. Male rats (n=12) weighing 200±10g were subjected to an adjustment phase of 10 days in an obesogenic diet containing 30% sheep fat. After this period, the rats were divided into two homogeneous groups. The first group (HF-SBp) consumes the obesogenic diet supplemented with 30% of by-products flour (F-SBp), and the second (HF) continuous to consume the obesogenic diet and serve as control. At day 30, in HF-SBp versus HF group: a reduction was noted in diastolic (-11%) and systolic (-10%) pressure, glycemia (-19%), glycated hemoglobin percent (-43%), serum total lipids concentration (-22%), triacylglycerols (-37%), total cholesterol (-29%) and unesterified cholesterol (-30%), cholesteryl esters (-30%), cholesterol of very low density lipoprotein (-37%) and low density (-37%) was noted. Inversely, high-density lipoprotein cholesterol and LCAT activity were enhanced by 19% and 77%, respectively. However, the atherogenicity index and membrane fluidity were reduced (P<0.05). Sardine by-products probably by their bioactive compounds properties seem to have antihypertensive, antidiabetic, hypolipidemic and antiatherogenic properties that could prevent and/or attenuate some metabolic disorders associated with obesity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.


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    Arneth Tobías-Arias


    Full Text Available Objetivo. Se estudió la ecología trófica de la doncella (Ageneiosus pardalis Lütken, 1874 en la cuenca del río Sinú entre enero y diciembre 2002. Materiales y Métodos. El contenido estomacal se evaluó con el coeficiente de vacuidad, grado de llenado, grado de digestión, frecuencia de ocurrencia, frecuencia numérica, gravimetría, índice de importancia relativa (IIR y la relación longitud intestinal (LI-longitud total (LT. Resultados. El 58.3% de los estómagos se encontró vacío y el 6.4% de las presas en estado fresco. Se identificaron cuatro ítems alimenticios: peces, crustáceos, insectos y otros. Peces fue el ítem más frecuente (46.5% y abundante (44.7% con especies como cocobolo, yalúa, cachana, chipe y sardina, y con mayor composición en peso (85.7%. Conclusión. El índice de importancia relativa (IIR alcanzado por peces (40.0%, indican que la doncella es un pez carnívoro, con tendencia piscívora

  9. Ecological energetics of forage fish from the Mediterranean Sea: Seasonal dynamics and interspecific differences (United States)

    Albo-Puigserver, M.; Muñoz, A.; Navarro, J.; Coll, M.; Pethybridge, H.; Sánchez, S.; Palomera, I.


    Small and medium pelagic fishes play a central role in marine food webs by transferring energy from plankton to top predators. In this study, direct calorimetry was used to analyze the energy density of seven pelagic species collected over four seasons from the western Mediterranean Sea: anchovy Engraulis encrasicolus, sardine Sardina pilchardus, round sardinella Sardinella aurita, horse mackerels Trachurus trachurus and T. mediterraneus, and mackerels Scomber scombrus and S. colias. Inter-specific differences in energy density were linked to spawning period, energy allocation strategies for reproduction and growth, and feeding ecologies. Energy density of each species varied over time, with the exception of S. colias, likely due to its high energetic requirements related to migration throughout the year. In general, higher energy density was observed in spring for all species, regardless of their breeding strategy, probably as a consequence of the late-winter phytoplankton bloom. These results provide new insights into the temporal availability of energy in the pelagic ecosystem of the Mediterranean Sea, which are pivotal for understanding how the population dynamics of small and medium pelagic fishes and their predators may respond to environmental changes and fishing impacts. In addition, the differences found in energy density between species highlighted the importance of using species specific energy-values in ecosystem assessment tools such as bioenergetic and food web models.

  10. Environmental factors affecting larval fish community in the salt marsh area of Guadiana estuary (Algarve, Portugal

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    Renata Gonçalves


    Full Text Available Salt marsh areas in the Guadiana estuary are important nursery sites for many fish species of commercial and recreational value. More effective protection measures should be adopted as the area is highly affected by anthropogenic and natural threats. Studying larval fish communities in these impacted nursery areas will be relevant to the management of local ecosystems and to larval fish ecology in general. Spatial and seasonal distribution and the effect of environmental factors on the larval fish community of this ecosystem were studied for one year (April 2010 to March 2011. Larvae were sampled monthly in parallel with phytoplankton and zooplankton. Hydrological data and physical parameters were monitored. A decision tree model was used to assess the influence of environmental factors on the larval fish community. A total of 130 larvae and 1171 eggs were caught. Diplodus sargus, Sardina pilchardus, and Pomatoschistus microps were the most abundant larval fish species. The peaks of fish larvae abundance occurred in March and April. The output of the model demonstrates that the abundance of larval fish is determined by the abundance of eggs, zooplanktonic food, and water flood and flow. This study shows the importance of the Guadiana salt marsh as an area for fish nursery and highlights the need for conservation of this area.

  11. 210Po and 210Pb trophic transfer within the phytoplankton-zooplankton-anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea). (United States)

    Strady, Emilie; Harmelin-Vivien, Mireille; Chiffoleau, Jean François; Veron, Alain; Tronczynski, Jacek; Radakovitch, Olivier


    The transfer of (210)Po and (210)Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of (210)Po and (210)Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on (210)Po, (210)Pb activity concentrations and (210)Po/(210)Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter. This variability, also observed for C and N stable isotopes ratios, is connected to local specific pelagic habitats and hydrodynamics. The sampling strategy suggests that (210)Po bioaccumulation in the GoL remains at a constant level from the first (dominated by phytoplankton) to the second trophic level (zooplankton), while (210)Pb bioaccumulation shows an increase in winter. Based on stable N isotope ratios and (210)Po activity concentrations measured in anchovies and sardines, we evidence (210)Po bio-magnification along the trophic food web of these two planktivorous pelagic fishes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Molecular and epidemiological data on Anisakis spp. (Nematoda: Anisakidae) in commercial fish caught off northern Sardinia (western Mediterranean Sea). (United States)

    Piras, M C; Tedde, T; Garippa, G; Virgilio, S; Sanna, D; Farjallah, S; Merella, P


    Anisakiasis is a fish-borne zoonosis caused by third stage larvae of the nematode Anisakis sp. present in fish or cephalopods. This is the first contribution to the molecular identification and epidemiology of Anisakis spp. in commercial fish from the Gulf of Asinara (Sardinia, western Mediterranean Sea). Between April 2006 to November 2011, 777 specimens of 10 fish species (Engraulis encrasicolus, Merluccius merluccius, Micromesistius poutassou, Phycis blennoides, Sardina pilchardus, Sardinella aurita, Scomber colias, Sphyraena viridensis, Trachurus mediterraneus, Trachurus trachurus) were examined for Anisakis sp. larvae. A total of 1286 larvae were found in 218 fish. The great majority of larvae were located in the body cavity, and only a small part (60, 4.7%) in the muscle. All the Type I larvae (1272) were identified as Anisakis pegreffii and all the Type II (14) as Anisakis physeteris, confirming that A. pegreffii is the dominant species and the most important agent of human anisakiasis in the western Mediterranean Sea. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Ecology and genetic structure of zoonotic Anisakis spp. from adriatic commercial fish species. (United States)

    Mladineo, Ivona; Poljak, Vedran


    Consumption of raw or thermally inadequately treated fishery products represents a public health risk, with the possibility of propagation of live Anisakis larvae, the causative agent of the zoonotic disease anisakidosis, or anisakiasis. We investigated the population dynamics of Anisakis spp. in commercially important fish-anchovies (Anisakis), sardines (Sardina pilchardus), European hake (Merluccius merluccius), whiting (Merlangius merlangus), chub mackerel (Scomber japonicus), and Atlantic bluefin tuna (Thunnus thynnus)-captured in the main Adriatic Sea fishing ground. We observed a significant difference in the numbers of parasite larvae (1 to 32) in individual hosts and between species, with most fish showing high or very high Anisakis population indices. Phylogenetic analysis confirmed that commercial fish in the Adriatic Sea are parasitized by Anisakis pegreffii (95.95%) and Anisakis simplex sensu stricto (4.05%). The genetic structure of A. pegreffii in demersal, pelagic, and top predator hosts was unstructured, and the highest frequency of haplotype sharing (n = 10) was between demersal and pelagic fish.

  14. Is natural bait type a stochastic process for size and condition of fishes in the recreational fishery of Ιzmir Bay?

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    I. AYDIN


    Full Text Available Determining bait type might be one of the most important factors that influence the amount and size of the fish catch in marine recreational fishery. To this end, the relationships between two types of natural bait and catch per unit effort (CPUE, yield per unit effort (YPUE, fish size and condition (K=W/TL3 were evaluated in recreational fishery İzmir Bay (Middle Eastern Aegean Sea, Turkey. The most abundant angling species in Turkish coasts; annular sea bream (Diplodus annularis, blotched picarel (Spicara flexuosa, two banded sea bream (Diplodus vulgaris and bogue (Boops boops were collected by anglers between September 2006 – February 2007 with using baits; onyx (Solen vagina, and sardine (Sardina pilchardus. The average CPUE and YPUE of hooks baited with onyx were significantly higher than the bait sardine. Eventhough the averages of specimens caught with bait sardine were bigger than onyx except for bogue but, total length-frequency distributions were revealed some differences only for annular sea bream and blotched picarel between two baits. High conditioned individuals of bogue were caught with bait sardine and the rest of the other species with onyx.

  15. Fish community structure in San Agustín Bay, Huatulco, Mexico Estructura comunitaria de peces en bahía San Agustín, Huatulco, México

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    Full Text Available San Agustín bay is one of the most important bays in the Huatulco National Park because it includes the broadest coral reef surface of this park, which supports a great diversity of fish species. The importance of the present work is that describes quantitatively, for first time, the fish assemblage of this reef area. Visual censuses were realized on transects, according to the coral reef size, on coral and rocky reefs, and coral rubble environments. 64 species, 46 genus and 29 families were registered. Seasonal variation in fish assemblage was observed; reflecting the influence of pelagic shoaling species associated with the Gulf of Tehuantepec upwelling, during the dry season. Thus species were Selar crumenophthalmus, Caranx caninus, and Sardinops caeruleus. For species more closely associated to the reef habitat little seasonal variation was observed for each species, except Chromis atrilobata, which exhibited high density during the dry season. Pomacentrids exhibited more affinity for coral reef, labrids and haemulids for coral rubble environments. The highest diversity values were on coral rubble and the highest density was on the coral reef. Our study suggests that in this region, the Gulf of Tehuantepec upwelling is an important factor as well as the heterogeneity of habitats in shaping the fish assemblages, which must be protected to maintain the biodiversity of this important ecosystemLa bahía de San Agustín es una de las más importantes del Parque Nacional Huatulco debido a que incluye al arrecife coralino más grande de este parque, el cual alberga una gran diversidad de especies de peces. La importancia del presente trabajo es describir cuantitativamente, por primera vez, la comunidad de peces de este habitat de arrecifes. Para ello se realizaron censos visuales en transectos de acuerdo al tamaño de los ambientes coralino, rocoso y de escombros. 64 especies, 46 géneros y 29 familias fueron registrados. Se observaron cambios

  16. Using non-systematic surveys to investigate effects of regional climate variability on Australasian gannets in the Hauraki Gulf, New Zealand (United States)

    Srinivasan, Mridula; Dassis, Mariela; Benn, Emily; Stockin, Karen A.; Martinez, Emmanuelle; Machovsky-Capuska, Gabriel E.


    Few studies have investigated regional and natural climate variability on seabird populations using ocean reanalysis datasets (e.g. Simple Ocean Data Assimilation (SODA)) that integrate atmospheric information to supplement ocean observations and provide improved estimates of ocean conditions. Herein we use a non-systematic dataset on Australasian gannets (Morus serrator) from 2001 to 2009 to identify potential connections between Gannet Sightings Per Unit Effort (GSPUE) and climate and oceanographic variability in a region of known importance for breeding seabirds, the Hauraki Gulf (HG), New Zealand. While no statistically significant relationships between GSPUE and global climate indices were determined, there was a significant correlation between GSPUE and regional SST anomaly for HG. Also, there appears to be a strong link between global climate indices and regional climate in the HG. Further, based on cross-correlation function coefficients and lagged multiple regression models, we identified potential leading and lagging climate variables, and climate variables but with limited predictive capacity in forecasting future GSPUE. Despite significant inter-annual variability and marginally cooler SSTs since 2001, gannet sightings appear to be increasing. We hypothesize that at present underlying physical changes in the marine ecosystem may be insufficient to affect supply of preferred gannet main prey (pilchard Sardinops spp.), which tolerate a wide thermal range. Our study showcases the potential scientific value of lengthy non-systematic data streams and when designed properly (i.e., contain abundance, flock size, and spatial data), can yield useful information in climate impact studies on seabirds and other marine fauna. Such information can be invaluable for enhancing conservation measures for protected species in fiscally constrained research environments.

  17. Gap analysis on the biology of Mediterranean marine fishes.

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    Donna Dimarchopoulou

    Full Text Available We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310 of the Mediterranean fish species, whereas for an additional 15% (n = 109 of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%, diet (29%, growth (25%, maturity (24%, lifespan (19% and fecundity (17%. The gap is larger in natural mortality for which information is very scarce (8%. European hake (Merluccius merluccius, red mullet (Mullus barbatus, annular seabream (Diplodus annularis, common pandora (Pagellus erythrinus, European anchovy (Engraulis encrasicolus, European pilchard (Sardina pilchardus and bogue (Boops boops were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays and mortality/fecundity instead of

  18. Discards of the purse seine fishery targeting small pelagic fish in the eastern Mediterranean Sea

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    Konstantinos Tsagarakis


    Full Text Available We analysed data collected on board commercial purse seine vessels in the Aegean and Ionian Seas (eastern Mediterranean Sea, Greece in 13 seasonal sampling periods from 2003 to 2008 in order to describe the composition of the retained and discarded catch and shed light on discarding practices. In each area, five species constituted the majority of the marketable catch (> 97%: sardine (Sardina pilchardus, anchovy (Engraulis encrasicolus, round sardinella (Sardinella aurita, bogue (Boops boops (in both areas, mackerel (Scomber japonicus; in the Aegean Sea and picarel (Spicara smaris; in the Ionian Sea. Discarded quantities were on average 4.6% and 2.2% of the total catch in terms of weight in the Aegean and Ionian Seas respectively. Discards on the marketable ratio fluctuated over years and seasons without showing any particular trend. At the species level, sardine and mackerel were seldom discarded while large amounts of anchovy were discarded only during its recruitment period (autumn, when juvenile fish dominate the population. The discarding ratio for bogue, picarel and round sardinella ranged from zero to total discarding because they constitute a supplementary source of income for the fishers. Discarded fish comprised mainly small individuals for all species considered with the exception of round sardinella. However, the lengths at which 50% of the individuals were discarded were generally small, often smaller than the species minimum landing sizes. Geographical coordinates and marketable catch explained part of the variability of the discarded quantities, as revealed by generalized additive models. Discarding practices and implications for management of purse seine fisheries are also discussed.

  19. Helmintofauna de Opisthonema libertate y Harengula thrissina (Osteichthyes: Clupeidae de la bahía de Chamela, Jalisco, México

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    Gerardo Pérez-Ponce de León


    Full Text Available El registro helmintológico de las "sardinas" Harengula thrissina (N=61 y Opisthonema libertate (N=43en la Bahía de Chamela, Jalisco, México, establecido en este trabajo, está integrado por 12 y seis especies, respectivamente. De éstas, la que alcanzó los valores más elevados de prevalencia y abundancia en O. libertate fue el nemátodo Pseudoterranova sp. (11.6% y 0.13 gusanos por pez revisado, mientras que para H. thrissina lo fue tremátodo Parahemiurus merus con 49.1% y 1.40 helmintos por hospedero muestreado. La reducida similitud cualitativa y cuantitativa registrada entre las helmintofaunas de ambos hospederos, se atribuye a la naturaleza oportunista de su alimentación (100% de las especies parásitas de H. thrissina y 66% de las de O. libertate las infectan a través de esta vía, así como a la exposición diferencial de ambas especies de hospederos a los helmintos.We collected helminths from the "sardines" Harengula thrissina (N=61 and Opisthonema libertate (n=43, from Chamela Bay, Jalisco State, Mexico (12 and six species, respectively. The nematode Pseudoterranova sp., reached the highest values of prevalence and mean abundance in O. libertate (11.6% and 0.13 worms per host, respectively, while in H. thrissina the digenean Parahemiurus merus reached a prevalence of 49.1% and a mean abundance of 1.40 worms per host. Low similarity values (qualitative and quantitative between helminths of both host species is a result of their opportunistic feeding habits (100% of the parasitic species in H. thrissina and 66% of those from O. libertate infect their host from prey and differential exposure to helminth larvae.

  20. Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction. (United States)

    Brosset, Pablo; Lloret, Josep; Muñoz, Marta; Fauvel, Christian; Van Beveren, Elisabeth; Marques, Virginie; Fromentin, Jean-Marc; Ménard, Frédéric; Saraux, Claire


    Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy ( Engraulis encrasicolus ) and sardine ( Sardina pilchardus ) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.

  1. Spatial and temporal variation in fish community of the Ria de Aveiro estuarine lagoon (Portugal.

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    Eva García-Seoane


    Full Text Available Fish assemblages of Ria de Aveiro coastal lagoon (Northwest Portugal were studied from February 2012 and January 2013. Sampling were monthly conducted with a traditional beach-seine net (“chincha” at 9 sites. Multivariate approach were used in order to analyse the spatial and temporal variation in fish community. A total of 58,201 fishes, weighting 249,540 g, were identified, representing 37 taxa and 21 families. Four taxa (Atherina spp., Dicentrarchus labrax, Liza spp., and Sardina pilchardus were responsible for 94.7% and 85.4% of the total abundance, in number and weight. There were significant differences in fish community, in terms of fish number and weight, between sites and between months (ANOSIM, p<0.01. A total of 12 species appeared as characteristics of one of more sampling sites either in terms of number and weight. In both cases, D. labrax, Liza spp. and Atherina spp. were typical throughout the study area. Other species, such as Spondyliosoma cantharus appeared as typical only in the part of the lagoon more influenced by marine waters, whereas Anguilla anguilla was typical of the inner area. A total of 11 (in number or 13 (in weight species appeared as typical of at least one month of the year. Liza spp. and Atherina spp. were typical all the year round for number and weight data. In both cases, D. labrax, Diplodus spp. and S. pilchardus, appeared as a typical from spring to autumn. The number of typical species varied with the season, being maximum in May and minimum in winter. Finally, results of this work were discussed in comparison to previous studies.

  2. Energy density of zooplankton and fish larvae in the southern Catalan Sea (NW Mediterranean) (United States)

    Barroeta, Ziortza; Olivar, M. Pilar; Palomera, Isabel


    In marine communities, energy of small planktonic organisms is transferred to their predators through feeding. The energy accumulated as organic substances by the different plankton organisms (Energetic Density content, ED) has been analysed in high latitudes and tropical areas, but not in the Mediterranean Sea. In this study, we approach this type of investigation for Mediterranean plankton through measures of total calorimetric content using an oxygen bomb calorimeter. We examined the spatiotemporal variation in the ED of microplankton (50-200 μm) and mesozooplankton (200-2000 μm), and two plankton-consumers, sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) larvae. The study was carried out during the winter and summer of 2013 off the Ebro River Delta (NW Mediterranean Sea). Both plankton fractions showed a more coastal distribution and higher biomasses during winter, the period of sardine larvae occurrences, in front of a wider cross-shelf distribution and lower biomasses in summer, when anchovy appeared. ED values increased with the size of each plankton component, i.e., microzooplankton associated to the more productive waters there. Sardine and anchovy larvae showed an increasing trend in the amount of energy during development, with significantly lower ED between early larvae (6-10 mm standard length) and late postflexion stages (16-20 mm standard length). Small larvae of both species departed from a similarly low ED content, but in the next two size classes sardine larvae showed higher ED values than anchovy, being significantly higher in the 16-20 mm size class. Information on larval feeding patterns and larval growth rates for each species were used to discuss differences in energy allocation strategies.

  3. Survey of viral haemorrhagic septicaemia virus in wild fishes in the southeastern Black Sea. (United States)

    Ogut, H; Altuntas, C


    Species diversity in the Black Sea ecosystem has been declining rapidly over the last 2 decades. To assess the occurrence and distribution of viral haemorrhagic septicaemia virus (VHSV) in various wild fish species, a wild marine fish survey was carried out in 2009, 2010, and 2011. The pooled or individual samples of kidney, liver, and spleen of 5025 specimens, belonging to 17 fish species, were examined virologically using cell culture. The cells showing cytopathic effects (CPE) were subjected to ELISA and multiplex reverse transcriptase polymerase chain reaction (RT-mPCR), for VHSV and infectious pancreatic necrosis virus (IPNV), after blind passaging to determine the virus species causing CPE. The virus species and possibility of co-infection with IPNV were verified by the RT-mPCR developed in this study. Twelve species of fish (pontic shad Alosa immaculata, red mullet Mullus barbatus, three-bearded rockling Gaidropsarus vulgaris, black scorpionfish Scorpaena porcus, Mediterranean horse mackerel Trachurus mediterraneus, whiting Merlangius merlangus euxinus, stargazer Uranoscopus scaber, pilchard Sardina pilchardus, garfish Belone belone, round goby Neogobius melanostomus, thornback ray Raja clavata, and anchovy Engraulis encrasicolus) tested positive for VHSV Genotype Ie (VHSV-Ie). Except whiting, pilchard, and round goby, the rest are new host records for VHSV. The extent and spread of VHSV-Ie was significantly higher among bottom fish than among pelagic fish. Sensitivity and specificity of the RT-mPCR developed was sufficiently high, suggesting that this assay may be used for both diagnostic and surveillance testing. According to the RT-mPCR results, IPNV was not present in wild fish. These results support the hypothesis that the VHSV-Ie genotype, highly prevalent among fish species in the Black Sea, may have a serious impact on the population dynamics of wild fish stocks.

  4. Habitat selection response of small pelagic fish in different environments. Two examples from the oligotrophic Mediterranean Sea.

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    Angelo Bonanno

    Full Text Available A number of scientific papers in the last few years singled out the influence of environmental conditions on the spatial distribution of fish species, highlighting the need for the fisheries scientific community to investigate, besides biomass estimates, also the habitat selection of commercially important fish species. The Mediterranean Sea, although generally oligotrophic, is characterized by high habitat variability and represents an ideal study area to investigate the adaptive behavior of small pelagics under different environmental conditions. In this study the habitat selection of European anchovy Engraulis encrasicolus and European sardine Sardina pilchardus is analyzed in two areas of the Mediterranean Sea that largely differentiate in terms of environmental regimes: the Strait of Sicily and the North Aegean Sea. A number of environmental parameters were used to investigate factors influencing anchovy and sardine habitat selection. Acoustic surveys data, collected during the summer period 2002-2010, were used for this purpose. The quotient analysis was used to identify the association between high density values and environmental variables; it was applied to the entire dataset in each area in order to identify similarities or differences in the "mean" spatial behavioral pattern for each species. Principal component analysis was applied to selected environmental variables in order to identify those environmental regimes which drive each of the two ecosystems. The analysis revealed the effect of food availability along with bottom depth selection on the spatial distribution of both species. Furthermore PCA results highlighted that observed selectivity for shallower waters is mainly associated to specific environmental processes that locally increase productivity. The common trends in habitat selection of the two species, as observed in the two regions although they present marked differences in hydrodynamics, seem to be driven by the

  5. Gap analysis on the biology of Mediterranean marine fishes. (United States)

    Dimarchopoulou, Donna; Stergiou, Konstantinos I; Tsikliras, Athanassios C


    We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length

  6. Organochlorine compounds (PCBs, PCDDs and PCDFs) in seafish and seafood from the Spanish Atlantic Southwest Coast. (United States)

    Bordajandi, L R; Martín, I; Abad, E; Rivera, J; González, M J


    Concentrations and congener specific profiles of PCDD/Fs and PCBs were determined in edible fish and seafood species from the Coast of Huelva, in the Spanish southwest Atlantic coast. Five fish species, namely wegde sole (Dicologoglossa cuneata), common sole (Solea vulgaris), white seabream (Diplodus sargus), sardine (Sardina pilchardus), angler fish (Lophius piscatorius), two shellfish species (Donax trunculus and Chamelea gallina), common cuttlefish (Sepia officinalis) and prawns (Parapenaeus longirostris), frequently found and consumed in the area were analysed. Concentrations ranged from 861 to 23787pg/g wet weight for total PCBs, while 2,3,7,8-PCDD/Fs showed concentrations ranging from 0.2 to 1.18pg/g wet weight. WHO-TEQ concentrations ranged from 0.038 to 0.186pg WHO-TEQ(PCDD/Fs)/g wet weight, values well below the maximum concentrations established by the EU. When non- and mono-ortho PCBs were included the values increased to a maximum of 0.99pg WHO-TEQ(PCDD/Fs+PCBs)/g wet weight. The PCB and PCDD/F accumulation pattern found in the samples analysed showed a distribution typically reported for marine samples, and no remarkable differences were found between species. The PCBs were the ones contributing with the highest percentage to the total TEQ content in most species studied. Concerning the seafood, specially prawns and shellfish, the opposite was observed and PCDD/Fs were found to contribute with a higher percentage than PCBs. The congener specific contribution to the TEQ showed PCB 126 followed by 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF as the most abundant ones.

  7. Ecología trófica del Liso (Rhamdia quelen Quoy & Gaimard, 1824 en el río Sinú, Colombia

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    Charles W. Olaya-Nieto


    Full Text Available Objetivo. Estudiar la ecología trófica del Liso en el río Sinú como contribución al conocimiento de su biología y ecología, a su preservación en el medio natural y al ordenamiento de su pesquería en la cuenca. Materiales y métodos. El contenido estomacal se evaluó con el Coeficiente de vacuidad, Grado de digestión, Frecuencia de ocurrencia, Frecuencia numérica, Gravimetría, Índice de importancia relativa (IIR y la relación longitud intestinal (LI-longitud total (LT. Resultados. El 38.2% de los estómagos estaban vacíos y el 92.5% de las presas estaban medio digeridas, identificándose 5 grupos alimentarios: Peces, Crustáceos, Insectos, Material vegetal y Otros. Peces, conformado por Cachana, Cocobolo, Mayupa, Sardina y Restos de peces, fue la presa más frecuente (69.9%, abundante (45.5% y con mayor composición por peso (76.8%. El Índice de importancia relativa (IIR indica que Peces fue el alimento principal (IIR =53.7%, y que las demás presas eran de baja importancia relativa, circunstanciales o incidentales. Conclusiones. Los resultados alcanzados en este estudio indican que el Liso es un pez con hábitos alimentarios nocturnos y carnívoros, con tendencia a consumir Peces.

  8. Feeding strategies and ecological roles of three predatory pelagic fish in the western Mediterranean Sea (United States)

    Navarro, Joan; Sáez-Liante, Raquel; Albo-Puigserver, Marta; Coll, Marta; Palomera, Isabel


    Knowing the feeding ecology of marine predators is pivotal to developing an understanding of their ecological role in the ecosystem and determining the trophic relationships between them. Despite the ecological importance of predatory pelagic fish species, research on these species in the Mediterranean Sea is limited. Here, by combining analyses of stomach contents and stable isotope values, we examined the feeding strategies of swordfish, Xiphias gladius, little tunny, Euthynnus alletteratus and Atlantic bonito, Sarda sarda, in the western Mediterranean Sea. We also compared the trophic niche and trophic level of these species with published information of other sympatric pelagic predators present in the ecosystem. Results indicated that, although the diet of the three species was composed mainly by fin-fish species, a clear segregation in their main feeding strategies was found. Swordfish showed a generalist diet including demersal species such as blue whiting, Micromesistius poutassou, and European hake, Merluccius merluccius, and pelagic fin-fish such as barracudina species (Arctozenus risso and Lestidiops jayakari) or small pelagic fish species. Little tunny and Atlantic bonito were segregated isotopically between them and showed a diet basically composed of anchovy, Engraulis encrasicolus, and round sardinella, Sardinella aurita, and sardines, Sardina pilchardus, respectively. This trophic segregation, in addition to potential segregation by depth, is likely a mechanism that allows their potential coexistence within the same pelagic habitat. When the trophic position of these three predatory pelagic fish species is compared with other pelagic predators such as bluefin tuna, Thunnus thynnus, and dolphinfish, Coryphaena hippurus, present in the western Mediterranean Sea, we found that they show similar intermediate trophic position in the ecosystem. In conclusion, the combined stomach and isotopic results highlight, especially for little tunny and Atlantic

  9. Desodorización de aceite de pescado mediante destilación a alto vacío: preservación de las características químicas del aceite

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    Nieto, S.


    Full Text Available The construction and the operation conditions of a high vacuum glass-equipment for deodorizing sardine oil at laboratory scale is described. The equipment working at 120°C and at a pressure of 0.05-0.1 mmHg maintains unchanged the n-3 fatty acid composition of the oil producing a considerable reduction in the cholesterol and peroxide content of the oil. The stripper, having a throughput of 1500-1800 mL/hr, allows the obtaining of a high quality fish oil suitable for experimental and for pharmacological and/or nutritional applications.

    Se describe la construcción y condiciones de operación de un destilador de vidrio de alto vacío que permite, a escala de laboratorio, la desodorización del aceite de sardina española. El equipo operando a temperaturas no superiores a 120°C y a una presión constante de 0,05-0,1 mmHg no altera la composición de ácidos grasos n-3 del aceite y permite una disminución considerable del colesterol y de los peróxidos orgánicos. La destilación permite obtener un aceite de alta calidad con un rendimiento de 1500-1800 mL/hr que puede ser utilizado para fines experimentales o para uso farmacológico y/o nutricional.

  10. The use of pelagic fish as proxies of environmental contamination: a case study with sardine populations

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    Bruno Silva Nunes


    Full Text Available The use of bioindicators to analyze marine ecosystems contamination is often made difficult due to the absence of appropriate species. Pelagic fish species, captured by commercial fishing fleets around the world, can be successfully used to assess contaminant levels, by determining their body burden in specific compounds. However the study of biological responses elicited by such compounds, through the analysis of biomarkers, is highly dependent on the physiological and reproductive status of the organisms. Such confounding factors elicit seasonal fluctuations that difficult the extrapolation of data. Sardine (Sardina pilchardus is a marine species common in the North Atlantic Ocean, being easily available through commercial fisheries. The present work intended to explore the potential of this species in biomonitoring studies, by simultaneously using enzymatic biomarkers and condition indices determined in fish landed in three commercial harbors along the west coast of Portugal. This strategy allowed devising spatial and temporal patterns in the sardine metapopulation. Results evidenced significant variability in both biochemical and physiological profiles of the fish, which were coherent among all sampling sites. Throughout the year, large seasonal differences for most markers were reported, which were strongly linked to the reproductive cycle and its physiological consequences (acquisition of energy, mobilization of energy reserves, etc.. It was possible to conclude that seasonality acts as a strong factor underlying chronological physiological adaptations, influencing biochemical markers that are usually employed as indicators of contamination. These effects can limit the usefulness of such a biomarker approach unless seasonality is not accounted for, and if no background values are known from previous studies. In this sense, studies such as this are pivotal to establish a baseline for biomonitoring studies. Also, despite the difficulty in

  11. Quantifying the predation on sardine and hake by cetaceans in the Atlantic waters of the Iberian peninsula (United States)

    Begoña Santos, M.; Saavedra, Camilo; Pierce, Graham J.


    Construction of ecosystem models requires detailed information on trophic interactions which may not be readily available, especially for top predators such as cetaceans. Such information can also be useful to estimate natural mortality (M) for fish stock assessments and to evaluate the potential for competition between cetaceans and fisheries. In the present paper we provide estimates and confidence limits, taking into account sampling error, for consumption of fish by the four most common cetaceans along the Atlantic coast of the Iberian Peninsula, while highlighting the uncertainties and biases inherent in the information presently available on energy requirements, diet and population size. We estimated that common dolphins (Delphinus delphis) consume around 6800 (95% CI, 4871-9476) tons of sardine (Sardina pilchardus), 8800 (6195-12,647) tons of gadids, 1100 (721-1662) tons of hake (Merluccius merluccius) and 1900 (1222-2752) tons of scads (Trachurus sp.) annually. For striped dolphins (Stenella coeruleoalba), prey consumed were 900 (196-2661) tons of sardine, 6200 (3448-11,129) tons of gadids, 200 (11-504) tons of hake and 1600 (0-5318) tons of scads. Estimated amounts taken by harbour porpoises (Phocoena phocoena) and bottlenose dolphins (Tursiops truncatus) are much lower, reflecting their low abundance in the area. Cetacean predation on sardine represents 2-8% of the current M value, indicating that cetaceans probably have little influence on sardine population dynamics. For the southern hake stock, estimated average removal by cetaceans often exceeds M. While this may indicate that both M and the consumption estimates for hake require revision it also suggests that cetaceans could have a more significant impact on hake populations. Different approaches to estimation of energy requirements of cetaceans can result in figures that differ by at least a factor of 2. The lack of good estimates of field metabolic rate for most species probably represents the most

  12. Detection of a diverse marine fish fauna using environmental DNA from seawater samples. (United States)

    Thomsen, Philip Francis; Kielgast, Jos; Iversen, Lars Lønsmann; Møller, Peter Rask; Rasmussen, Morten; Willerslev, Eske


    Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation. This is greatly impacting global biodiversity, economy and human health. Intriguingly, marine fish are largely surveyed using selective and invasive methods, which are mostly limited to commercial species, and restricted to particular areas with favourable conditions. Furthermore, misidentification of species represents a major problem. Here, we investigate the potential of using metabarcoding of environmental DNA (eDNA) obtained directly from seawater samples to account for marine fish biodiversity. This eDNA approach has recently been used successfully in freshwater environments, but never in marine settings. We isolate eDNA from ½-litre seawater samples collected in a temperate marine ecosystem in Denmark. Using next-generation DNA sequencing of PCR amplicons, we obtain eDNA from 15 different fish species, including both important consumption species, as well as species rarely or never recorded by conventional monitoring. We also detect eDNA from a rare vagrant species in the area; European pilchard (Sardina pilchardus). Additionally, we detect four bird species. Records in national databases confirmed the occurrence of all detected species. To investigate the efficiency of the eDNA approach, we compared its performance with 9 methods conventionally used in marine fish surveys. Promisingly, eDNA covered the fish diversity better than or equal to any of the applied conventional methods. Our study demonstrates that even small samples of seawater contain eDNA from a wide range of local fish species. Finally, in order to examine the potential dispersal of eDNA in oceans, we performed an experiment addressing eDNA degradation in seawater, which shows that even small (100-bp) eDNA fragments degrades beyond detectability within days. Although further studies are needed to validate the eDNA approach in varying environmental conditions, our

  13. Spatial distribution and species composition of small pelagic fishes in the Gulf of California

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    Edgar Lanz


    regiones, incluyen áreas arbitrarias y homogéneas sobre las cuales se realiza estadística básica o inferencias relacionadas con la distribución y la abundancia de estos recursos. El presente trabajo describe una metodología para la regionalización y el análisis de la actividad pesquera de pelágicos menores en el Golfo de California basado en los patrones espaciales de la información de lances y capturas utilizando herramientas de Sistemas de Información Geográfica (SIG. La información pesquera, con atributos espaciales, provino de bitácoras de pesca para el periodo comprendido de octubre 2002 a junio 2007. Los datos de lances y capturas fueron transformados a un Índice de Región Ponderada (WRI utilizando operadores de lógica difusa. El WRI reveló centros de actividad pesquera caracterizados por áreas con los valores más altos de WRI y se obtuvo un orden jerárquico para denotar la importancia relativa de cada región, siendo las regiones de Guaymas, el Desemboque de Caborca, Isla Patos y Bahía San Rafael, los más prominentes. El análisis de la frecuencia relativa de la composición de especies mostró que la sardina Monterrey tuvo una abundancia relativa mayor al 80% en la región de las Grandes Islas y permaneció como la especie más importante en las regiones del alto golfo, mientras que en la parte central del golfo las abundancias de la sardina Monterrey y la ancho-veta norteña estuvieron más equilibradas. La abundancia relativa de la macarela fue significativamente mayor en la región de la Isla Patos, respecto a cualquier otra región. La región de Guaymas mostró la mayor composición relativa de anchoveta norteña, en contraste con los más bajos valores de sardina Monterrey. El Desemboque de Caborca mostró la mayor homogeneidad en la composición relativa de especies. Estos resultados provienen de datos in situ, mientras que los resultados previamente reportados provienen de estadísticas de lances por puerto. En consecuencia, el

  14. Elucidating dynamic responses of North Pacific fish populations to climatic forcing: Influence of life-history strategy (United States)

    Yatsu, A.; Aydin, K. Y.; King, J. R.; McFarlane, G. A.; Chiba, S.; Tadokoro, K.; Kaeriyama, M.; Watanabe, Y.


    In order to explore mechanistic linkages between low-frequency ocean/climate variability, and fish population responses, we undertook comparative studies of time-series of recruitment-related productivity and the biomass levels of fish stocks representing five life-history strategies in the northern North Pacific between the 1950s and the present. We selected seven species: Japanese sardine ( Sardinopus melanostictus) and California sardine ( Sardinopus sagax) (opportunistic strategists), walleye pollock ( Theragra chalcogramma, intermediate strategist), pink salmon ( Oncorhynchus gorbuscha, salmonic strategist), sablefish ( Anoplopoma fimbria) and Pacific halibut ( Hippoglossus stenolepis) (periodic strategists) and spiny dogfish ( Squalus acanthias, equilibrium strategist). The responses in terms of productivity of sardine, pink salmon, sablefish and halibut to climatic regime shifts were generally immediate, delayed, or no substantial responses depending on the particular regime shift year and fish stock (population). In walleye pollock, there were some periods of high productivity and low productivity, but not coincidental to climatic regime shifts, likely due to indirect climate forcing impacts on both bottom-up and top-down processes. Biomass of zooplankton and all fish stocks examined, except for spiny dogfish whose data were limited, indicated a decadal pattern with the most gradual changes in periodic strategists and most intensive and rapid changes in opportunistic strategists. Responses of sardine productivity to regime shifts were the most intense, probably due to the absence of density-dependent effects and the availability of refuges from predators when sardine biomass was extremely low. Spiny dogfish were least affected by environmental variability. Conversely, spiny dogfish are likely to withstand only modest harvest rates due to their very low intrinsic rate of increase. Thus, each life-history strategy type had a unique response to climatic

  15. Linkages between coastal and open-ocean habitats and dynamics of Japanese stocks of chum salmon and Japanese sardine (United States)

    Yatsu, Akihiko; Kaeriyama, Masahide


    Coastal-ocean-open-ocean migrations, prey-predator relations and long-term population dynamics of chum salmon ( Oncorhynchus keta) and Japanese sardine ( Sardinops melanostictus), associated with large-scale climate and oceanographic conditions, are reviewed. After early marine life in coastal waters in northern Japan, chum salmon of Japanese origin spend their first summer in the Okhotsk Sea, then move to the Western Subarctic Gyre for the first winter at sea. Thereafter, they migrate between summer feeding grounds in the Bering Sea and wintering grounds in the Alaskan Gyre for a period of usually up to four years, and finally return to their natal rivers to spawn. Carrying capacity ( K) for chum salmon at an unfished equilibrium level was estimated from a Ricker spawner-recruitment curve, and the residual carrying capacity ( RCC=(K-abundance)K-1). was positively correlated with body size at age 4, and negatively correlated with age at maturity. Marine survival of Hokkaido chum populations was affected by body size at release, but neither by Aleutian low pressure activity nor sea-surface temperature (SST) around coastal Hokkaido in spring, although there is some correlation between survival rate and coastal SST. Juveniles of the Pacific stock of Japanese sardine become broadly distributed in the Kuroshio Extension (KE) as far east as 180° longitude during spring. Adults disperse as far as the central Pacific and the southern areas of the Okhotsk Sea and Western Subarctic Gyre in years of high abundance. Somatic growth and age at maturation of sardine are density-dependent. We used catch, biomass and residuals of observed recruitment numbers from a Ricker curve (LNRR) as a measure of sardine population dynamics. LNRR was highly correlated with SST of KE in winter, which shifted in 1970 and 1988. Recent biomass and catch remain at extremely low levels due to a combination of adverse environmental conditions and intensive fishing. We suggest that Japanese

  16. Are coastal resources of NW Portugal fingerprinting hydrocarbons released from the Prestige accident?; Estan los recursos costeros del NO de Portugal mostrando las huellas especificas de los hidrocarburos derramados por el Prestige?

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    Ferreira, Ana Maria; Micaelo, Cristina; Vale, Carlos [Instituto de Investigacion Agraria y de Pesca IPIMAR, Lisboa (Portugal)


    Seventy-one samples of mussels, sardine, hake, blue whiting and pouting from the NW Portuguese coast, collected between 18 November 2002 and 6 January 2003, were analyzed for total hydrocarbons, individual n-alkanes and major isoprenoids, pristane and phytane. Hydrocarbons (expressed on chrysene equivalents) registered in whole soft tissues of mussels were below 0.5 milligrams g{sup -}1, with a few exceptions (maximum 1.6 milligrams g{sup -}1). Relatively low levels and sporadic enhanced values were also found in fish fillet samples. In spite of this, analyses of individual n-alkanes and major isoprenoids showed that 10-61 % of the samples (according to the species) exhibited these compounds in the proportions of the Prestige fuel signature. Similar diagnostic ratios in biological samples and Prestige fuel and n-alkane composition corroborate the fingerprint hypothesis in coastal resources from NW Portugal. [Spanish] Se analizaron los hidrocarburos totales, n-alcanos individuales e isoprenoides mayores, pristano y fitano, en 71 muestras de mejillones, sardina, merluza, bacaladilla y faneca de la costa NO de Portugal, recolectadas entre el 18 de noviembre de 2002 y el 6 de enero de 2003. Las concentraciones de hidrocarburos (expresadas en equivalentes de criseno) registradas en los tejidos blandos de los mejillones fueron menores a 0.5 miligramos g{sup -}1, salvo algunas excepciones (maximo 1.6 miligramos g{sup -}1). En las muestras de filetes de pescado tambien se encontraron niveles bajos e incrementos esporadicos de hidrocarburos. A pesar de ello, los analisis de n-alcanos individuales e isoprenoides mayores mostraron que entre el 10 y 61 % de las muestras (dependiendo de la especie) tuvieron estos compuestos en las mismas proporciones que la huella especifica del fuel del Prestige. Las razones diagnosticas similares en muestras biologicas y en el fuel del Prestige y la composicion de n-alcanos corroboran la hipotesis de la huella especifica dejada por este

  17. Trol ve uzatma ağları ile İzmir körfezinden yakalanan dil (Solea solea balığının yaşama yüzdesi; kültür şartlarına adaptasyonu ve beslenme davranışı.

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    Doç.Dr. Fatih Başaran


    Full Text Available Trol ve uzatma ağları ile İzmir körfezinden yakalanan dil (Solea solea balığının yaşama yüzdesi; kültür şartlarına adaptasyonu ve beslenme davranışı. Bu araştırmada, doğal ortamdan yakalanan dil balığının (Solea solea, kültür şartlarına adaptasyonu ve beslenme davranışı incelenmiştir. Dil balıkları, 2007 Mart-Nisan döneminde, İzmir Körfezi’nden trol ve uzatma ağlarıyla yakalanmıştır. 270 adet dil balığının ön adaptasyonu sırasında, ilk beş gün boyunca, karanlık ortamda antibiyotik (100 ppm fruzolidon ilavesi, 60 dak/gün uygulaması gerçekleştirilmiştir. Kültür şartlarında ilk besleme için, kalamar (Loligo vulgaris, boru kurdu (Diopatra neopolitana, kara midye (Mytilus galloprovincialis, sülünes (Solen marginatus, istiridye (Ostrea edulis, japon şapkası (Patella spp., deniz salyangozu (Monodonta turbinata ve taze sardalya (Sardina pilchardus kullanılmıştır. Dil balıkları 0-2 gün içinde beslenmeye başlamıştır ve boru kurdu, en çok tercih ettikleri tür olmuştur. Bir aylık adaptasyon dönemi sonunda, uzatma ağlarıyla yakalanan dil balıklarının yaşama oranının (%58, trol ile yakalananların yaşama oranından (%29 önemli düzeyde yüksek bulunmuştur (p

  18. Toxic metals in tissues of fishes from the Black Sea and associated human health risk exposure. (United States)

    Plavan, Gabriel; Jitar, Oana; Teodosiu, Carmen; Nicoara, Mircea; Micu, Dragos; Strungaru, Stefan-Adrian


    The anthropogenic activities in the Black Sea area are responsible for toxic metal contamination of sea food products. In this study, several toxic metals: cadmium, lead, nickel, chromium, and copper were quantified in different tissues (digestive tract, muscle, skeleton, skin) of nine fish species (Neogobius melanostomus, Belone belone, Solea solea, Trachurus mediterraneus ponticus, Sardina pilchardus, Engraulis encrasicolus, Pomatomus saltatrix, Sprattus sprattus, Scorpaena porcus) by using atomic absorption spectrometer with a high-resolution continuum source and graphite furnace technique (HR-CS GF-AAS), and the risk of fish meat consumption by the young human population was evaluated. These metals are used in high amounts in industries located near the coastline such as shipyard construction and industrial plants. Toxic metal accumulation depends on fish feeding behavior, abiotic conditions, metal chemistry, and animal physiology. For instance, cadmium was measured in the muscle of the investigated species and average values of 0.0008-0.0338 mg kg-1 were obtained. The lowest average value of this metal was measured at benthic species N. melanostomus and the highest at the pelagic predator T. mediterraneus ponticus. Generally, the highest metal concentration was measured in the digestive tract that has the role of biofilter for these contaminants. The risk of contamination is significantly reduced by avoiding the consumption of certain fish tissues (digestive tract and skin for copper and skeleton for nickel). An estimation of the dietary metal intake to young consumers was realized for each of the studied species of fish from Romanian, Bulgarian, and Turkish waters, during the period 2001-2014 in order to evaluate the risks of chronic exposure in time due to metal toxicity. This estimation is important for the prevention of chronic exposure due to metal toxicity. Food exposure to studied metals showed a negative trend for Romania, Turkey, and Bulgaria based

  19. Detection of a diverse marine fish fauna using environmental DNA from seawater samples.

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    Philip Francis Thomsen

    Full Text Available Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation. This is greatly impacting global biodiversity, economy and human health. Intriguingly, marine fish are largely surveyed using selective and invasive methods, which are mostly limited to commercial species, and restricted to particular areas with favourable conditions. Furthermore, misidentification of species represents a major problem. Here, we investigate the potential of using metabarcoding of environmental DNA (eDNA obtained directly from seawater samples to account for marine fish biodiversity. This eDNA approach has recently been used successfully in freshwater environments, but never in marine settings. We isolate eDNA from ½-litre seawater samples collected in a temperate marine ecosystem in Denmark. Using next-generation DNA sequencing of PCR amplicons, we obtain eDNA from 15 different fish species, including both important consumption species, as well as species rarely or never recorded by conventional monitoring. We also detect eDNA from a rare vagrant species in the area; European pilchard (Sardina pilchardus. Additionally, we detect four bird species. Records in national databases confirmed the occurrence of all detected species. To investigate the efficiency of the eDNA approach, we compared its performance with 9 methods conventionally used in marine fish surveys. Promisingly, eDNA covered the fish diversity better than or equal to any of the applied conventional methods. Our study demonstrates that even small samples of seawater contain eDNA from a wide range of local fish species. Finally, in order to examine the potential dispersal of eDNA in oceans, we performed an experiment addressing eDNA degradation in seawater, which shows that even small (100-bp eDNA fragments degrades beyond detectability within days. Although further studies are needed to validate the eDNA approach in varying environmental

  20. Temperature and food-mediated variability of European Atlantic sardine recruitment (United States)

    Garrido, Susana; Silva, Alexandra; Marques, Vitor; Figueiredo, Ivone; Bryère, Philippe; Mangin, Antoine; Santos, A. Miguel P.


    The influence of the environmental conditions during larval development on the resulting recruitment strength was investigated for European sardine (Sardina pilchardus) at Atlanto-Iberian waters. Satellite-derived Sea Surface Temperature (SST) and Chlorophyll-a concentration (Chla) data from the previous spawning seasons (January to March/April and October to December of the previous year) were related to recruitment success data in the main recruitment hotspots. Recruitment data was taken from yearly acoustic scientific cruises and from the ICES recruitment index estimated by an age-structured model for the entire stock. A linear discriminant analysis model using SST, Chla, and the abundance of spawners during the spawning season identified years of high and low recruitment for all the recruitment hotspots with an accuracy of ≥79%. In general, high recruitment years were associated with high Chla and low SST, although the most important variables to discriminate between the groups were area-specific. High recruitment years were mostly related to high food availability (Chla), particularly during the last quarter of the previous year. In Western Iberia and in the Gulf of Cadiz, high recruitment years were also associated to lower SST, whereas in the Bay of Biscay, where SST during the winter was generally below the optimal range ≈11-12 °C for sardine larval development, higher recruitment was associated with high SST. For ICES data of the southern European sardine stock, lower SST and higher Chla during the last quarter of the previous year were associated with high recruitment years and SST alone was able to discriminate between the two recruitment groups with 73% accuracy. Although the time-series of available data are still small, these significant relationships are consistent with field and laboratory studies relating larval growth and mortality with main environmental drivers. These relationships should be further investigated in the following years to


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    V.J. Atencio-García


    Full Text Available El objeto del estudio fue evaluar el régimen alimentario de siete especies de peces que se han establecidoen el embalse de la Hidroeléctrica Urrá (HU. Se analizaron 453 estómagos, distribuidos así: 115 deperico (Tracheolypterus badeli cf, 111 de cacucho (Panaque gibbosus, 108 de yalúa (Cyphocharaxmagdalenae, 89 de mojarra amarilla (Caquetaia kraussii , 11 de moncholo (Hoplias malabaricus, 10 debarbul ( Pimelodus clarias y 9 de doncella ( Ageneoisus pardales . Los contenidos estomacales se evaluaronmediante frecuencia de ocurrencia (FO, frecuencia numérica (FN y el método gravimétrico (G. Sedeterminó la importancia de cada presa mediante el índice de categorización de presa (ICP y lasuperposición de dietas se analizó mediante el Índice de Morosita (IM. La distribución porcentual de loscontenidos estomacales de la yalúa mostró que el 95.5% correspondió al ítem detritus y el restante 4.5%a microlagas (Clorofitas y Bacillariofitas y protozoarios/rotíferos. La dieta del cacucho la conformaron enun 70.9% microalgas (Cianofitas, Clorofitas y Bacilariofitas y protozoarios/rotíferos y el restante 29.1%correspondieron al ítem detritus. Barbul (FO = 50%, FN = 46.2% y perico se alimentaron principalmentede insectos (FO = 73.9%, FN = 86.4%. La mojarra amarilla (FO = 87.1%, FN = 83.3%, doncella(FO = 92.3%, FN = 92.0% y moncholo (FO = 90.9%, FN = 90.9% prefieren peces como cachanita(Roeboides dayi y sardinas ( Astianax sp. Los resultados sugieren que yalúa es detritívoro iliófago, cacuchoes detritívoro, perico y barbul son carnívoros insectívoros y doncella, moncholo y mojarra amarilla soncarnívoros piscívoros.

  2. Distribución del ictioplancton en la Patagonia austral de Chile: potenciales efectos del deshielo de Campos de Hielo Sur Ichthyoplankton distribution in South Patagonia, Chile: potential effects of ice melting from the Southern Ice Field

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    Mauricio F Landaeta


    Full Text Available Durante octubre-noviembre de 2009 se realizó un crucero oceanográfico entre 50 y 53°S de Chile austral, en las cercanías del glaciar Campos de Hielo Sur. Las estaciones cercanas al glaciar presentaron baja temperatura (1-3°C y salinidad ( 0,1 ciclos s-1. Los principales taxa del ictioplancton fueron huevos y larvas de sardina fueguina Sprattus fuegensis, pez hacha Maurolicus parvipinnis, Macrouridae y merluza austral Merluccius australis. El desove principal de S. fuegensis (~ 8000 huevos 10 m-2 ocurrió en zonas mezcladas de la plataforma continental adyacente, mientras que el desove de M. parvipinnis ocurrió en canales intermedios asociado a valores intermedios de estabilidad (N~0,06 ciclos s-1. Se observó una nula o baja abundancia de huevos y larvas de peces en las cercanías del glaciar, y la abundancia de huevos de M. parvipinnis estuvo relacionada positivamente con la temperatura y salinidad de la columna de agua y negativamente con la estabilidad de la columna de agua. Además, hubo una relación negativa entre la densidad del agua de mar y el diámetro de los huevos de S. fuegensis. La relación entre deshielo e ictioplancton podría tener consecuencias en el transporte advectivo y mortalidad masiva de huevos y larvas de peces y el acople pelágico-bentónico en la Patagonia austral de Chile. Como el cambio climático global ha incrementado los deshielos de glaciares en latitudes altas, y el aumento del ingreso de aguas de baja temperatura y salinidad podría tener consecuencias en el ictioplancton de la Patagonia chilena.In October-November 2009, an oceanographic survey was carried out between 50 and 53°S off southern Chile, near the Southern Ice Field. The stations near the glacier showed low temperatures (1-3°C and salinity ( 0.1 cycles s-1. Main ichthyoplankton taxa were eggs and larvae of southern sprat Sprattus fuegensis, lightfish Maurolicus parvipinnis, Macrouridae, and southern hake Merluccius australis. The main

  3. Ecophysiological behavior of Caquetaia kraussii (Steindachner, 1878 (Pisces: Cichlidae exposed to different temperatures and salinities

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    M.I. Segnini de Bravo


    Full Text Available Tropical river sardine, Caquetaia kraussii, captured from La Aguá lagoon (Sucre State, Venezuela were acclimatized for four weeks at 22, 24, 30 and 32ºC and at 0, 5, 10, 15 and 17 ‰ salinity. To evaluate effects of thermal response to acclimatization level, the fish were transferred suddenly from lower temperatures (22 and 24ºC to higher ones (32 and 30ºC respectively. Then thermal resistance time was measured at the lethal temperature of 40.9ºC for 30 days. We considered that acclimatization process completed when resistance time was stabilized at the new temperature regime. For the saline effect, the concentrations of sodium and potassium were measured in the tissues at each treatment: gills, white muscle, gut and heart. The results showed that thermal tolerance increased rapidly in 3 h with a 6ºC rise in temperature (from 24 to 30ºC and in 24 h with a 10ºC rise (22 to 32ºC. With decreasing temperatures, the acclimatization level reached its lowest in 11 days with a 6ºC decreases (from 30 to 24ºC and in 14 days with a 10ºC decrease (32 to 22ºC. Caquetaia kraussii regulates as much sodium as potassium in gills and white muscle tissues at all salinity levels tested; however, gut and heart tissues showed significantly different regulations among salinities examined.La sardina tropical de río, Caquetaia kraussii, capturada en la laguna La Aguá (Estado Sucre, Venezuela fue aclimatada durante cuatro semanas a la temperatura de 22, 24, 30 y 32ºC y a 0, 5, 10, 15 y 17 ‰ de salinidad. Para evaluar los efectos de respuestas térmicas a los niveles de aclimatación, los peces fueron transferidos abruptamente desde las temperaturas bajas (22 y 24ºC hasta las altas (32 y 30ºC respectivamente. Se midió entonces la resistencia térmica a la temperatura letal de 40.9ºC durante 30 días. Se consideró que los peces habían alcanzado completamente su aclimatación cuando se estabilizaba al nuevo régimen de temperatura. Para el efecto

  4. Sondeo ecológico rápido de las comunidades de peces tropicales en un área de explotación minera en Costa Rica

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    Mario Espinoza Mendiola


    Full Text Available El impacto de las minerías de oro ha generado una gran preocupación por el deterioro de los hábitats acuáticos y la fragmentación de los sistemas naturales. Las perturbaciones antropogénicas sobre la estructura y heterogeneidad del sistema pueden influir en la estabilidad de las comunidades acuáticas. Sondeos ecológicos rápidos (1996, 2002, 2007 fueron empleados para determinar la estructura, composición y distribución de las comunidades de peces tropicales en varios ríos y quebradas del área de una minería de oro en el Cerro Crucitas, Costa Rica. Además, la composición de especies y abundancia relativa se relacionó con la estructura del hábitat. Se registró un total de 35 especies, de las cuales la sardina Astyanax aeneus (Characidae y la olomina Alfaro cultratus (Poeciliidae fueron las especies más abundantes (71%. La mayor riqueza de especies se observó en el Caño Crucitas (s = 19 y la quebrada Minas (s = 18. Se encontró una gran variación en la estructura y composición de las comunidades de peces, principalmente, en el río Infiernillo y Minas (λ = 0.0, F132, 66 = 2.24, p Rapid ecological assessment of tropical fish communities in a gold mine area of Costa Rica. Gold mining impacts have generated a great concern regarding aquatic systems and habitat fragmentation. Anthropogenic disturbances on the structure and heterogeneity of a system can have an important effect on aquatic community stability. Ecological rapid assessments (1996, 2002, and 2007 were employed to determine the structure, composition and distribution of tropical fish communities in several rivers and smaller creeks from a gold mining area in Cerro Crucitas, Costa Rica. In addition, species composition and relative abundance were related with habitat structure. A total of 35 species were registered, among which sardine Astyanax aeneus (Characidae and livebearer Alfaro cultratus (Poeciliidae were the most abundant fish (71%. The highest species

  5. İzmir İç Körfezi İhtiyoplankton Kompozisyonu.

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    Dilek Türker Çakır


    Full Text Available Ege Denizi’ndeki en önemli balıkçılık alanlarından biri olan İzmir Körfezi’nde geçmiş yıllarda meydana gelen kirliliğin neden olduğu biyolojik çeşitlilikte olumsuz yönde değişmeler olmuştur. 2001 büyük kanal projesinin devreye girmesi ile meydana gelmiş olumsuz değişimler tersine dönmeye başlamıştır. Bu değişimler üzerine çok çeşitli araştırmalar yapılmış ve halen yapılmaktadır. Bu çalışma “Büyük Kanal Projesinin Aktif Hale Geçirilmesinin İzmir Körfezi Sularında Alt Besinsel Seviyeler Üzerine Etkileri (YDABAG 102Y116” adlı proje kapsamında yürütülmüş olup İzmir İç Körfezi’nde yaşayan balıkların yumurta ve larvalarının tür çeşitliliği, bolluğu, dağılımları ve mortaliteleri araştırılmıştır. İhtiyoplankton örnekleri 19.12.2002-26.12.2003 tarihleri arasında 15’er günlük periyotlarda 3 istasyondan toplanmış olup ağız çapı 51 cm, uzunluğu 2.5 m ve 200 μm göz açıklığında UNESCO-WP2 model plankton kepçesi ile vertikal olarak gerçekleştirilmiştir. Çalışma süresince toplam 9613.8 adet/m2 yumurta, 568.4 adet/m2 larva tespit edilmiştir. Sardina pilchardus (Walbaum, 1792, Engraulis encrasicolus (Linnaeus, 1758, Diplodus sp., Symphodus melops (Linnaeus, 1758, Callionymus pusillus Delaroche, 1809, Callionymus sp., Gobius niger Linnaeus, 1758, Gobius paganellus Linnaeus, 1758, Arnoglossus sp., Buglossidium luteum (Risso, 1810 türlerinin yumurta ve/veya larvaları tayin edilmiştir. E. encrasicolus türüne ait yumurta, prelarva ve postlarva dominanttır. Bu türün yumurtalarında %12.05 oranında mortalite belirlenmiştir