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Sample records for juvenile marine fish

  1. The influence of turbidity on juvenile marine fish in the estuaries of Natal, South africa

    Science.gov (United States)

    Cyrus, D. P.; Blaber, S. J. M.

    1987-11-01

    Results from field studies in Natal estuaries show that the distribution of juvenile marine fish is influenced by turbidity. Laboratory studies on turbidity preference, with other variables excluded, showed good correlation with the field data for eight of ten species tested. The importance of turbidity and other factors to juvenile fish is discussed in relation to the role which estuaries play as nursery areas for juveniles of numerous marine species.

  2. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [State Key Laboratory of Oceanography in the Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Huang Liangmin [State Key Laboratory of Oceanography in the Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, HKUST, Clear Water Bay, Kowloon (Hong Kong)

    2011-10-15

    Highlights: Radiotracer technique was used to quantify the biokinetics of As(V) in a marine fish. As(V) had a low bioavailability to Terapon jarbua. Dietary assimilation of As was only 3.1-7.4% for fish fed with different preys. Dietary uptake could be the primary route for As bioaccumulation in fish. - Abstract: Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 {mu}g L{sup -1}, with a corresponding uptake rate constant of 0.0015 L g{sup -1} d{sup -1}. The assimilation efficiencies (AEs) of dietary As were only 3.1-7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d{sup -1}. Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua.

  3. Feeding ecology of juvenile marine fish in a shallow coastal lagoon of southeastern Mexico

    OpenAIRE

    Daniel Arceo-Carranza; Xavier Chiappa-Carrara

    2015-01-01

    Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analys...

  4. Feeding ecology of juvenile marine fish in a shallow coastal lagoon of southeastern Mexico

    Directory of Open Access Journals (Sweden)

    Daniel Arceo-Carranza

    2015-09-01

    Full Text Available Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analysis we determined the trophic differences among Caranx latus, Oligoplites saurus, Trachinotus falcatus, Synodus foetens, Lutjanus griseus, and Strongylura notata. C. latus, O. saurus, S. foetens, and S. notate, which are ichthyophagous species (>80% by number. L. griseus feeds mainly on crustaceans (>55% and fish (35%, while T. falcatus feeds on mollusks (>50% bivalves, >35% gastropods. The analysis of similarities (ANOSIM showed differences in the diet of all species. Cluster analysis, based on the Bray-Curtis similarity matrix revealed three groups; one characterized by the ichthyophagous guild (S. notata, S. foetens, C. latus, and O. saurus, other group formed by the crustacean consumers (L. griseus, and the third, composed by the mollusk feeder (T. falcatus. Species of the ichthyophagous guild showed overlap in their diets, which under conditions of low prey abundance may trigger competition, hence affecting juvenile stages of these marine species that use coastal lagoons to feed and grow.

  5. Stable isotopes in juvenile marine fishes and their invertebrate prey from the Thames Estuary, UK, and adjacent coastal regions

    Science.gov (United States)

    Leakey, Chris D. B.; Attrill, Martin J.; Jennings, Simon; Fitzsimons, Mark F.

    2008-04-01

    Estuaries are regarded as valuable nursery habitats for many commercially important marine fishes, potentially providing a thermal resource, refuge from predators and a source of abundant prey. Stable isotope analysis may be used to assess relative resource use from isotopically distinct sources. This study comprised two major components: (1) development of a spatial map and discriminant function model of stable isotope variation in selected invertebrate groups inhabiting the Thames Estuary and adjacent coastal regions; and (2) analysis of stable isotope signatures of juvenile bass ( Dicentrarchus labrax), sole ( Solea solea) and whiting ( Merlangius merlangus) for assessment of resource use and feeding strategies. The data were also used to consider anthropogenic enrichment of the estuary and potential energetic benefits of feeding in estuarine nursery habitat. Analysis of carbon (δ 13C), nitrogen (δ 15N) and sulphur (δ 34S) isotope data identified significant differences in the 'baseline' isotopic signatures between estuarine and coastal invertebrates, and discriminant function analysis allowed samples to be re-classified to estuarine and coastal regions with 98.8% accuracy. Using invertebrate signatures as source indicators, stable isotope data classified juvenile fishes to the region in which they fed. Feeding signals appear to reflect physiological (freshwater tolerance) and functional (mobility) differences between species. Juvenile sole were found to exist as two isotopically-discrete sub-populations, with no evidence of mixing between the two. An apparent energetic benefit of estuarine feeding was only found for sole.

  6. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change.

    Science.gov (United States)

    Ong, Joyce Jia Lin; Rountrey, Adam Nicholas; Meeuwig, Jessica Jane; Newman, Stephen John; Zinke, Jens; Meekan, Mark Gregory

    2015-06-08

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations.

  7. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus)

    Science.gov (United States)

    Sarker, Pallab K.; Kapuscinski, Anne R.; Lanois, Alison J.; Livesey, Erin D.; Bernhard, Katie P.; Coley, Mariah L.

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds. PMID:27258552

  8. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Sarker, Pallab K; Kapuscinski, Anne R; Lanois, Alison J; Livesey, Erin D; Bernhard, Katie P; Coley, Mariah L

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.

  9. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus.

    Directory of Open Access Journals (Sweden)

    Pallab K Sarker

    Full Text Available We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc to determine the optimum level of fish-oil substitution (partial or complete for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet, we found significantly higher weight gain and protein efficiency ratio (PER, and lower (improved feed conversion ratio (FCR and feed intake compared to a control diet containing fish oil (Sc0; and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.

  10. Amending reduced fish-meal feeds with marine lecithin, but not soy lecithin, improves the growth of juvenile cobia and may attenuate heightened responses to stress challenge.

    Science.gov (United States)

    Trushenski, J; Schwarz, M; Pessoa, W V N; Mulligan, B; Crouse, C; Gause, B; Yamamoto, F; Delbos, B

    2013-02-01

    Sparing of marine resources in aquafeeds can be environmentally and economically advantageous; however, fish meal (FM) replacement can affect the production performance and physiological competence. Phospholipids are increasingly understood to be involved in maintaining growth and vigour in fish and may be deficient in reduced FM formulations. Accordingly, we evaluated the growth and stress tolerance of juvenile cobia fed typical (50% FM) or reduced FM feeds (12% FM) with or without phospholipid amendment [1% marine lecithin (12% FM + Marine PL) or soy lecithin (12% FM + Soy PL)] for 6 weeks in triplicate tanks (N = 3) in a recirculation aquaculture system. The 50% FM feed yielded significantly superior growth and growth efficiency in comparison with the 12% FM and 12% FM+ Soy PL feeds, but the 12% FM+ Marine PL feed yielded comparable results to 50% FM feed. A low-water stress challenge induced elevated plasma glucose, cortisol and lactate levels in all treatments. However, a significant interaction (diet × stress) effect suggested a lesser cortisol response among fish fed the 12% FM+ Marine PL and 50% FM diets. These findings demonstrate that growth performance and, perhaps, resilience of cobia raised on reduced FM feeds may be improved by the addition of marine-origin phospholipid to the diet. © 2011 Blackwell Verlag GmbH.

  11. Biochemical composition of copepods for evaluation of feed quality in production of juvenile marine fish

    OpenAIRE

    van der Meeren, Terje; Olsen, Rolf Erik; Hamre, Kristin; Fyhn, Hans Jørgen

    2007-01-01

    To increase current knowledge on the nutritional value of natural prey organisms, the biochemical components of mainly three copepods (Acartia grani, Centropages hamatus, and Eurytemora affinis) from a marine pond system were analysed once a week from spring until late fall, over two years. The analysed components were total lipid, lipid class composition, total lipid fatty acid composition, free amino acids, total protein, protein-bound amino acids, pigment (astaxanthin and ß-carotene), and ...

  12. Juvenile yield index to highlight intensive culture potential in tropical marine fish Índice de rendimiento de juveniles para resaltar la potencialidad para el cultivo intensivo de peces marinos tropicales

    Directory of Open Access Journals (Sweden)

    Luis Álvarez-Lajonchère

    2012-04-01

    Full Text Available Juvenile seedstock availability and costs are some of the main biological aspects to be considered on species for intensive culture assessment studies, together with market importance and performance under culture conditions, especially the growth rate and yields. A juvenile yield index (JYi is described, as one of the judgment indicator of juvenile efficiency utilization on edible size culture production of tropical marine fishes. This index is expressed asthe number of juveniles required per metric ton per year, and combines fish growth rate during grow-out, survival, and commercial size at harvest. The JYi could be combined with production costs and wholesale prices, to estimate a juvenile gross profit index (JGPi, and expressed in terms of estimated gross profit per juvenile number required per ton produced per year.La disponibilidad y costos de los organismos juveniles que serán criados están entre los principales aspectos biológicos a considerar en los estudios de evaluación de especies para el cultivo intensivo, además de la importancia comercial y el comportamiento de los organismos bajo condiciones de cultivo, especialmente la tasa de crecimiento y los rendimientos. Se describe un índice de rendimiento de juveniles (IRJ como uno de los indicadores para evaluar la eficiencia en la utilización de juveniles en la producción del cultivo de peces marinos tropicales de talla comestible. Este índice está expresado como el número de juveniles requerido para cada tonelada métrica por año y combina la tasa de crecimiento durante la engorda, la supervivencia y la talla comercial a la cosecha. Es posible combinar el IRJ de rendimiento de juveniles con los costos de producción y los precios mayoristas, para estimar un índice de ganancias brutas de juveniles y expresar en términos de ganancia bruta el número de juveniles requerido por tonelada producida al año.

  13. Effects of multi-stressors on juveniles of the marine fish Pomatoschistus microps: Gold nanoparticles, microplastics and temperature.

    Science.gov (United States)

    Ferreira, Pedro; Fonte, Elsa; Soares, M Elisa; Carvalho, Felix; Guilhermino, Lúcia

    2016-01-01

    Knowledge on multi-stressors effects required for environmental and human risk assessments is still limited. This study investigated the combined effects of gold nanoparticles (Au-NP), microplastics (MP) and temperature increase on Pomatoschistus microps, an important prey for several higher level predators, including some species edible to humans. Four null hypotheses were tested: H01: P. microps juveniles do not take up Au-NP through the water; H02: Au-NP (ppb range) are not toxic to juveniles; H03: the presence of MP do not influence the effects of Au-NP on juveniles; H04: temperature increase (20-25°C) does not change the effects of the tested chemicals on juveniles. Wild juveniles were acclimated to laboratory conditions. Then, they were exposed to Au-NP (≈5nm diameter) and MP (polyethylene spheres, 1-5μm diameter), alone and in mixture, at 20°C and 25°C, in semi-static conditions. After 96h of exposure to Au-NP, fish had gold in their body (0.129-0.546μg/g w.w.) leading to H01 refusal. Exposure to Au-NP alone caused a predatory performance decrease (≈-39%, pmicroplastics, either alone or in mixture. This knowledge is most important to improve the basis for environmental and human risk assessments of these environmental contaminants of high concern.

  14. Increase of marine juvenile fish abundances in the middle Gironde estuary related to warmer and more saline waters, due to global changes

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    Pasquaud, Stéphanie; Béguer, Mélanie; Larsen, Maja Hjort; Chaalali, Aurélie; Cabral, Henrique; Lobry, Jérémy

    2012-06-01

    Estuaries have an essential ecological function for several marine fish species, that use these systems as nurseries. Previous studies in the Gironde estuary have reported an increase in water temperature and an extended seawater intrusion associated to global changes. In this study, we evaluated whether these changes impact the nursery function in the middle part of the system, based on the analyses of long-term data series (1991-2009) collected in that area. Trend analysis, correlations and generalized additive models (GAM) were computed in order to study the influence of water temperature and salinity changes on marine juveniles occurrence/densities. Results showed that densities of all the studied species (i.e. Engraulis encrasicolus, Sprattus sprattus, Dicentrarchus labrax, Solea solea, Argyrosomus regius, Merlangius merlangus) significantly increased over the period considered. Changes in water temperature and seawater intrusion contributed to explain the variability in presence/absence and in densities of the majority of these species. However, the deviance explained by GAM and the relevance of these two explanatory variables differed considerably according to species. For most species, it was suggested that the interaction of these two factors, and their effects on other variables, may explain the increase in abundance in the middle part of the Gironde. The effects of global changes in this estuarine system may favour its nursery function for marine juveniles, but some evidence of effects at a wider scale (community and ecosystem levels) may alter the structure and functioning of this system.

  15. Climatic influence on a marine fish assemblage.

    Science.gov (United States)

    Attrill, Martin J; Power, Michael

    2002-05-16

    Understanding the fluctuations in marine fish stocks is important for the management of fisheries, and attempts have been made to demonstrate links with oceanographic and climatic variability, including the North Atlantic Oscillation (NAO). The NAO has been correlated with a range of long-term ecological measures, including certain fish stocks. Such environmental influences are most likely to affect susceptible juveniles during estuarine residency, as estuaries are critical juvenile nursery or over-wintering habitats. Here we show that, during a 16-year period, climatic forcing (by means of the NAO) is consistently the most important parameter explaining variation in assemblage composition, abundance and growth of juvenile marine fish during estuarine residency. A possible mechanism for the effect of the NAO is a temperature differential between estuarine and marine waters that allows fish to facultatively exploit optimal thermal habitats. The connection has potentially important implications for the size and numbers of individuals recruited to the fishery, for understanding and predicting the composition of juvenile fish stocks using estuaries, and for the appropriate conservation of estuarine systems in relation to fish stocks.

  16. Epigenomics in marine fishes.

    Science.gov (United States)

    Metzger, David C H; Schulte, Patricia M

    2016-12-01

    Epigenetic mechanisms are an underappreciated and often ignored component of an organism's response to environmental change and may underlie many types of phenotypic plasticity. Recent technological advances in methods for detecting epigenetic marks at a whole-genome scale have launched new opportunities for studying epigenomics in ecologically relevant non-model systems. The study of ecological epigenomics holds great promise to better understand the linkages between genotype, phenotype, and the environment and to explore mechanisms of phenotypic plasticity. The many attributes of marine fish species, including their high diversity, variable life histories, high fecundity, impressive plasticity, and economic value provide unique opportunities for studying epigenetic mechanisms in an environmental context. To provide a primer on epigenomic research for fish biologists, we start by describing fundamental aspects of epigenetics, focusing on the most widely studied and most well understood of the epigenetic marks: DNA methylation. We then describe the techniques that have been used to investigate DNA methylation in marine fishes to date and highlight some new techniques that hold great promise for future studies. Epigenomic research in marine fishes is in its early stages, so we first briefly discuss what has been learned about the establishment, maintenance, and function of DNA methylation in fishes from studies in zebrafish and then summarize the studies demonstrating the pervasive effects of the environment on the epigenomes of marine fishes. We conclude by highlighting the potential for ongoing research on the epigenomics of marine fishes to reveal critical aspects of the interaction between organisms and their environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Marine Fish Hybridization

    KAUST Repository

    He, Song

    2017-04-01

    Natural hybridization is reproduction (without artificial influence) between two or more species/populations which are distinguishable from each other by heritable characters. Natural hybridizations among marine fishes were highly underappreciated due to limited research effort; it seems that this phenomenon occurs more often than is commonly recognized. As hybridization plays an important role in biodiversity processes in the marine environment, detecting hybridization events and investigating hybridization is important to understand and protect biodiversity. The first chapter sets the framework for this disseration study. The Cohesion Species Concept was selected as the working definition of a species for this study as it can handle marine fish hybridization events. The concept does not require restrictive species boundaries. A general history and background of natural hybridization in marine fishes is reviewed during in chapter as well. Four marine fish hybridization cases were examed and documented in Chapters 2 to 5. In each case study, at least one diagnostic nuclear marker, screened from among ~14 candidate markers, was found to discriminate the putative hybridizing parent species. To further investigate genetic evidence to support the hybrid status for each hybrid offspring in each case, haploweb analysis on diagnostic markers (nuclear and/or mitochondrial) and the DAPC/PCA analysis on microsatellite data were used. By combining the genetic evidences, morphological traits, and ecological observations together, the potential reasons that triggered each hybridization events and the potential genetic/ecology effects could be discussed. In the last chapter, sequences from 82 pairs of hybridizing parents species (for which COI barcoding sequences were available either on GenBank or in our lab) were collected. By comparing the COI fragment p-distance between each hybridizing parent species, some general questions about marine fish hybridization were discussed: Is

  18. Epidemiological characterization of VNNV in hatchery-reared and wild marine fish on Hainan Island, China, and experimental infection of golden pompano (Trachinotus ovatus) juveniles.

    Science.gov (United States)

    Ma, Hongling; Wen, Weigeng; Su, Youlu; Feng, Juan; Xu, Liwen; Peng, Chao; Guo, Zhixun

    2015-12-01

    The current epidemiological situation of viral nervous necrosis virus (VNNV) on Hainan Island was investigated. A total of 490 hatchery-reared fish and 652 wild fish were sampled for VNNV detection from March 2013 to May 2014. Positive detection rates of 84.53% (153/181) and 0.97 % (3/309) were obtained in diseased and healthy hatchery-reared samples, respectively, by conventional RT-PCR. However, using more-sensitive nested RT-PCR, the positive detection rates in healthy hatchery-reared fish reached up to 64.08% (198/309), suggesting that asymptomatic VNNV carriers commonly exist among larvae and juveniles breeding on Hainan Island. In wild-fish samples, 2.6% (17/652) and 34.2% (223/652) positive detection rates were observed using RT-PCR and nested RT-PCR, respectively, indicating that wild fish may be a potential reservoir for VNNV. Phylogenetic analysis showed that all 52 VNNV isolates from cultured fish belong to the RGNNV genotype, but 2 out of 48 VNNV isolates from wild fish samples were found to be of the SJNNV genotype. This study is the first to confirm the existence of SJNNV-genotype VNNV in China. Golden pompano, an important fish species for culture, was selected as a fish model to investigate the optimal conditions for RGNNV disease progression in artificial infection experiments. The effects of temperature, salinity, and fish size were evaluated. Results showed that 28 °C and 20 ‰ are the optimal infection temperature and salinity, respectively, and golden pompano juveniles with small body sizes are more susceptible to RGNNV. These findings are highly consistent with those conditions involved in the natural outbreak of RGNNV.

  19. Survivorship of coral juveniles in a fish farm environment.

    Science.gov (United States)

    Villanueva, Ronald D; Yap, Helen T; Montaño, Marco Nemesio E

    2005-01-01

    Intensive fish farming is an emerging coastal activity that can potentially enhance sedimentation and promote eutrophication in fringing coral reefs. Here, we investigate the effect of fish farm effluent on the juvenile survivorship of the reef-building coral Seriatopora caliendrum. One-month old juvenile corals (on terracotta tiles) were deployed in fish farm and reference (reef) sites in Bolinao, the Philippines at a depth of 2m. After forty days, no survivor was recovered in the fish farm, while survivorship was low (11%) in the reference site, with the survivors' growth rate at 3.3polypsmo(-1) or 1.3mm(2)mo(-1). The fish farm deployed tiles were covered with muddy sediment and were colonized by barnacles, whereas those in the reference site were overgrown by a short stand of filamentous macroalgae. Environmental monitoring revealed higher nutrient levels (ammonia and phosphate), sedimentation rate, and organic matter flux, as well as diminished water transparency and dissolved oxygen levels in the fish farm compared to the reference site. Hence, intensive fish farming offers a suite of physical, chemical and biological modifications of the coastal marine environment which have a detrimental effect on the survivorship of coral juveniles.

  20. Biodiversity of arctic marine fishes

    DEFF Research Database (Denmark)

    Mecklenburg, Catherine W.; Møller, Peter Rask; Steinke, Dirk

    2011-01-01

    Taxonomic and distributional information on each fish species found in arctic marine waters is reviewed, and a list of families and species with commentary on distributional records is presented. The list incorporates results from examination of museum collections of arctic marine fishes dating b...

  1. Marine line fish research programme

    CSIR Research Space (South Africa)

    SANCOR

    1979-04-01

    Full Text Available This report outlines the framework for a marine line fish programme under the aegis of the South African National Committee for Oceanographic Research (SANCOR). An attempt is made to assess the state of knowledge about South African marine line...

  2. Conservation physiology of marine fishes

    DEFF Research Database (Denmark)

    Jørgensen, Christian; Peck, Myron A.; Antognarelli, Fabio

    2012-01-01

    At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology...... to different extents, ranging from no explicit consideration to detailed physiological mechanisms, and across scales from a single fish to global fishery resources. Biologists from different sub-disciplines are collaborating to rise to the challenge of projecting future changes in distribution and productivity...

  3. Marine genetic swamping: hybrids replace an obligately estuarine fish.

    Science.gov (United States)

    Roberts, David G; Gray, Charles A; West, Ronald J; Ayre, David J

    2010-02-01

    Populations of obligately estuarine taxa are potentially small and isolated and may lack genetic variation and display regional differentiation as a result of drift and inbreeding. Hybridization with a wide-ranging marine congener should introduce genetic variation and reduce the effects of inbreeding depression and genetic drift. However, high levels of hybridization can cause demographic and genetic swamping. In southeastern Australia hybridization occurs between obligately estuarine Black bream (Acanthopagrus butcheri) and migratory marine Yellowfin bream (Acanthopagrus australis). Here, we surveyed genetic variation at eight microsatellite loci and the mitochondrial control region of juvenile fish from five coastal lagoons (including temporal replication in two lagoons) (total n = 970) to determine the frequency and persistence of hybridization, and its likely consequence for the estuarine restricted A. butcheri. Of 688 juvenile fish genotyped 95% were either A. australis (347) or hybrids (309); only 5% (32) were A. butcheri. Most hybrids were later generation hybrids or A. butcheri backcrosses, which are likely multi-generational residents within lagoons. Far greater proportions of hybrid juveniles were found within two lagoons that are generally closed to the ocean (>90% hybrid fish within generally closed lagoons vs. 12-27% in permanently or intermittently open lagoons). In both lagoons, this was consistent across multiple cohorts of fish [79-97% hybrid fish (n = 282)]. Hybridization and introgression represent a major threat to the persistence of A. butcheri and have yet to be investigated for large numbers of estuarine taxa.

  4. Ascertaining the potential effects of temperature on growth, survival and feeding of different juvenile clown fish

    Directory of Open Access Journals (Sweden)

    Vishwas Rao Methari

    2015-02-01

    Full Text Available Objective: To determine the physiological and ecological responses of marine ornamental fishes to the change of water temperature with its potential effects on the growth, survival and feeding in clown fish. Methods: Three different sea anemone fish (Premnas biaculeatus, Amphiprion clarkii, Amphiprion akallopisos were reared in confinement at water temperatures of 26, 28, 30, 32, and 34 °C using thermostat and they were maintained up to the marketable size, and growth, survival and feeding were evaluated during the experimental period. Results: The results illustrated that water temperature influenced the physiological performance of juveniles of three different sea anemone fish significantly. The growth and survival rates of juveniles of three different clown fish significantly increased with the increase of water temperature from 26 °C to 34 °C (P<0.05. Water temperature also influenced the feeding of three different clown fish significantly with feed conversion ratio increased from (0.071±0.020, (0.075±0.030 and (0.079±0.028 to (0.057±0.040, (0.047±0.030 and (0.045±0.028 for Premnas biaculeatus, Amphiprion clarkii and Amphiprion akallopisos respectively with increase of water temperature from 26 °C to 34 °C (P<0.05. Specific growth rates (P<0.05 increased significantly with increase of water temperature and positively correlated with the feed conversion ratio, indicating that growth rates are significantly increased with increase of temperature. Conclusions: This study deliberately reveals that the physiological response of juveniles of clown fish as the change of water temperature and substantiated that water temperature influenced juvenile growth, survival and feeding significantly. This study also put forward that the reduced growth, survival and feeding of juveniles at lower temperature which have ecological impacts on clown fish juveniles in settlement and population replacement in the wild.

  5. Habitat associations of juvenile fish at Ningaloo Reef, Western Australia: the importance of coral and algae.

    Science.gov (United States)

    Wilson, Shaun K; Depczynski, Martial; Fisher, Rebecca; Holmes, Thomas H; O'Leary, Rebecca A; Tinkler, Paul

    2010-12-07

    Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres) 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting) were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and protecting reefs

  6. Habitat associations of juvenile fish at Ningaloo Reef, Western Australia: the importance of coral and algae.

    Directory of Open Access Journals (Sweden)

    Shaun K Wilson

    Full Text Available Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and

  7. Mangrove habitat use by juvenile reef fish: meta-analysis reveals that tidal regime matters more than biogeographic region.

    Directory of Open Access Journals (Sweden)

    Mathias M Igulu

    Full Text Available Identification of critical life-stage habitats is key to successful conservation efforts. Juveniles of some species show great flexibility in habitat use while other species rely heavily on a restricted number of juvenile habitats for protection and food. Considering the rapid degradation of coastal marine habitats worldwide, it is important to evaluate which species are more susceptible to loss of juvenile nursery habitats and how this differs across large biogeographic regions. Here we used a meta-analysis approach to investigate habitat use by juvenile reef fish species in tropical coastal ecosystems across the globe. Densities of juvenile fish species were compared among mangrove, seagrass and coral reef habitats. In the Caribbean, the majority of species showed significantly higher juvenile densities in mangroves as compared to seagrass beds and coral reefs, while for the Indo-Pacific region seagrass beds harbored the highest overall densities. Further analysis indicated that differences in tidal amplitude, irrespective of biogeographic region, appeared to be the major driver for this phenomenon. In addition, juvenile reef fish use of mangroves increased with increasing water salinity. In the Caribbean, species of specific families (e.g. Lutjanidae, Haemulidae showed a higher reliance on mangroves or seagrass beds as juvenile habitats than other species, whereas in the Indo-Pacific family-specific trends of juvenile habitat utilization were less apparent. The findings of this study highlight the importance of incorporating region-specific tidal inundation regimes into marine spatial conservation planning and ecosystem based management. Furthermore, the significant role of water salinity and tidal access as drivers of mangrove fish habitat use implies that changes in seawater level and rainfall due to climate change may have important effects on how juvenile reef fish use nearshore seascapes in the future.

  8. Ocean acidification erodes crucial auditory behaviour in a marine fish.

    Science.gov (United States)

    Simpson, Stephen D; Munday, Philip L; Wittenrich, Matthew L; Manassa, Rachel; Dixson, Danielle L; Gagliano, Monica; Yan, Hong Y

    2011-12-23

    Ocean acidification is predicted to affect marine ecosystems in many ways, including modification of fish behaviour. Previous studies have identified effects of CO(2)-enriched conditions on the sensory behaviour of fishes, including the loss of natural responses to odours resulting in ecologically deleterious decisions. Many fishes also rely on hearing for orientation, habitat selection, predator avoidance and communication. We used an auditory choice chamber to study the influence of CO(2)-enriched conditions on directional responses of juvenile clownfish (Amphiprion percula) to daytime reef noise. Rearing and test conditions were based on Intergovernmental Panel on Climate Change predictions for the twenty-first century: current-day ambient, 600, 700 and 900 µatm pCO(2). Juveniles from ambient CO(2)-conditions significantly avoided the reef noise, as expected, but this behaviour was absent in juveniles from CO(2)-enriched conditions. This study provides, to our knowledge, the first evidence that ocean acidification affects the auditory response of fishes, with potentially detrimental impacts on early survival.

  9. SAB Juvenile Reef Fish (2002-2015)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Trawls were made during the summer months in shallow seagrass beds to monitor the number and species of juvenile snapper using the grass as a nursery.

  10. National Marine Recreational Fishing Expenditure Survey 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine recreational fishing is a popular pastime across the United States that generates significant economic impacts to both local economies and to the nation. In...

  11. National Marine Recreational Fishing Expenditure Survey 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine recreational fishing is a popular pastime across the United States that generates significant economic impacts to both local economies and to the nation. In...

  12. Fishing gear-related injury in California marine wildlife.

    Science.gov (United States)

    Dau, Brynie Kaplan; Gilardi, Kirsten V K; Gulland, Frances M; Higgins, Ali; Holcomb, Jay B; Leger, Judy St; Ziccardi, Michael H

    2009-04-01

    We reviewed medical records from select wildlife rehabilitation facilities in California to determine the prevalence of injury in California Brown Pelicans (Pelecanus occidentalis), gulls (Larus spp.), and pinniped species (Zalophus californianus, Mirounga angustirostris, and Phoca vitulina) due to fishing gear entanglement and ingestion from 2001 to 2006. Of 9,668 Brown Pelican, gull, and pinniped cases described during the 6-yr study period (2001-06), 1,090 (11.3%) were fishing gear-related. Pelican injuries caused by fishing gear were most common in the Monterey Bay region, where 59.6% of the pelicans rescued in this area and admitted to a rehabilitation center were injured by fishing gear over the 6-yr period. The highest prevalence of fishing gear-related injury in gulls was documented in the Los Angeles/Orange County region (16.1%), whereas the highest prevalences in pinnipeds were seen in the San Diego region (3.7%). Despite these higher prevalences of gull and pinniped fishing gear-related injuries in these specific regions, there was no statistical significance in these trends. Juvenile gulls and pinnipeds were more commonly injured by fishing gear than adults (gulls: P = 0.03, odds ratio = 1.29; pinnipeds: P = 0.01, odds ratio = 2.07). Male pinnipeds were twice as likely to be injured by fishing gear as females (P gear-related injury cases that were successfully rehabilitated and released (percentage of cases successfully rehabilitated to the point of release out of the total number of fishing gear-related injury cases) was high in all three species groups (pelicans: 63%; gulls: 54%; pinnipeds: 70%). Fishing gear-related injuries in Brown Pelicans and gulls were highest in the fall, but there was only a significant difference between seasons for fishing gear-related injuries in pelicans. Fishing gear-related injuries in pinnipeds most commonly occurred in summer; however, a statistical difference was not detected between seasons for pinnipeds. Derelict

  13. Detecting age-structured effects in growth performance of coral reef fish juveniles

    OpenAIRE

    Mellin, Camille; Galzin, R.; Ponton, Dominique; Vigliola, Laurent

    2009-01-01

    The growth performance of coral reef fish juveniles collected in different habitats is often used as a proxy for habitat quality for juveniles. However, back-calculated growth trajectories of juveniles may be age-structured, for instance, because of potential differences in initial offspring size and/or quality or size-selective mortality. A novel approach is proposed to isolate growth performance of coral reef fish juveniles from potential age-based factors. Juveniles of Chromis viridis (Pom...

  14. Transaction of Marine Fishing Right: Theoretical Analysis

    Institute of Scientific and Technical Information of China (English)

    Huang Jishen; Long Wenjun

    2008-01-01

    The difference between fishermen's fishing catch and the optimal fishing catch is the basic reason for the transaction of marine fishing rights (TMFR). The effects of productive cost, non-productive cost, use-cost, transaction cost, productive revenue and non-productive revenue on the TMFR and the optimal fishing catch are analyzed. This paper draws following conclusions: the non-productive revenue has a positive effect on the TMFR, and other factors, such as non-productive cost, usecost and transaction cost, have a negative effect; the TMFR will promote the resource allocation; the high transaction cost may affect the implementation of TMFR.

  15. Alaska Arctic marine fish ecology catalog

    Science.gov (United States)

    Thorsteinson, Lyman K.; Love, Milton S.

    2016-08-08

    The marine fishes in waters of the United States north of the Bering Strait have received new and increased scientific attention over the past decade (2005–15) in conjunction with frontier qualities of the region and societal concerns about the effects of Arctic climate change. Commercial fisheries are negligible in the Chukchi and Beaufort Seas, but many marine species have important traditional and cultural values to Alaska Native residents. Although baseline conditions are rapidly changing, effective decisions about research and monitoring investments must be based on reliable information and plausible future scenarios. For the first time, this synthesis presents a comprehensive evaluation of the marine fish fauna from both seas in a single reference. Although many unknowns and uncertainties remain in the scientific understanding, information presented here is foundational with respect to understanding marine ecosystems and addressing dual missions of the U.S. Department of the Interior for energy development and resource conservation. 

  16. Marine soundscape shaped by fishing activity

    Science.gov (United States)

    Lossent, Julie; Grall, Jacques; Chauvaud, Laurent

    2017-01-01

    Marine communities face anthropogenic pressures that degrade ecosystems. Because underwater soundscapes carry information about habitat quality, we explored whether destructive impacts of fishing could be evaluated via the soundscape. Maerl beds are recognized as biodiversity hotspots and they experience major worldwide degradation owing to fishing. We collected field acoustic recordings in maerl beds exposed to different fishing practices. We found that unfished maerl beds were threefold louder and exhibited sound frequencies more diversified than those recorded in fished maerl beds. Analyses of associated fauna samples indicated that snapping shrimps provided a major contribution to the maerl bed soundscape. Moreover, sea urchins and squat lobsters most likely contributed to differences between the soundscapes of unfished and fished maerl beds. Our results supported the idea that the soundscape can provide valuable information on maerl bed ecosystem health related to fishing activity. PMID:28280559

  17. Abiotic factors influencing the spatial and temporal variability of juvenile fish in Pamlico Sound, North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Pietrafesa, L.J.; Janowitz, G.S.; Miller, J.M.; Noble, E.B.; Ross, S.W.; Epperly, S.P.

    1985-07-01

    A 3-D, time dependent model of the circulation in Pamlico Sound, NC, is used to relate the direction and magnitude of winds to the number of juvenile fish sampled at specified estuarine nursery locations. NC marine sport fishes are known to be spawned in NC continental waters, and then make transit to an through barrier island inlets, into Pamlico Sound. The juveniles then move 40-70 kilometers across the Sound to the nurseries. It is hypothesized that wind driven, pressure gradient induced and topographically steered currents, all abiotic factors, provide the transport mechanisms, during the recruitment period February-April, necessary for the transect. Moreover, the inherent variability in the atmospherically derived physical factors and the influence of topographic irregularities such as a large shoal which laterally bisects the Sound and bifurcates the bottom currents are seen as sources of the temporal and spatial variation observed in the distribution of juvenile fish, while the influence of biological processes is viewed as providing fine-tuned structuring.

  18. Investigations on juvenile fish excluder cum shrimp sorting device (JFE-SSD).

    Science.gov (United States)

    Boopendranath, Menothuparambil Ravunny; Pravin, Puthra; Gibinkumar, Therodath Rajan; Sabu, Sarasan; Madhu, Vettiyattil Ramakrishnan

    2013-12-01

    Penaeid shrimp is a major resource in India contributing about 7.4% of the total marine fish landings. They are mostly landed by small mechanized trawlers. Shrimp trawling generates large quantities of bycatch mostly consisting of juvenile fishes, due to use of small mesh size in codends of trawl nets. Juvenile Fish Excluder cum Shrimp Sorting Device (JFE-SSD) is a bycatch reduction device with an in situ sorting mechanism, which replaces the conventional codend in a trawl. The device was designed to catch shrimps and commercially important fish species using a specially designed oval sorting grid with appropriate bar spacing and dual codends. Shrimp sorting efficiency and bycatch exclusion characteristics of JFE-SSD attached to a 29.6 m shrimp trawl, was tested by experimental fishing along the coastal waters off Cochin, India. Out of a total of 317.07 kg of catch encountered in the JFE-SSD installed trawl, 58.22% was retained in lower codend, 17.53% in upper codend and 24.25%, mostly consisting of juveniles and sub-adults of finfishes and shellfishes, was excluded from upper codend. The mean CPUE registered for upper and lower codend were 7.23±1.04 SE and 5.84±0.96 SE kg h(-1) respectively. The CPUE of shrimps retained in upper and lower codends were significantly different (Kruskal-Wallis test (1,62), P<0.001), but the mean CPUE for fishes did not vary significantly. The average escapement of shrimps and juvenile fishes from upper codend were 0.06±0.02 SE kg h(-1) and 2.40±0.44 SE kg h(-1) respectively. Significant differences in the length composition between upper and lower codends were noticed for Megalaspis cordyla, Stolephorus waitei, Metapenaeus dobsoni and Parapenaeopsis stylifera. The experiments demonstrated in situ sorting ability of the device and its potential to reduce the bycatch of juveniles and sub-adults in shrimp trawls.

  19. Collapse and recovery of marine fishes.

    Science.gov (United States)

    Hutchings, J A

    2000-08-24

    Overexploitation and subsequent collapse of marine fishes has focused attention on the ability of affected populations to recover to former abundance levels and on the degree to which their persistence is threatened by extinction. Although potential for recovery has been assessed indirectly, actual changes in population size following long-term declines have not been examined empirically. Here I show that there is very little evidence for rapid recovery from prolonged declines, in contrast to the perception that marine fishes are highly resilient to large population reductions. With the possible exception of herring and related species that mature early in life and are fished with highly selective equipment, my analysis of 90 stocks reveals that many gadids (for example, cod, haddock) and other non-clupeids (for example, flatfishes) have experienced little, if any, recovery as much as 15 years after 45-99% reductions in reproductive biomass. Although the effects of overfishing on single species may generally be reversible, the actual time required for recovery appears to be considerable. To exempt marine fishes from existing criteria used to assign extinction risk would be inconsistent with precautionary approaches to fisheries management and the conservation of marine biodiversity.

  20. Identification of marine-derived lipids in juvenile coho salmon and aquatic insects through fatty acid analysis

    Science.gov (United States)

    Heintz, Ron A.; Wipfli, Mark S.; Hudson, John P.

    2010-01-01

    The energetic benefits enjoyed by consumers in streams with salmon runs depend on how those benefits are accrued. Adult Pacific salmon Oncorhynchus spp. deliver significant amounts of nutrients (i.e., nitrogen and phosphorus) and carbon to streams when they spawn and die; these nutrient additions can have demonstrable effects on primary production in streams. Consumption of carcass tissues or eggs provides for direct energy subsidies to consumers and may have significant effects on their condition. In this study, comparisons of juvenile coho salmon O. kisutch and aquatic insects exposed to terrestrial and marine energy sources demonstrated that direct consumption of marine-derived lipids had a significant effect on the lipid reserves of consumers. Direct consumption of marine-derived tissues was verified through fatty acid analysis. Selected aquatic insects and juvenile coho salmon were reared for 6 weeks in experimental streams supplied with terrestrial or marine energy sources. Chironomid midges, nemourid stoneflies, and juvenile coho salmon exposed to the marine energy source altered their fatty acid compositions by incorporating the long-chain polyunsaturated fatty acids that are characteristic of marine fish. The fatty acid composition of baetid mayflies was unaffected. The direct movement of specific fatty markers indicated that direct consumption of marine-derived tissues led to increased energy reserves (triacylglycerols) in consumers. Similar results were obtained for juvenile coho salmon sampled from natural streams before and after the arrival of adult salmon runs. These data indicate that marine-derived lipids from anadromous fish runs are an important source of reserve lipids for consumers that overwinter in streams.

  1. Ecological speciation in marine v. freshwater fishes.

    Science.gov (United States)

    Puebla, O

    2009-10-01

    Absolute barriers to dispersal are not common in marine systems, and the prevalence of planktonic larvae in marine taxa provides potential for gene flow across large geographic distances. These observations raise the fundamental question in marine evolutionary biology as to whether geographic and oceanographic barriers alone can account for the high levels of species diversity observed in marine environments such as coral reefs, or whether marine speciation also operates in the presence of gene flow between diverging populations. In this respect, the ecological hypothesis of speciation, in which reproductive isolation results from divergent or disruptive natural selection, is of particular interest because it may operate in the presence of gene flow. Although important insights into the process of ecological speciation in aquatic environments have been provided by the study of freshwater fishes, comparatively little is known about the possibility of ecological speciation in marine teleosts. In this study, the evidence consistent with different aspects of the ecological hypothesis of speciation is evaluated in marine fishes. Molecular approaches have played a critical role in the development of speciation hypotheses in marine fishes, with a role of ecology suggested by the occurrence of sister clades separated by ecological factors, rapid cladogenesis or the persistence of genetically and ecologically differentiated species in the presence of gene flow. Yet, ecological speciation research in marine fishes is still largely at an exploratory stage. Cases where the major ingredients of ecological speciation, namely a source of natural divergent or disruptive selection, a mechanism of reproductive isolation and a link between the two have been explicitly documented are few. Even in these cases, specific predictions of the ecological hypothesis of speciation remain largely untested. Recent developments in the study of freshwater fishes illustrate the potential for

  2. Dataset for Alaska marine fish ecology catalog

    Science.gov (United States)

    Thorsteinson, Lyman K.

    2017-01-01

    This collection of GIS layers was prepared for the report Alaska Arctic Marine Fish Ecology Catalog (U.S. Geological Survey Scientific Investigations Report 2016–5038). The layers display geographic distribution and sampling locations for Arctic marine fish species in the region of United States sectors of the Chukchi and Beaufort Seas. Certain diadromous species (for example, Pacific salmon, char, and whitefishes) are treated as marine fishes (McDowall, 1987) because much of their life cycle is in marine and brackish environments. This synthesis of information is meant to provide current information and understanding of this fauna and its relative vulnerability to changing Arctic conditions.There are 104 species in the collection - some species have both polygon and point data layers. The report (SIR 2016-5038) also describes for each species its names - species, common, and colloquial; ecological role; physical description/attributes; range (geographic); relative abundance; depth range; habitats and life history; behavior; populations or stocks, reproduction, food and feeding, biological interactions, resilience, traditional and cultural importance, commercial fisheries, potential effects of climate change, areas for future research, cited references, and bibliography.  The published report has one map for each species showing the polygon and point data as well as land and relevant administrative boundaries. Although some of the species also have an inland water presence, this report was concerned only with their marine conditions; therefore, the land component (from the original sources) has been clipped and removed. The distribution areas may be greater in extent than that shown in the report map bounding box limits. Distributions of marine fishes are shown in adjacent Arctic seas where reliable data are available. The report can be accessed at: https://doi.org/10.3133/sir20165038This metadata document describes the collection of species data layers. Each

  3. Juvenile fish condition in estuarine nurseries along the Portuguese coast

    Science.gov (United States)

    Vasconcelos, R. P.; Reis-Santos, P.; Fonseca, V.; Ruano, M.; Tanner, S.; Costa, M. J.; Cabral, H. N.

    2009-03-01

    Connectivity between estuarine fish nurseries and coastal adult habitats can be affected by variations in juvenile growth and survival. Condition indices are renowned proxies of juvenile nutritional status and growth rates and are valuable tools to assess habitat quality. Biochemical (RNA:DNA ratio) and morphometric (Fulton's condition factor K) condition indices were determined in juveniles of Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax collected in putative nursery areas of nine estuaries along the Portuguese coast (Minho, Douro, Ria de Aveiro, Mondego, Tejo, Sado, Mira, Ria Formosa and Guadiana) in the Spring and Summer of two consecutive years (2005 and 2006) with distinct climatic characteristics. Individual condition showed significant variation amongst species. The combined use of both condition indices highlighted the low correlation between them and that RNA:DNA had a higher sensitivity. RNA:DNA varied between years but overall the site relative patterns in condition were maintained from one year to the other. Higher RNA:DNA values were found in Spring than in Summer in most species. Intra-estuarine variation also occurred in several cases. Species specific trends in the variability of condition amongst estuaries were highlighted. Some estuaries had higher juvenile condition for more than one species but results did not reveal an identical trend for all species and sites, hindering the hypotheses of one estuarine nursery promoting superior growth for all present species. Significant correlations were found between condition indices, juvenile densities and environmental variables (water temperature, salinity and depth) in the estuarine nurseries. These influenced juvenile nutritional condition and growth, contributing to the variability in estuarine nursery habitat quality. Management and conservation wise, interest in multi-species approaches is reinforced as assessments based on a single species may not

  4. Early marine life history of juvenile Pacific salmon in two regions of Puget Sound

    Science.gov (United States)

    Duffy, E.J.; Beauchamp, D.A.; Buckley, R.M.

    2005-01-01

    Puget Sound could differentially represent either a simple migration corridor or an important rearing environment during the potentially critical early marine residence period for different species of Pacific salmon. Recent declines in various stocks of Puget Sound salmon could reflect degraded rearing conditions or changes in temporal-spatial utilization patterns by juvenile salmon in Puget Sound, and these patterns could vary between habitats and regions of Puget Sound in response to different environmental conditions or hatchery practices. In April-September 2001 and 2002, we evaluated spatial and temporal differences in distribution and size structure among juvenile chum, pink, coho, and chinook salmon at delta and nearshore habitats in a northern and southern region of Puget Sound, Washington. Water was consistently warmer (8-18.8??C) and less saline (0.0-27.7) in the northern (N) than in the southern region (S: 9.5-14.6??C, 13.0-30.4). Salinities were lower and water temperatures more variable in delta sites than exposed nearshore marine sites. Peak densities of juvenile salmon coincided at delta and nearshore sites within sampling regions but differed between regions. Nearshore densities were highest during April-June with pink and chum salmon generally preceding chinook and coho salmon, and peak catch rates of most species occurred in May. A second, late pulse of chinook salmon also occurred during July at northern sites. Juvenile chinook salmon were predominantly of hatchery origin in the southern region (98%), and of mixed origin in the northern region (44% marked hatchery fish) during 2002. The lengths of chinook and chum salmon in nearshore regions increased steadily through time, whereas pink and coho salmon varied inconsistently. Mean sizes of juvenile salmon were slightly but consistently smaller at delta than nearshore sites and at northern versus southern sites. Hatchery chinook salmon were slightly larger than their unmarked counterparts. Extended

  5. Feeding habit of juvenile fishes associated with drifting seaweeds in the East China Sea with reference to oceanographic parameters

    OpenAIRE

    Hasegawa, Takamasa; Manda, Atsuyoshi; Takatsuki, Naoki; KAWABATA, YUUKI; NISHIHARA Gregory N.; Fujita, Shinji; Kawabe, Ryo; Yamada, Misato; Kinoshita, Tsukasa; Yamawaki, Nobuhiro; Morii, Yasuhiro; Sakakura, Yoshitaka

    2016-01-01

    Many commercially important fishes associate with drifting seaweeds in their juvenile stage, however, the ecological significance of drifting seaweeds for juvenile fishes is still unclear. We postulated that the following two hypotheses may be applicable for juvenile fishes associate with drifting seaweeds, the “concentration of food supply” hypothesis: juvenile fishes are attracted by phytal animals on the drifting seaweeds and the “indicator-log” hypothesis: fish use accumulations of drifti...

  6. Spatial variations in dietary organic matter sources modulate the size and condition of fish juveniles in temperate lagoon nursery sites

    Science.gov (United States)

    Escalas, Arthur; Ferraton, Franck; Paillon, Christelle; Vidy, Guy; Carcaillet, Frédérique; Salen-Picard, Chantal; Le Loc'h, François; Richard, Pierre; Darnaude, Audrey Michèle

    2015-01-01

    Effective conservation of marine fish stocks involves understanding the impact, on population dynamics, of intra-specific variation in nursery habitats use at the juvenile stage. In some regions, an important part of the catching effort is concentrated on a small number of marine species that colonize coastal lagoons during their first year of life. To determine the intra-specific variation in lagoon use by these fish and their potential demographic consequences, we studied diet spatiotemporal variations in the group 0 juveniles of a highly exploited sparid, the gilthead seabream (Sparus aurata L.), during their ∼6 months stay in a NW Mediterranean lagoon (N = 331, SL = 25-198 mm) and traced the origin of the organic matter in their food webs, at two lagoon sites with contrasted continental inputs. This showed that the origin (marine, lagoonal or continental) of the organic matter (OM) available in the water column and the sediment can vary substantially within the same lagoon, in line with local variations in the intensity of marine and continental inputs. The high trophic plasticity of S. aurata allows its juveniles to adapt to resulting differences in prey abundances at each site during their lagoon residency, thereby sustaining high growth irrespective of the area inhabited within the lagoon. However, continental POM incorporation by the juveniles through their diet (of 21-37% on average depending on the site) is proportional to its availability in the environment and could be responsible for the greater fish sizes (of 28 mm SL on average) and body weights (of 40.8 g on average) observed at the site under continental influence in the autumn, when the juveniles are ready to leave the lagoon. This suggests that continental inputs in particulate OM, when present, could significantly enhance fish growth within coastal lagoons, with important consequences on the local population dynamics of the fish species that use them as nurseries. As our results indicate that

  7. Recruitment of juvenile fishes into a small temperate choked lagoon (Argentina and the influence of environmental factors during the process

    Directory of Open Access Journals (Sweden)

    Daniel O. Bruno

    2015-03-01

    Full Text Available Juvenile fishes were sampled every 15 days from September 2009 to April 2010 along the marine-estuarine gradient (surf zone, estuary and a freshwater stream of the Mar Chiquita lagoon, Argentina. The temporal variations of juvenile assemblages in spring-summer and the environmental variables related to the spatial and temporal patterns were analysed. Four groups of sampling stations were defined, indicating differences in fish composition among zones during the spring–early summer period (Groups I to III, while the composition of juvenile fishes was homogeneous along the marine-estuarine gradient during the late summer–early autumn period (Group IV. Platanichthys platana and Ramnogaster arcuata (Group A and Odontesthes argentinensis and Brevoortia aureaz (Group B contributed most to the temporal differences observed. The three first species reached this estuarine system in spring, although with lower abundances than in early summer, while B. aurea was dominant in late summer–early autumn, showing different periods of recruitment of these species into the lagoon. After factoring out variation due to shared spatial-temporal-environmental factors (4.43%, canonical correspondence analysis (CCA showed that temporal factors had an almost five times greater contribution (15.15% than spatial factors (2.85% and almost twice as great as the pure environmental factors (8.11% to explaining the variation in abundance of the juvenile fishes. From the significant environmental variables incorporated in the CCA, wind direction contributed more than water temperature, salinity or transparency in explaining data variability. Indeed, most species were related to “onshore winds” and therefore the importance of wind in the successful recruitment of juveniles into this shallow and micro-tidal estuary is discussed.

  8. Nursery use patterns of commercially important marine fish species in estuarine systems along the Portuguese coast

    Science.gov (United States)

    Vasconcelos, R. P.; Reis-Santos, P.; Maia, A.; Fonseca, V.; França, S.; Wouters, N.; Costa, M. J.; Cabral, H. N.

    2010-03-01

    Analysing the estuarine use patterns of juveniles of marine migrant fish species is vital for identifying important sites for juveniles as well as the basic environmental features that characterize these sites for different species. This is a key aspect towards understanding nursery function. Various estuarine systems along the Portuguese coast (Minho, Douro, Ria de Aveiro, Mondego, Tejo, Sado, Mira, Ria Formosa and Guadiana) were sampled during Spring and Summer 2005 and 2006. Juveniles of commercially important marine fish species Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax, predominantly 0-group individuals, were amongst the most abundant species and had distinct patterns of estuarine use as well as conspicuous associations with several environmental features. Juvenile occurrence and density varied amongst estuaries and sites within them, and differed with species. Sites with consistently high juvenile densities were identified as important juvenile sites (i.e. putative nursery grounds). Through generalized linear models (GLM), intra-estuarine variation in occurrence and density of each of the individual species was largely explained by environmental variables (temperature; salinity; depth; percentage of mud in the sediment; presence of seagrass; importance of intertidal areas; relative distance to estuary mouth; macrozoobenthos densities; and latitude). Decisive environmental factors defining important sites for juveniles varied depending on the system as a result of different environmental gradients, though there were common dominant features for each species regardless of the estuary considered. Analysed environmental variables in the GLM also accounted for inter-estuarine variation in species' occurrence and density. In several estuaries, the identified important juvenile sites were used by many of these species simultaneously and may be of increased value to both management and conservation. Overall, the

  9. Protecting the hand that feeds us: seagrass (Zostera marina) serves as commercial juvenile fish habitat.

    Science.gov (United States)

    Bertelli, Chiara M; Unsworth, Richard K F

    2014-06-30

    Although fisheries are of major economic and food security importance we still know little about specific juvenile habitats that support such production. This is a major issue given the degradation to and lack of protection afforded to potential juvenile habitats such as seagrass meadows. In the present study we investigate the role of seagrass in supporting juvenile fish of commercial value. By assessing seagrass relative to adjacent sand we determined the presence of abundant juvenile fish. Nine commercial species were recorded and the most abundant of these were Plaice, Pollock and Herring. We provide the first quantitative evidence of the presence of juvenile fish of commercial value in seagrass surrounding Great Britain. Although the species that we found in seagrass as juveniles are not obligate seagrass users the resources that seagrass meadows offer to these fish provide significant long-term fitness benefits, potentially enhancing the whole population.

  10. Nocturnal relocation of adult and juvenile coral reef fishes in response to reef noise

    Science.gov (United States)

    Simpson, S. D.; Jeffs, A.; Montgomery, J. C.; McCauley, R. D.; Meekan, M. G.

    2008-03-01

    Juvenile and adult reef fishes often undergo migration, ontogenic habitat shifts, and nocturnal foraging movements. The orientation cues used for these behaviours are largely unknown. In this study, the use of sound as an orientation cue guiding the nocturnal movements of adult and juvenile reef fishes at Lizard Island, Great Barrier Reef was examined. The first experiment compared the movements of fishes to small patch reefs where reef noise was broadcast, with those to silent reefs. No significant responses were found in the 79 adults that were collected, but the 166 juveniles collected showed an increased diversity each morning on the reefs with broadcast noise, and significantly greater numbers of juveniles from three taxa (Apogonidae, Gobiidae and Pinguipedidae) were collected from reefs with broadcast noise. The second experiment compared the movement of adult and juvenile fishes to reefs broadcasting high (>570 Hz), or low (Gobiidae and Blenniidae) preferred these reefs. A similar trend was observed in the 372 juveniles collected, with higher diversity at the reefs with low frequency noises. This preference was seen in the juvenile apogonids; however, juvenile gobiids were attracted to both high and low sound treatments equally, and juvenile stage Acanthuridae preferred the high frequency noises. This evidence that juvenile and adult reef fishes orientate with respect to the soundscape raises important issues for management, conservation and the protection of sound cues used in natural behaviour.

  11. Accumulation of Co by marine fish

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Taishi; Nakahara, Motokazu (National Inst. of Radiological Sciences, Chiba (Japan))

    1983-04-01

    To know the effect of chemical forms of Co on its accumulation by marine fish, the accumulation and excreton of Co by the organism were observed using /sup 60/CoCl/sub 2/ and /sup 57/Co cyanocobalamin. The biological half life of the long component of /sup 60/CoCl/sub 2/ was 166 days, and that of /sup 57/Co cyanocobalamin was 43 days at 15 deg C. The concentration factor at the steady state was calculated as 32 for /sup 60/CoCl/sub 2/ and 3 for /sup 57/Co cyanocobalamin. The higher concentration factor of /sup 60/CoCl/sub 2/ than /sup 57/Co cyanocobalamin was characteristic in comparison with other marine organisms. The distribution (%) of /sup 57/Co cyanocobalamin in the liver was three times higher than that of /sup 60/CoCl/sub 2/. It was estimated from the gel filtrations on Sephadex G-75 and Sepharose CL-4B that /sup 60/Co combined with five constituents in the liver of Acanthopagrus schlegeli and Chasmichthys gulosus, and with two constituents in the liver of Girella punctata. The gel filtration profiles of /sup 57/Co cyanocobalamin in the liver of C. gulosus was similar to those of /sup 60/Co. These constituents were considered to be protein by referring to the optical density at 280 nm. A constituent with a molecular weight of 2 x 10/sup 5/ which combined with Co was characteristic in livers of fish among the marine organisms.

  12. Viral haemorrhagic septicaemia virus in marine fish and its implications for fish farming - a review

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Mellergaard, Stig

    2005-01-01

    marine fish show no to low pathogenicity to rainbow trout and Atlantic salmon, although several are pathogenic for turbot. Marine VHSV isolates are so far serologically indistinguishable from freshwater isolates. Genotyping based on VHSV G- and N-genes reveals four groups indicating the geographical...... of possible transfer of virus from free-living marine fish to farmed fish are discussed, as are measures to prevent introduction of VHSV from the marine environment to aquaculture....

  13. Marine Fish Proteins and Peptides for Cosmeceuticals: A Review

    Directory of Open Access Journals (Sweden)

    Jayachandran Venkatesan

    2017-05-01

    Full Text Available Marine fish provide a rich source of bioactive compounds such as proteins and peptides. The bioactive proteins and peptides derived from marine fish have gained enormous interest in nutraceutical, pharmaceutical, and cosmeceutical industries due to their broad spectrum of bioactivities, including antioxidant, antimicrobial, and anti-aging activities. Recently, the development of cosmeceuticals using marine fish-derived proteins and peptides obtained from chemical or enzymatical hydrolysis of fish processing by-products has increased rapidly owing to their activities in antioxidation and tissue regeneration. Marine fish-derived collagen has been utilized for the development of cosmeceutical products due to its abilities in skin repair and tissue regeneration. Marine fish-derived peptides have also been utilized for various cosmeceutical applications due to their antioxidant, antimicrobial, and matrix metalloproteinase inhibitory activities. In addition, marine fish-derived proteins and hydrolysates demonstrated efficient anti-photoaging activity. The present review highlights and presents an overview of the current status of the isolation and applications of marine fish-derived proteins and peptides. This review also demonstrates that marine fish-derived proteins and peptides have high potential for biocompatible and effective cosmeceuticals.

  14. Hypoxia, blackwater and fish kills: experimental lethal oxygen thresholds in juvenile predatory lowland river fishes.

    Directory of Open Access Journals (Sweden)

    Kade Small

    Full Text Available Hypoxia represents a growing threat to biodiversity in freshwater ecosystems. Here, aquatic surface respiration (ASR and oxygen thresholds required for survival in freshwater and simulated blackwater are evaluated for four lowland river fishes native to the Murray-Darling Basin (MDB, Australia. Juvenile stages of predatory species including golden perch Macquaria ambigua, silver perch Bidyanus bidyanus, Murray cod Maccullochella peelii, and eel-tailed catfish Tandanus tandanus were exposed to experimental conditions of nitrogen-induced hypoxia in freshwater and hypoxic blackwater simulations using dried river red gum Eucalyptus camaldulensis leaf litter. Australia's largest freshwater fish, M. peelii, was the most sensitive to hypoxia but given that we evaluated tolerances of juveniles (0.99 ± 0.04 g; mean mass ±SE, the low tolerance of this species could not be attributed to its large maximum attainable body mass (>100,000 g. Concentrations of dissolved oxygen causing 50% mortality (LC50 in freshwater ranged from 0.25 ± 0.06 mg l(-1 in T. tandanus to 1.58 ± 0.01 mg l(-1 in M. peelii over 48 h at 25-26 °C. Logistic models predicted that first mortalities may start at oxygen concentrations ranging from 2.4 mg l(-1 to 3.1 mg l(-1 in T. tandanus and M. peelii respectively within blackwater simulations. Aquatic surface respiration preceded mortality and this behaviour is documented here for the first time in juveniles of all four species. Despite the natural occurrence of hypoxia and blackwater events in lowland rivers of the MDB, juvenile stages of these large-bodied predators are vulnerable to mortality induced by low oxygen concentration and water chemistry changes associated with the decomposition of organic material. Given the extent of natural flow regime alteration and climate change predictions of rising temperatures and more severe drought and flooding, acute episodes of hypoxia may represent an underappreciated risk to riverine fish

  15. Retrospective quantification of estuarine feeding activity by coastally caught marine fishes

    Science.gov (United States)

    Leakey, Chris D. B.; Attrill, Martin J.; Jennings, Simon; Fitzsimons, Mark F.

    2008-10-01

    Many commercially important marine fishes are found in estuaries, particularly as juveniles. The estuaries may provide a thermal resource, refuge from predators and a source of abundant prey. Here, carbon ( δ13C) and sulphur ( δ34S) stable isotope data from coastally caught common sole ( Solea solea) and whiting ( Merlangius merlangus) were used in independent mixing models to determine relative contributions of estuarine prey to white muscle composition. The influence of assumed trophic fractionation was also investigated with sensitivity analysis. At the population level, there was evidence for estuarine contributions to muscle tissue in both species (means from 16.37% to 61.28%), though among-individual variability was considerable. δ13C and δ34S model outputs implied different estuarine contributions for the same individual, likely reflecting the slower turnover of δ34S than δ13C. Sole exhibited population level plasticity in their feeding as juveniles, separating into two distinct juvenile sub-populations; but they are less plastic as older fish when they adopt increasingly marine diets. Whiting show individual plasticity as both juveniles and adults, feeding on prey of estuarine and coastal origin.

  16. Debris ingestion by juvenile marine turtles: an underestimated problem.

    Science.gov (United States)

    Santos, Robson Guimarães; Andrades, Ryan; Boldrini, Marcillo Altoé; Martins, Agnaldo Silva

    2015-04-15

    Marine turtles are an iconic group of endangered animals threatened by debris ingestion. However, key aspects related to debris ingestion are still poorly known, including its effects on mortality and the original use of the ingested debris. Therefore, we analysed the impact of debris ingestion in 265 green turtles (Chelonia mydas) over a large geographical area and different habitats along the Brazilian coast. We determined the death rate due to debris ingestion and quantified the amount of debris that is sufficient to cause the death of juvenile green turtles. Additionally, we investigated the original use of the ingested debris. We found that a surprisingly small amount of debris was sufficient to block the digestive tract and cause death. We suggested that debris ingestion has a high death potential that may be masked by other causes of death. An expressive part of the ingested debris come from disposable and short-lived products. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The importance of estuary head waters as nursery areas for young estuary- and marine-spawned fishes in temperate South Africa

    Science.gov (United States)

    Wasserman, Ryan J.; Strydom, Nadine A.

    2011-07-01

    The restriction of freshwater flow into estuaries, the presence of in-stream barriers and the occurrence of invasive fish species in these habitats are identified as major threats to these young estuary- and marine-spawned fish species. These aspects have been investigated using the distribution and abundance of young estuary- and marine-spawned fish species in the headwater environments of four permanently open estuaries of the Eastern Cape, South Africa. Fishes were collected twice per season over the 2009 and 2010 period, using mixed method sampling with seine net hauls and overnight fyke net deployments. Of the 74,751 fishes collected, 37,444 fishes, 18 families and 34 species were taken in fyke net catches, while 34,308 fishes, 21 families and 38 species were caught in seine nets. In the Great Fish, Kowie, Kariega and Sundays River systems, juveniles of estuarine residents dominated headwater catches, followed by juveniles of estuary-dependent marine species. The prevalence of larval and small juvenile stages of estuary- and marine-spawned fish species highlights the potential importance of these transitional areas for young fish.

  18. Differences in fatty acid composition between cerebral brain lobes in juvenile pigs after fish oil feeding

    NARCIS (Netherlands)

    Dullemeijer, C.; Zock, P.L.; Coronel, R.; Ruijter, den H.M.; Katan, M.B.; Brummer, R.J.; Kok, F.J.; Beekman, J.; Brouwer, I.A.

    2008-01-01

    Very long-chain n-3 PUFA from fish are suggested to play a role in the development of the brain. Fish oil feeding results in higher proportions of n-3 PUFA in the brains of newborn piglets. However, the effect of fish oil on the fatty acid composition of specific cerebral brain lobes in juvenile

  19. Overview of current marine juvenile salmon research by the United States

    Science.gov (United States)

    Helle, John H.; Eisner, L.B.; Farley, Edward V.; Martinson, Ellen C.; Martinson, Angela; Moss, Jamal H.; Murphy, James M.; Orsi, Joseph A.; Sturdevant, Mollly V.; Wertheimer, Alex C.; Wing, Bruce L.; Brodeur, R.D.; Emmett, Robert; Bucher, Cynthia; MacFarlane, Bruce; Harding, Jeff; Ammann, Arnold; Zimmerman, Christian E.

    2007-01-01

    A history of juvenile salmon research on Pacific salmon in coastal areas conducted by the United States (U.S.) was published by Brodeur et al. (2003). Presently, juvenile Pacific salmon research in the U.S. occurs in the coastal areas of all of the Pacific states: California, Oregon, Washington, and Alaska (Fig. 1). Major objectives of this research are to understand how dynamics in marine ecosystems influence migration, distribution, growth, and survival of juvenile salmon during their early ocean residence. Several large-scale studies in coastal areas from California to Alaska are currently being conducted by the National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS), in collaboration with university and state scientists. Studies off California are operated by the Southwest Fisheries Science Center, Santa Cruz Laboratory in Santa Cruz, California and University of California Santa Cruz. Studies off Oregon and Washington are operated by the Northwest Fisheries Science Center, Newport Laboratory and Oregon State University in Newport, Oregon. Studies in the Gulf of Alaska, Bering Sea and in the seaward migration corridors in the coastal waters of southeastern Alaska are operated by the Alaska Fisheries Science Center, Auke Bay Laboratory in Juneau, Alaska, in collaboration with Alaska Department of Fish and Game, University of Alaska Fairbanks, Bering Sea Fishermen’s Association, and Yukon River Drainage Fishermen’s Association. In addition to these large studies, smaller estuarine studies on juvenile salmon occur in northwestern Alaska in Kuskokwim Bay by the U.S. Geological Survey (Anchorage) and University of Alaska Fairbanks (Juneau), and, in Norton Sound by LGL Alaska Research Associates and Norton Sound Economic Development Corporation both headquartered in Anchorage (Fig. 1). The estuarine studies on juvenile salmon in Alaska operate in shallow water and a variety of gear is used to capture salmon. A small trawl

  20. Estuary fish data - Juvenile salmon in migratory corridors of lower Columbia River estuary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sampling juvenile salmon and associated fishes in open waters of the lower Columbia River estuary. Field work includes bi-weekly sampling during the spring...

  1. Evaluation of Juvenile Fish Bypass and Adult Fish Facilities at Water Diversions in the Umatilla River; 1992 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Suzanne M.

    1993-03-01

    We report on our progress from October 1991 through September 1992 in evaluating juvenile fish bypass facilities at Three Mile Falls and Westland dams on the Umatilla River. We also report on our progress from October 1991 through June 1992 in evaluating adult fish passage in the lower Umatilla River and adult fish passage facilities at Three Mile Falls Dam. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). These are the study objectives addressed by ODFW and CTUIR: (1) Report A (ODFW): To evaluate the juvenile fish bypass facility in the West Extension Irrigation District Canal at Three Mile Falls Dam and document juvenile salmonid passage through the juvenile fish bypass facility and east-bank adult fish ladder. To measure velocity and develop trap designs at Westland Dam. (2) Report B (CTUIR): To examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin, including restoration of coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), as well as enhancement of summer steelhead (Oncorhynchus mykiss).

  2. Habitat type and nursery function for coastal marine fish species, with emphasis on the Eastern Cape region, South Africa

    Science.gov (United States)

    Whitfield, Alan K.; Pattrick, Paula

    2015-07-01

    A considerable amount of research has been undertaken to document and assess the nursery function of a variety of coastal habitats for marine fish species around the world. Most of these studies have focused on particular habitats and have generally been confined to a limited range of fish species associated with specific nursery areas. In this review we conduct a general assessment of the state of knowledge of coastal habitats in fulfilling the nursery-role concept for marine fishes, with particular emphasis on biotic and abiotic factors that influence nursery value. A primary aim was to synthesize information that can be used to drive sound conservation planning and provide a conceptual framework so that new marine protected areas (MPAs) incorporate the full range of nursery areas that are present within the coastal zone. We also use published data from a coastal section in the Eastern Cape Province, South Africa, to highlight the differential use of shallow aquatic habitats by a range of juvenile marine fish species within this region. Although the Eastern Cape case study does not assess the relative growth, food availability or predation in nursery and non-nursery areas within the coastal zone, it does document which habitats are important to the juveniles of dominant marine species within each area. These habitats, which range from intertidal pools, subtidal gulleys and surf zones to estuaries, do appear to perform a key role in the biological success of species assemblages, with the juveniles of particular marine fishes tending to favour specific nursery areas. According to a multivariate analysis of nursery habitat use within this region, marine species using estuaries tend to differ considerably from those using nearshore coastal waters, with a similar pattern likely to occur elsewhere in the world.

  3. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Water Diversions in the Umatilla River; 1993 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Suzanne M.

    1994-03-01

    This report presents progress from October 1992 through September 1993 in evaluating juvenile fish bypass facilities at Three Mile Falls, Maxwell, Westland, and Feed Canal dams on the Umatilla River, and in evaluating adult fish passage in the lower Umatilla River. Also reported is an effort to evaluate delayed mortality and stress responses of juvenile salmonids resulting from trapping and transport at high temperatures. These studies are part of a program to rehabilitate anadromous fish stocks in the matilla River Basin, including restoration of coho salmon and chinook salmon, as well as enhancement of summer steelhead.

  4. Indirect consequences of fishing: reduction of coralline algae suppresses juvenile coral abundance

    Science.gov (United States)

    O'Leary, J. K.; Potts, D. C.; Braga, J. C.; McClanahan, T. R.

    2012-06-01

    Removing predatory fishes has effects that cascade through ecosystems via interactions between species and functional groups. In Kenyan reef lagoons, fishing-induced trophic cascades produce sea urchin-dominated grazing communities that greatly reduce the overall cover of crustose coralline algae (CCA). Certain species of CCA enhance coral recruitment by chemically inducing coral settlement. If sea urchin grazing reduces cover of settlement-inducing CCA, coral recruitment and hence juvenile coral abundance may also decline on fished reefs. To determine whether fishing-induced changes in CCA influence coral recruitment and abundance, we compared (1) CCA taxonomic compositions and (2) taxon-specific associations between CCA and juvenile corals under three fisheries management systems: closed, gear-restricted, and open-access. On fished reefs (gear-restricted and open-access), abundances of two species of settlement-inducing CCA, Hydrolithon reinboldii and H. onkodes, were half those on closed reefs. On both closed and fished reefs, juveniles of four common coral families (Poritidae, Pocilloporidae, Agariciidae, and Faviidae) were more abundant on Hydrolithon than on any other settlement substrate. Coral densities were positively correlated with Hydrolithon spp. cover and were significantly lower on fished than on closed reefs, suggesting that fishing indirectly reduces coral recruitment or juvenile success over large spatial scales via reduction in settlement-inducing CCA. Therefore, managing reefs for higher cover of settlement-inducing CCA may enhance coral recruitment or juvenile survival and help to maintain the ecological and structural stability of reefs.

  5. Columbia River System Operation Review : Final Environmental Impact Statement, Appendix C: Anadromous Fish and Juvenile Fish Transportation.

    Energy Technology Data Exchange (ETDEWEB)

    Columbia River System Operation Review (U.S.)

    1995-11-01

    This Appendix C of the Final Environmental Impact Statement for the Columbia River System discusses impacts on andromous fish and juvenile fish transportation. The principal andromous fish in the Columbia basin include salmonid species (Chinook, coho, and sockeye salmon, and steelhead) and nonsalmoinid andromous species (sturgeon, lamprey, and shad). Major sections in this document include the following: background, scope and process; affected environment for salmon and steelhead, shaded, lamprey, sturgeon; study methods; description of alternatives: qualitative and quantitative findings.

  6. Larval dispersal and movement patterns of coral reef fishes, and implications for marine reserve network design.

    Science.gov (United States)

    Green, Alison L; Maypa, Aileen P; Almany, Glenn R; Rhodes, Kevin L; Weeks, Rebecca; Abesamis, Rene A; Gleason, Mary G; Mumby, Peter J; White, Alan T

    2015-11-01

    Well-designed and effectively managed networks of marine reserves can be effective tools for both fisheries management and biodiversity conservation. Connectivity, the demographic linking of local populations through the dispersal of individuals as larvae, juveniles or adults, is a key ecological factor to consider in marine reserve design, since it has important implications for the persistence of metapopulations and their recovery from disturbance. For marine reserves to protect biodiversity and enhance populations of species in fished areas, they must be able to sustain focal species (particularly fishery species) within their boundaries, and be spaced such that they can function as mutually replenishing networks whilst providing recruitment subsidies to fished areas. Thus the configuration (size, spacing and location) of individual reserves within a network should be informed by larval dispersal and movement patterns of the species for which protection is required. In the past, empirical data regarding larval dispersal and movement patterns of adults and juveniles of many tropical marine species have been unavailable or inaccessible to practitioners responsible for marine reserve design. Recent empirical studies using new technologies have also provided fresh insights into movement patterns of many species and redefined our understanding of connectivity among populations through larval dispersal. Our review of movement patterns of 34 families (210 species) of coral reef fishes demonstrates that movement patterns (home ranges, ontogenetic shifts and spawning migrations) vary among and within species, and are influenced by a range of factors (e.g. size, sex, behaviour, density, habitat characteristics, season, tide and time of day). Some species move marine reserves in tropical marine ecosystems to maximise benefits for conservation and fisheries management for a range of taxa. We recommend that: (i) marine reserves should be more than twice the size of the home

  7. The fish community of a moderately exposed beach on the southwestern Cape coast of South Africa and an assessment of this habitat as a nursery for juvenile fish

    Science.gov (United States)

    Bennett, B. A.

    1989-03-01

    The ichthyofauna of a moderately exposed surf-zone habitat on the southwestern Cape coast of South Africa was sampled by seine netting monthly for 13 months. Twenty species of fish, 40 306 individuals weighing a total of 211 kg were captured. The number of species and standing crop varied seasonally with higher values occurring during the summer (January-March). The average summer standing stock of 38·6 g m -2 was considerably higher than any previously recorded from a surf-zone habitat and the annual average (10·1 g m -2 was comparable with that in estuaries. Eighteen of the species sampled occurred almost exclusively as juveniles and only two as adults. Four species were present throughout the year, 11 of them seasonally and the remaining five sporadically. Small juveniles (20-35 mm) typically appeared in the surf-zone 2-4 months after they were spawned. These 0+ juveniles remained there for between three months and one year depending on species, before vacating the surf-zone for their adult habitats. A comparison of the abundance of juveniles in the surf-zone with other inshore marine habitats suggested that five species ( Amblyrhynchotes honckenii, Cheilodonichthys capensis, Diplodus sargus, Lithognathus mormyrus and Pomadasys olivaceum) may be entirely, and three species ( Lichia amia, Liza richardsoni and Rhabdosargus globiceps) largely, dependent on the surf-zone as a nursery area. It was concluded that the surf-zone of sandy beaches may be as important as estuaries as a nursery habitat for juvenile fish.

  8. Larval export from marine reserves and the recruitment benefit for fish and fisheries.

    Science.gov (United States)

    Harrison, Hugo B; Williamson, David H; Evans, Richard D; Almany, Glenn R; Thorrold, Simon R; Russ, Garry R; Feldheim, Kevin A; van Herwerden, Lynne; Planes, Serge; Srinivasan, Maya; Berumen, Michael L; Jones, Geoffrey P

    2012-06-05

    Marine reserves, areas closed to all forms of fishing, continue to be advocated and implemented to supplement fisheries and conserve populations. However, although the reproductive potential of important fishery species can dramatically increase inside reserves, the extent to which larval offspring are exported and the relative contribution of reserves to recruitment in fished and protected populations are unknown. Using genetic parentage analyses, we resolve patterns of larval dispersal for two species of exploited coral reef fish within a network of marine reserves on the Great Barrier Reef. In a 1,000 km(2) study area, populations resident in three reserves exported 83% (coral trout, Plectropomus maculatus) and 55% (stripey snapper, Lutjanus carponotatus) of assigned offspring to fished reefs, with the remainder having recruited to natal reserves or other reserves in the region. We estimate that reserves, which account for just 28% of the local reef area, produced approximately half of all juvenile recruitment to both reserve and fished reefs within 30 km. Our results provide compelling evidence that adequately protected reserve networks can make a significant contribution to the replenishment of populations on both reserve and fished reefs at a scale that benefits local stakeholders.

  9. Larval export from marine reserves and the recruitment benefit for fish and fisheries

    KAUST Repository

    Harrison, Hugo B.

    2012-06-01

    Marine reserves, areas closed to all forms of fishing, continue to be advocated and implemented to supplement fisheries and conserve populations [1-4]. However, although the reproductive potential of important fishery species can dramatically increase inside reserves [5-8], the extent to which larval offspring are exported and the relative contribution of reserves to recruitment in fished and protected populations are unknown [4, 9-11]. Using genetic parentage analyses, we resolve patterns of larval dispersal for two species of exploited coral reef fish within a network of marine reserves on the Great Barrier Reef. In a 1,000 km 2 study area, populations resident in three reserves exported 83% (coral trout, Plectropomus maculatus) and 55% (stripey snapper, Lutjanus carponotatus) of assigned offspring to fished reefs, with the remainder having recruited to natal reserves or other reserves in the region. We estimate that reserves, which account for just 28% of the local reef area, produced approximately half of all juvenile recruitment to both reserve and fished reefs within 30 km. Our results provide compelling evidence that adequately protected reserve networks can make a significant contribution to the replenishment of populations on both reserve and fished reefs at a scale that benefits local stakeholders. © 2012 Elsevier Ltd.

  10. Status of Coral Reef Fish Communities within the Mombasa Marine ...

    African Journals Online (AJOL)

    Keywords: Ecological monitoring, no-take area, partially-protected area, Marine ... abundance of haemulids (nocturnal carnivores) and acanthurids (herbivores) in ... This was also positively ... was little detectable effect on fish abundance.

  11. Are Caribbean mangroves important feeding grounds for juvenile reef fish from adjacent seagrass beds?

    NARCIS (Netherlands)

    Nagelkerken, I.A.; Velde, G. van der

    2004-01-01

    Little evidence is available on how juvenile fishes utilise seagrass beds and adjacent mangroves as feeding habitats. In this study we tested the degree to which Caribbean mangroves are utilised as feeding grounds by the fish community from adjacent seagrass beds. Stable carbon and nitrogen isotope

  12. Are Caribbean mangroves important feeding grounds for juvenile reef fish from adjacent seagrass beds?

    NARCIS (Netherlands)

    Nagelkerken, I.A.; Velde, G. van der

    2004-01-01

    Little evidence is available on how juvenile fishes utilise seagrass beds and adjacent mangroves as feeding habitats. In this study we tested the degree to which Caribbean mangroves are utilised as feeding grounds by the fish community from adjacent seagrass beds. Stable carbon and nitrogen isotope

  13. Trace metals (Cu, Zn, Cd and Pb in juvenile fish from estuarine nurseries along the Portuguese coast

    Directory of Open Access Journals (Sweden)

    Rita P. Vasconcelos

    2011-02-01

    Full Text Available Organic and inorganic pollution can impact organisms directly and affect condition, growth and survival of juvenile fish which use estuaries as nurseries, and thereby affect marine adult populations quantitatively and qualitatively. Trace element contamination (Cu, Zn, Cd, Pb in juveniles of commercial fish Solea solea, Solea senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax collected in putative nurseries of the main Portuguese estuaries (with diverse intensities and sources of anthropogenic pressures was determined via atomic absorption spectrometry. Contamination was significantly different among species. Similar levels of contamination were found among estuaries, except for D. vulgaris. Cu and Zn concentrations ranged from 1.0 to 2.1 and 14 to 59 μg g-1 muscle dry weight respectively; while Cd and Pb concentrations were very low. The results indicate that juvenile migration to off-shore habitats is associated with low export of contamination, and no particular estuary increases the potential contamination of adult stocks. This knowledge is of the utmost importance in view of the ecological and economical value of these species and their use of estuarine areas as nurseries.

  14. MARKETING SYSTEM OF MARINE FISH IN BANGLADESH: AN EMPIRICAL STUDY

    OpenAIRE

    Islam, M. Serajul; Miah, Tofazzal Hossain; Haque, Md. Mojammel

    2000-01-01

    This paper was designed to investigate the present status of marine fish marketing aiming to determine marketing costs, margins and profits of marketing intermediaries both in domestic and export marketing. Primary data were collected by survey method wherein various market intermediaries were interviewed from selected districts for eliciting information at various stages of marine fish marketing. The study revealed that marketing margin as well as marketing profit both were relatively higher...

  15. Seasonal and ontogenetic patterns of habitat use in coral reef fish juveniles

    OpenAIRE

    Mellin, Camille; Kulbicki, Michel; Ponton, Dominique

    2007-01-01

    We investigated the diversity of patterns of habitat use by juveniles of coral reef fishes according to seasons and at two spatial scales (10-100 m and 1-10 km). We conducted underwater visual censuses in New Caledonia's Lagoon between 1986 and 2001. Co-inertia analyses highlighted the importance of mid-shelf habitats at large spatial scale (1-10 km) and of sandy and vegetated habitats at small spatial scale (10-100 m) for most juveniles. Among all juvenile species, 53% used different habitat...

  16. Repeated and Widespread Evolution of Bioluminescence in Marine Fishes.

    Science.gov (United States)

    Davis, Matthew P; Sparks, John S; Smith, W Leo

    2016-01-01

    Bioluminescence is primarily a marine phenomenon with 80% of metazoan bioluminescent genera occurring in the world's oceans. Here we show that bioluminescence has evolved repeatedly and is phylogenetically widespread across ray-finned fishes. We recover 27 independent evolutionary events of bioluminescence, all among marine fish lineages. This finding indicates that bioluminescence has evolved many more times than previously hypothesized across fishes and the tree of life. Our exploration of the macroevolutionary patterns of bioluminescent lineages indicates that the present day diversity of some inshore and deep-sea bioluminescent fish lineages that use bioluminescence for communication, feeding, and reproduction exhibit exceptional species richness given clade age. We show that exceptional species richness occurs particularly in deep-sea fishes with intrinsic bioluminescent systems and both shallow water and deep-sea lineages with luminescent systems used for communication.

  17. Structure, food and shade attract juvenile coral reef fish to mangrove and seagrass habitats: a field experiment

    NARCIS (Netherlands)

    Verweij, M.C.; Nagelkerken, I.; Graaff, de D.; Peeters, M.; Bakker, E.J.; Velde, van der G.

    2006-01-01

    Mangroves and seagrass beds are considered nurseries for juvenile fish, but little experimental evidence exists to elucidate which factors make them attractive habitats. A multifactorial field experiment on the use of these habitats by juvenile reef fish and their behaviour was performed during dayt

  18. Structure, food and shade attract juvenile coral reef fish to mangrove and seagrass habitats: a field experiment.

    NARCIS (Netherlands)

    Verwey, M.C.; Nagelkerken, I.; Graaff, D. de; Peeters, M.; Bakker, E.J.; Velde, G. van der

    2006-01-01

    Mangroves and seagrass beds are considered nurseries for juvenile fish, but little experimental evidence exists to elucidate which factors make them attractive habitats. A multifactorial field experiment on the use of these habitats by juvenile reef fish and their behaviour was performed during dayt

  19. Juveniles Are More Resistant to Warming than Adults in 4 Species of Antarctic Marine Invertebrates.

    Science.gov (United States)

    Peck, Lloyd S; Souster, Terri; Clark, Melody S

    2013-01-01

    Juvenile stages are often thought to be less resistant to thermal challenges than adults, yet few studies make direct comparisons using the same methods between different life history stages. We tested the resilience of juvenile stages compared to adults in 4 species of Antarctic marine invertebrate over 3 different rates of experimental warming. The species used represent 3 phyla and 4 classes, and were the soft-shelled clam Laternula elliptica, the sea cucumber Cucumaria georgiana, the sea urchin Sterechinus neumayeri, and the seastar Odontaster validus. All four species are widely distributed, locally abundant to very abundant and are amongst the most important in the ecosystem for their roles. At the slowest rate of warming used (1°C 3 days(-1)) juveniles survived to higher temperatures than adults in all species studied. At the intermediate rate (1°C day(-1)) juveniles performed better in 3 of the 4 species, with no difference in the 4(th), and at the fastest rate of warming (1°C h(-1)) L. elliptica adults survived to higher temperatures than juveniles, but in C. georgiana juveniles survived to higher temperatures than adults and there were no differences in the other species. Oxygen limitation may explain the better performance of juveniles at the slower rates of warming, whereas the loss of difference between juveniles and adults at the fastest rate of warming suggests another mechanism sets the temperature limit here.

  20. Biofilm responses to marine fish farm wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sanz-Lazaro, Carlos, E-mail: carsanz@um.es [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100 Murcia (Spain); Navarrete-Mier, Francisco; Marin, Arnaldo [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100 Murcia (Spain)

    2011-03-15

    The changes in the biofilm community due to organic matter enrichment, eutrophication and metal contamination derived from fish farming were studied. The biofilm biomass, polysaccharide content, trophic niche and element accumulation were quantified along an environmental gradient of fish farm wastes in two seasons. Biofilm structure and trophic diversity was influenced by seasonality as well as by the fish farm waste load. Fish farming enhanced the accumulation of organic carbon, nutrients, selenium and metals by the biofilm community. The accumulation pattern of these elements was similar regardless of the structure and trophic niche of the community. This suggests that the biofilm communities can be considered a reliable tool for assessing dissolved aquaculture wastes. Due to the ubiquity of biofilms and its wide range of consumers, its role as a sink of dissolved wastes may have important implications for the transfer of aquaculture wastes to higher trophic levels in coastal systems. - Research highlights: > Biofilms can act as a trophic pathway of fish farm dissolved wastes. > Biofilms are reliable tools for monitoring fish farm dissolved wastes. > The influence of the fish farm dissolved wastes can be detected 120-350 m from farm. - Under the influence of fish farming biofilm accumulates organic carbon, nutrients, selenium and metals, regardless of the structure and trophic niche of the community.

  1. Seascape attributes, at different spatial scales, determine settlement and post-settlement of juvenile fish

    Science.gov (United States)

    Cuadros, Amalia; Moranta, Joan; Cardona, Luis; Thiriet, Pierre; Pastor, Jérémy; Arroyo, Nina Larissa; Cheminée, Adrien

    2017-02-01

    Concern has increased in recent decades regarding processes influencing fish juvenile density distributions; indeed, juveniles determine the replenishment of populations and their habitats are often found in shallow coastal areas, where human impacts are concentrated. We aimed to measure the relative importance of seascape attributes at various spatial scales (from seascape to microhabitat) in fish settlement and post-settlement processes. Along the coast of Minorca Island (NW Mediterranean), Diplodus sargus settlement variability was higher among the southern coast compared to the variability in the northern one. Independently of coast location, sheltered nurseries presented lower settlement intensity and recruitment levels compared to exposed ones. Such patterns suggested differential larval supply according to exposure level. Furthermore, subsequent density-dependent post-settlement mortality reduced the cove-specific variability of initial settlement. In addition, inside each cove, juveniles displayed ontogenetic changes of microhabitat use: smaller juveniles were more abundant in the most heterogeneous microhabitat. Consequently, juvenile density distributions responded to seascape attributes at different spatial scales; this suggests that both lager scale attributes and microhabitat influence both settlement and post-settlement processes, and may be limiting for recruitment. Our study demonstrated the importance of a diversified seascape to promote fish population replenishment.

  2. Size, growth, temperature and the natural mortality of marine fish

    DEFF Research Database (Denmark)

    Gislason, Henrik; Daan, Niels; Rice, Jake C.;

    2010-01-01

    such as mesh-size regulations. To test the assumption, we critically review the empirical estimates of the natural mortality, M (year(-1)), of marine and brackish water fish stocks and model them as a function of von Bertalanffy growth parameters, L-infinity (cm) and K (year(-1)), temperature (Kelvin...... conclude that natural mortality is significantly related to length and growth characteristics and recommend to use the empirical formula: ln(M) = 0.55) - 1.61ln(L) + 1.44ln(L-infinity) + ln(K), for estimating the natural mortality of marine and brackish water fish....

  3. Artificial propagation and breeding of marine fish in China

    Science.gov (United States)

    Hong, Wan-Shu; Zhang, Qi-Yong

    2002-03-01

    Since the 1990s, artificial propagation and breeding technique of marine fish in China have developed by way of increasing species and fry numbers, with special stress laid on valuable species. Large quantities of artificial fry can meet the needs of both marine cage culture and pond culture for most species. Experimental results obtained by scientists have been put into use in actual production. Fish fry production has entered a period of sustainable development. So far, at least 44 species (21 families) of marine fish have been successfully bred in China. The artificial fry number of large yellow croaker ( Pseudosciaena crocea) exceeded 300 million in 1999. The species whose artificial fry numbers have each surpassed 10 million annually are red drum ( Sciaenops ocellatus), Japanese seabass ( Lateolabrax japonicus), cuneate drum ( Nibea miichthioides), spring spawning red seabream ( Pagrosomus major) and threebanded sweetlip ( Plectorhynchus cinctus). Millions of artificial fry are bred annually in the species of black porgy ( Sparus macrocephalus), Russell's snapper ( Lutjanus russelli), javelin grunt ( Pomadasys hasta), miiuy croaker ( Miichthys miiuy) and skewband grunt ( Hapalogenys nitens). The fish in the family Sciaenidae are the main species in artificial propagation and breeding. Some problems and prospects on marine fish culture and stock enhancement are also discussed and some proposals for sustainable development are put forward in this article.

  4. ARTIFICIAL PROPAGATION AND BREEDING OF MARINE FISH IN CHINA

    Institute of Scientific and Technical Information of China (English)

    洪万树; 张其永

    2002-01-01

    Since the 1990s, artificial propagation and breeding technique of marine fish in China have developed by way of increasing species and fry numbers, with special stress laid on valuable species. Large quantities of artificial fry can meet the needs of both marine cage culture and pond culture for most species. Experimental results obtained by scientists have been put into use in actual production. Fish fry production has entered a period of sustainable development. So far, at least 44 species (21 families) of marine fish have been successfully bred in China. The artificial fry number of large yellow croaker (Pseudosciaena crocea) exceeded 300 million in 1999. The species whose artificial fry numbers have each surpassed 10 million annually are red drum (Sciaenops ocellatus), Japanese seabass (Lateolabrax japonicus), cuneate drum (Nibea miichthioides), spring spawning red seabream (Pagrosomus major) and threebanded sweetlip (Plectorhynchus cinctus). Millions of artificial fry are bred annually in the species of black porgy (Sparus macrocephalus), Russell's snapper (Lutjanus russelli), javelin grunt (Pomadasys hasta), miiuy croaker (Miichthys miiuy) and skewband grunt (Hapalogenys nitens). The fish in the family Sciaenidae are the main species in artificial propagation and breeding. Some problems and prospects on marine fish culture and stock enhancement are also discussed and some proposals for sustainable development are put forward in this article.

  5. Bony fish and their contribution to marine inorganic carbon cycling

    Science.gov (United States)

    Salter, Michael; Perry, Chris; Wilson, Rod; Harborne, Alistair

    2016-04-01

    Conventional understanding of the marine inorganic carbon cycle holds that CaCO3 (mostly as low Mg-calcite and aragonite) precipitates in the upper reaches of the ocean and sinks to a point where it either dissolves or is deposited as sediment. Thus, it plays a key role controlling the distribution of DIC in the oceans and in regulating their capacity to absorb atmospheric CO2. However, several aspects of this cycle remain poorly understood and have long perplexed oceanographers, such as the positive alkalinity anomaly observed in the upper water column of many of the world's oceans, above the aragonite and calcite saturation horizons. This anomaly would be explained by extensive dissolution of a carbonate phase more soluble than low Mg-calcite or aragonite, but major sources for such phases remain elusive. Here we highlight marine bony fish as a potentially important primary source of this 'missing' high-solubility CaCO3. Precipitation of CaCO3 takes place within the intestines of all marine bony fish as part of their normal physiological functioning, and global production models suggest it could account for up to 45 % of total new marine CaCO3 production. Moreover, high Mg-calcite containing >25 % mol% MgCO3 - a more soluble phase than aragonite - is a major component of these precipitates. Thus, fish CaCO3 may at least partially explain the alkalinity anomaly in the upper water column. However, the issue is complicated by the fact that carbonate mineralogy actually varies among fish species, with high Mg-calcite (HMC), low Mg-calcite (LMC), aragonite, and amorphous calcium carbonate (ACC) all being common products. Using data from 22 Caribbean fish species, we have generated a novel production model that resolves phase proportions. We evaluate the preservation/dissolution potential of these phases and consider potential implications for marine inorganic carbon cycling. In addition, we consider the dramatic changes in fish biomass structure that have resulted

  6. Nearshore marine fish assemblages in southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish benthic trawls were completed by the Southern California Coastal Water Research Project (SCCWRP). Data from 425 fisheries independent trawls ranging from 2-215...

  7. Effects of Copper, Cadmium, Lead, and Arsenic in a Live Diet on Juvenile Fish Growth

    Science.gov (United States)

    The effects of dietborne copper, cadmium, lead, and arsenic on juvenile fish were evaluated using a live diet consisting of the oligochaete Lumbriculus variegatus. In 30-d exposures, no effects on growth and survival of rainbow trout, fathead minnow, and channel catfish were obs...

  8. Role of mangroves as a nursery ground for juvenile reef fishes in the southern Egyptian Red Sea

    Directory of Open Access Journals (Sweden)

    Mohamed A. Abu El-Regal

    2014-01-01

    Full Text Available This work aims to study the importance of mangrove area as nursery grounds for the juvenile of reef fishes in the Red Sea. Juvenile fishes were collected during three seasons in 2010 from three mangrove swamps by a beach seine net. The net was dragged on the bottom for 100 m three times. A total of 269 juvenile fishes were collected, representing 21 species in 19 families. The most abundant species formed about 86% of all collected fishes. Nine species were collected for the first time from mangrove areas in the Egyptian Red Sea. Most of the collected fishes are economically important fishes. Moreover, eleven families were belonging to coral reef fishes. The highest species richness value was recorded in Hamata mangroves. This finding showed that how mangroves could support the life history of many coral reef fishes.

  9. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.

    2016-11-15

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  10. Characteristics of Marine Recreational Fishing in the anakkale Strait (Turkey

    Directory of Open Access Journals (Sweden)

    V. UNAL

    2012-12-01

    Full Text Available The economic and harvest impacts of Marine Recreational Fishing (MRF in Çanakkale Strait were analysed along with fishing policy, sociology and habits of fishers. Data sources included field survey data carried out along the entire length of the Çanakkale strait and policy information gathered from published sources. MRF policy is commendable, even in the fishing tourism sector, and is better developed than that in many other European countries. In Çanakkale, 9.9% of the population is recreational fishers. Recreational fishers are typically men (90%, primarily those between the ages of 25 and 49 yrs. The occupation of the recreational fishers ranged from self-employed (28%, students (28%, retired persons (22% and public employees (15%, to currently-unemployed persons (7%. An analysis of diel behaviour showed that most recreational fishers preferred fishing during the day (56.1%, while the evening was the next most preferred time for fishing (18%, followed by the night-time (9.8%, while a substantial number of recreational fishers (16.1% reported that they fished at any time of day. The most popular type of fishing was shore-based (68%, followed by boat-based (21%, and underwater fishing (11%. The mean daily fishing times were 6.07 h d-1, 6.18 h d-1 4.75 d-1 for boat-based, underwater and shore-based fishing, respectively. Summer and autumn were the preferred seasons for shore-based and underwater fishing, while autumn and winter were preferred for boat-based fishing. The highest Catch per Unit Effort (CPUE was observed for boat-based fishing (2.77 kg h-1, followed by underwater (0.97 kg h-1 and shore-based fishing (0.81 kg h-1. The catch composition included 51 species, though the catch composition of each fishing type was mostly comprised of only 3 or 4 species. The impact of the MRF harvest was high (30% of commercial fishing, particularly for bluefish (Pomatomus saltatrix and picarel (Spicara smaris species. The economic impact of MRF was

  11. Characteristics of Marine Recreational Fishing in the anakkale Strait (Turkey

    Directory of Open Access Journals (Sweden)

    V. UNAL

    2010-11-01

    Full Text Available The economic and harvest impacts of Marine Recreational Fishing (MRF in Çanakkale Strait were analysed along with fishing policy, sociology and habits of fishers. Data sources included field survey data carried out along the entire length of the Çanakkale strait and policy information gathered from published sources. MRF policy is commendable, even in the fishing tourism sector, and is better developed than that in many other European countries. In Çanakkale, 9.9% of the population is recreational fishers. Recreational fishers are typically men (90%, primarily those between the ages of 25 and 49 yrs. The occupation of the recreational fishers ranged from self-employed (28%, students (28%, retired persons (22% and public employees (15%, to currently-unemployed persons (7%. An analysis of diel behaviour showed that most recreational fishers preferred fishing during the day (56.1%, while the evening was the next most preferred time for fishing (18%, followed by the night-time (9.8%, while a substantial number of recreational fishers (16.1% reported that they fished at any time of day. The most popular type of fishing was shore-based (68%, followed by boat-based (21%, and underwater fishing (11%. The mean daily fishing times were 6.07 h d-1, 6.18 h d-1 4.75 d-1 for boat-based, underwater and shore-based fishing, respectively. Summer and autumn were the preferred seasons for shore-based and underwater fishing, while autumn and winter were preferred for boat-based fishing. The highest Catch per Unit Effort (CPUE was observed for boat-based fishing (2.77 kg h-1, followed by underwater (0.97 kg h-1 and shore-based fishing (0.81 kg h-1. The catch composition included 51 species, though the catch composition of each fishing type was mostly comprised of only 3 or 4 species. The impact of the MRF harvest was high (30% of commercial fishing, particularly for bluefish (Pomatomus saltatrix and picarel (Spicara smaris species. The economic impact of MRF was

  12. Damped trophic cascades driven by fishing in model marine ecosystems

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Pedersen, Martin

    2010-01-01

    that fishing does not change the overall slope of the size spectrum, but depletes the largest individuals and induces trophic cascades. A trophic cascade can propagate both up and down in trophic levels driven by a combination of changes in predation mortality and food limitation. The cascade is damped...... cascade triggered by the removal of top predators. Here we use a novel size- and trait-based model to explore how marine ecosystems might react to perturbations from different types of fishing pressure. The model explicitly resolves the whole life history of fish, from larvae to adults. The results show...

  13. Role of NO in arterial vascular function of intertidal fish (Girella laevifrons) and marine fish (Isacia conceptionis).

    Science.gov (United States)

    Moraga, F A; Urriola-Urriola, N

    2016-06-01

    Previous studies performed in intertidal fish (Girella laevifrons),as well as marine fish (Isacia conceptionis), showed that acetylcholine (ACh) produced contractions mediated by cyclooxygenases that were dependent on the area and potency of contraction in several arterial vessels. Given that the role of nitric oxide is poorly understood in fish, the objective of our study was to evaluate the role of nitric oxide in branchial afferent (ABA), branchial efferent (ABE), dorsal (DA) and mesenteric (MA) arterial vessels from both Girella laevifrons and Isacia conceptionis. We studied afferent and efferent branchial, dorsal and mesenteric arteries that were dissected from 6 juvenile specimens. Isometric tension studies were done using dose response curves (DRC) for Ach (10-13 to 10-3 M) and blockade with L-NAME (10-5 M), and DRC for sodium nitroprusside (SNP, a donor of NO). L-NAME produced an attenuation of the contractile response in the dorsal, afferent and efferent branchial arteries and a potentiation of the contraction in the MA. SNP caused 70% dilation in the mesenteric artery and 40% in the dorsal artery. Our results suggest that Ach promotes precarious dilatation in MA mediated by NO; data that is supported by the use of sodium nitroprusside. In contrast, in the vessels DA, ABA and EBA our results support that the pathway Ach-NO-relaxation is absent in both species.

  14. Domestication of Marine Fish Species: Update and Perspectives

    Directory of Open Access Journals (Sweden)

    Fabrice Teletchea

    2015-10-01

    Full Text Available Domestication is a long and endless process during which animals become, generations after generations, more adapted to both captive conditions and humans. Compared to land animals, domestication of fish species has started recently. This implies that most farmed marine fish species have only changed slightly from their wild counterparts, and production is based partly or completely on wild inputs. In the past decades, global marine fish production has increased tremendously, particularly since the 1990s, to reach more than 2.2 million tons in 2013. Among the 100 marine fish species listed in the FAO’s database in 2013, 35 are no longer produced, and only six have a production higher than 100,000 tons. The top ten farmed marine species accounted for nearly 90% of global production. The future growth and sustainability of mariculture will depend partly on our ability to domesticate (i.e., control the life cycle in captivity of both currently farmed and new species.

  15. High-seas fish wars generate marine reserves.

    Science.gov (United States)

    Herrera, Guillermo E; Moeller, Holly V; Neubert, Michael G

    2016-04-05

    The effective management of marine fisheries is an ongoing challenge at the intersection of biology, economics, and policy. One way in which fish stocks-and their habitats-can be protected is through the establishment of marine reserves, areas that are closed to fishing. Although the potential economic benefits of such reserves have been shown for single-owner fisheries, their implementation quickly becomes complicated when more than one noncooperating harvester is involved in fishery management, which is the case on the high seas. How do multiple self-interested actors distribute their fishing effort to maximize their individual economic gains in the presence of others? Here, we use a game theoretic model to compare the effort distributions of multiple noncooperating harvesters with the effort distributions in the benchmark sole owner and open access cases. In addition to comparing aggregate rent, stock size, and fishing effort, we focus on the occurrence, size, and location of marine reserves. We show that marine reserves are a component of many noncooperative Cournot-Nash equilibria. Furthermore, as the number of harvesters increases, (i) both total unfished area and the size of binding reserves (those that actually constrain behavior) may increase, although the latter eventually asymptotically decreases; (ii) total rents and stock size both decline; and (iii) aggregate effort used (i.e., employment) can either increase or decrease, perhaps nonmonotonically.

  16. Marine recreational fishing: resource usage, management and research

    CSIR Research Space (South Africa)

    Van der Elst, R

    1990-01-01

    Full Text Available This report contains papers presented at a symposium on marine recreational fishing: resource usage, management and research held on 22 and 23 May 1989 in the East London Museum under the auspices of the South African Deep Sea Angling Association...

  17. The ecological significance of juvenile Diplodus sargus as ectoparasite fish cleaners in the north-eastern Atlantic

    Directory of Open Access Journals (Sweden)

    José Neto

    2015-11-01

    different habitats and a detailed juvenile diet analysis. This will clarify the geographic expression of cleaning behaviour in this species and the relative importance of ectoparasites in their diet. These results are also useful to call the attention to the potential use of juvenile D. sargus as cleaners in marine temperate aquaculture fish farms.

  18. Juvenile Fish Data - Coastwide Cooperative Pre-Recruit Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project currently supports two main efforts: 1. An annual sampling regime of the hydrology, plankton and small fish along transects over the Continental Shelf...

  19. DNA barcoding of marine ornamental fishes from India.

    Science.gov (United States)

    Bamaniya, Dhaval C; Pavan-Kumar, A; Gireesh-Babu, P; Sharma, Niti; Reang, Dhalongsaih; Krishna, Gopal; Lakra, W S

    2016-09-01

    India has rich marine ornamental fish diversity with 400 fish species distributed in Gulf of Munnar/Palk Bay, Gulf of Kutch, and in reefs around Andaman & Nicobar and Lakshadweep Islands. Marine ornamental fish identification at the field level is very difficult because of their high diversity and profound changes in appearance during their developmental stages and camouflage. To facilitate ornamental fish trading with ease and in compliance with the biodiversity act, DNA barcoding technique could be used to accurately identify species. In this study, DNA barcodes were generated for 31 species of commercially important marine ornamental fishes from India. The average genetic distance (K2P model) within species, genus, and family was 0.446, 13.08, and 20.09%, respectively. Intraspecific variation has increased several folds (15-20 times) after including conspecific sequences from different geographical locations. The presence of allopatric lineages/cryptic species was observed in the Indo-pacific region. The NJ tree constructed based on K2P values showed distinct clusters shared by congeneric species specific to populations.

  20. Energy density of marine pelagic fish eggs

    DEFF Research Database (Denmark)

    Riis-Vestergaard, J.

    2002-01-01

    Analysis of the literature on pelagic fish eggs enabled generalizations to be made of their energy densities, because the property of being buoyant in sea water appears to constrain the proximate composition of the eggs and thus to minimize interspecific variation. An energy density of 1.34 J mul...

  1. Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2001 Data Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.S.; Morris, K.J.; Bisset, J.E.

    2002-03-01

    The Wigwam River juvenile bull trout and fish habitat monitoring program is a co-operative initiative of the British Columbia Ministry of Water, Land, and Air Protection and Bonneville Power Administration. The Wigwam River has been characterized as the single most important bull trout spawning stream in the Kootenay Region. This report provides a summary of results obtained during the second year (2001) of the juvenile bull trout enumeration and fish habitat assessment program. This project was commissioned in planning for fish habitat protection and forest development within the upper Wigwam River valley. The broad intent is to develop a better understanding of juvenile bull trout and Westslope cutthroat trout recruitment and the ongoing hydrologic and morphologic processes in the upper Wigwam River, especially as they relate to spawning and rearing habitat quality. Five permanent sampling sites were established August 2000 in the Wigwam river drainage (one site on Bighorn Creek and four sites on the mainstem Wigwam River). At each site, juvenile (0{sup +}, 1{sup +} and 2{sup +} age classes) fish densities and stream habitat conditions were measured over two stream meander wavelengths. Bull trout represented 95.1% of the catch and the mean density of juvenile bull trout was estimated to be 20.7 fish/100m{sup 2} (range 0.9 to 24.0 fish/100m{sup 2}). This compares to 17.2 fish/100m{sup 2} (+20%) for the previous year. Fry (0{sup +}) dominated the catch and this was a direct result of juvenile bull trout ecology and habitat partitioning among life history stages. Site selection was biased towards sample sites which favored high bull trout fry capture success. Comparison of fry density estimates replicated across both the preliminary survey (1997) and the current study (Cope and Morris 2001) illustrate the stable nature of these high densities. Bull trout populations have been shown to be extremely susceptible to habitat degradation and over-harvest and are

  2. Effects of Tidal Turbine Noise on Fish Hearing and Tissues - Draft Final Report - Environmental Effects of Marine and Hydrokinetic Energy

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30

    Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa

  3. Dependence of juvenile reef fishes on semi-arid hypersaline estuary microhabitats as nurseries.

    Science.gov (United States)

    Sales, N S; Dias, T L P; Baeta, A; Pessanha, A L M

    2016-07-01

    The differences between fish assemblages in three microhabitat types, in relation to vegetation and sediment characteristics of a hypersaline estuary located in an semi-arid zone in north-eastern Brazil, were investigated. Fishes were collected using a beach seine during the rainy and dry seasons in 2012. A total of 78 species were recorded, with the most common families being Gerreidae, Lutjanidae and Tetraodontidae. The majority of species were represented by juveniles, with Eucinostomus argenteus, Ulaema lefroyi and Sphoeroides greeleyi being the dominant species. The fish assemblage structures differed significantly among microhabitat types, with the narrow intertidal flat adjacent to the mangrove fringe supporting the most diverse fish fauna. In addition, only 27 species were common to all of the microhabitats. The results support the hypothesis that hypersaline estuaries serve as important nursery areas for various reef fish species, due to the structural complexity provided by their macroalgae beds and mangroves.

  4. Mediterranean Aquaculture: Marine Fish Farming Development

    OpenAIRE

    Basurco, B

    2001-01-01

    in many parts of the world, aquaculture production in the Mediterranean has been expanding rapidly over recent years. Total aquaculture production in the region reached 1,266,959 t in 1999, which represents approximately 6% of the world aquaculture production (3% in 1995). Although Mediterranean aquaculture still focuses more on mollusc production (53.9%), the share of fish production is progressing constantly (46% in 1999, and 35% in 1995), parallel to global trends of world a...

  5. Biomarkers of endocrine disruption in juveniles and females of the estuarine fish Pomatoschistus microps.

    Science.gov (United States)

    Dias, Lídia C A; Soares, Amadeu M V M; Ferreira, Abel L G; Santos, Cátia S; Monteiro, Marta S

    2014-07-15

    The presence of endocrine disruptor chemicals (EDCs) in aquatic compartments, including estuaries, has been object of major concern. However, the effects of EDCs on autochthonous estuarine fish species are far less known than in freshwater fish. Therefore, the response of biomarkers in the estuarine fish Pomatoschistus microps was evaluated after 21-days of exposure to different EDCs: 17β-estradiol (E2); PCB-77 and p,p'DDE. In juveniles, Vtg (vitellogenin)-like proteins were significantly induced by E2. PCB-77 led to a decrease of Vtg-like proteins in juveniles, while in female liver they increased at the highest concentrations tested, suggesting a mode of action of PCB-77 that depends on the fish life stage. p,p'-DDE did not induce significant changes in Vtg-like proteins. Overall, P. microps juveniles seemed to respond to environmental relevant concentrations of EDCs. Thus, the evaluation of Vtg-like proteins in this life stage seems to be a promising tool to track EDC contamination in biomonitoring studies.

  6. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    Science.gov (United States)

    Kok, Judith E.; Graham, Nicholas A. J.; Hoogenboom, Mia O.

    2016-06-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes ( Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reefs: present-day reefs that are vulnerable to climate-induced coral bleaching, and reefs with more bleaching-robust coral taxa, thereby simulating the likely future of coral reefs under a warming climate. Fish communities were allowed to establish naturally on the reefs during the summer recruitment period. Climate-robust reefs had lower total species richness of coral-reef fishes than climate-vulnerable reefs, but total fish abundance was not significantly different between reef types (pooled across all species and life-history stages). The nature of aggressive interactions, measured as the number of aggressive chases, varied according to coral composition; on climate-robust reefs, juveniles used the substratum less often to avoid aggression from competitors, and interspecific aggression became relatively more frequent than intraspecific aggression for juveniles of the coral-obligate P. moluccensis. This study highlights the importance of coral composition as a determinant of behaviour and diversity of coral-reef fishes.

  7. Energy density of marine pelagic fish eggs

    DEFF Research Database (Denmark)

    Riis-Vestergaard, J.

    2002-01-01

    Analysis of the literature on pelagic fish eggs enabled generalizations to be made of their energy densities, because the property of being buoyant in sea water appears to constrain the proximate composition of the eggs and thus to minimize interspecific variation. An energy density of 1.34 J mul......(-1) of total egg volume is derived for most species spawning eggs without visible oil globules. The energy density of eggs with oil globules is predicted by (σ) over cap = 1.34 + 40.61 x (J mul(-1)) where x is the fractional volume of the oil globule. (C) 2002 The Fisheries Society of the British...

  8. THE UTILIZATION OF THE KINDS OF LIVE FOOD ON CLOWN LOACH FISH JUVENILES (Chromobotia macracanthus Bleeker

    Directory of Open Access Journals (Sweden)

    Nina Meilisza

    2011-06-01

    Full Text Available Domestication and mass production technology of clown loaches fish have been developed by the Research Institute for Ornamental Fish Culture, Depok and the Institute de Recherche pour le Developpement (IRD. In the process, some constraints has been found and one of them was the cost of production and sustainable supply of Artemia as the only one of live food which used for clown loaches post-larvae until 2-3 months old juvenile. To solve this constraints, the use of other live feed as a substitute or replacement of Artemia should be applied, caused by it research of the utilization of the kinds of live food on clown loach juvenile need to be done. This research aims to determine the kinds of live food which be recommended for the substitution of Artemia on clown loaches fish juvenile (Chromobotia macracanthus Bleeker. Research carried out using 1 month old clown loach juveniles designed into the Complete Randomized Design in two factors namely are class of fish size S (35-50 mg, M (55-70 mg, L (75-90 mg and the kinds of live food in the form of Artemia as a control, Moina, mini maggot, blood worms (Chironomus, and silk worms (Tubifex. Three levels treatment by class of fish size factor and five levels treatment by the kinds of live food factor produce 15 kinds of interactions with duplications. The research was conducted at recirculation system for 8 weeks to 3 months old juveniles. Observations were carried and measuring the growth parameters including weight, total length of fish, as well as survival rate parameters based on the number of fish that live at the end of the research. The support is done by measuring the water quality of pH, DO, temperature, ammonia, conductivity, and nitrites, proximate analysis of feed also performed. The two of research step analyzed by ANOVA (Analysis of Variance and continued by Tukey test.

  9. Juvenile Salmonid Pit-Tag Studies at Prosser Dam and the Chandler Canal Fish Collection Facility, Yakima River, 1991 and 1992 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ruehle, Thomas E.; Sandford, Benjamin P.

    1996-01-01

    In 1991 and 1992, the National Marine Fisheries Service completed the second and third years of a 3-year study to estimate juvenile salmonid (Oncorhynchus spp.) timing and survival characteristics related to passage through the Prosser Dam complex, including the Chandler Canal and the Chandler fish collection facility, on the Yakima River. Yearling chinook (O. tshawyacha) and coho salmon (O. kisutch) were collected at the Chandler facility, PIT tagged, and released at various locations in the Yakima River, Chandler Canal, and the Chandler facility. Individual fish were subsequently detected at PIT-tag detection monitors at the Chandler facility and/or McNary Dam on the Columbia River. Survival through various reaches, PIT-tag detection efficiency, and Chandler Canal fish entrainment proportion parameters were estimated using maximum likelihood techniques. The research objectives in 1991 and 1992 were to: (1) assess the effects of passage through the Chandler Canal and the Chandler facility on the survival of juvenile salmonids, (2) determine the entrainment rate of juvenile salmonids into the Chandler Canal as a function of river flow, and (3) determine the efficiency and reliability of the PIT-tag monitoring system at the Chandler facility. The initial 1990 research plan was expanded in 1991 and 1992 to include several more release locations and many more release days.

  10. Fish embryo and juvenile size under hypoxia in the mouth- brooding African cichlid Pseudocrenilabrus multicolor

    Directory of Open Access Journals (Sweden)

    E.E. REARDON, L.J. CHAPMAN

    2012-06-01

    Full Text Available We used a field survey and a laboratory rearing experiment to (a examine response (size and survival to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers and (b explore the degree to which developmental response can be environmentally-induced. Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO concentrations. In the laboratory, first generation (F1 broods of low-DO origin were reared under high or low DO. Brooding period was quantified for the mothers; and egg size, egg metabolic rate and juvenile size-at-release were quantified in their (F2 offspring. The F2 offspring were split and grown for 3 months post-release under high or low DO, and juvenile size and survival were quantified. In the field survey, across stages, embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations. In the laboratory experiment, F2 eggs and juveniles-at-release from mother’s mouth did not differ in mass, length, survival regardless of development DO environment. However, juveniles diverged in size after leaving mother’s mouth, exhibiting smaller size when grown under low DO. Size differences in embryo size across field populations and divergence in embryo size after release from the mother’s mouth support predictions for smaller body size under hypoxia. There was no evidence for negative effects on survival of juveniles after 3 months. Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development. This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes [Current Zoology 58 (3: 401-412, 2012].

  11. Fish embryo and juvenile size under hypoxia in the mouth-brooding African cichlid Pseudocrenilabrus multicolor

    Institute of Scientific and Technical Information of China (English)

    E.E.REARDON; L.J.CHAPMAN

    2012-01-01

    We used a field survey and a laboratory rearing experiment to (a) examine response (size and survival) to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers) and (b) explore the degree to which developmental response can be environmentally-induced.Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO) concentrations.In the laboratory,first generation (F1) broods of low-DO origin were reared under high or low DO.Brooding period was quantified for the mothers; and egg size,egg metabolic rate and juvenile size-at-release were quantified in their (F2) offspring.The F2 offspring were split and grown for 3 months post-release under high or low DO,and juvenile size and survival were quantified.In the field survey,across stages,embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations.In the laboratory experiment,F2 eggs and juveniles-at-release from mother's mouth did not differ in mass,length,survival regardless of development DO environment.However,juveniles diverged in size after leaving mother's mouth,exhibiting smaller size when grown under low DO.Size differences in embryo size across field populations and divergence in embryo size after release from the mother's mouthsupport predictions for smaller body size under hypoxia.There was no evidence for negative effects on survival of juveniles after 3 months.Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development.This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes.

  12. Projected impacts of climate change on marine fish and fisheries

    DEFF Research Database (Denmark)

    Hollowed, Anne B.; Barange, Manuel; Beamish, Richard J.;

    2013-01-01

    ) implications for food security and associated changes; and (v) uncertainty and modelling skill assessment. Climate change will impact fish and shellfish, their fisheries, and fishery-dependent communities through a complex suite of linked processes. Integrated interdisciplinary research teams are forming...... in many regions to project these complex responses. National and international marine research organizations serve a key role in the coordination and integration of research to accelerate the production of projections of the effects of climate change on marine ecosystems and to move towards a future where...

  13. Production and use of copepods in marine fish larviculture

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Norsker, N.H.

    1997-01-01

    substratum. Two such systems were compared in terms of area productivity and the use of ammonia excretion as a means for controlling feeding of the copepods was investigated. Finally, the potential benefits of the use of copepods as live food for marine fish larvae are discussed. (C) 1997 Elsevier Science B.V...... swimming behaviour in terms of vertical distribution in a typical fish larval tank and the use of T. holothuriae nauplii as live food for first-feeding turbot larvae were investigated. It was possible to cultivate harpacticoid copepods in shallow trays or in continuous bioreactors with large area...

  14. Isolation and identification of marine fish tumour (odontoma) associated bacteria

    Institute of Scientific and Technical Information of China (English)

    Ramalingam Vijayakumar; Kuzhanthaivel Raja; Vijayapoopathi Singaravel; Ayyaru Gopalakrishnan

    2015-01-01

    Objective: To identify fish tumour associated bacteria. Methods: The marine fish Sphyraena jello with odontoma was collected from in Tamil Nadu (Southeast India), and tumour associated bacteria were isolated. Then the isolated bacteria were identified based on molecular characters. Results: A total of 4 different bacterial species were isolated from tumour tissue. The bacterial species were Bacillus sp., Pontibacter sp., Burkholderia sp. and Macrococcus sp., and the sequences were submitted in DNA Data Bank of Japan with accession numbers of AB859240, AB859241, AB859242 and AB859243 respectively. Conclusions: Four different bacterial species were isolated from Sphyraena jello, but the role of bacteria within tumour needs to be further investigated.

  15. Synthesis of Biological Reports on Juvenile Fish Passage and Survival at Bonneville Dam through 2005

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R.; Johnson, Gary E.; Giorgi, Albert E.; Johnson, Richard L.; Stevenson, John R.; Schilt, Carl R.; Johnson, Peter N.; Patterson, Deborah S.

    2005-06-01

    This report describes a review of available literature on juvenile salmonid passage at Bonneville Dam from 1939 through 2005. Studies of interest included project-wide fish-passage efficiency (FPE) studies by radio telemetry and fixed-aspect hydroacoustics, fish survival studies (direct and indirect), FGE studies, powerhouse and unit (by netting, hydroacoustics, and radio telemetry), predation studies in the forebay and tailrace, behavioral studies on forebay approach and egress, and surface-bypass studies. The FPE effort will include a review of available distribution data (horizontal, diel, and vertical) for juvenile salmon. This study does not repeat the results of previous review and synthesis studies but cites them. Where no previous review exists for a subject area, all reports were reviewed and synthesized. The report includes an annotated bibliography summarizing each of the documents reviewed and a DVD disk containing all of the original papers and reports along with an HTML index to the documents.

  16. Diverse juvenile life-history behaviours contribute to the spawning stock of an anadromous fish population

    Science.gov (United States)

    Walsworth, Timothy E.; Schindler, Daniel E.; Griffiths, Jennifer R.; Zimmerman, Christian E.

    2015-01-01

    Habitat quality often varies substantially across space and time, producing a shifting mosaic of growth and mortality trade-offs across watersheds. Traditional studies of juvenile habitat use have emphasised the evolution of single optimal strategies that maximise recruitment to adulthood and eventual fitness. However, linking the distribution of individual behaviours that contribute to recruitment at the population level has been elusive, particularly for highly fecund aquatic organisms. We examined juvenile habitat use within a population of sockeye salmon (Oncorhynchus nerka) that spawn in a watershed consisting of two interconnected lakes and a marine lagoon. Otolith microchemical analysis revealed that the productive headwater lake accounted for about half of juvenile growth for those individuals surviving to spawn in a single river in the upper watershed. However, 47% of adults had achieved more than half of their juvenile growth in the downstream less productive lake, and 3% of individuals migrated to the estuarine environment during their first summer and returned to freshwater to overwinter before migrating back to sea. These results describe a diversity of viable habitat-use strategies by juvenile sockeye salmon that may buffer the population against poor conditions in any single rearing environment, reduce density-dependent mortality and have implications for the designation of critical habitat for conservation purposes. A network of accessible alternative habitats providing trade-offs in growth and survival may be important for long-term viability of populations.

  17. Fatty acid profiles in marine and freshwater fish from fish markets in northeastern Poland

    Directory of Open Access Journals (Sweden)

    Łuczyńska Joanna

    2014-09-01

    Full Text Available The fatty acid compositions were studied in eight commercially important fish from fish markets: salmon, Salmo salar L.; cod, Gadus morhua L.; common sole, Solea solea (L.; European flounder, Platichthys flesus (L.; catfish, Clarias gariepinus (Burchell; rainbow trout, Oncorhynchus mykiss (Walb.; Nile tilapia, Oreochromis niloticus (L.; and pangasius, Pangasianodon hypophthalmus (Sauvage. The freshwater fish contained 25.69-42.18% saturated, 34.90-43.79% monounsaturated, 8.46-16.32% n-6 polyunsaturated, and 5.01-20.43% n-3 polyunsaturated acid, while marine fish contained 18.53-32.77% saturated, 17.95-49.89% monounsaturated, 3.40-11.51% n-6 polyunsaturated, and 18.74-45.42% n-3 polyunsaturated acid. Marine fish contained significantly more Ʃn-3 PUFA (29.79%, EPA (12.26%, DHA (13.20%, and a higher n-3/n-6 (6.95 ratio than freshwater fish (13.13, 2.47, 7.14, 1.29% (P≤ 0.05. There were statistically significant differences in the n-3/n-6 ratio among fish species (cod (13.40 > sole (8.47 > flounder (4.30 > rainbow trout (2.41 > catfish (1.83 ≈ salmon (1.63 > tilapia (0.57 ≈ pangasius (0.36 (P ≤0.05.

  18. Population genomics of marine fishes: next generation prospects and challenges

    DEFF Research Database (Denmark)

    Hansen, Jakob Hemmer; Therkildsen, Nina Overgaard; Pujolar, J.M.

    2014-01-01

    Over the past few years, technological advances have facilitated giant leaps forward in our ability to generate genome-wide molecular data, offering exciting opportunities for gaining new insights into the ecology and evolution of species where genomic information is still limited. Marine fishes...... time scales, identifying genomic signatures associated with population divergence under gene flow, and determining the genetic basis of phenotypic traits. We also consider future challenges pertaining to the implementation of genome-wide coverage through next-generation sequencing and genotyping...... methods in marine fishes. Complications associated with fast decay of linkage disequilibrium, as expected for species with large effective population sizes, and the possibility that adaptation is associated with both soft selective sweeps and polygenic selection, leaving complex genomic signatures...

  19. Phototoxicity of individual polycyclic aromatic hydrocarbons and petroleum to marine invertebrate larvae and juveniles

    Energy Technology Data Exchange (ETDEWEB)

    Pelletier, M.C.; Burgess, R.M.; Ho, K.T.; Kuhn, A.; McKinney, R.A.; Ryba, S.A. [Environmental Protection Agency, Narragansett, RI (United States)

    1997-10-01

    Phototoxicity resulting from photoactivated polycyclic aromatic hydrocarbons (PAHs) has been reported in the literature for a variety of freshwater organisms. The magnitude of increase in PAH toxicity often exceeds a factor of 100. In the marine environment phototoxicity to marine organisms has not been reported for individual or complex mixtures of PAHs. In this study, larvae and juveniles of the bivalve, Mulinia lateralis, and juveniles of the mysid shrimp, Mysidopsis bahia, were exposed to individual known phototoxic PAHs (anthracene, fluoranthene, pyrene), as well as the water-accommodated fractions of several petroleum products (Fuel Oil {number_sign}2, Arabian Light Crude, Prudhoe Bay Crude, Fuel Oil {number_sign}6) containing PAHs. Phototoxicity of individual PAHs was 12 to >50,000 times that of conventional toxicity. Three of the petroleum products demonstrated phototoxicity while the lightest product, Fuel Oil {number_sign}2, was not phototoxic at the concentrations tested. The phototoxicity of petroleum products appears to be dependent on the composition and concentrations of phototoxic PAHs present: lighter oils have fewer multiple aromatic ring, phototoxic compounds while heavier oils have higher levels of these types of molecules. This study shows that phototoxicity can occur in marine waters to marine species. Further, the occurrence of oil in marine waters presents the additional risk of phototoxicity not routinely assessed for during oil spills.

  20. Environmental management of marine fish culture in Hong Kong.

    Science.gov (United States)

    Lee, J H W; Choi, K W; Arega, F

    2003-01-01

    Marine fish farming is an important commercial practice in Hong Kong. Marine fish farms located in eutrophic coastal waters often face the threat of severe dissolved oxygen depletion associated with algal blooms and red tides. On the other hand, mariculture activities also contribute to pollution. The sustainable management of mariculture requires proper siting of the fish farms and stocking density control. Both of these are related to the carrying capacity of the water body concerned, which is mainly governed by its flushing characteristics. A simple method to determine the carrying capacity of a fish farm has been developed by using three-dimensional (3D) hydrodynamic modelling and its effective coupling with a diagenetic water quality model. A systematic methodology using numerical tracer experiments has been developed to compute the tidal flushing in a fish farm. The flushing time is determined from the results of a numerical tracer experiment using robust 3D hydrodynamic and mass transport models. A unit tracer concentration is initially prescribed inside the region of interest and zero elsewhere; the subsequent mass transport and the mass removal process are then tracked. The fish farms are usually situated in well-sheltered shallow embayments and may not connect directly to the open water. It is found that it is necessary to define both "local" and "system-wide" flushing times to represent the effectiveness of the mass exchange with the surrounding water body and the open sea respectively. A diagenetic water quality model simulating the sediment-water-pollutant interaction is employed to address the response of the water column and the benthic layer to pollution discharges. With the flushing rate reliably computed, the carrying capacity of the fish farm can be determined in terms of key water quality parameters: chlorophyll-a, dissolved oxygen, organic nitrogen and potential lowest dissolved oxygen level on a day of negligible photosynthetic production. The

  1. Antagonistic potential of marine Actinobacteria against fish and shellfish pathogens

    OpenAIRE

    DHARMARAJ, Selvakumar

    2011-01-01

    A total of 94 marine actinobacterial isolates were found to be associated with 4 sponges: Callyspongia diffusa, Mycale mytilorum, Tedania anhelans, and Dysidea fragilis. Among the cultures 7 strains showed antagonism against fish and shellfish pathogens. Analysis of morphological, physiological, biochemical, and protein profile characteristics suggested that the actinobacterial strains belonged to the genus Streptomyces. The initial screening of the isolates by the spot inoculation method exh...

  2. Evidence of melanoma in wild marine fish populations.

    Directory of Open Access Journals (Sweden)

    Michael Sweet

    Full Text Available The increase in reports of novel diseases in a wide range of ecosystems, both terrestrial and marine, has been linked to many factors including exposure to novel pathogens and changes in the global climate. Prevalence of skin cancer in particular has been found to be increasing in humans, but has not been reported in wild fish before. Here we report extensive melanosis and melanoma (skin cancer in wild populations of an iconic, commercially-important marine fish, the coral trout Plectropomus leopardus. The syndrome reported here has strong similarities to previous studies associated with UV induced melanomas in the well-established laboratory fish model Xiphophorus. Relatively high prevalence rates of this syndrome (15% were recorded at two offshore sites in the Great Barrier Reef Marine Park (GBRMP. In the absence of microbial pathogens and given the strong similarities to the UV-induced melanomas, we conclude that the likely cause was environmental exposure to UV radiation. Further studies are needed to establish the large scale distribution of the syndrome and confirm that the lesions reported here are the same as the melanoma in Xiphophorus, by assessing mutation of the EGFR gene, Xmrk. Furthermore, research on the potential links of this syndrome to increases in UV radiation from stratospheric ozone depletion needs to be completed.

  3. Stress profile influences learning approach in a marine fish

    Directory of Open Access Journals (Sweden)

    Vincent Raoult

    2017-06-01

    Full Text Available The spatial learning skills of high and low stress juvenile mulloway (Argyrosomus japonicus were tested in a dichotomous choice apparatus. Groups of fish were formed based on background blood cortisol levels and required to learn the location of a food reward hidden in one of two compartments. Low stress fish characterised by low background levels of the stress hormone cortisol had higher activity levels and entered both rewarded and unrewarded rooms frequently. Within the first week of exposure, however, their preference for the rewarded room increased, indicative of learning. Fish that had high background levels of cortisol, in contrast, showed low levels of activity but when they chose between the two rooms they chose the rewarded room most often but showed less improvement over time. After 12 days in the apparatus, both low and high stress fish had similar ratios of rewarded vs unrewarded room entrances. Our results suggest that proactive coping styles may increase exposure to novel contexts and thus favour faster learning but at the cost of reduced initial accuracy.

  4. [Histology of gill, liver and kidney in juvenile fish Colossoma macropomum exposed to three temperatures].

    Science.gov (United States)

    Rojas, Luz-Marina; Mata, Claunis; Oliveros, Aridays; Salazar-Lugo, Raquel

    2013-06-01

    Abstract: Histology of gill, liver and kidney in juvenile fish Colossoma macropomum exposed to three temperatures. Water temperature is an important factor that affects growth and antioxidant enzyme activities in fish, and when adverse, it may trigger diseases in fish populations. C. macropomum is a freshwater neotropical fish widely distributed in South America and abundant in river basins as the Amazon and Orinoco. It is highly used for intensive aquaculture development and is a very important product for the local riverside economy in Venezuela. The purpose of our study was to examine the water temperature effect on gills, liver and kidneys of juvenile fishes of C macropomum. Eighteen juveniles with biometrical index of 17.87 +/- 7.88 cm and 87.69 +/- 34.23 g were respectively exposed to three culture temperatures (T18, T29 and T35 degrees C) during a period of 21 days. Histological analyses on gills, liver and kidney were made according to standard methodologies. Our results showed that these tissues exhibited normal citoarchitecture at T29. On the contrary, T18-gills displayed brachiallipid droplets inside brachial epithelium; and disorganization in the brachial tissue was observed at T35. Furthermore, we observed two kinds of hepatocytes (dark and light) on T180 degrees C-liver. The T35-liver samples showed cytoplasmatic granulation and damages in cytoplasmatic membrane. Kidney samples from T18 observed alterations in the cellular distribution of the hematopoietic tissue; while, at T35, the most important feature observed was the disorganization of the glomerular structure. We concluded that T18 and T35 are respectively critical and severe temperatures to C. macropomum; besides, the most sensible tissues to changes induced by temperature in this species were the liver and gills.

  5. Chlorophycean parasite on a marine fish, Sillago japonica (Japanese sillago).

    Science.gov (United States)

    Koike, Kazuhiko; Akai, Noriko; Liao, Lawrence M; Ikeda, Shota; Yoshimatsu, Sadaaki

    2013-12-01

    A green spotted Japanese sillago (Sillago japonica) was caught by a fisherman and brought to the laboratory for pathological inspection. The green spots were abundant on the lateral line and more extensively so within the mouth cavity. In both sites, green spots were embedded within the fish flesh and formed 2-3mm dome-shaped colonies. SEM revealed these colonies to harbor numerous unknown cells with small, surface warts (ornamentations). Molecular analysis showed the cells were Desmodesmus (D. komarekii), a common freshwater coccoid green alga found in ponds and rivers worldwide. It is uncertain how the host fish came to be infected with the alga which was not merely attached externally but embedded within the flesh and inside the mouth cavity. This is the first case of parasitic form of coccoid green algae in marine fish and provides new insights into the variable nature of green algae.

  6. Screening for Viral Hemorrhagic Septicemia Virus in Marine Fish along the Norwegian Coastal Line

    DEFF Research Database (Denmark)

    Sandlund, Nina; Gjerset, Britt; Bergh, Øivind

    2014-01-01

    Viral hemorrhagic septicemia virus (VHSV) infects a wide range of marine fish species. To study the occurrence of VHSV in wild marine fish populations in Norwegian coastal waters and fjord systems a total of 1927 fish from 39 different species were sampled through 5 research cruises conducted...

  7. Spatial match-mismatch between juvenile fish and prey provides a mechanism for recruitment variability across contrasting climate conditions in the eastern Bering Sea.

    Directory of Open Access Journals (Sweden)

    Elizabeth Calvert Siddon

    Full Text Available Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma support the largest single-species commercial fishery in the United States and represent an ecologically important component of the Bering Sea ecosystem. Variability in walleye pollock growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches, informed by observations, to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1 a bioenergetics model that included local predator and prey energy densities, and (2 an individual-based model that included a mechanistic feeding component dependent on larval development and behavior, local prey densities and size, and physical oceanographic conditions. Prey composition in late-summer shifted from predominantly smaller copepod species in the warmer 2005 season to larger species in the cooler 2010 season, reflecting differences in zooplankton composition between years. In 2010, the main prey of juvenile walleye pollock were more abundant, had greater biomass, and higher mean energy density, resulting in better growth conditions. Moreover, spatial patterns in prey composition and water temperature lead to areas of enhanced growth, or growth 'hot spots', for juvenile walleye pollock and survival may be enhanced when fish overlap with these areas. This study provides evidence that a spatial mismatch between juvenile walleye pollock and growth 'hot spots' in 2005 contributed to poor recruitment while a higher degree of overlap in 2010 resulted in improved recruitment. Our results indicate that climate-driven changes in prey quality and composition can impact growth of juvenile walleye pollock, potentially severely affecting

  8. Effects of dietary protein levels on growth performance and body composition of juvenile parrot fish, Oplegnathus fasciatus

    National Research Council Canada - National Science Library

    Kim, Kang-Woong; Moniruzzaman, Mohammad; Kim, Kyoung-Duck; Han, Hyon Sob; Yun, Hyeonho; Lee, Seunghan; Bai, Sungchul C

    2016-01-01

    The present study was conducted to evaluate the effects of dietary protein levels on growth, biometrics, hematology and body composition in juvenile parrot fish Oplegnathus fasciatus. Fish averaging 7.1 ± 0.06 g (mean ± SD...

  9. Spawning Behavior, Egg Development, Larvae and Juvenile Morphology of Hyphessobrycon eques (Pisces: Characidae) Characidae Fishes

    Science.gov (United States)

    Park, Jae-Min; Kim, Na-Ri; Han, Kyeong-Ho; Han, Ji-Hyeong; Son, Maeng-Hyun; Cho, Jae-Kwon

    2014-01-01

    Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2–3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at 28°C. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of 0.92 ± 0.01 mm. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged 2.90 ± 0.16 mm in total length (LT). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were 12.5 ± 1.60 mm LT and had reached the juvenile stage. PMID:25949194

  10. Patterns and persistence of larval retention and connectivity in a marine fish metapopulation

    KAUST Repository

    Saenz Agudelo, Pablo

    2012-08-14

    Connectivity, the demographic linking of local populations through the dispersal of individuals, is one of the most poorly understood processes in population dynamics, yet has profound implications for conservation and harvest strategies. For marine species with pelagic larvae, direct estimation of connectivity remains logistically challenging and has mostly been limited to single snapshots in time. Here, we document seasonal and interannual patterns of larval dispersal in a metapopulation of the coral reef fish Amphiprion polymnus. A 3-year record of larval trajectories within and among nine discrete local populations from an area of approximately 35 km was established by determining the natal origin of settled juveniles through DNA parentage analysis. We found that spatial patterns of both self-recruitment and connectivity were remarkably consistent over time, with a low level of self-recruitment at the scale of individual sites. Connectivity among sites was common and multidirectional in all years and was not significantly influenced by seasonal variability of predominant surface current directions. However, approximately 75% of the sampled juveniles could not be assigned to parents within the study area, indicating high levels of immigrations from sources outside the study area. The data support predictions that the magnitude and temporal stability of larval connectivity decreases significantly with increasing distance between subpopulations, but increases with the size of subpopulations. Given the considerable effort needed to directly measure larval exchange, the consistent patterns suggest snapshot parentage analyses can provide useful dispersal estimates to inform spatial management decisions. © 2012 Blackwell Publishing Ltd.

  11. Marine reserves: fish life history and ecological traits matter.

    Science.gov (United States)

    Claudet, J; Osenberg, C W; Domenici, P; Badalamenti, F; Milazzo, M; Falcón, J M; Bertocci, I; Benedetti-Cecchi, L; García-Charton, J A; Goñi, R; Borg, J A; Forcada, A; De Lucia, G A; Perez-Ruzafa, A; Afonso, P; Brito, A; Guala, I; Le Diréach, L; Sanchez-Jerez, P; Somerfield, P J; Planes, S

    2010-04-01

    Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.

  12. Evaluation of Fish Passage Conditions for Juvenile Salmonids Using Sensor Fish at Detroit Dam, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Joanne P.

    2010-01-29

    Fish passage conditions through two spillways at Detroit Dam on the North Santiam River in Oregon were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE), Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions through Spillbay 3 and Spillbay 6 at 1.5- and 3.5-ft gate openings, identifying potential fish injury regions of the routes. The study was performed in July 2009, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish and live fish were deployed at elevations approximately 3 ft above structure at depths determined using a computational fluid dynamics model. Data collected were analyzed to estimate 1) exposure conditions, particularly exposure to severe collision and shear events by passage route sub-regions; 2) differences in passage conditions between passage routes; and 3) relationships to live-fish injury and mortality data estimates.

  13. Assessing juvenile native fish demographic responses to a steady flow experiment in a large regulated river

    Science.gov (United States)

    Finch, Colton G.; Pine, William E.; Yackulic, Charles B.; Dodrill, Michael J.; Yard, Michael D.; Gerig, Brandon S.; Coggins,, Lewis G.; Korman, Josh

    2016-01-01

    The Colorado River below Glen Canyon Dam, Arizona, is part of an adaptive management programme which optimizes dam operations to improve various resources in the downstream ecosystem within Grand Canyon. Understanding how populations of federally endangered humpback chub Gila cypha respond to these dam operations is a high priority. Here, we test hypotheses concerning temporal variation in juvenile humpback chub apparent survival rates and abundance by comparing estimates between hydropeaking and steady discharge regimes over a 3-year period (July 2009–July 2012). The most supported model ignored flow type (steady vs hydropeaking) and estimated a declining trend in daily apparent survival rate across years (99.90%, 99.79% and 99.67% for 2009, 2010 and 2011, respectively). Corresponding abundance of juvenile humpback chub increased temporally; open population model estimates ranged from 615 to 2802 individuals/km, and closed model estimates ranged from 94 to 1515 individuals/km. These changes in apparent survival and abundance may reflect broader trends, or simply represent inter-annual variation. Important findings include (i) juvenile humpback chub are currently surviving and recruiting in the mainstem Colorado River with increasing abundance; (ii) apparent survival does not benefit from steady fall discharges from Glen Canyon Dam; and (iii) direct assessment of demographic parameters for juvenile endangered fish are possible and can rapidly inform management actions in regulated rivers.

  14. Seasonal and ontogenetic patterns of habitat use in coral reef fish juveniles

    Science.gov (United States)

    Mellin, C.; Kulbicki, M.; Ponton, D.

    2007-12-01

    We investigated the diversity of patterns of habitat use by juveniles of coral reef fishes according to seasons and at two spatial scales (10-100 m and 1-10 km). We conducted underwater visual censuses in New Caledonia's Lagoon between 1986 and 2001. Co-inertia analyses highlighted the importance of mid-shelf habitats at large spatial scale (1-10 km) and of sandy and vegetated habitats at small spatial scale (10-100 m) for most juveniles. Among all juvenile species, 53% used different habitats across seasons (e.g. Lutjanus fulviflamma and Siganus argenteus) and 39% used different habitats as they grow (e.g. Lethrinus atkinsoni and Scarus ghobban). During their ontogeny, at large and small scales, respectively, 21% and 33% of the species studied showed an increase in the number of habitats used (e.g. L. fulviflamma, L. atkinsoni), 10% and 3% showed a decrease in the number of habitats used (e.g. Amphiprion melanopus, Siganus fuscescens), 23% and 3% showed a drastic change of habitat used (e.g. S. ghobban, Scarus sp.) whereas 46% and 61% showed no change of habitat used (e.g. Lethrinus genivittatus, Ctenochaetus striatus). Changes in habitat use at both small and large spatial scales occurred during the ontogeny of several species (e.g. S. ghobban, Scarus sp.). Results pointed out the different spatial and temporal scales of juvenile habitat use to account for in conservation decisions regarding both assemblage and species-specific levels.

  15. Biodiversity conservation should focus on no-take Marine Reserves: 94% of Marine Protected Areas allow fishing.

    Science.gov (United States)

    Costello, Mark J; Ballantine, Bill

    2015-09-01

    Conservation needs places where nature is left wild; but only a quarter of coastal countries have no-take Marine Reserves. 'Marine Protected Areas' (MPAs) have been used to indicate conservation progress but we found that 94% allow fishing and thus cannot protect all aspects of biodiversity. Biodiversity conservation should focus on Marine Reserves, not MPAs.

  16. Effects of Two Progestins, Norethindrone and Levonorgestrel, On Reproduction in a Marine Fish, Tautogolabrus adspersus.

    Science.gov (United States)

    Endocrine-active pharmaceuticals that enter the aquatic environment through sewage effluent may have unintended impacts on reproduction in fish, which in turn may affect the sustainability of exposed populations. Laboratory experiments were conducted with the marine fish cunner (...

  17. Effects of Two Progestins, Norethindrone and Levonorgestrel, On Reproduction in a Marine Fish, Tautogolabrus adspersus.

    Science.gov (United States)

    Endocrine-active pharmaceuticals that enter the aquatic environment through sewage effluent may have unintended impacts on reproduction in fish, which in turn may affect the sustainability of exposed populations. Laboratory experiments were conducted with the marine fish cunner (...

  18. The year-class phenomenon and the storage effect in marine fishes

    Science.gov (United States)

    Secor, David H.

    2007-02-01

    Factors contributing to population growth through strong year-class formation have driven a century of directed research in fisheries science. A central discovery of Hjort's paradigm was that multiple generations overlap and longevity is matched with frequency of strong recruitments. Here, I elaborate on this tenet by examining how intra-population modalities in spawning and early habitat use favour population resiliency. A modern theory that has application is the storage effect [Warner, R.R., Chesson, P.L., 1985. Coexistence mediated by recruitment fluctuations - a field guide to the storage effect. Am. Nat. 125, 769-787], whereby spawning stock biomass accumulates each year so that when early survival conditions are favourable, stored egg production can result in explosive population growth. I review two early life history behaviours that contribute to the storage effect: split cohorts (i.e., seasonal pulses of eggs and larvae) and contingent behaviour (i.e., dispersive and retentive patterns in early dispersal). Episodic and pulsed production of larvae is a common feature for marine fishes, well documented through otolith microstructure and hatch-date analyses. In temperate and boreal fishes, early and late spawned cohorts of larvae and juveniles may have differing fates dependent upon seasonal and inter-annual fluctuations in weather and climate. Often, a coastal fish may spawn for a protracted period, yet only a few days' egg production will result in successful recruitment. In these and other instances, it is clear that diversity in spawning behaviour can confer resilience against temporal variations in early survival conditions. Although many factors contribute to intra-population spawning modalities, size and age structure of adults play an important role. Contingent structure, an idea dating to Hjort (herring contingents) and Gilbert (salmon contingents), has been resurrected to describe the diversity of intra-population modalities observed through

  19. Some camallanid nematodes from marine perciform fishes off New Caledonia.

    Science.gov (United States)

    Moravec, Frantisek; Justine, Jean-Lou; Rigby, Mark C

    2006-09-01

    Two new, one known and three unidentified species of the nematode family Camallanidae are reported and described from the intestines of marine perciform fishes off the southwestern coast of New Caledonia, South Pacific: Camallanus carangis Olsen, 1952 from the forked-tailed threadfin bream Nemipterus furcosus (Nemipteridae), the yellowstriped goatfish Upeneus vittatus and the whitesaddle goatfish Parupeneus ciliatus (both Mullidae) (new host records); Procamallanus (Spirocamallanus) variolae sp. n. from the white-edged lyretail Variola albimarginata (type host) and the blacktip grouper Epinephelus fasciatus (both Serranidae); Procamallanus (Spirocamallanus) longus sp. n. from the twotone tang Zebrasoma scopas (Acanthuridae); Procamallanus (Spirocamallanus) sp. 1 (female tail with 2 terminal spikes on a digit-like projection) from the speckled sand-perch Parapercis hexophtalma (Pinguipedidae); Procamallanus (Spirocamallanus) sp. 2 (female tail with 1 spike on a digit-like projection) from the drab emperor Lethrinus ravus (Lethrinidae) and Procamallanus (Spirocamallanus) sp. 3 (female tail with a smooth digit-like protrusion) from the two-lined monocle bream Scolopsis bilineata (Nemipteridae). Camallanus paracarangis Velasquez, 1980 is synonymized with C. carangis. Several additional species of Camallanus from marine fish of the Indo-Pacific region may be synonymous with C. carangis as it has a poorly sclerotized left spicule and 3 small caudal projections on the tail of young (i.e., non-gravid) females. The fourth-stage larva of C. carangis is described for the first time. P. (S.) variolae differs from most similar species of this region mainly in the position (i.e., at level or posterior to the nerve ring) and shape of deirids. P. (S.) longus differs from the similar P. (S.) chaimha mainly in a different arrangement of postanal papillae, shape of the female tail, much longer right spicule (429 microm) and longer body of gravid females (38-55 mm). All Camallanus and

  20. Isolation and identification of marine fish tumour (odontoma associated bacteria

    Directory of Open Access Journals (Sweden)

    Ramalingam Vijayakumar

    2015-09-01

    Full Text Available Objective: To identify fish tumour associated bacteria. Methods: The marine fish Sphyraena jello with odontoma was collected from in Tamil Nadu (Southeast India, and tumour associated bacteria were isolated. Then the isolated bacteria were identified based on molecular characters. Results: A total of 4 different bacterial species were isolated from tumour tissue. The bacterial species were Bacillus sp., Pontibacter sp., Burkholderia sp. and Macrococcus sp., and the sequences were submitted in DNA Data Bank of Japan with accession numbers of AB859240, AB859241, AB859242 and AB859243 respectively. Conclusions: Four different bacterial species were isolated from Sphyraena jello, but the role of bacteria within tumour needs to be further investigated.

  1. Effects of introduced fishes on wild juvenile coho salmon in three shallow pacific northwest lakes

    Science.gov (United States)

    Bonar, Scott A.; Bolding, B.D.; Divens, M.; Meyer, W.

    2005-01-01

    Declines in Pacific salmon Oncorhynchus spp. have been blamed on hydropower, overfishing, ocean conditions, and land use practices; however, less is known about the impacts of introduced fish. Most of the hundreds of lakes and ponds in the Pacific Northwest contain introduced fishes, and many of these water bodies are also important for salmon production, especially of coho salmon O. kisutch. Over 2 years, we examined the predation impacts of 10 common introduced fishes (brown bullhead Ameiurus nebulosus, black crappie Pomoxis nigro-maculatus, bluegill Lepomis macrochirus, golden shiner Notemigonus crysoleucas, green sunfish L. cyanellus, largemouth bass Micropterus salmoides, pumpkinseed L. gibbosus, rainbow trout O. mykiss, warmouth L. gulosus, and yellow perch Perca flavescens) and two native fishes (cutthroat trout O. clarkii and prickly sculpin Cottus asper) on wild juvenile coho salmon in three shallow Pacific Northwest lakes, all located in different watersheds. Of these species, largemouth bass were responsible for an average of 98% of the predation on coho salmon in all lakes, but the total impact to each run varied among lakes and years. Very few coho salmon were eaten by black crappies, brown bullheads, cutthroat trout, prickly sculpin, or yellow perch, whereas other species were not observed to eat coho salmon. Juvenile coho salmon growth in all lakes was higher than in nearby streams. Therefore, food competition between coho salmon and introduced fishes in lakes was probably not limiting coho salmon populations. Largemouth bass are widespread and are present in 85% of lowland warmwater public-access lakes in Washington (n = 421), 84% of those in Oregon (n = 179), and 74% of those in the eight northwesternmost counties in California (n = 19). Future research would help to identify the impact of largemouth bass predation across the region and prioritize lakes where impacts are most severe. Nevertheless, attempts to transplant or increase largemouth bass

  2. Marine fish diversity and habitat use along the western coast of the Black Sea

    OpenAIRE

    Viorel Dumitru Gavril

    2015-01-01

    Over the years the conditions of the Black Sea marine habitats have been modified due to anthropogenic impacts and climate change, and it is likely that the diversity of fish fauna changed as a result. This study provides new data regarding marine fish population diversity and habitat use along the western coast of the Black Sea. I recorded fish species and habitat data between 2011 and 2014 in two locations: Constanta, Romania and Shabla-Tyulenovo coast, Bulgaria, using fishing (only in R...

  3. Hexabromocyclododecanes (HBCDs) in marine fishes along the Chinese coastline.

    Science.gov (United States)

    Xia, Chonghuan; Lam, James C W; Wu, Xiaoguo; Sun, Liguang; Xie, Zhouqing; Lam, Paul K S

    2011-03-01

    This study reports concentrations of hexabromocyclododecanes (HBCDs) in two species of marine fish, large yellow croaker (Pseudosciaenacrocea) and silver pomfret (Pampusargenteus) (n = 46), from nine Chinese coastal cities (Dalian, Tianjin, Qingdao, Shanghai, Zhoushan, Wenzhou, Fuzhou, Quanzhou and Xiamen). HBCDs were detectable in all samples analyzed, indicating ubiquitous contamination of these compounds in the Chinese coastal environment. The average total HBCD concentration was 3.7 ng g⁻¹ lipid weight (range: 0.57-10.1 ng g⁻¹ lipid weight), which is relatively lower than other regions of the world, especially Europe, where HBCDs are intensively used. Among the three individual HBCD isomers (α-, β- and γ-HBCD) in all fish samples, the α-isomer showed a remarkable predominance (from 87.5% to 100% of total contribution), indicating its higher bioaccumulative potential. Geographically, the highest HBCD level present in fish was found in Dalian in northern China, and the lowest occurred in Wenzhou. Estimated daily intakes of HBCDs via fish consumption for the Chinese population were 0.004-1.00 ng kg body weight⁻¹ d⁻¹. These exposure levels were much lower than the effect levels.

  4. Evaluation of Juvenile Fish Bypass and Adult Fish Passage Facilities at Three-Mile Falls Dam; Umatilla River, Oregon, 1989 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Nigro, Anthony A.

    1990-09-01

    We report on our progress from October 1989 through September 1990 on evaluating juvenile fish bypass and adult fish passage facilities at Three Mile Falls Dam on the Umatilla River. The study is a cooperative effort by the Oregon Department of Fish and Wildlife (ODFW) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). Study objectives addressed by ODFW and CTUIR are: (1) ODFW (Report A): Operate and evaluate the juvenile fish bypass system in the West Extension Irrigation District canal at Three Mile Falls Dam; and (2) CTUIR (Report 8): Examine the passage of adult salmonids at Three Mile Falls Dam. The study is part of a program to rehabilitate anadromous fish stocks in the Umatilla River Basin that includes restorations of coho salmon Oncorhynchus Wsutch and chinook salmon 0. tshawytscha and enhancement of summer steelhead 0. mytiss.

  5. Induction of cytochrome p-450-ia1 in juvenile fish by creosote-contaminated sediment

    Energy Technology Data Exchange (ETDEWEB)

    Schoor, W.P.; Williams, D.E.; Takahashi, N.

    1991-01-01

    Intact sediment cores, including their surface layers, were used in simulated field exposure tests of juvenile guppies (Poecilia reticulata) to creosote-contaminated sediments. Mixed-function oxygenase activity was induced in the fish after 43 days of exposure to environmentally realistic, sublethal concentrations of creosote-related compounds. An average 50-fold induction in the cytochrome P-450-IA1 was found in the liver in the absence of any histopathological lesions. The possibility that a threshold level for proliferative liver changes was not reached is discussed in the light of the observed biochemical activation.

  6. 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

    2012-01-01

    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....... 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...

  7. Spillover of fish naïveté from marine reserves.

    Science.gov (United States)

    Januchowski-Hartley, Fraser A; Graham, Nicholas A J; Cinner, Joshua E; Russ, Garry R

    2013-02-01

    Spillover of adult fish biomass is an expected benefit from no-take marine reserves to adjacent fisheries. Here, we show fisher-naïve behaviour in reef fishes also spills over from marine reserves, potentially increasing access to fishery benefits by making fishes more susceptible to spearguns. The distance at which two targeted families of fishes began to flee a potential fisher [flight initiation distance (FID)] was lower inside reserves than in fished areas, and this reduction extended outside reserve boundaries. Reduced FID persisted further outside reserves than increases in fish biomass. This finding could help increase stakeholder support for marine reserves and improve current models of spillover by informing estimates for spatial changes in catchability. Behavioural changes of fish could help explain differences between underwater visual census and catch data in quantifying the spatial extent of spillover from marine reserves, and should be considered in the management of adjacent fisheries.

  8. Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities

    Science.gov (United States)

    Abesamis, Rene A.; Saenz-Agudelo, Pablo; Berumen, Michael L.; Bode, Michael; Jadloc, Claro Renato L.; Solera, Leilani A.; Villanoy, Cesar L.; Bernardo, Lawrence Patrick C.; Alcala, Angel C.; Russ, Garry R.

    2017-09-01

    Networks of no-take marine reserves (NTMRs) are a widely advocated strategy for managing coral reefs. However, uncertainty about the strength of population connectivity between individual reefs and NTMRs through larval dispersal remains a major obstacle to effective network design. In this study, larval dispersal among NTMRs and fishing grounds in the Philippines was inferred by conducting genetic parentage analysis on a coral-reef fish ( Chaetodon vagabundus). Adult and juvenile fish were sampled intensively in an area encompassing approximately 90 km of coastline. Thirty-seven true parent-offspring pairs were accepted after screening 1978 juveniles against 1387 adults. The data showed all types of dispersal connections that may occur in NTMR networks, with assignments suggesting connectivity among NTMRs and fishing grounds ( n = 35) far outnumbering those indicating self-recruitment ( n = 2). Critically, half (51%) of the inferred occurrences of larval dispersal linked reefs managed by separate, independent municipalities and constituent villages, emphasising the need for nested collaborative management arrangements across management units to sustain NTMR networks. Larval dispersal appeared to be influenced by wind-driven seasonal reversals in the direction of surface currents. The best-fit larval dispersal kernel estimated from the parentage data predicted that 50% of larvae originating from a population would attempt to settle within 33 km, and 95% within 83 km. Mean larval dispersal distance was estimated to be 36.5 km. These results suggest that creating a network of closely spaced (less than a few tens of km apart) NTMRs can enhance recruitment for protected and fished populations throughout the NTMR network. The findings underscore major challenges for regional coral-reef management initiatives that must be addressed with priority: (1) strengthening management of NTMR networks across political or customary boundaries; and (2) achieving adequate population

  9. Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities

    KAUST Repository

    Abesamis, Rene A.

    2017-03-24

    Networks of no-take marine reserves (NTMRs) are a widely advocated strategy for managing coral reefs. However, uncertainty about the strength of population connectivity between individual reefs and NTMRs through larval dispersal remains a major obstacle to effective network design. In this study, larval dispersal among NTMRs and fishing grounds in the Philippines was inferred by conducting genetic parentage analysis on a coral-reef fish (Chaetodon vagabundus). Adult and juvenile fish were sampled intensively in an area encompassing approximately 90 km of coastline. Thirty-seven true parent-offspring pairs were accepted after screening 1978 juveniles against 1387 adults. The data showed all types of dispersal connections that may occur in NTMR networks, with assignments suggesting connectivity among NTMRs and fishing grounds (n = 35) far outnumbering those indicating self-recruitment (n = 2). Critically, half (51%) of the inferred occurrences of larval dispersal linked reefs managed by separate, independent municipalities and constituent villages, emphasising the need for nested collaborative management arrangements across management units to sustain NTMR networks. Larval dispersal appeared to be influenced by wind-driven seasonal reversals in the direction of surface currents. The best-fit larval dispersal kernel estimated from the parentage data predicted that 50% of larvae originating from a population would attempt to settle within 33 km, and 95% within 83 km. Mean larval dispersal distance was estimated to be 36.5 km. These results suggest that creating a network of closely spaced (less than a few tens of km apart) NTMRs can enhance recruitment for protected and fished populations throughout the NTMR network. The findings underscore major challenges for regional coral-reef management initiatives that must be addressed with priority: (1) strengthening management of NTMR networks across political or customary boundaries; and (2) achieving adequate population

  10. Juvenile exposure to predator cues induces a larger egg size in fish

    Science.gov (United States)

    Segers, Francisca H. I. D.; Taborsky, Barbara

    2012-01-01

    When females anticipate a hazardous environment for their offspring, they can increase offspring survival by producing larger young. Early environmental experience determines egg size in different animal taxa. We predicted that a higher perceived predation risk by juveniles would cause an increase in the sizes of eggs that they produce as adults. To test this, we exposed juveniles of the mouthbrooding cichlid Eretmodus cyanostictus in a split-brood experiment either to cues of a natural predator or to a control situation. After maturation, females that had been confronted with predators produced heavier eggs, whereas clutch size itself was not affected by the treatment. This effect cannot be explained by a differential female body size because the predator treatment did not influence growth trajectories. The observed increase of egg mass is likely to be adaptive, as heavier eggs gave rise to larger young and in fish, juvenile predation risk drops sharply with increasing body size. This study provides the first evidence that predator cues perceived by females early in life positively affect egg mass, suggesting that these cues allow her to predict the predation risk for her offspring. PMID:21976689

  11. The potential for a fish ladder to mitigate against the loss of marine ...

    African Journals Online (AJOL)

    2013-05-21

    May 21, 2013 ... construction of a saltwater barrier across the Mzingazi River .... The major life cycle categories of fishes and crustaceans utilising the Mzingazi ..... The success of a fishway in re-establishing a migration .... will be critical to its success. ... physical factors in larval and juvenile fish recruitment to estuarine.

  12. Laboratory Experiments on the Effects of Blade Strike from Hydrokinetic Energy Technologies on Larval and Juvenile Freshwater Fishes

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, Peter E [ORNL; Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL

    2012-03-01

    There is considerable interest in the development of marine and hydrokinetic energy projects in rivers, estuaries, and coastal ocean waters of the United States. Hydrokinetic (HK) technologies convert the energy of moving water in river or tidal currents into electricity, without the impacts of dams and impoundments associated with conventional hydropower or the extraction and combustion of fossil fuels. The Federal Energy Regulatory Commission (FERC) maintains a database that displays the geographical distribution of proposed HK projects in inland and tidal waters (FERC 2012). As of March 2012, 77 preliminary permits had been issued to private developers to study HK projects in inland waters, the development of which would total over 8,000 MW. Most of these projects are proposed for the lower Mississippi River. In addition, the issuance of another 27 preliminary permits for HK projects in inland waters, and 3 preliminary permits for HK tidal projects (totaling over 3,100 MW) were under consideration by FERC. Although numerous HK designs are under development (see DOE 2009 for a description of the technologies and their potential environmental effects), the most commonly proposed current-based projects entail arrays of rotating devices, much like submerged wind turbines, that are positioned in the high-velocity (high energy) river channels. The many diverse HK designs imply a diversity of environmental impacts, but a potential impact common to most is the risk for blade strike to aquatic organisms. In conventional hydropower generation, research on fish passage through reaction turbines at low-head dams suggested that strike and mortality for small fish could be low. As a consequence of the large surface area to mass ratio of small fish, the drag forces in the boundary layer flow at the surface of a rotor blade may pull small fish around the leading edge of a rotor blade without making physical contact (Turnpenny 1998, Turnpenny et al. 2000). Although there is

  13. Social isolation and aggressiveness in the Amazonian juvenile fish Astronotus ocellatus

    Directory of Open Access Journals (Sweden)

    E. Gonçalves-de-Freitas

    Full Text Available We tested the effect of social isolation on the aggressiveness of an Amazonian fish: Astronotus ocellatus. Ten juvenile fishes were transferred from a group aquarium (60 x 60 x 40 cm containing 15 individuals (without distinguishing sex to an isolation aquarium (50 x 40 x 40 cm. Aggressiveness was tested by means of attacks on and displays toward the mirror image. The behavior was video-recorded for 10 min at a time on 4 occasions: at 30 min, 1 day, 5 days and 15 days after isolation. The aggressive drive was analyzed in three ways: latency to display agonistic behavior, frequency of attacks and specific attacks toward the mirror image. The latency to attack decreased during isolation, but the frequency of mouth fighting (a high aggressive attack tended to increase, indicating an augmented aggressive drive. Our findings are congruent with the behavior of the juvenile cichlid, Haplochromis burtoni but differ from the behavior observed in another cichlid, Pterophylum scalare. Increased aggressiveness in A. ocellatus may be mediated by means of the primer effect, the effect of prior residence or processes involving recognition of a conspecific.

  14. Marine chemistry, fish / shell-fish surveys, benthic organisms, and marine toxic substances and pollutants data from current meter and other instruments in the Gulf of Mexico from 26 January 1993 to 13 June 1994 (NODC Accession 9500088)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine chemistry, fish / shell-fish surveys, benthic organisms, and marine toxic substances and pollutants data were collected using current meter and other...

  15. Effects of the environment on fish juvenile growth in West African stressful estuaries

    Science.gov (United States)

    Diouf, K.; Guilhaumon, F.; Aliaume, C.; Ndiaye, P.; Chi, T. Do; Panfili, J.

    2009-06-01

    The knowledge of juvenile fish growth in extreme environmental conditions is a key to the understanding of adaptive responses and to the relevant management of natural populations. The juvenile growth of an extreme euryhaline tilapia species, Sarotherodon melanotheron (Cichlidae), was examined across a salinity gradient (20-118) in several West African estuarine ecosystems. Juveniles were collected during the reproduction period of two consecutive years (2003 and 2004) in six locations in the Saloum (Senegal) and Gambia estuaries. Age and growth were estimated using daily otolith microincrements. For each individual, otolith growth rates showed three different stages (slow, fast, decreasing): around 4 ± 0.5 μm d -1 during the first five days, 9 ± 0.5 μm d -1 during the next 15 days and 4 ± 0.50 μm d -1 at 60 days. Growth modelling and model comparisons were objectively made within an information theory framework using the multi-model inference from five growth models (linear, power, Gompertz, von Bertalanffy, and logistic). The combination of both the model adjustment inspection and the information theory model selection procedure allowed identification of the final set of models, including the less parameterised ones. The estimated growth rates were variable across spatial scales but not across temporal scales (except for one location), following exactly the salinity gradient with growth decrease towards the hypersaline conditions. The salinity gradient was closely related to all measured variables (condition factor, mean age, multi-model absolute growth rate) demonstrating the strong effect of hypersaline environmental conditions—induced by climate changes—on fish populations at an early stage.

  16. Conservation physiology of marine fishes: state of the art and prospects for policy

    DEFF Research Database (Denmark)

    McKenzie, David J.; Axelsson, Michael; Chabot, Denis

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes is the ...

  17. Conservation physiology of marine fishes: state of the art and prospects for policy

    NARCIS (Netherlands)

    McKenzie, D.J.; Axelsson, M.; Chabot, D.; Van der Meer, J.; Metcalfe, J.D.

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of howit can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiologicalknowledge for conservation of marine fishes is the limit

  18. Conservation physiology of marine fishes: state of the art and prospects for policy

    NARCIS (Netherlands)

    Mckenzie, David J.; Axelsson, Michael; Chabot, Denis; Claireaux, Guy; Cooke, Steven J.; Corner, Richard A.; Boeck, De Gudrun; Domenici, Paolo; Guerreiro, Pedro M.; Hamer, Bojan; Jørgensen, Christian; Killen, Shaun S.; Lefevre, Sjannie; Marras, Stefano; Michaelidis, Basile; Nilsson, Göran E.; Peck, Myron A.; Perez-Ruzafa, Angel; Rijnsdorp, Adriaan D.; Shiels, Holly A.; Steffensen, John F.; Svendsen, Jon C.; Svendsen, Morten B.S.; Teal, Lorna R.; Meer, Van Der Jaap; Wang, Tobias; Wilson, Jonathan M.; Wilson, Rod W.; Metcalfe, Julian D.

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of knowledge for conservation of marine fishes is the limited knowledge base; international collaboration is needed to study the environmental p

  19. Conservation physiology of marine fishes: state of the art and prospects for policy

    NARCIS (Netherlands)

    McKenzie, D.J.; Axelsson, M.; Chabot, D.; Claireaux, G.; Cooke, S.J.; Corner, R.A.; De Boeck, G.; Domenici, P.; Guerreiro, P.M.; Hamer, B.; Jørgensen, C.; Killen, S.S.; Lefevre, S.; Marras, S.; Michaelidis, B.; Nilsson, G.E.; Peck, M.A.; Perez-Ruzafa, A.; Rijnsdorp, A.D.; Shiels, H.A.; Steffensen, J.F.; Svendsen, J.C.; Svendsen, M.B.S.; Teal, L.R.; Van der Meer, J.; Wang, T.; Wilson, J.M.; Wilson, R.W.; Metcalfe, J.D.

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes is the lim

  20. Conservation physiology of marine fishes: state of the art and prospects for policy

    NARCIS (Netherlands)

    McKenzie, D.J.; Axelsson, M.; Chabot, D.; Van der Meer, J.; Metcalfe, J.D.

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of howit can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiologicalknowledge for conservation of marine fishes is the limit

  1. Conservation physiology of marine fishes: state of the art and prospects for policy

    NARCIS (Netherlands)

    Mckenzie, David J.; Axelsson, Michael; Chabot, Denis; Claireaux, Guy; Cooke, Steven J.; Corner, Richard A.; Boeck, De Gudrun; Domenici, Paolo; Guerreiro, Pedro M.; Hamer, Bojan; Jørgensen, Christian; Killen, Shaun S.; Lefevre, Sjannie; Marras, Stefano; Michaelidis, Basile; Nilsson, Göran E.; Peck, Myron A.; Perez-Ruzafa, Angel; Rijnsdorp, Adriaan D.; Shiels, Holly A.; Steffensen, John F.; Svendsen, Jon C.; Svendsen, Morten B.S.; Teal, Lorna R.; Meer, Van Der Jaap; Wang, Tobias; Wilson, Jonathan M.; Wilson, Rod W.; Metcalfe, Julian D.

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of knowledge for conservation of marine fishes is the limited knowledge base; international collaboration is needed to study the environmental p

  2. Nutritive value of diets containing fish silage for juvenile Litopenaeus vannamei (Bonne, 1931).

    Science.gov (United States)

    Gallardo, Pedro; Gaxiola, Gabriela; Soberano, Sofía; Taboada, J Gabriel; Pérez, Marquelia; Rosas, Carlos; Cuzon, Gerard; Espinosa, L Gabriela; Sotelo, Angela

    2012-08-30

    Fish wastes has been used for many years as an alternative in feeds for aquaculture. In the present study weight gain of juvenile white shrimp Litopenaeus vannamei fed diets including fish waste silage (WS), fish waste silage with soybean meal SBM (WS + S) or fish waste meal (WM) was compared. A conventional acidic silage process was applied to obtain from wastes (skin, heads, bones and viscera) of snapper (Lutjanus spp.), grunt (Haemulon plumieri), and grouper (Epinephelus spp.) an ingredient rich in protein. After 3 days ensilage more than 90% protein was hydrolysed. Waste material processed at pH 3.8 lost about 24% tryptophan. Butylated hydroxytoluene (BHT) prevented lipid oxidation, as shown after 45 days with malonaldehyde production. Shrimp fed WS + S diet gained 0.7 g per week higher than those fed WS and WM diets with 0.3 g per week (P < 0.05). WS processed with formic acid under conditions of low pH is beneficial for the white shrimp L. vannamei. It sustained reasonable weight gain combined with soybean meal in practical diets. On the other hand, BHT addition was beneficial in preventing oxidative action during silage preparation. Copyright © 2012 Society of Chemical Industry.

  3. Quality of coastal and estuarine essential fish habitats: estimations based on the size of juvenile common sole ( Solea solea L.)

    Science.gov (United States)

    Le Pape, O.; Holley, J.; Guérault, D.; Désaunay, Y.

    2003-12-01

    Survival and growth of early fish stages are maximal in coastal and estuarine habitats where natural shallow areas serve as nurseries for a variety of widely distributed species on the continental shelf. Processes occurring in these nursery grounds during the juvenile stage affect growth and may be important in regulating the year-class strength of fishes and population size. The need, therefore, exists to protect these essential fish habitats hence to develop indicators to estimate their quality. The purpose of the present study was to use the growth of juvenile sole as a means of comparing the quality of coastal and estuarine nursery habitats in the Bay of Biscay (France). These sole nurseries were clearly identified from studies based on trawl surveys carried out during the last two decades. The size of 1-group juveniles at the end of their second summer, as estimated from these surveys, is an indicator of growth in these habitats during the juvenile phase and can be used to compare habitat quality. A model taking into account the role of seawater temperature in spatial and interannual variations of juvenile size was developed to compare growth performance in the different nursery sectors. This study shows that the size of juvenile sole after two summers of life is not density-dependent, probably because the size of the population adapts to habitat capacity after high mortality during early-juvenile stages. Size is on one hand positively related to temperature and on the other hand higher in estuarine than in non-estuarine habitats. This high growth potential of juvenile fish in estuarine areas confirms the very important role played by estuaries as nursery grounds and the essential ecological interest of these limited areas in spite of their low water quality. If a general conclusion on habitat quality is to be reached about studies based on the growth of juvenile fish, it is necessary to use not only an integrative indicator of growth, like size

  4. Laboratory Experiments on the Effects of Blade Strike from Hydrokinetic Energy Technologies on Larval and Juvenile Freshwater Fishes

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, Peter E [ORNL; Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL

    2012-03-01

    There is considerable interest in the development of marine and hydrokinetic energy projects in rivers, estuaries, and coastal ocean waters of the United States. Hydrokinetic (HK) technologies convert the energy of moving water in river or tidal currents into electricity, without the impacts of dams and impoundments associated with conventional hydropower or the extraction and combustion of fossil fuels. The Federal Energy Regulatory Commission (FERC) maintains a database that displays the geographical distribution of proposed HK projects in inland and tidal waters (FERC 2012). As of March 2012, 77 preliminary permits had been issued to private developers to study HK projects in inland waters, the development of which would total over 8,000 MW. Most of these projects are proposed for the lower Mississippi River. In addition, the issuance of another 27 preliminary permits for HK projects in inland waters, and 3 preliminary permits for HK tidal projects (totaling over 3,100 MW) were under consideration by FERC. Although numerous HK designs are under development (see DOE 2009 for a description of the technologies and their potential environmental effects), the most commonly proposed current-based projects entail arrays of rotating devices, much like submerged wind turbines, that are positioned in the high-velocity (high energy) river channels. The many diverse HK designs imply a diversity of environmental impacts, but a potential impact common to most is the risk for blade strike to aquatic organisms. In conventional hydropower generation, research on fish passage through reaction turbines at low-head dams suggested that strike and mortality for small fish could be low. As a consequence of the large surface area to mass ratio of small fish, the drag forces in the boundary layer flow at the surface of a rotor blade may pull small fish around the leading edge of a rotor blade without making physical contact (Turnpenny 1998, Turnpenny et al. 2000). Although there is

  5. Potential of Pigeon Creek, San Salvador, Bahamas, as Nursery Habitat for Juvenile Reef Fish

    Directory of Open Access Journals (Sweden)

    Conboy, Ian Christopher

    2011-10-01

    Full Text Available This project assessed the significance of Pigeon Creek, San Salvador, Bahamas as a nursery habitat for coral reef fishes. Pigeon Creek’s perimeter is lined with mangrove and limestone bedrock. The bottom is sand or seagrass and ranges in depth from exposed at low tide to a 3-m deep, tide-scoured channel. In June 2006 and January 2007, fish were counted and their maturity was recorded while sampling 112 of 309 possible 50-m transects along the perimeter of the Pigeon Creek. Excluding silversides (Atherinidae, 52% of fish counted, six families each comprised >1% of the total abundance (Scaridae/parrotfishes, 35.3%; Lutjanidae/snappers, 23.9%; Haemulidae/grunts, 21.0%; Gerreidae/mojarras, 8.5%; Pomacentridae/damselfishes, 6.1%; Labridae/wrasses, 2.4%. There were few differences in effort-adjusted counts among habitats (mangrove, bedrock, mixed, sections (north, middle, southwest and seasons (summer 2006 and winter 2007. Red Mangrove (Rhizophora mangle, covering 68% of the perimeter was where 62% of the fish were counted. Snappers, grunts and parrotfishes are important food fishes and significant families in terms of reef ecology around San Salvador. Mangrove was the most important habitat for snappers and grunts; bedrock was most important for parrotfishes. The southwest section was important for snappers, grunts and parrotfishes, the north section for grunts and parrotfishes, and the middle section for snappers. Among the non-silverside fish counted, 91.2% were juveniles. These results suggest that Pigeon Creek is an important nursery for the coral reefs surrounding San Salvador and should be protected from potential disturbances.

  6. Effects of chronic exposure to petroleum hydrocarbons on two species of marine fish infected with a hemoprotozoan, Trypanosoma murmanensis

    Energy Technology Data Exchange (ETDEWEB)

    Khan, R.A. (Memorial Univ. of Newfoundland St. John' s, NF (Canada))

    1987-01-01

    The present study was undertaken to ascertain the effects of a blood protozoan, Trypanosoma murmanensis, on two species of marine fish exposed to petroleum hydrocarbons. Infected juvenile and adult winter flounder were exposed for 6 weeks to sediment contaminated with a Venezuelan crude (total hydrocarbon concentration, 2600-3200 {mu}g/g) whereas Atlantic cod were exposed to water-accommodated fractions (50-100 {mu}g/l) for 12 weeks. Three other groups, uninfected controls, fish infected with trypanosomes only, and oil-treated, uninfected fish, were held in aquaria in a continuously flowing seawater system. Mortality was higher in the infected, oil-treated flounder and subadult cod than in the trypanosome-infected only, oil-treated, and control groups. Death in oil-treated flounder was associated with severe tail rot and hypersecretion of mucus from the gills, whereas blood values (hematocrit, hemoglobin, total plasma protein) were significantly depressed in both infected groups. Low body condition, excessive mucus secretion by the gills, and retarded gonadal development were observed in adult, oil-treated cod but these were more pronounced in the infected, oil-treated groups. Prevalence of the infection and parasitemias were higher in the oil-treated groups than in untreated fish. These results provide evidence that the combined effects of parasites and chronic oil pollution can not only cause mortality but can also jeopardize health and reproduction in surviving fish. 41 refs., 5 tabs.

  7. Recruitment of fish larvae and juveniles into two estuarine nursery areas with evidence of ebb tide use

    Science.gov (United States)

    Pattrick, Paula; Strydom, Nadine

    2014-08-01

    Recruitment of larvae and early juveniles, against the ebb tide in the shallower, slower-flowing marginal areas of two permanently open estuaries in the Eastern Cape, South Africa was observed. To determine tidal, diel and seasonal variations of larval and juvenile fish recruitment, fyke nets were used during a 24-hour cycle over two years from December 2010 to October 2012. On either side of each estuary bank, two fyke nets with mouth openings facing opposite directions (i.e. one net facing the incoming or outgoing tide and the other facing the opposing direction) were used to sample fishes. The aims of this study were to determine if 1) on the flood tide, were the nets facing the incoming tide collecting more larvae and early juveniles recruiting into the estuarine nursery area, than the nets facing the opposing direction and 2) on the ebb tide, were the nets facing the sea, and hence the opposing direction of the outgoing ebb tide, collecting more fishes recruiting into the nursery against the ebb tide, than the nets facing the outgoing ebb tide? Larval and juvenile fish CPUE, species diversity and richness varied seasonally between estuarine systems and between diel and tidal conditions. Highest catches were recorded on the flood tide, which coincided with sunrise in the Swartkops Estuary. Greatest catches of larvae and early juveniles were observed during the ebb tide at night in the Sundays Estuary. On the ebb tide, higher catches of several dominant species and several commercially important fishery species, occurred in the fyke nets which faced the sea, indicating the early developmental stages of these fish species are not necessarily being lost from the nursery. These larvae and juveniles are actively swimming against the ebb tide in the shallower, slower-flowing marginal areas facilitating recruitment against ebb flow.

  8. Fish predation on brachyuran larvae and juveniles in the Pinheiros river, Guaratuba Bay, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo V. Costa

    2009-06-01

    Full Text Available Fish predation is thought to exert an important influence on the demographical dynamics of larvae and juveniles of estuarine brachyuran crabs but few studies have investigated this phenomenon in nature. In this study, fishes were captured during full moons (in January and February 2005, when many brachyuran species are known to release their larvae. Samples were carried out in the Pinheiros river, Guaratuba Bay, Paraná, Brazil. The stomach contents of collected fishes were surveyed to determine the species that are most likely to prey on brachyuran immature forms in this location. Two techniques were used to capture fishes: manual samplings, using a 5-mm mesh size net (1.8m depth, and bottom trawling with a 20-mm mesh size net. The collected specimens were fixed using 10% formaldehyde and preserved in 70% ethanol. A total of 2941 fishes of 43 different species were collected and the stomach contents of 962 individuals were analyzed in laboratory. Food items were identified and quantified. The fish species captured using manual nets that showed the highest number of preyed zoeae per stomach was the clupeid Platanichthys platana (Regan, 1917. Sphoeroides testudineus (Linnaeus, 1758 and Centropomus parallelus Poey, 1860 showed the highest levels of predation on megalopae. Of the fish species captured using trawl nets, Genidens genidens (Cuvier, 1829 showed the highest average number of zoeae per analyzed stomach and Bairdiella ronchus (Cuvier, 1830 was the most important predator on brachyuran megalopae and on young juveniles. The obtained data indicate that brachyuran crab restocking efforts performed in the Guaratuba Bay should include strategies to avoid or, at least, reduce the access of fishes to the released early juvenile stages, given the potential substantial losses caused by fish predation. Considering that, in general, predation potential was 8.5 times lower in juveniles than in megalopae, releasing immature forms produced in laboratory

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  10. Arctic marine fishes and their fisheries in light of global change

    OpenAIRE

    Jørgen S. Christiansen; Mecklenburg, Catherine W; Karamushko, Oleg V

    2013-01-01

    In light of ocean warming and loss of Arctic sea ice, harvested marine fishes of boreal origin (and their fisheries) move poleward into yet unexploited parts of the Arctic seas. Industrial fisheries, already in place on many Arctic shelves, will radically affect the local fish species as they turn up as unprecedented bycatch. Arctic marine fishes are indispensable to ecosystem structuring and functioning, but they are still beyond credible assessment due to lack of basic biological data. The ...

  11. Exposure assessment for trace elements from consumption of marine fish in Southeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Kunito, Takashi [Department of Environmental Sciences, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto 390-8621 (Japan); Sudaryanto, Agus [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Monirith, In [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Kan-Atireklap, Supawat [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Iwata, Hisato [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Ismail, Ahmad [Department of Biology, Faculty of Science and Environmental Studies, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sanguansin, Joompol [Eastern Marine Fisheries Development Center, Ban Phe, Muang, Rayong 21160 (Thailand); Muchtar, Muswerry [Research and Development Center for Oceanology Indonesia Institute of Sciences, Jl. Pasir Putih 1, Ancol Timur, Jakarta 11048 (Indonesia); Tana, Touch Seang [Social and Cultural Observation Unit (OBSES), Office of the Council of Ministers, Phnom Penh (Cambodia); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)]. E-mail: shinsuke@agr.ehime-u.ac.jp

    2007-02-15

    Concentrations of 20 trace elements were determined in muscle and liver of 34 species of marine fish collected from coastal areas of Cambodia, Indonesia, Malaysia and Thailand. Large regional difference was observed in the levels of trace elements in liver of one fish family (Carangidae): the highest mean concentration was observed in fish from the Malaysian coastal waters for V, Cr, Zn, Pb and Bi and those from the Java Sea side of Indonesia for Sn and Hg. To assess the health risk to the Southeast Asian populations from consumption of fish, intake rates of trace elements were estimated. Some marine fish showed Hg levels higher than the guideline values by U.S. Environmental Protection Agency and Joint FAO/WHO Expert Committee on Food Additives (JECFA). This suggests that consumption of these fish may be hazardous to the people. -- Intake of mercury through consumption of some marine fish species might be hazardous to the people in Southeast Asia.

  12. Anthropogenic chemical cues can alter the swimming behaviour of juvenile stages of a temperate fish.

    Science.gov (United States)

    Díaz-Gil, Carlos; Cotgrove, Lucy; Smee, Sarah Louise; Simón-Otegui, David; Hinz, Hilmar; Grau, Amalia; Palmer, Miquel; Catalán, Ignacio A

    2017-04-01

    Human pressure on coastal areas is affecting essential ecosystems including fish nursery habitats. Among these anthropogenic uses, the seasonal increment in the pressure due to leisure activities such as coastal tourism and yachting is an important environmental stressor in many coastal zones. These pressures may elicit understudied impacts due to, for example, sunscreens or other seasonal pollutants. The island of Majorca, northwest Mediterranean Sea, experiences one of the highest number of tourist visits per capita in the world, thus the surrounding coastal habitat is subject to high anthropogenic seasonal stress. Studies on early stages of fishes have observed responses to coastal chemical cues for the selection or avoidance of habitats. However, the potential interferences of human impacts on these signals are largely unknown. A choice chamber was used to determine water type preference and behaviour in naïve settled juvenile gilt-head sea bream (Sparus aurata), a temperate species of commercial interest. Fish were tested individually for behavioural changes with respect to water types from potential beneficial habitats, such as seawater with extract of the endemic seagrass Posidonia oceanica, anthropogenically influenced habitats such as water extracted from a commercial and recreational harbour and seawater mixed with sunscreen at concentrations observed in coastal waters. Using a Bayesian approach, we investigated a) water type preference; b) mean speed; and c) variance in the movement (as an indicator of burst swimming activity, or "sprint" behaviour) as behavioural descriptors with respect to water type. Fish spent similar percentage of time in treatment and control water types. However, movement descriptors showed that fish in sunscreen water moved slower (98.43% probability of being slower) and performed fewer sprints (90.1% probability of having less burst in speed) compared to control water. Less evident increases in sprints were observed in harbour

  13. Feeding ecology of pelagic fish larvae and juveniles in slope waters of the Gulf of Mexico.

    Science.gov (United States)

    Wells, R J D; Rooker, J R

    2009-11-01

    Stable isotope ratios of carbon (delta13C) and nitrogen (delta15N) were used to investigate feeding patterns of larval and early juvenile pelagic fishes in slope waters of the Gulf of Mexico. Contribution of organic matter supplied to fishes and trophic position within this pelagic food web was estimated in 2007 and 2008 by comparing dietary signatures of the two main producers in this ecosystem: phytoplankton [based on particulate organic matter (POM)] and Sargassum spp. Stable isotope ratios of POM and pelagic Sargassum spp. were significantly different from one another with delta13C values of POM depleted by 3-6 per thousand and delta15N values enriched by 2 relative to Sargassum spp. Stable isotope ratios were significantly different among the five pelagic fishes examined: blue marlin Makaira nigricans, dolphinfish Coryphaena hippurus, pompano dolphinfish Coryphaena equiselis, sailfish Istiophorus platypterus and swordfish Xiphias gladius. Mean delta13C values ranged almost 2 among fishes and were most depleted in I. platypterus. In addition, mean delta15N values ranged 4-5 with highest mean values found for both C. hippurus and C. equiselis and the lowest mean value for M. nigricans during both years. Increasing delta13C or delta15N with standard length suggested that shifts in trophic position and diet occurred during early life for several species examined. Results of a two-source mixing model suggest approximately an equal contribution of organic matter by both sources (POM=55%; pelagic Sargassum spp.=45%) to the early life stages of pelagic fishes examined. Contribution of organic matter, however, varied among species, and sensitivity analyses indicated that organic source estimates changed from 2 to 13% for a delta(13)C fractionation change of +/-0.25 per thousand or a delta15N fractionation change of +/-1.0 per thousand relative to original fractionation values.

  14. Fate of PBDEs in juvenile lake trout estimated using a dynamic multichemical fish model.

    Science.gov (United States)

    Bhavsar, Satyendra P; Gandhi, Nilima; Gewurtz, Sarah B; Tomy, Gregg T

    2008-05-15

    Biotransformation half-lives (HL) and gut absorption efficiencies (GAE) of PBDE congeners in fish are poorly known and challenging to quantify experimentally. These values are needed in order to accurately assess their food web dynamics, and in turn, for policy development We recently developed a multichemical aquatic food web model, which was used to estimate HL of four PBDE congeners in a simple Arctic food web. However, an application of this model to more complex food webs would dramatically increase the uncertainties in the results due to the large number of unknowns that would need to be considered simultaneously. As such, an in-depth analysis of possible HL and GAE of additional PBDE congeners at the scale of individual fish species would facilitate model application to more complex food webs. For this purpose, we developed a fugacity-based dynamic multichemical fish model and applied it to previously published experimental laboratory data. The model was calibrated by maximizing correspondence between the modeled and observed concentrations for each of the thirteen congeners at two dietary concentrations in juvenile lake trout (Salvelinus namaycush) during uptake and depuration phases mainly by varying HL and GAE. A robust parametrization and calibration procedure gave us confidence in our back-calculated congener-specific HL of 42-420 days and GAE of 20-45%. These values can be used as a starting point for model applications to natural fish populations. The fate/transport results suggest that not only loss of PBDE congeners via degradation, but also input through biotransformation of higher brominated congeners, should be accounted for in order to accurately portray dynamics of PBDEs in fish.

  15. Effects of marine wind farms on the distribution of fish, shellfish and marine mammals in the Horns Rev area

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, E.; Astrup, J.; Larsen, Finn; Munch-Petersen, S.

    2000-05-15

    The purpose of the report is: 1) to give a quantitative description of the abundance of the fish and shellfish in the area surrounding the windmill area and to evaluate the effects of the physically presence of the windmills on the abundance of fish and shellfish in the area; 2) to evaluate the artificial reef effect in the windmill area; 3) to evaluate the effects of noise and electromagnetic fields on the abundance of fish and marine mammals. (au)

  16. Taurine supplementation to alternative dietary proteins used in fish meal replacement enhances growth of juvenile cobia (Rachycentron canadum)

    Science.gov (United States)

    Two separate 8 week feeding trials were conducted to examine the impacts of fish meal replacement with an organically certifiable yeast-based protein source with and without supplementation of methionine, tryptophan, and taurine to diets for juvenile cobia. In the first trial, diets were formulated ...

  17. Relative importance of interlinked mangroves and seagrass beds as feeding habitats for juvenile reef fish on a Caribbean island

    NARCIS (Netherlands)

    Nagelkerken, I.A.; Velde, G. van der

    2004-01-01

    Mangroves and seagrass beds are important daytime shelter habitats for juvenile Caribbean reef fish species, but little is known about their relative importance as feeding grounds. In the present study, we tested the degree to which these 2 habitats are used as a feeding ground for 4 nocturnally

  18. STABLE ISOTOPE STUDIES ON THE USE OF MARINE-DERIVED NUTRIENTS BY COHO SALMON JUVENILES IN THE OREGON COAST RANGE

    Science.gov (United States)

    Greatly reduced spawning runs of anadromous salmon in streams of the Pacific Northwest (USA) have led to concerns about the effects of reduced marine derived nutrients (MDN's) on sustaining over-wintering juvenile salmon in those streams. In response to these concerns, state a...

  19. Lipid composition - Sustainable aquafeeds for marine finfish: Effects of vegetable oil replacement feeds containing novel microalgal and fungal oils on growth performance of juvenile sablefish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The concomitant replacement of fish meal and fish oil in carnivorous marine fish feeds by more sustainable terrestrial alternatives is problematic due to the limited...

  20. Chemical composition - Sustainable aquafeeds for marine finfish: Effects of vegetable oil replacement feeds containing novel microalgal and fungal oils on growth performance of juvenile sablefish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The concomitant replacement of fish meal and fish oil in carnivorous marine fish feeds by more sustainable terrestrial alternatives is problematic due to the limited...

  1. Growth - Sustainable aquafeeds for marine finfish: Effects of vegetable oil replacement feeds containing novel microalgal and fungal oils on growth performance of juvenile sablefish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The concomitant replacement of fish meal and fish oil in carnivorous marine fish feeds by more sustainable terrestrial alternatives is problematic due to the limited...

  2. Comparative assessment of Vibrio virulence in marine fish larvae.

    Science.gov (United States)

    Rønneseth, A; Castillo, D; D'Alvise, P; Tønnesen, Ø; Haugland, G; Grotkjaer, T; Engell-Sørensen, K; Nørremark, L; Bergh, Ø; Wergeland, H I; Gram, L

    2017-10-01

    Vibrionaceae infections are a major obstacle for marine larviculture; however, little is known about virulence differences of Vibrio strains. The virulence of Vibrio strains, mostly isolated from vibriosis outbreaks in farmed fish, was tested in larval challenge trials with cod (Gadus morhua), turbot (Scophthalmus maximus) and halibut (Hippoglossus hippoglossus) using a multiwell dish assays with single-egg/larvae cultures. The strains differed significantly in virulence as some caused a high mortality of larva reaching 100% mortality after a few days, while others had no or only marginal effects on survival. Some Vibrio strains were pathogenic in all of the larva species, while some caused disease only in one of the species. Twenty-nine of the Vibrio anguillarum strains increased the mortality of larvae from at least one fish species; however, pathogenicity of the strains differed markedly. Other Vibrio species had no or less pronounced effects on larval mortalities. Iron uptake has been related to V. anguillarum virulence; however, the presence or absence of the plasmid pJM1 encoding anguibactin did not correlate with virulence. The genomes of V. anguillarum were compared (D. Castillo, P.W. D'Alvise, M. Middelboe & L. Gram, unpublished data) and most of the high-virulent strains had acquired virulence genes from other pathogenic Vibrio. © 2017 John Wiley & Sons Ltd.

  3. Induction and recovery of morphofunctional changes in the intestine of juvenile carnivorous fish (Epinephelus coioides) upon exposure to foodborne benzo[a]pyrene

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, Bonny B.H. [Centre for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Nicholas School of the Environment, Duke University, Durham, NC (United States); Wong, Chris K.C. [Department of Biology, Baptist University of Hong Kong, Waterloo Road, Kowloon, Hong Kong (China); Woo, N.Y.S. [Department of Biology, Chinese University of Hong Kong, New Territory, Hong Kong (China); Au, Doris W.T. [Centre for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: bhdwtau@cityu.edu.hk

    2007-05-15

    The sublethal toxicity of dietary benzo[a]pyrene, B[a]P, on fish growth and intestinal morphofunctional changes [as measured by epithelial turnover, cell proliferation, hyperplasia, de novo crypt formation and protein absorption efficiency (i.e. expression of proton/peptide co-transporter, PepT-1, on the mucosal brush border)] were studied for the carnivorous orange-spotted grouper (Epinephelus coioides). Juvenile fish were force-fed daily with pellets containing environmentally realistic concentrations of B[a]P (dissolved in corn oil) at 0.25 {mu}g/g body weight (low-dose) and 12.5 {mu}g/g body weight (high-dose) for 4 weeks, followed by a control diet for a further 4 weeks to assess recovery. Although growth inhibition was observed in fish treated with high-dose B[a]P during the exposure period, no mortality was observed throughout the 8-week experiment. Significant hyperplasia of basal enterocytes of mucosal folds was detected shortly after 3-day exposure to the high-dose B[a]P. Moreover, a faster epithelial turnover was measured in the high-dose B[a]P exposed fish at exposure week 1, which was followed by an increase of basal cell proliferation and a reduction of PepT-1 expression at exposure week 2. The formation of de novo crypts, resemblance to the cancer predisposition syndrome 'juvenile polyposis', was significantly higher in the intestine of high-dose treated fish as compared to the control at exposure week 2 and onwards. Abnormal cytoplasmic extrusions were frequently observed in mucosal folds of high-dose fish at exposure week 4. In the low-dose treatment group, only the expression of PepT-1 was significantly reduced at exposure week 2 and an early adaptive response was observed at exposure week 4. Despite all these intestinal disturbances were reversible in fish upon the abatement to dietary B[a]P (within 1-4 weeks), environmental realistic levels of foodborne B[a]P could induce sublethal toxicity to E. coioides, and probably impose potential

  4. Anisakids in marine fish from the coast of Chon Buri Province, Thailand.

    Science.gov (United States)

    Nuchjangreed, Chadaporn; Hamzah, Zulhainan; Suntornthiticharoen, Pattra; Sorosjinda-Nunthawarasilp, Prapa

    2006-01-01

    A total of 1,600 specimens, consisting of 16 different species of marine fish, were dissected and examined for anisakid larvae and adults in visceral organs, abdominal cavity, and muscles. One species of adult-stage nematode was found in two of 16 species of marine fish studied, Johnius carouna and Dendrophysa russelli. No anisakid larvae (third-stage) was found in any of the 16 species of marine fish studied. Morphological study of the adult-stage nematode showed similar morphology to Anisakis simplex. We found that the nematode adult recovered from the marine fish differed from other anisakids in morphology, life cycle and locality of infection in the fish. The anisakid adults recovered were ovoviviparous or larviparous, but not oviparous as is seen in most other anisakids. The intensity and prevalence of nematode infection in Johnius carouna were 2.4 and 31.7%, respectively, and in Dendrophysa russelli 3.9 and 87.5%, respectively.

  5. Characterizing ontogenetic habitat shifts in marine fishes: advancing nascent methods for marine spatial management.

    Science.gov (United States)

    Galaiduk, Ronen; Radford, Ben T; Saunders, Benjamin J; Newman, Stephen J; Harvey, Euan S

    2017-09-01

    Niche requirements and habitat resource partitioning by conspecific fishes of different sizes are significant knowledge gaps in the species distribution modelling domain. Management actions and operations are typically concentrated on static habitats, or specific areas of interest, without considering movement patterns of species associated with ontogenetic shifts in habitat usage. Generalized additive models were used to model the body-length-habitat relationships of six fish species. These models were used to identify subsets of environmental parameters that drive and explain the continuous length-habitat relationships for each of the study species, which vary in their degree of ecological and/or commercial importance. Continuous predictive maps of the length distributions for each of the six study species across approximately 200 km(2) of the study area were created from these models. The spatial patterns in habitat partitioning by individuals of different body lengths for all six study species provide strong evidence for ontogenetic shifts. This highlights the importance of considering ontogenetic processes for marine spatial management. Importantly, predictive hotspot maps were created that identify potential areas that accumulate individuals of similar life stages of multiple species (e.g., multispecies nursery areas). In circumstances where limited resources are available for monitoring and management of fish resources, predictive modelling is a valuable tool for studying previously overlooked processes such as ontogenetic habitat shifts. Predictive modelling provides crucial information that elucidates spatial patterns in community composition across mosaics of benthic habitats. This novel technique can contribute to the spatial management of coastal fish and fisheries by identifying areas that are important for different life history stages of multiple fish species. © 2017 by the Ecological Society of America.

  6. Juvenile and small fishes in a mangrove estuary in Trang province, Thailand: seasonal and habitat differences

    Science.gov (United States)

    Ikejima, K.; Tongnunui, P.; Medej, T.; Taniuchi, T.

    2003-03-01

    Juvenile and small resident fish assemblages at three sites (beach with mangroves, beach without mangroves and middle reach of mangrove creek), comprising the major habitat types of a mangrove estuary in Trang Province, Thailand, were studied for 3 years. A total of 6616 individuals, comprising 89 species (30 families), were collected using a small seine net. In terms of number of species per family, Gobiidae (18 species) was the most diverse, followed by Engraulidae (nine species) and Leiognathidae (seven species). In terms of individuals, Engraulidae, Leiognathidae, Gerreidae, Atherinidae and Gobiidae were the dominant families. Species richness was significantly greater in the mangrove creek than at the two beach sites, and greater in the wet season than the dry season. Fish abundance (individuals per tow) was also greater in the wet season, with no significant differences among sites. On the other hand, biomass (weight per tow) was greater in the mangrove creek than the mangrove beach, but with no significant difference between seasons. Cluster and ordination analysis based on the number of individuals of each species demonstrated that the fish assemblage structures were markedly different between the beach and creek sites, the assemblages at the two beach sites being similar in the wet season. Most species were specific to a particular habitat type (or types), some occurring exclusively in the creek or beach sites, and some in both the mangrove sites. Such distributional differences were found even between species within a single family. The results indicated that creek and beach habitats function as nursery sites for different fish species, the former being utilized by a grater diversity of species than the latter.

  7. [Nutrition of juvenile prawn Macrobrachium carcinus (Crustacea: Decapoda) with diets of vegetable and marine residues].

    Science.gov (United States)

    Casas-Sánchez, R; Vaillard-Nava, Y; Re-Araujo, A D

    1995-01-01

    Juvenile prawn Macrobrachium carcinus were fed two different diets: restaurant by-products (diet I) and fish and vegetable market by-products (diet II). These diets were evaluated by proximal analysis, assimilation efficiency and the factor conversion rate (FCR). Diet I registered a higher efficiency, but there was no difference in the growth rate. The growth mean (G. L.) for three months was 0.254 +/- 0.13 cm (diet I) and 0.191 +/- 0.1 cm (diet II). The conversion rate was good for both, suggesting that 6 to 7 kg of food are needed to obtain 1 kg of prawn. Survival was 76% and 100% for diets I and II, respectively.

  8. Rearing diet may determine fish restocking success: a case study of hatchery-reared juvenile meagre, Argyrosomus regius

    Directory of Open Access Journals (Sweden)

    María del Mar Gil

    2015-12-01

    Full Text Available The resilience of released hatchery-reared specimens increases with age and size, but production costs are also greater for these individuals. Therefore, for a given budget, the consequences of increasing age and size impose a trade-off between producing a large number of vulnerable (small fish or a small number of resilient (large fish. Once the optimal size for releasing fish has been defined, the choice of rearing protocol will determine the number and quality of the fish that can be released. In this study, different rearing protocols were compared using meagre juveniles (Argyrosomus regius, which are presently the target of a restocking programme conducted in the Balearic Islands (western Mediterranean. Seven different diets were compared during the grow-out phase to identify the diets that produced good-quality juveniles of a given size at the lowest cost. Most of the diets produced juveniles of suitable biological quality in terms of growth, fish condition (relationships between length and total weight, liver weight and mesenteric fat weight and tissue biochemical composition. A semi-moist diet (Diet G provided the best growth rate, closely followed by commercial meagre pellets (Diet A. In contrast, the cost of growing fish with Diet A was lower for any possible size at release. This study demonstrates the need to consider both growth rate and production cost to select the rearing protocol that maximizes the number of juveniles that can be produced for a given budget and desired release size. These considerations will ultimately increase the chance of success of restocking programmes.

  9. Assessing Dispersal Patterns of Fish Propagules from an Effective Mediterranean Marine Protected Area

    Science.gov (United States)

    Di Franco, Antonio; Coppini, Giovanni; Pujolar, José Martin; De Leo, Giulio A.; Gatto, Marino; Lyubartsev, Vladyslav; Melià, Paco; Zane, Lorenzo; Guidetti, Paolo

    2012-01-01

    Successfully enforced marine protected areas (MPAs) have been widely demonstrated to allow, within their boundaries, the recovery of exploited species and beyond their boundaries, the spillover of juvenile and adult fish. Little evidence is available about the so-called ‘recruitment subsidy’, the augmented production of propagules (i.e. eggs and larvae) due to the increased abundance of large-sized spawners hosted within effective MPAs. Once emitted, propagules can be locally retained and/or exported elsewhere. Patterns of propagule retention and/or export from MPAs have been little investigated, especially in the Mediterranean. This study investigated the potential for propagule production and retention/export from a Mediterranean MPA (Torre Guaceto, SW Adriatic Sea) using the white sea bream, Diplodus sargus sargus, as a model species. A multidisciplinary approach was used combining 1) spatial distribution patterns of individuals (post-settlers and adults) assessed through visual census within Torre Guaceto MPA and in northern and southern unprotected areas, 2) Lagrangian simulations of dispersal based on an oceanographic model of the region and data on early life-history traits of the species (spawning date, pelagic larval duration) and 3) a preliminary genetic study using microsatellite loci. Results show that the MPA hosts higher densities of larger-sized spawners than outside areas, potentially guaranteeing higher propagule production. Model simulations and field observation suggest that larval retention within and long-distance dispersal across MPA boundaries allow the replenishment of the MPA and of exploited populations up to 100 km down-current (southward) from the MPA. This pattern partially agrees with the high genetic homogeneity found in the entire study area (no differences in genetic composition and diversity indices), suggesting a high gene flow. By contributing to a better understanding of propagule dispersal patterns, these findings provide

  10. Evidence of genetic selection for growth in new recruits of a marine fish.

    Science.gov (United States)

    Planes, S; Romans, P

    2004-07-01

    Abstract A cohort of Diplodus sargus, a coastal marine fish abundant in the Mediterranean Sea, has been surveyed from its settlement following the pelagic larval stage up to 4 months of age, when the juveniles are moving to adult habitats in order to assess selective processes. We followed the mortality by looking at the decrease in population abundance and, simultaneously, the genetic structure using allozymes and the growth associated with each genotype to test for a relationship between genotype and phenotype. The recruitment survey demonstrated that 80% of individuals arrived within a single night and that they show very similar age providing a discrete pulse of new recruits that we followed for changes in survival and allele frequencies. After 4 months, there was a total mortality of 80.8%, with the disappearance of 181 of 224 fish that initially colonized the rocky barrier. The decrease in number followed a logarithmic model with a maximum decrease in the early period (first 30 days). The model derived from the 4 months of data demonstrates that most of the mortality in the cohort occurs over the first 120 days following settlement and the model predicted a final abundance of 10 individuals after 1 year. Within the same period of 4 months, we observed significant decrease in multilocus heterozygosity. Such a decrease in heterozygosity partly resulted from a purge of the Pgm-80* allele. Together with this major change in a natural population, an aquarium experiment demonstrated that individuals with Pgm-80* alleles show significantly lower growth than other new recruits. We propose that the decrease in frequency of Pgm-80* in the natural environment is the result of targeted predation that eliminates smaller individuals and therefore individuals bearing Pgm-80*. The potential metabolic effect as well as a scenario that could lead to the maintenance of polymorphism is discussed.

  11. Assessing dispersal patterns of fish propagules from an effective mediterranean marine protected area.

    Directory of Open Access Journals (Sweden)

    Antonio Di Franco

    Full Text Available Successfully enforced marine protected areas (MPAs have been widely demonstrated to allow, within their boundaries, the recovery of exploited species and beyond their boundaries, the spillover of juvenile and adult fish. Little evidence is available about the so-called 'recruitment subsidy', the augmented production of propagules (i.e. eggs and larvae due to the increased abundance of large-sized spawners hosted within effective MPAs. Once emitted, propagules can be locally retained and/or exported elsewhere. Patterns of propagule retention and/or export from MPAs have been little investigated, especially in the Mediterranean. This study investigated the potential for propagule production and retention/export from a Mediterranean MPA (Torre Guaceto, SW Adriatic Sea using the white sea bream, Diplodus sargus sargus, as a model species. A multidisciplinary approach was used combining 1 spatial distribution patterns of individuals (post-settlers and adults assessed through visual census within Torre Guaceto MPA and in northern and southern unprotected areas, 2 Lagrangian simulations of dispersal based on an oceanographic model of the region and data on early life-history traits of the species (spawning date, pelagic larval duration and 3 a preliminary genetic study using microsatellite loci. Results show that the MPA hosts higher densities of larger-sized spawners than outside areas, potentially guaranteeing higher propagule production. Model simulations and field observation suggest that larval retention within and long-distance dispersal across MPA boundaries allow the replenishment of the MPA and of exploited populations up to 100 km down-current (southward from the MPA. This pattern partially agrees with the high genetic homogeneity found in the entire study area (no differences in genetic composition and diversity indices, suggesting a high gene flow. By contributing to a better understanding of propagule dispersal patterns, these findings

  12. Assessing dispersal patterns of fish propagules from an effective mediterranean marine protected area.

    Science.gov (United States)

    Di Franco, Antonio; Coppini, Giovanni; Pujolar, José Martin; De Leo, Giulio A; Gatto, Marino; Lyubartsev, Vladyslav; Melià, Paco; Zane, Lorenzo; Guidetti, Paolo

    2012-01-01

    Successfully enforced marine protected areas (MPAs) have been widely demonstrated to allow, within their boundaries, the recovery of exploited species and beyond their boundaries, the spillover of juvenile and adult fish. Little evidence is available about the so-called 'recruitment subsidy', the augmented production of propagules (i.e. eggs and larvae) due to the increased abundance of large-sized spawners hosted within effective MPAs. Once emitted, propagules can be locally retained and/or exported elsewhere. Patterns of propagule retention and/or export from MPAs have been little investigated, especially in the Mediterranean. This study investigated the potential for propagule production and retention/export from a Mediterranean MPA (Torre Guaceto, SW Adriatic Sea) using the white sea bream, Diplodus sargus sargus, as a model species. A multidisciplinary approach was used combining 1) spatial distribution patterns of individuals (post-settlers and adults) assessed through visual census within Torre Guaceto MPA and in northern and southern unprotected areas, 2) Lagrangian simulations of dispersal based on an oceanographic model of the region and data on early life-history traits of the species (spawning date, pelagic larval duration) and 3) a preliminary genetic study using microsatellite loci. Results show that the MPA hosts higher densities of larger-sized spawners than outside areas, potentially guaranteeing higher propagule production. Model simulations and field observation suggest that larval retention within and long-distance dispersal across MPA boundaries allow the replenishment of the MPA and of exploited populations up to 100 km down-current (southward) from the MPA. This pattern partially agrees with the high genetic homogeneity found in the entire study area (no differences in genetic composition and diversity indices), suggesting a high gene flow. By contributing to a better understanding of propagule dispersal patterns, these findings provide

  13. Estrogenic followed by anti-estrogenic effects of PCBs exposure in juvenil fish (Spaurus aurata).

    Science.gov (United States)

    Calò, M; Alberghina, D; Bitto, A; Lauriano, E R; Lo Cascio, P

    2010-01-01

    Vitellogenin (Vtg) is a phospho-lipo-glycoprotein produced by oviparous animals in response to estrogen receptor (ER) binding. The presence of Vtg in juvenile and male fish liver and plasma has been used as biomarker to evaluate levels of environmental contaminants as dioxin and PCBs. Interaction of dioxins and PCBs with aryl hydrocarbon receptor (AhR) may affect reproduction by recruitment of estrogen receptor alpha (ERalpha). The aim of this study was to investigate the effects of PCB-126, a co-planar PCB prototypical AhR agonist, and of PCB-153, a non-coplanar PCB lacking dioxine-like activity, on Vtg expression in young fish (Spaurus aurata) after a 12 or 24h exposure to PCBs as well as 48h following PCBs removal. Vtg expression was evaluated by immunohistochemistry and by Western-blot analysis. Our results showed an increased Vtg expression following PCBs administration, with a maximum level after 12h of exposure to either PCB-126, PCB-153 or a mixture of both PCBs. Following this estrogenic activity, an anti-estrogenic activity was detected after 24h of incubation with PCB-126 (alone or mixed with PCB-153), suggested by a decrease in Vtg expression likely through AhR, as a consequence of a hypothetic defence mechanism to endogenous or exogenous ligands.

  14. Effects of Norethindrone and Metabolite Ethynylestradiol on Reproductive Parameters in a Marine Fish

    Science.gov (United States)

    Norethindrone (NOR) is a progestin used in human contraceptives and has been detected in low concentrations (ng/L) in aquatic environments. Laboratory experiments were conducted with the marine fish cunner (Tautogolabrus adspersus) to evaluate whether NOR could affect reproductiv...

  15. Variations in stomach contents and biochemical composition of tissues in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Jacob, P.G.; Rajagopal, M.D.

    Relationship between calorific values and protein, fat and carbohydrate of the stomach contents (food) and body tissues of marine fishes, Sardinella longiceps, Valenciennes, Rastrelliger kanagurta (Cuvier), Otolithus ruber (Schneider) and Lactarius...

  16. Fish diversity in southern California using trawl data from the National Marine Fisheries Service

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Shannon Index of diversity was calculated from National Marine Fisheries Service Groundfish Survey Program (NMFS GSP) fish trawl data. Data from 477 fishery...

  17. Fish assemblages in southern California using trawl data from the National Marine Fisheries Service

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish benthic trawls were completed by the National Marine Fisheries Service Groundfish Survey Program (NMFS GSP). Data from 477 fishery independent trawls ranging...

  18. Estuarine refugia and fish responses to a large anoxic, hydrogen sulphide, “black tide” event in the adjacent marine environment

    Science.gov (United States)

    Lamberth, S. J.; Branch, G. M.; Clark, B. M.

    2010-01-01

    The fish fauna of the Berg River Estuary was sampled from the mouth to 40 km upstream using a small-meshed seine-net before (summer 1993), during (summer 1994) and after (summer 1996) a low-oxygen, hydrogen sulphide "black tide" event that caused a mass mortality of fish in St Helena Bay. These data were compared to determine how the species composition, abundance and distribution of the fish fauna of the Berg River Estuary differed before, during and after the event as well as to ascertain which species, if any, found refuge in the estuary. The overall catch-per-unit-effort of 1637 fish.haul -1 during the event was almost double the 932 fish.haul -1 and 643 fish.haul -1 in the years before and after respectively. All the fish recorded alive in the estuary during the event were species known to have some degree of estuarine association. No representatives of the purely marine species found dead on the adjacent shoreline were recorded live in the estuary during the event. Of the 10 estuarine-associated species sampled, 5 extended their range and/or modal peaks of abundance further upstream during the event. One species, Liza richardsonii, was abundant enough to examine its size distribution in different breaches of the estuary. Large/adult fish were concentrated further upstream than small/juvenile fish, which appeared to be unable to escape tidal currents and were concentrated at the edge of the low-oxygen front. Collectively this circumstantial evidence indicates that (1) fish used the Berg Estuary as a refuge from low-oxygen conditions in the marine environment during the "black tide" event, and (2) the ability to secure refuge in the estuary was restricted to species described as "estuarine-associated" or "estuarine-dependent".

  19. Conservation physiology of marine fishes: state of the art and prospects for policy

    OpenAIRE

    McKenzie, David J.; Axelsson, Michael; Chabot, Denis; Claireaux, Guy; Cooke, Steven J.; Corner, Richard A.; Boeck, de, H.J.; Domenici, Paolo; Guerreiro, Pedro M.; Hamer, Bojan; Jørgensen, Christian; Killen, Shaun S.; Lefevre, Sjannie; Marras, Stefano; Michaelidis, Basile

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes is the limited knowledge base; international collaboration is needed to study the environmental physiology of a wider range of species. Multifactorial field and laboratory studies on biomarkers hold promise ...

  20. Bioaccumulation and trophic transfer of dioxins in marine copepods and fish

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qiong [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); School of Environment, State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing University, Nanjing (China); Yang Liuyan [School of Environment, State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing University, Nanjing (China); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2011-12-15

    Despite the great concerns about dioxins in the marine environments, the biokinetics and bioaccumulation of these compounds in marine organisms remains little known. Using radioactive tracers the aqueous uptake, dietary assimilation efficiency, and elimination of dioxins were measured in marine phytoplankton, copepods and seabream. The calculated uptake rate constant of dioxins decreased with increasing trophic levels, whereas the dietary assimilation efficiency (AE) was 28.5-57.6% in the copepods and 36.6-70.2% in the fish. The dietary AE was highly dependent on the food concentrations and food type. The elimination rate constant of dioxin in the copepods varied with different exposure pathways as well as food concentration and food type. Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish. Aqueous uptake can be an important pathway only when the bioconcentration of dioxins in the phytoplankton was low. - Highlights: > Radiotracer was used to quantify the biokinetics of dioxins in a marine food chain. > Aqueous uptake rate of dioxins decreased with increasing trophic levels. > Dietary assimilation efficiencies were comparable between the copepods and the fish. > Both food type and density significantly affected the dietary assimilation of dioxins. > Diet was the predominant pathway for dioxin accumulation in marine copepods and fish. - Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish.

  1. Are vegetated areas of mangroves attractive to juvenile and small fish? The case of Dongzhaigang Bay, Hainan Island, China

    Science.gov (United States)

    Wang, Mao; Huang, Zhenyuan; Shi, Fushan; Wang, Wenqing

    2009-11-01

    Well-developed aerial roots of mangroves make it difficult to study how fish utilize the mangrove forest as a habitat. In the present study, we compared the differences in fish assemblages in three major types of habitats of mangrove estuary (vegetated area, treeless mudflat, and creek) of a mangrove bay in Hainan Island, China, at different seasons during two consecutive years. Three types of gears, centipede net, gill net and cast net, were used in the different habitats of mangrove estuary and sampling efficiencies among gears were evaluated. Centipede nets were used in all the three types of habitats and cast nets and gill nets in treeless mudflats and creeks. Fish assemblages were dependent on gears used. Centipede net could efficiently catch fish occurring both inside and outside of vegetated areas efficiently. A total of 115 fish species in 51 families were collected. In terms of numbers of species per family, Gobiidae was the most diverse (17 species), followed by Mugilidae (5 species). Almost all of the fish were juvenile or small fish and few predators were recorded, implying low predation pressure in the bay. ANOVA analysis showed that significant seasonal and spatial variation existed in species richness, abundance, and biomass, which were less in the vegetated areas than those of treeless mudflats and creeks. The attraction of vegetated areas to fish was less than that of creeks and mudflats. Many species were specific to a particular habitat type, 4 species occurring exclusively in the creeks, 45 species occurring exclusively in the treeless mudflats, and 5 species occurring exclusively in the vegetated areas. The results indicated that mangrove estuaries were potentially attractive habitats for juvenile and small fish, but this attraction was accomplished by a connection of vegetated areas, treeless mudflats and creeks, not only by vegetated areas.

  2. Conservation physiology of marine fishes: advancing the predictive capacity of models

    NARCIS (Netherlands)

    Jorgensen, C.; Peck, M.A.; Antognarelli, F.; Teal, L.R.

    2012-01-01

    At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology to diff

  3. Seabird, fish, marine mammal and oceanography coordinated investigations (SMMOCI) in the Pribilof Islands, Alaska, July 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We conducted a survey of seabirds, fishes, marine mammals and oceanographic conditions near the Pribilof Islands, Alaska (Fig. 1) from the M/V Tiˆglaˆx during 20-26...

  4. The functional importance of Acropora austera as nursery areas for juvenile reef fish on South African coral reefs

    Science.gov (United States)

    Floros, C.; Schleyer, M. H.

    2017-03-01

    Many coral reef fish species use mangrove and seagrass beds as nursery areas. However, in certain regions, the absence or scarcity of such habitats suggests that juvenile coral reef fish may be seeking refuge elsewhere. The underlying biogenic substratum of most coral reefs is structurally complex and provides many types of refuge. However, on young or subtropical coral reefs, species may be more reliant on the living coral layer as nursery areas. Such is the case on the high-latitude coral reefs of South Africa where the coral communities consist of a thin veneer of coral overlaying late Pleistocene bedrock. Thus, the morphology of coral species may be a major determinant in the availability of refuge space. Acropora austera is a branching species that forms large patches with high structural complexity. Associated with these patches is a diverse community of fish species, particularly juveniles. Over the past decade, several large (>100 m2) A. austera patches at Sodwana Bay have been diminishing for unknown reasons and there is little evidence of their replacement or regrowth. Seven patches of A. austera (AP) and non- A. austera (NAP) were selected and monitored for 12 months using visual surveys to investigate the importance of AP as refugia and nursery areas. There were significant differences in fish communities between AP and NAP habitats. In total, 110 species were recorded within the patches compared to 101 species outside the patches. Labrids and pomacentrids were the dominant species in the AP habitats, while juvenile scarids, acanthurids, chaetodons and serranids were also abundant. The diversity and abundance of fish species increased significantly with AP size. As the most structurally complex coral species on the reefs, the loss of APs may have significant implications for the recruitment and survival of certain fish species.

  5. Exposure assessment for trace elements from consumption of marine fish in Southeast Asia.

    Science.gov (United States)

    Agusa, Tetsuro; Kunito, Takashi; Sudaryanto, Agus; Monirith, In; Kan-Atireklap, Supawat; Iwata, Hisato; Ismail, Ahmad; Sanguansin, Joompol; Muchtar, Muswerry; Tana, Touch Seang; Tanabe, Shinsuke

    2007-02-01

    Concentrations of 20 trace elements were determined in muscle and liver of 34 species of marine fish collected from coastal areas of Cambodia, Indonesia, Malaysia and Thailand. Large regional difference was observed in the levels of trace elements in liver of one fish family (Carangidae): the highest mean concentration was observed in fish from the Malaysian coastal waters for V, Cr, Zn, Pb and Bi and those from the Java Sea side of Indonesia for Sn and Hg. To assess the health risk to the Southeast Asian populations from consumption of fish, intake rates of trace elements were estimated. Some marine fish showed Hg levels higher than the guideline values by U.S. Environmental Protection Agency and Joint FAO/WHO Expert Committee on Food Additives (JECFA). This suggests that consumption of these fish may be hazardous to the people.

  6. Fish with chips: tracking reef fish movements to evaluate size and connectivity of Caribbean marine protected areas.

    Directory of Open Access Journals (Sweden)

    Simon J Pittman

    Full Text Available Coral reefs and associated fish populations have experienced rapid decline in the Caribbean region and marine protected areas (MPAs have been widely implemented to address this decline. The performance of no-take MPAs (i.e., marine reserves for protecting and rebuilding fish populations is influenced by the movement of animals within and across their boundaries. Very little is known about Caribbean reef fish movements creating a critical knowledge gap that can impede effective MPA design, performance and evaluation. Using miniature implanted acoustic transmitters and a fixed acoustic receiver array, we address three key questions: How far can reef fish move? Does connectivity exist between adjacent MPAs? Does existing MPA size match the spatial scale of reef fish movements? We show that many reef fishes are capable of traveling far greater distances and in shorter duration than was previously known. Across the Puerto Rican Shelf, more than half of our 163 tagged fish (18 species of 10 families moved distances greater than 1 km with three fish moving more than 10 km in a single day and a quarter spending time outside of MPAs. We provide direct evidence of ecological connectivity across a network of MPAs, including estimated movements of more than 40 km connecting a nearshore MPA with a shelf-edge spawning aggregation. Most tagged fish showed high fidelity to MPAs, but also spent time outside MPAs, potentially contributing to spillover. Three-quarters of our fish were capable of traveling distances that would take them beyond the protection offered by at least 40-64% of the existing eastern Caribbean MPAs. We recommend that key species movement patterns be used to inform and evaluate MPA functionality and design, particularly size and shape. A re-scaling of our perception of Caribbean reef fish mobility and habitat use is imperative, with important implications for ecology and management effectiveness.

  7. The ecological significance of juvenile Diplodus sargus as ectoparasite fish cleaners in the north-eastern Atlantic

    OpenAIRE

    2015-01-01

    Cleaning behaviour was recently described for the omnivorous species Diplodus sargus. Although previous studies have reported the existence of ectoparasites in the stomach contents of some individuals this commercially important fish was never considered a cleaner species. Here we make the first characterization of this behaviour based on field observations. This behaviour was exclusively performed by juvenile D. sargus and, until now, was only observed in confined or semi-confined areas such...

  8. Fishing the line near marine reserves in single and multispecies fisheries.

    Science.gov (United States)

    Kellner, Julie B; Tetreault, Irene; Gaines, Steven D; Nisbet, Roger M

    2007-06-01

    Throughout the world "fishing the line" is a frequent harvesting tactic in communities where no-take marine reserves are designated. This practice of concentrating fishing effort at the boundary of a marine reserve is predicated upon the principle of spillover, the net export of stock from the marine reserve to the surrounding unprotected waters. We explore the consequences and optimality of fishing the line using a spatially explicit theoretical model. We show that fishing the line: (1) is part of the optimal effort distribution near no-take marine reserves with mobile species regardless of the cooperation level among harvesters; (2) has a significant impact on the spatial patterns of catch per unit effort (CPUE) and fish density both within and outside of the reserve; and (3) can enhance total population size and catch simultaneously under a limited set of conditions for overexploited populations. Additionally, we explore the consequences of basing the spatial distribution of fishing effort for a multispecies fishery upon the optimality of the most mobile species that exhibits the greatest spillover. Our results show that the intensity of effort allocated to fishing the line should instead be based upon more intermediate rates of mobility within the targeted community. We conclude with a comparison between model predictions and empirical findings from a density gradient study of two important game fish in the vicinity of a no-take marine-life refuge on Santa Catalina Island, California (USA). These results reveal the need for empirical studies to account for harvester behavior and suggest that the implications of spatial discontinuities such as fishing the line should be incorporated into marine-reserve design.

  9. Bioaccumulation of heavy metals in commercially important marine fishes from Mumbai Harbor, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Velusamy, A.; SatheeshKumar, P.; Ram, A.; Chinnadurai, S.

    Mumbai Harb A. Velusamy a, P. Satheesh Kumar Univers ciences, phy, Mu olluscan toxic metals and negatively affect fish health. Pollution can be caused by various sources, including agricultural drainage, industrial effluent discharge, sewage discharge... metals, such as iron (Fe), copper (Cu) and zinc (Zn), are important for fishFish are considered an important protein source for human health. Marine pollution can increase aquatic concentrations oflevel, feeding habits, age, size, duration of exhttp...

  10. Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: comparison of baited videos and opera-house traps.

    Directory of Open Access Journals (Sweden)

    Corey B Wakefield

    Full Text Available Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment and modified (rockwall and dredge channel habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.

  11. Marine Biogeochemistry Under The Influence of Fish And Fisheries: An Ecosystem Modeling Study

    Science.gov (United States)

    Disa, Deniz; Akoglu, Ekin; Salihoglu, Baris

    2017-04-01

    The ocean and the marine ecosystems are important controllers of the global carbon cycle. They play a pivotal role in capturing atmospheric carbon into the ocean body, transforming it into organic carbon through photosynthesis and transporting it to the depths of the ocean. Fish, which has a significant role in the marine food webs, is thought to have a considerable impact on carbon export. More specifically, fish has a control on plankton dynamics as a predator, it provides nutrient to the ecosystem by its metabolic activities and it has the ability of moving actively and transporting materials. Fishing is also expected to impact carbon cycle because it directly changes the fish biomasses. However, how fish impacts the biogeochemistry of marine ecosystems is not studied extensively. The aim of this study is to analyze the impact of fish and fisheries on marine biogeochemical processes by setting up an end-to-end model, which simulates lower and higher tropic levels of marine ecosystems simultaneously. For this purpose, a one dimensional biogeochemical model simulating lower tropic level dynamics (e.g. carbon export, nutrient cycles) and an food web model simulating fisheries exploitation and higher tropic level dynamics were online and two-way coupled. Representing the marine ecosystem from one end to the other, the coupled model served as a tool for the analysis of fishing impacts on marine biogeochemical dynamics. Results obtained after incorporation of higher trophic level model changed the plankton compositions and enhanced detritus pools and increased carbon export. Additionally, our model showed that active movement of fish contributed to transport of carbon from surface to the deeper parts of the ocean. Moreover, results after applying different fishing intensities indicated that changes in fisheries exploitation levels directly influence the marine nutrient cycles and hence, the carbon export. Depending on the target and the intensity of fisheries

  12. Biochemical characteristics of four marine fish skins in Korea.

    Science.gov (United States)

    Cho, Jae-Kwon; Jin, Young-Guk; Rha, Sung-Ju; Kim, Seon-Jae; Hwang, Jae-Ho

    2014-09-15

    In this study, we investigated the biochemical characteristics of the fish skins of four industrial species: olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), sea bass (Lateolabrax maculatus) and red sea bream (Pagrus major). There is high domestic demand in Korea for farming of these fish for human consumption. Crude protein contents in the skin of these fish ranged from 73% to 94% by dry weight; this was in part due to a high content of the structural protein, collagen. Among the four species, olive flounder had the thickest dermal and epidermal layers in the dorsal skin. This species was also associated with the highest extraction ratio of acid-soluble collagen. We also examined whether fish skin could be a cost-effective alternative to current fish meal sources. Our analysis indicates that, when supplemented with additional fish oils and essential amino acids, fish skin is a viable alternative for fish meal formulations.

  13. A survey of fish viruses isolated from wild marine fishes from the coastal waters of southern Korea.

    Science.gov (United States)

    Kim, Wi-Sik; Choi, Shin-Young; Kim, Do-Hyung; Oh, Myung-Joo

    2013-11-01

    A survey was conducted to investigate viral infection in 253 wild marine fishes harvested in the southern coastal area of Korea from 2010 to 2012. The fish that were captured by local anglers were randomly bought and sampled for virus examination. The samples were tested for presence of virus by virus isolation with FHM, FSP, and BF-2 cells and molecular methods (polymerase chain reaction and sequencing). Of the 253 fish sampled, 9 fish were infected with virus. Aquabirnaviruses (ABVs), Viral hemorrhagic septicemia virus (VHSV), and Red seabream iridovirus (RSIV) were detected in 7, 1, and 1 fish, respectively. Molecular phylogenies demonstrated the detected viruses (ABV, VHSV, and RSIV) were more closely related to viruses reported of the same type from Korea and Japan than from other countries, suggesting these viruses may be indigenous to Korean and Japanese coastal waters.

  14. Large Recovery of Fish Biomass in a No-Take Marine Reserve

    Science.gov (United States)

    Aburto-Oropeza, Octavio; Erisman, Brad; Galland, Grantly R.; Mascareñas-Osorio, Ismael; Sala, Enric; Ezcurra, Exequiel

    2011-01-01

    No-take marine reserves are effective management tools used to restore fish biomass and community structure in areas depleted by overfishing. Cabo Pulmo National Park (CPNP) was created in 1995 and is the only well enforced no-take area in the Gulf of California, Mexico, mostly because of widespread support from the local community. In 1999, four years after the establishment of the reserve, there were no significant differences in fish biomass between CPNP (0.75 t ha−1 on average) and other marine protected areas or open access areas in the Gulf of California. By 2009, total fish biomass at CPNP had increased to 4.24 t ha−1 (absolute biomass increase of 3.49 t ha−1, or 463%), and the biomass of top predators and carnivores increased by 11 and 4 times, respectively. However, fish biomass did not change significantly in other marine protected areas or open access areas over the same time period. The absolute increase in fish biomass at CPNP within a decade is the largest measured in a marine reserve worldwide, and it is likely due to a combination of social (strong community leadership, social cohesion, effective enforcement) and ecological factors. The recovery of fish biomass inside CPNP has resulted in significant economic benefits, indicating that community-managed marine reserves are a viable solution to unsustainable coastal development and fisheries collapse in the Gulf of California and elsewhere. PMID:21858183

  15. First genealogy for a wild marine fish population reveals multigenerational philopatry

    KAUST Repository

    Salles, Océane C.

    2016-11-01

    Natal philopatry, the return of individuals to their natal area for reproduction, has advantages and disadvantages for animal populations. Natal philopatry may generate local genetic adaptation, but it may also increase the probability of inbreeding that can compromise persistence. Although natal philopatry is well documented in anadromous fishes, marine fish may also return to their birth site to spawn. How philopatry shapes wild fish populations is, however, unclear because it requires constructing multigenerational pedigrees that are currently lacking for marine fishes. Here we present the first multigenerational pedigree for a marine fish population by repeatedly genotyping all individuals in a population of the orange clownfish (Amphiprion percula) at Kimbe Island (Papua New Guinea) during a 10-y period. Based on 2927 individuals, our pedigree analysis revealed that longitudinal philopatry was recurrent over five generations. Progeny tended to settle close to their parents, with related individuals often sharing the same colony. However, successful inbreeding was rare, and genetic diversity remained high, suggesting occasional inbreeding does not impair local population persistence. Local reproductive success was dependent on the habitat larvae settled into, rather than the habitat they came from. Our study suggests that longitudinal philopatry can influence both population replenishment and local adaptation of marine fishes. Resolving multigenerational pedigrees during a relatively short period, as we present here, provides a framework for assessing the ability of marine populations to persist and adapt to accelerating climate change.

  16. Large recovery of fish biomass in a no-take marine reserve.

    Directory of Open Access Journals (Sweden)

    Octavio Aburto-Oropeza

    Full Text Available No-take marine reserves are effective management tools used to restore fish biomass and community structure in areas depleted by overfishing. Cabo Pulmo National Park (CPNP was created in 1995 and is the only well enforced no-take area in the Gulf of California, Mexico, mostly because of widespread support from the local community. In 1999, four years after the establishment of the reserve, there were no significant differences in fish biomass between CPNP (0.75 t ha(-1 on average and other marine protected areas or open access areas in the Gulf of California. By 2009, total fish biomass at CPNP had increased to 4.24 t ha(-1 (absolute biomass increase of 3.49 t ha(-1, or 463%, and the biomass of top predators and carnivores increased by 11 and 4 times, respectively. However, fish biomass did not change significantly in other marine protected areas or open access areas over the same time period. The absolute increase in fish biomass at CPNP within a decade is the largest measured in a marine reserve worldwide, and it is likely due to a combination of social (strong community leadership, social cohesion, effective enforcement and ecological factors. The recovery of fish biomass inside CPNP has resulted in significant economic benefits, indicating that community-managed marine reserves are a viable solution to unsustainable coastal development and fisheries collapse in the Gulf of California and elsewhere.

  17. The community structure of over-wintering larval and small juvenile fish in a large estuary

    Science.gov (United States)

    Munk, Peter; Cardinale, Massimiliano; Casini, Michele; Rudolphi, Ann-Christin

    2014-02-01

    The Skagerrak and Kattegat are estuarine straits of high hydrographical and ecological diversity, situated between the saline waters of the North Sea and the brackish waters of the Baltic Sea. These sustain important nursery grounds of many fish species, of which several overwinter during the larval and early juvenile stages. In order to give more insight into the communities of the overwintering ichthyoplankton in estuarine areas, we examine an annual series of observations from a standard survey carried out 1992-2010. Species differences and annual variability in distributions and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed large annual fluctuations in abundances. The species showed quite specific patterns of distribution although species assemblages with common distributional characteristics were identified. Within these assemblages, the ichthyoplankton abundances showed linkage to environmental characteristics described by bottom-depth and surface temperature and salinity. Hence the study points to a significant structuring of overwintering ichthyoplankton communities in large estuaries, based on the species habitat choice and its response to physical gradients.

  18. Extinction risk and overfishing: reconciling conservation and fisheries perspectives on the status of marine fishes.

    Science.gov (United States)

    Davies, Trevor D; Baum, Julia K

    2012-01-01

    Anthropogenic disturbances are ubiquitous in the ocean, but their impacts on marine species are hotly debated. We evaluated marine fish statuses using conservation (Red List threatened or not) and fisheries (above or below reference points) metrics, compared their alignment, and diagnosed why discrepancies arise. Whereas only 13.5% of Red Listed marine fishes (n = 2952) are threatened, 40% and 21% of populations with stock assessments (n = 166) currently are below their more conservative and riskier reference points, respectively. Conservation and fisheries metrics aligned well (70.5% to 80.7%), despite their mathematical disconnect. Red Listings were not biased towards exaggerating threat status, and egregious errors, where populations were categorized at opposite extremes of fisheries and conservation metrics, were rare. Our analyses suggest conservation and fisheries scientists will agree on the statuses of exploited marine fishes in most cases, leaving only the question of appropriate management responses for populations of mutual concern still unresolved.

  19. Hyperoxia Elevates Adrenic Acid Peroxidation in Marine Fish and Is Associated with Reproductive Pheromone Mediators

    Directory of Open Access Journals (Sweden)

    Ming Long Sirius Chung

    2015-04-01

    Full Text Available The development of oxidative stress in the marine ecosystem is a concurring concern in fish reproductive behavior. Marine fish being rich in polyunsaturated fatty acids (PUFA are precursors of prostaglandin pheromone mediators but also vulnerable to lipid peroxidation. It is yet to be determined if hypoxia or hyperoxia environment, a cumulative effect in the marine ecosystem affect pheromone mediators in fish, and to understand if this is associated with the generation of oxidized lipid products of PUFA. Novel oxidized lipid metabolites, isoprostanoids (15-F2t-isoprostane, 7(RS-7-F2t-dihomo-isoprostane, 17(RS-17-F2t-dihomo-isoprostane, 8-F3t-isoprostane, 4(RS-4-F4t-neuroprostane, 10-F4t-neuroprostane, isofuranoids (isofurans, 10-epi-17(RS-SC-Δ15-11-dihomo-isofuran and neurofurans, hydroxyeicosatetraenoic acids and resolvins, PUFA (arachidonic, adrenic, eicosapentaenoic and docosahexaenoic acids and prostaglandin pheromone mediators in fish muscle were determined in marine male and female fish muscles before and after interaction in a hypoxia or hyperoxia environment. Reproductive behaviors were also assessed. Our study showed oxidized lipid metabolites of arachidonic, eicosapentaenoic, and docosahexaenoic acids were not influenced by hypoxia and hyperoxia exposure in the fishes and no gender differences were found. However, adrenic acid and its oxidized products, 17(RS-17-F2t-dihomo-isoprostane and 10-epi-17(RS-SC-Δ15-11-dihomo-isofuran showed strong correspondence with male fish pheromone mediators and reproductive behavior when under oxidative stress especially, hyperoxia. The occurrence of hypoxia and hyperoxia in the marine ecosystem may not be detrimental to marine fish and instead presents as being beneficial in reproductive behavior.

  20. Self-recruitment in a coral reef fish population in a marine reserve

    KAUST Repository

    Herrera Sarrias, Marcela

    2014-12-01

    Marine protected areas (MPAs) have proliferated in the past decades to protect biodiversity and sustain fisheries. However, most of the MPA networks have been designed without taking into account a critical factor: the larval dispersal patterns of populations within and outside the reserves. The scale and predictability of larval dispersal, however, remain unknown due to the difficulty of measuring dispersal when larvae are minute (~ cm) compared to the potential scale of dispersal (~ km). Nevertheless, genetic approaches can now be used to make estimates of larval dispersal. The following thesis describes self-recruitment and connectivity patterns of a coral reef fish species (Centropyge bicolor) in Kimbe Bay, Papua New Guinea. To do this, microsatellite markers were developed to evaluate fine-scale genetics and recruit assignment via genetic parentage analysis. In this method, offspring are assigned to potential parents, so that larval dispersal distances can then be inferred for each individual larvae. From a total of 255 adults and 426 juveniles collected only 2 parentoffspring pairs were assigned, representing less than 1% self-recruitment. Previous data from the same study system showed that both Chaetodon vagagundus and Amphiprion percula have consistent high self-recuitment rates (~ 60%), despite having contrasting life history traits. Since C. bicolor and C. vagabundus have similar characteristics (e.g. reproductive mode, pelagic larval duration), comparable results were expected. On the contrary, the results of this study showed that dispersal patterns cannot be generalized across species. Hence the importance of studying different species and seascapes to better understand the patterns of larval dispersal. This, in turn, will be essential to improve the design and implementation of MPAs as conservation and management tools.

  1. Oxidative Stability and Sensory Attributes of Fermented Milk Product Fortified with Fish Oil and Marine Phospholipids

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Thomsen, Birgitte Raagaard; Hyldig, Grethe;

    2013-01-01

    to be the main factor that influenced the lipid oxidation in the marine PL emulsion and fermented milk system. In addition, both oxidative stability and sensory acceptability of fortified products varied depending on the quality of the marine PL used for fortification.......Marine phospholipids (PL) are potential ingredients for food fortification due to its numerous advantages. The main objective of this study was to investigate whether a fermented milk product fortified with a mixture of marine PL and fish oil had better oxidative stability than a fermented milk...... product fortified with fish oil alone. Fortification of a fermented milk product with marine PL was performed by incorporating 1 % w/w lipids, either in the form of neat oil or in the form of a pre-emulsion. Lipid oxidation was investigated in the neat emulsions and fortified products by the measurements...

  2. On the edge of death: Rates of decline and lower thresholds of biochemical condition in food-deprived fish larvae and juveniles

    Science.gov (United States)

    Meyer, S.; Caldarone, E. M.; Chícharo, M. A.; Clemmesen, C.; Faria, A. M.; Faulk, C.; Folkvord, A.; Holt, G. J.; Høie, H.; Kanstinger, P.; Malzahn, A.; Moran, D.; Petereit, C.; Støttrup, J. G.; Peck, M. A.

    2012-05-01

    Gaining reliable estimates of how long fish early life stages can survive without feeding and how starvation rate and time until death are influenced by body size, temperature and species is critical to understanding processes controlling mortality in the sea. The present study is an across-species analysis of starvation-induced changes in biochemical condition in early life stages of nine marine and freshwater fishes. Data were compiled on changes in body size (dry weight, DW) and biochemical condition (standardized RNA-DNA ratio, sRD) throughout the course of starvation of yolk-sac and feeding larvae and juveniles in the laboratory. In all cases, the mean biochemical condition of groups decreased exponentially with starvation time, regardless of initial condition and endogenous yolk reserves. A starvation rate for individuals was estimated from discrete 75th percentiles of sampled populations versus time (degree-days, Dd). The 10th percentile of sRD successfully approximated the lowest, life-stage-specific biochemical condition (the edge of death). Temperature could explain 59% of the variability in time to death whereas DW had no effect. Species and life-stage-specific differences in starvation parameters suggest selective adaptation to food deprivation. Previously published, interspecific functions predicting the relationship between growth rate and sRD in feeding fish larvae do not apply to individuals experiencing prolonged food deprivation. Starvation rate, edge of death, and time to death are viable proxies for the physiological processes under food deprivation of individual fish pre-recruits in the laboratory and provide useful metrics for research on the role of starvation in the sea.

  3. Analysis of EPA and DHA in the viscera of marine fish using gas chromatography.

    Science.gov (United States)

    Zhang, De-Yong; Xu, Xiao-Lu; Shen, Xiu-Ying; Mei, Yu; Xu, Hui-Ying

    2016-03-01

    The viscera of 10 kinds of marine fishes were collected for fish oil extraction and detection of DHA and EPA, two most important polyunsaturated fatty acids. The fish oil extraction ratio for the evaluated fishes varied from 0.95% to 10.18% (wt%). Pseudosciaena crocea presented the highest fish oil yield, followed by Mustelus manazo, Hippoglossus and Sciaenopsocellatus. A gas chromatography method was then established for analysis of EPA/DHA. The EPA concentration (in methyl ester form) in the fish oil varied from 1.39 to 10.65(mg/g). Epinephelus awoara presented the highest EPA concentration (pfish oil varied from 0.58 to 37.02 (mg/g). Epinephelus awoara presented the highest DHA concentration (pfish live was observed. The fishes living in middle depth presented highest EPA/DHA concentration.

  4. Marine-entry timing and growth rates of juvenile Chum Salmon in Alaskan waters of the Chukchi and northern Bering seas

    Science.gov (United States)

    Vega, Stacy L.; Sutton, Trent M.; Murphy, James M.

    2017-01-01

    Climate change in the Arctic has implications for influences on juvenile Chum Salmon Oncorhynchus keta early life-history patterns, such as altered timing of marine entry and/or early marine growth. Sagittal otoliths were used to estimate marine entry dates and daily growth rates of juvenile Chum Salmon collected during surface trawl surveys in summers 2007, 2012, and 2013 in the Chukchi and northern Bering seas. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to discriminate between freshwater and marine sagittal growth on the otoliths, and daily growth increments were counted to determine marine-entry dates and growth rates to make temporal and regional comparisons of juvenile Chum Salmon characteristics. Marine-entry dates ranged from mid-June to mid-July, with all region and year combinations exhibiting similar characteristics in entry timing (i.e. larger individuals at the time of capture entered the marine environment earlier in the growing season than smaller individuals in the same region/year), as well as similar mean marine-entry dates. Juvenile Chum Salmon growth rates were on average 4.9% body weight per day in both regions in summers 2007 and 2012, and significantly higher (6.8% body weight per day) in the Chukchi Sea in 2013. These results suggest that juvenile Chum Salmon in the northern Bering and Chukchi seas currently exhibit consistent marine-entry timing and early marine growth rates, despite some differences in environmental conditions between regions and among years. This study also provides a baseline of early marine life-history characteristics of Chum Salmon for comparisons with future climate change studies in these regions.

  5. Evaluation of plant and animal protein sources as partial or total replacement of fish meal in diets for juvenile Nile tilapia

    Science.gov (United States)

    A feeding trial was conducted in a closed system with Nile tilapia (Oreochromis niloticus) juveniles (mean weight, 2.84 g) to examine the effects of total replacement of fish meal (FM), with and without supplementation of DL-methionine (Met) and L-lysine (Lys), by plant protein sources. Fish were f...

  6. Replacement of fishmeal with processed meal from knife fish Chitala ornata in diets of juvenile Nile tilapia Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Sherilyn T. Abarra

    2017-02-01

    Full Text Available A 60-day feeding trial was conducted to assess the effects of processed meal from knife fish Chitala ornata (KFM as fishmeal replacement in diets of Nile tilapia Oreochromis niloticus juveniles. Five iso-nitrogenous (36.4% in dry matter and isolipidic diets (8.6% in dry matter with 0 (D1, 25 (D2, 50 (D3, 75 (D4 and 100% (D5 KFM inclusions were prepared. With a stocking density of 15 fish (0.59 ± 0.01 g per tank, tilapia juveniles were distributed randomly in fifteen 30-L tanks. Results indicate a significant increase (P  0.05 among treatments. Results of hepatic histopathology showed absence of tumors, lesions and parenchymal inflammation in all treatments. However, mild cell membrane lysis and mild and mild to moderate apoptosis were evident in liver samples. Based on the results, KFM can partially and completely replace dietary protein from fishmeal. Moreover, D4 (75% KFM is considered the optimal KFM replacement level for Nile tilapia juveniles.

  7. A small-scale fishery near a rocky littoral marine reserve in the northwestern Mediterranean (Medes Islands after two decades of fishing prohibition

    Directory of Open Access Journals (Sweden)

    Paloma Martín

    2012-05-01

    Full Text Available Fishing in the Medes Islands Marine Reserve (511 ha, including a no-take zone and a buffer area was prohibited in 1983. This study is the result of a 2.5-year monitoring program (sampling on board fishing boats from June 2003 to December 2005 aimed at characterizing the small-scale fishing carried out near the reserve. A total of 109 species were identified. The various métiers in use with the fishing gears trammel net, longline and gillnet were identified on the basis of the landing profiles. The main fishing target species included striped red mullet (Mullus surmuletus, common sole (Solea solea, gilthead seabream (Sparus aurata, common cuttlefish (Sepia officinalis, common pandora (Pagellus erythrinus, seabass (Dicentrarchus labrax, spiny lobster (Palinurus elephas and hake (Merluccius merluccius. Most of the catches consisted of mature individuals and discards were very low or nil. The exception was Palinurus elephas, with catches made up mostly of juveniles. The estimated stock parameters for Mullus surmuletus, Pagellus erythrinus, Sparus aurata and Scorpaena porcus (Lc mean catch length; Lopt length at maximum yield per recruit; Y/Rc; Y/Rmax; Y/R at F(0.1, Y/R(0.1 and the distributions of the exploited sizes, with presence of very large individuals, suggest a situation of low fishing pressure.

  8. BACTERIOLOGICAL PROPERTIES OF MARINE WATER IN ADRIATIC FISH FARMS: ENUMERATION OF HETEROTROPHIC BACTERIA

    Directory of Open Access Journals (Sweden)

    Emin Teskeredžić

    2012-12-01

    Full Text Available Aquaculture is currently one of the fastest growing food production sectors in the world. Increase in nutrients and organic wastes lead to general deterioration of water quality. The problem of water quality is associated with both physical and chemical factors, as well as microbiological water quality. Heterotrophic bacteria play an important role in the process of decomposition of organic matter in water environment and indicate eutrophication process. Here we present our experience and knowledge on bacterial properties of marine water in the Adriatic fish farms with European sea bass (Dicentrarchus labrax L., 1758, with an emphasis on enumeration of heterotrophic bacteria in marine water. We applied two temperatures of incubation, as well as two methods for enumeration of heterotrophic bacteria: substrate SimPlate® test and spread plate method on conventional artificial media (Marine agar and Tryptic Soy agar with added NaCl. The results of analysis of bacteriological properties of marine water in the Adriatic fish farms showed that enumeration of heterotrophic bacteria in marine water depends on the applied incubation temperature and media for enumeration. At the same time, the incubation temperature of 22C favours more intense growth of marine heterotrophic bacteria, whereas a SimPlate test gives higher values of heterotrophic bacteria. Volatile values of heterotrophic bacteria during this research indicate a possible deterioration of microbiological water quality in the Adriatic fish farms and a need for regular monitoring of marine water quality.

  9. Marine survey techniques: A prerequisite for exploratory fishing

    Digital Repository Service at National Institute of Oceanography (India)

    Pathak, M.C.; Kotnala, K.L.

    stream_size 10 stream_content_type text/plain stream_name Trg_Course_Fish_Related_Oceanogr_1991_17.pdf.txt stream_source_info Trg_Course_Fish_Related_Oceanogr_1991_17.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  10. Strategy for increasing marine fish production in Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.

    stream_size 5 stream_content_type text/plain stream_name Proc_Workshop_Evol_Strat_Dev_Agric_Anim_Husb_Fish_Goa_1991_73.pdf.txt stream_source_info Proc_Workshop_Evol_Strat_Dev_Agric_Anim_Husb_Fish_Goa_1991_73.pdf.txt Content...

  11. Size, growth, temperature and the natural mortality of marine fish

    NARCIS (Netherlands)

    Gislason, H.; Daan, N.; Rice, J.C.; Pope, J.G.

    2010-01-01

    The natural mortality of exploited fish populations is often assumed to be a species-specific constant independent of body size. This assumption has important implications for size-based fish population models and for predicting the outcome of size-dependent fisheries management measures such as

  12. Linking adults and immatures of South African marine fishes.

    Science.gov (United States)

    Steinke, Dirk; Connell, Allan D; Hebert, Paul D N

    2016-11-01

    The early life-history stages of fishes are poorly known, impeding acquisition of the identifications needed to monitor larval recruitment and year-class strength. A comprehensive database of COI sequences, linked to authoritatively identified voucher specimens, promises to change this situation, representing a significant advance for fisheries science. Barcode records were obtained from 2526 early larvae and pelagic eggs of fishes collected on the inshore shelf within 5 km of the KwaZulu-Natal coast, about 50 km south of Durban, South Africa. Barcodes were also obtained from 3215 adults, representing 946 South African fish species. Using the COI reference library on BOLD based on adults, 89% of the immature fishes could be identified to a species level; they represented 450 species. Most of the uncertain sequences could be assigned to a genus, family, or order; only 92 specimens (4%) were unassigned. Accumulation curves based on inference of phylogenetic diversity indicate near-completeness of the collecting effort. The entire set of adult and larval fishes included 1006 species, representing 43% of all fish species known from South African waters. However, this total included 189 species not previously recorded from this region. The fact that almost 90% of the immatures gained a species identification demonstrates the power and completeness of the DNA barcode reference library for fishes generated during the 10 years of FishBOL.

  13. Historical DNA documents long-distance natal homing in marine fish.

    Science.gov (United States)

    Bonanomi, Sara; Overgaard Therkildsen, Nina; Retzel, Anja; Berg Hedeholm, Rasmus; Pedersen, Martin Waever; Meldrup, Dorte; Pampoulie, Christophe; Hemmer-Hansen, Jakob; Grønkjaer, Peter; Nielsen, Einar Eg

    2016-06-01

    The occurrence of natal homing in marine fish remains a fundamental question in fish ecology as its unequivocal demonstration requires tracking of individuals from fertilization to reproduction. Here, we provide evidence of long-distance natal homing (>1000 km) over more than 60 years in Atlantic cod (Gadus morhua), through genetic analysis of archived samples from marked and recaptured individuals. Using a high differentiation single-nucleotide polymorphism assay, we demonstrate that the vast majority of cod tagged in West Greenland and recaptured on Icelandic spawning grounds belonged to the Iceland offshore population, strongly supporting a hypothesis of homing. The high degree of natal fidelity observed provides the evolutionary settings for development of locally adapted populations in marine fish and emphasize the need to consider portfolio effects in marine fisheries management strategies.

  14. Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts.

    Directory of Open Access Journals (Sweden)

    Nathan B Furey

    Full Text Available Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka and steelhead (Oncorhynchus mykiss smolts detected at an array in the Strait of Georgia in 2004-2008 and 2010-2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait. While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20-40% of sockeye and 30-50% of steelhead exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the

  15. Biotransformation of inorganic arsenic in a marine herbivorous fish Siganus fuscescens after dietborne exposure.

    Science.gov (United States)

    Zhang, Wei; Chen, Lizhao; Zhou, Yanyan; Wu, Yun; Zhang, Li

    2016-03-01

    Arsenic (As) is well known to be biodiminished along marine food chains. The marine herbivorous fish at a lower trophic level are expected to accumulate more As. However, little is known about how marine herbivorous fish biotransform the potential high As bioaccumulation. Therefore, the present study quantified the biotransformation of two inorganic As species (As(III) and As(V)) in a marine herbivorous fish Siganus fuscescens following dietborne exposure. The fish were fed on As contaminated artificial diets at nominal concentrations of 400 and 1500 μg As(III) or As(V) g(-1) (dry weight) for 21 d and 42 d. After exposure, As concentrations in intestine, liver, and muscle tissues of rabbitfish increased significantly and were proportional to the inorganic As exposure concentrations. The present study demonstrated that both inorganic As(III) and As(V) in the dietborne phases were able to be biotransformed to the less toxic arsenobetaine (AsB) (63.3-91.3% in liver; 79.0%-95.2% in muscle). The processes of As biotransformation in rabbitfish could include oxidation of As(III) to As(V), reduction of As(V) to As(III), methylation to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), and subsequent conversion to AsB. These results also demonstrated that AsB synthesis processes were diverse facing different inorganic As species in different tissues. In summary, the present study elucidated that marine herbivorous fish had high ability to biotransform inorganic As to the organic forms (mainly AsB), resulting in high As bioaccumulation. Therefore, marine herbivorous fish could detoxify inorganic As in the natural environment.

  16. Identification of myogenic regulatory genes in the muscle transcriptome of beltfish (Trichiurus lepturus: A major commercial marine fish species with robust swimming ability

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2016-06-01

    Full Text Available The beltfish (Trichiurus lepturus is considered as one of the most economically important marine fish in East Asia. It is a top predator with a robust swimming ability that is a good model to study muscle physiology in fish. In the present study, we used Illumina sequencing technology (NextSeq500 to sequence, assemble and annotate the muscle transcriptome of juvenile beltfish. A total of 57,509,280 clean reads (deposited in NCBI SRA database with accession number of SRX1674471 were obtained from RNA sequencing and 26,811 unigenes (with N50 of 1033 bp were obtained after de novo assembling with Trinity software. BLASTX against NR, GO, KEGG and eggNOG databases show 100%, 49%, 31% and 96% annotation rate, respectively. By mining beltfish muscle transcriptome, several key genes which play essential role on regulating myogenesis, including pax3, pax7, myf5, myoD, mrf4/myf6, myogenin and myostatin were identified with a low expression level. The muscle transcriptome of beltfish can provide some insight into the understanding of genome-wide transcriptome profile of teleost muscle tissue and give useful information to study myogenesis in juvenile/adult fish.

  17. Trends in marine fish catches at Pattani Fishery Port (1999-2003

    Directory of Open Access Journals (Sweden)

    Wanchamai Karntanut

    2006-07-01

    Full Text Available This study aims to develop statistical models for forecasting the quantity of the various types of marine fish landed at Pattani Fishery Port, allowing for trend and seasonality, using official data during 1999-2003. The data comprise daily and monthly totals by weight for eight types of fish (mackerel, other food fish, squid, scads, trash fish, shrimp, lobster and crab. The statistical methods are one-way analysis of variance, multiple linear regression and time series forecasting using trend and seasonal models. It is found that mackerel, other food fish and squid catches tend to decrease, whereas the catches of scads tend to increase, and trash fish catches have no detectable trend up or down. Shrimp and lobster tend to decrease exponentially, and the trend of crab catch is constant. This study raises questions about the ecological and economic sustainability of the current fisheries policy in Thailand.

  18. Ecophys.Fish perspectives on growth of juvenile soles, Solea solea and Solea senegalensis, in the Tagus estuary, Portugal

    Science.gov (United States)

    Fonseca, Vanessa F.; Neill, William H.; Miller, John M.; Cabral, Henrique N.

    2010-07-01

    Ecophys.Fish, an ecophysiological framework to simulate fish growth in time-varying environments, was parameterized for two sole species, Solea solea (Linnaeus, 1758) and Solea senegalensis Kaup, 1858. The model gave reliable predictions of soles' growth and metabolic rates from published data under controlled environments. Differences in model parameters reflected specie's different environmental optima and were in accordance with their distributional range — northern range of S. solea and a southern range of S. senegalensis. Field application of this model to resolve the effects of varying habitat conditions on juvenile soles' growth in the Tagus estuary (Portugal), during the spring-summer period from 2003 to 2006, highlighted spatial and temporal differences in soles' metabolic scope for growth and estimated growth rates. Higher growth estimates were obtained for S. solea and S. senegalensis in Vila Franca de Xira during 2006, and for S. senegalensis in Alcochete during 2003, 2004 and 2006, and were fairly well explained by natural variation in abiotic conditions. Overall, the Ecophys.Fish model gave accurate field predictions of each sole species' growth rate and proved to be a useful tool for monitoring and assessment of habitat quality for juvenile sole.

  19. Pacific Island Network Marine Fish Monitoring Dataset - Transects

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The benthic marine community in the Pacific Island Network (PACN) is a complex ecologic system and a diverse taxonomic environment, including algae and corals and...

  20. Sensitivity of marine systems to climate and fishing: Concepts, issues and management responses

    DEFF Research Database (Denmark)

    Perry, Ian; Cury, Philippe; Brander, Keith

    2010-01-01

    Modern fisheries research and management must understand and take account of the interactions between climate and fishing, rather than try to disentangle their effects and address each separately. These interactions are significant drivers of change in exploited marine systems and have ramificati......Modern fisheries research and management must understand and take account of the interactions between climate and fishing, rather than try to disentangle their effects and address each separately. These interactions are significant drivers of change in exploited marine systems and have...

  1. Morphology, fine structure, biochemistry, and function of the spermatic ducts in marine fish.

    Science.gov (United States)

    Lahnsteiner, Franz

    2003-10-01

    The spermatic ducts and the testicular efferent ducts were investigated in different marine teleost fish species (Diplodus sargus, Mullus barbatus, Thalassoma pavo, Trachinus draco, Uranuscopus scaber, Sparisoma cretense, Synodon saurus). From the morphological, histological, fine structural and biochemical investigations it appeared that the testicular main ducts and spermatic ducts of the investigated marine fish have the following functions: storage of spermatozoa, monosacharide synthesis for nutrition of spermatozoa, synthesis of steroid glucuronides, synthesis of seminal plasma proteins, formation of a ionic gradient in the seminal fluid and phagocytotic activity. Species-specific differences were only found in the morphology of the gonads and in the histology of the spermatic duct epithelium.

  2. Purification, Characterization and Antitumor Activities of a New Protein from Syngnathus acus, an Officinal Marine Fish

    OpenAIRE

    Ying Peng; Fen He; Mengyue Wang; Chunfu Wu; Jingyu Yang; Yuxiao Nie; Xiaobo Li

    2011-01-01

    Discovery and development of new antitumor agents from abundant marine fish are attracting an increasing interest. In the present study, we extracted and purified a novel antitumor protein Syngnathusin from the whole body of Syngnathus acus L., a precious marine fish traditionally used for tumors. Syngnathusin was comprised of 16 kinds of amino acids, mainly acidic amino acids. Its molecular weight was 67.3 kDa and its isoelectric point was 4.57. The N-terminal amino acid sequence of Syngnath...

  3. Assessing the effect of marine reserves on household food security in Kenyan coral reef fishing communities.

    Science.gov (United States)

    Darling, Emily S

    2014-01-01

    Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management.

  4. Assessing the effect of marine reserves on household food security in Kenyan coral reef fishing communities.

    Directory of Open Access Journals (Sweden)

    Emily S Darling

    Full Text Available Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management.

  5. Assessing the Effect of Marine Reserves on Household Food Security in Kenyan Coral Reef Fishing Communities

    Science.gov (United States)

    Darling, Emily S.

    2014-01-01

    Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management. PMID:25422888

  6. Screening of marine bacteria with bacteriocin-like activities and probiotic potential for ornate spiny lobster (Panulirus ornatus) juveniles.

    Science.gov (United States)

    Nguyen, Van Duy; Pham, Thu Thuy; Nguyen, Thi Hai Thanh; Nguyen, Thi Thanh Xuan; Hoj, Lone

    2014-09-01

    Bacteriocins are ribosomally synthesized antimicrobial peptides, which have been found in diverse bacterial species of terrestrial origins and some from the sea. New bacteriocins with new characteristics, new origins and new applications are likely still awaiting discovery. The present study screened bacteria isolated from marine animals of interest to the aquaculture industry for antimicrobial and bacteriocin-like activities in order to uncover biodiversity of bacteriocin producers, and explore the potential application in aquaculture. In total, 24 of 100 screened isolates showed antimicrobial activities and 7 of these exerted bacteriocin-like activities. Sequencing of 16S rRNA genes identified the isolates as members of the six genera Proteus, Providencia, Klebsiella, Alcaligenes, Bacillus and Enterococcus. In some cases, further analysis of housekeeping genes, rpoB for Proteus and recA for Klebsiella, as well as biochemical tests was necessary for identification to species level, and some of the Proteus isolates may represent novel species. The seven bacteriocinogenic isolates showed a wide antimicrobial spectrum against foodborne and animal pathogens, which opens the way to their potential use as marine drugs and probiotics in food, aquaculture, livestock and clinical settings. As a case study, the protective effect of shortlisted bacteriocinogenic isolates were tested in aquaculture-raised spiny lobster (Panulirus ornatus) juveniles. A single-strain (Bacillus pumilus B3.10.2B) and a three-strain (B. pumilus B3.10.2B, Bacillus cereus D9, Lactobacillus plantarum T13) probiotic preparation were added to the feed of Panulirus ornatus juveniles, which were subsequently challenged with the pathogen Vibrio owensii DY05. Juveniles in the probiotic treatments displayed increased growth and reduced feed conversion rates after 60 days, and increased survival rate after pathogen challenge relative to the control. This study represents the first evidence of bacteriocin

  7. Histology as a Valid Tool To Differentiate Fresh from Frozen-Thawed Marinated Fish.

    Science.gov (United States)

    Meistro, Serena; Pezzolato, Marzia; Muscolino, Daniele; Giarratana, Filippo; Baioni, Elisa; Panebianco, Antonio; Bozzetta, Elena

    2016-08-01

    European Commission Regulation (EU) 1276/2011 requires that fishery products intended for raw consumption be frozen at -20°C for not less than 24 h or at -35°C for at least 15 h in order to kill viable parasites other than trematodes. But because marinating processes are not always effective in destroying nematode larvae, raw marinated fish preparations should be frozen before consumption. This study evaluated the performance of a standardized histological method to distinguish between fresh and frozen-thawed raw marinated fish. Sixty anchovy (Engraulis encrasicolus) fillets were sampled: 30 were marinated at +4°C for 24 h, and 30 were frozen at -20°C for 24 h before being marinated for 24 h. All 60 samples were fixed in formalin, processed for paraffin embedding, cut, and stained with hematoxylin and eosin. The slide preparations were examined microscopically by three independent histopathologists and classified as frozen-thawed or negative according to standard operating procedure criteria in use at our laboratory. Performance evaluation of the method showed 100% sensitivity (95% confidence interval [CI], 88.4 to 100%) and 100% specificity (95% CI, 88.4 to 100%), and the interrater agreement (Cohen's kappa) was 1 (95% CI, 0.85 to 1). Histology proved a valid and reliable tool to distinguish fresh from frozen-thawed marinated fish. It can be applied to deliver safe raw fishery products to consumers in order to minimize the risk of anisakidosis.

  8. Immunochemical analyses of soluble lens proteins in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens proteins of 10 fishes, belonging to the families Clupeidae, Hemirhamphidae, Lactaridae, Scombridae, Stromatidae, Psettodidae, Bothidae and Soleidae were studied by immunoelectrophoresis using the lens antiserum of Sardinella...

  9. Gender-specific Associations of Marine n-3 Fatty Acids and Fish Consumption with 10-year Incidence of Stroke

    NARCIS (Netherlands)

    Goede, de J.; Verschuren, W.M.M.; Boer, J.M.A.; Kromhout, D.; Geleijnse, J.M.

    2012-01-01

    Background There is some evidence that the association of fish and marine fatty acids with stroke risk differs between men and women. We investigated the gender-specific associations of habitual intake of the marine fatty acids eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) and fish on

  10. Family Key to the Fish Commonly Taken on Board the Orange County Schools Marine Science Floating Laboratory.

    Science.gov (United States)

    Valentine, David W.

    Provided is a dichotomous key to the families of marine fish commonly taken aboard the Orange County Schools Marine Science Floating Laboratory. This key has been designed for use by junior and senior high school students. Diagrams and drawings are provided which indicate diagnostic characteristics of various members of the fish families included.…

  11. Parasites and diseases in marine copepods: Challenges for future mass-production of live feed for fish larva production

    DEFF Research Database (Denmark)

    Skovgaard, Alf

    Copepods are the natural food for many marine fish larvae, and the use of cultured copepods as life feed is, therefore, becoming increasingly important as more marine fish species are being produced in aquaculture. Large-scale cultivation of copepods may be challenged by diseases and parasites...

  12. Egg Development of the Ussurian Bullhead Fish, Leiocassis ussuriensis (Pisces: Bagridae) and Morphological Development of Its Larvae and Juveniles

    OpenAIRE

    Park, Jae-Min; Yim, Hu-Sun; Lee, Yong-Sik; Kim, Heung-Yun; Han, Kyeong-Ho

    2015-01-01

    This study was examined the ovogenesis of Ussurian bullhead, Leiocassis ussuriensis and the morphological development of its larvae and juveniles and to use the results as basic information for the preservation of species and resource enhancement. For artificial egg collection, human chorionic gonadotropin (HCG) was injected at a rate of 10 IU per gram of fish weight. During breeding period, water temperature maintained at 24.5~26.5°C (mean 25.0±0.05°C). The process of ovogenesis reached the ...

  13. Reef Fishes at All Trophic Levels Respond Positively to Effective Marine Protected Areas.

    Directory of Open Access Journals (Sweden)

    German A Soler

    Full Text Available Marine Protected Areas (MPAs offer a unique opportunity to test the assumption that fishing pressure affects some trophic groups more than others. Removal of larger predators through fishing is often suggested to have positive flow-on effects for some lower trophic groups, in which case protection from fishing should result in suppression of lower trophic groups as predator populations recover. We tested this by assessing differences in the trophic structure of reef fish communities associated with 79 MPAs and open-access sites worldwide, using a standardised quantitative dataset on reef fish community structure. The biomass of all major trophic groups (higher carnivores, benthic carnivores, planktivores and herbivores was significantly greater (by 40% - 200% in effective no-take MPAs relative to fished open-access areas. This effect was most pronounced for individuals in large size classes, but with no size class of any trophic group showing signs of depressed biomass in MPAs, as predicted from higher predator abundance. Thus, greater biomass in effective MPAs implies that exploitation on shallow rocky and coral reefs negatively affects biomass of all fish trophic groups and size classes. These direct effects of fishing on trophic structure appear stronger than any top down effects on lower trophic levels that would be imposed by intact predator populations. We propose that exploitation affects fish assemblages at all trophic levels, and that local ecosystem function is generally modified by fishing.

  14. Effects of marine reserves versus nursery habitat availability on structure of reef fish communities.

    Science.gov (United States)

    Nagelkerken, Ivan; Grol, Monique G G; Mumby, Peter J

    2012-01-01

    No-take marine fishery reserves sustain commercial stocks by acting as buffers against overexploitation and enhancing fishery catches in adjacent areas through spillover. Likewise, nursery habitats such as mangroves enhance populations of some species in adjacent habitats. However, there is lack of understanding of the magnitude of stock enhancement and the effects on community structure when both protection from fishing and access to nurseries concurrently act as drivers of fish population dynamics. In this study we test the separate as well as interactive effects of marine reserves and nursery habitat proximity on structure and abundance of coral reef fish communities. Reserves had no effect on fish community composition, while proximity to nursery habitat only had a significant effect on community structure of species that use mangroves or seagrass beds as nurseries. In terms of reef fish biomass, proximity to nursery habitat by far outweighed (biomass 249% higher than that in areas with no nursery access) the effects of protection from fishing in reserves (biomass 21% lower than non-reserve areas) for small nursery fish (≤ 25 cm total length). For large-bodied individuals of nursery species (>25 cm total length), an additive effect was present for these two factors, although fish benefited more from fishing protection (203% higher biomass) than from proximity to nurseries (139% higher). The magnitude of elevated biomass for small fish on coral reefs due to proximity to nurseries was such that nursery habitats seem able to overrule the usually positive effects on fish biomass by reef reserves. As a result, conservation of nursery habitats gains importance and more consideration should be given to the ecological processes that occur along nursery-reef boundaries that connect neighboring ecosystems.

  15. Allometric growth in juvenile marine turtles: possible role as an antipredator adaptation.

    Science.gov (United States)

    Salmon, Michael; Scholl, Joshua

    2014-04-01

    Female marine turtles produce hundreds of offspring during their lifetime but few survive because small turtles have limited defenses and are vulnerable to many predators. Little is known about how small turtles improve their survival probabilities with growth though it is assumed that they do. We reared green turtles (Chelonia mydas) and loggerheads (Caretta caretta) from hatchlings to 13 weeks of age and documented that they grew wider faster than they grew longer. This pattern of allometric growth might enable small turtles to more quickly achieve protection from gape-limited predators, such as the dolphinfish (Coryphaena hippurus). As a test of that hypothesis, we measured how dolphinfish gape increased with length, reviewed the literature to determine how dolphinfish populations were size/age structured in nearby waters, and then determined the probability that a small turtle would encounter a fish large enough to consume it if it grew by allometry vs. by isometry (in which case it retained its hatchling proportions). Allometric growth more quickly reduced the probability of a lethal encounter than did isometric growth. On that basis, we suggest that allometry during early ontogeny may have evolved because it provides a survival benefit for small turtles. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. Drivers of redistribution of fishing and non-fishing effort after the implementation of a marine protected area network.

    Science.gov (United States)

    Cabral, Reniel B; Gaines, Steven D; Johnson, Brett A; Bell, Tom W; White, Crow

    2017-03-01

    Marine spatial planning (MSP) is increasingly utilized to sustainably manage ocean uses. Marine protected areas (MPAs), a form of spatial management in which parts of the ocean are regulated to fishing, are now a common tool in MSP for conserving marine biodiversity and managing fisheries. However, the use of MPAs in MSP often neglects, or simplifies, the redistribution of fishing and non-fishing activities inside and outside of MPAs following their implementation. This redistribution of effort can have important implications for effective MSP. Using long-term (14 yr) aerial surveys of boats at the California Channel Islands, we examined the spatial redistribution of fishing and non-fishing activities and their drivers following MPA establishment. Our data represent 6 yr of information before the implementation of an MPA network and 8 yr after implementation. Different types of boats responded in different ways to the closures, ranging from behaviors by commercial dive boats that support the hypothesis of fishing-the-line, to behaviors by urchin, sport fishing, and recreational boats that support the theory of ideal free distribution. Additionally, we found that boats engaged in recreational activities targeted areas that are sheltered from large waves and located near their home ports, while boats engaged in fishing activities also avoided high wave areas but were not constrained by the distance to their home ports. We did not observe the expected pattern of effort concentration near MPA borders for some boat types; this can be explained by the habitat preference of certain activities (for some activities, the desired habitat attributes are not inside the MPAs), species' biology (species such as urchins where the MPA benefit would likely come from larval export rather than adult spillover), or policy-infraction avoidance. The diversity of boat responses reveals variance from the usual simplified assumption that all extractive boats respond similarly to MPA

  17. Global mismatch between fishing dependency and larval supply from marine reserves

    Science.gov (United States)

    Andrello, Marco; Guilhaumon, François; Albouy, Camille; Parravicini, Valeriano; Scholtens, Joeri; Verley, Philippe; Barange, Manuel; Sumaila, U. Rashid; Manel, Stéphanie; Mouillot, David

    2017-07-01

    Marine reserves are viewed as flagship tools to protect exploited species and to contribute to the effective management of coastal fisheries. Yet, the extent to which marine reserves are globally interconnected and able to effectively seed areas, where fisheries are most critical for food and livelihood security is largely unknown. Using a hydrodynamic model of larval dispersal, we predict that most marine reserves are not interconnected by currents and that their potential benefits to fishing areas are presently limited, since countries with high dependency on coastal fisheries receive very little larval supply from marine reserves. This global mismatch could be reversed, however, by placing new marine reserves in areas sufficiently remote to minimize social and economic costs but sufficiently connected through sea currents to seed the most exploited fisheries and endangered ecosystems.

  18. Parasites of marine, freshwater and farmed fishes of Portugal: a review

    Directory of Open Access Journals (Sweden)

    Jorge da Costa Eiras

    Full Text Available Abstract An extensive literature review is made of the parasites in marine and freshwater fish in mainland Portugal, the Portuguese archipelagos of the Azores and Madeira, as well as in farmed fish. The host(s of each parasite species, its location in the host, site of capture of the host, whenever possible, and all the available bibliographic references are described. The economic importance of some parasites and the zoonotic relevance of some parasitic forms are discussed. A general overview of the data is provided, and some research lines are suggested in order to increase and complement the current body of knowledge about the parasites of fish from Portugal.

  19. Embryonic and Morphological Development of Larvae and Juvenile of the Buenos Aires Tetra, Hyphessobrycon anisitsi (Pisces Characidae) Characidae Fishes

    Science.gov (United States)

    Park, Jae-Min; Han, Kyeong-Ho; Han, Ran

    2015-01-01

    We have launched an investigation for Embryonic Development, Larvae and Juvenile Morphology, of Buenos aires tetra in order to build basic data of Characidae and fish seeding production. We brought 50 couples of Characidae from Bizidduck aquarium in Yeosu-si, Jeollanamdo, from Korea on March of 2015. We put them in the tetragonal glass aquarium (50×50×30 cm). Breeding water temperature was 27.5~28.5°C (mean 28.0±0.05°C) and being maintained. The shape of fertilized egg was round shape, and it was adhesive demersal egg. The egg size was 0.63~0.91 mm (mean 0.74±0.07 mm, n=20). After getting fertilized egg, the developmental stage was gastrula stage, and embryo covered almost two-thirds of Yolk. Incubation was happened after 16 hours 13 minutes from gastrula stage, and the tail of juvenile came out first with tearing egg capsule. Immediately after the incubation, prelarvae had 3.78~3.88 mm length (mean 3.84±0.04 mm, n=5), and it had no mouth and anus yet. 34 days after hatching from the incubation, juvenile had 8.63~13.1 mm (mean 10.9±1.66 mm), and it had similar silver-colored body shape with its mother. PMID:25949207

  20. Heavy metals in marine fish meat and consumer health: a review.

    Science.gov (United States)

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

    2016-01-15

    The numerous health benefits provided by fish consumption may be compromised by the presence of toxic metals and metalloids such as lead, cadmium, arsenic and mercury, which can have harmful effects on the human body if consumed in toxic quantities. The monitoring of metal concentrations in fish meat is therefore important to ensure compliance with food safety regulations and consequent consumer protection. The toxicity of these metals may be dependent on their chemical forms, which requires metal speciation processes for direct measurement of toxic metal species or the identification of prediction models in order to determine toxic metal forms from measured total metal concentrations. This review addresses various shortcomings in current knowledge and research on the accumulation of metal contaminants in commercially consumed marine fish globally and particularly in South Africa, affecting both the fishing industry as well as fish consumers.

  1. Diel and Lunar Variations in Larval Fish Supply in Malindi Marine ...

    African Journals Online (AJOL)

    samples were obtained by towing a 2 m long plankton net (500 µm mesh size, 0.2 m2 mouth area) ... different temporal scales (Dufour & Galzin, ..... Time-series of mean total fish larval abundance from March 2005 to December 2006 in Malindi .... proposed Greater Addo Marine Reserve,. Algoa Bay, South Africa. Estuarine,.

  2. 77 FR 45268 - Taking of Marine Mammals Incidental to Commercial Fishing Operations; Bottlenose Dolphin Take...

    Science.gov (United States)

    2012-07-31

    ... Incidental to Commercial Fishing Operations; Bottlenose Dolphin Take Reduction Plan AGENCY: National Marine... Dolphin Take Reduction Plan (BDTRP) and its implementing regulations by permanently continuing nighttime... November 1 through April 30. Members of the Bottlenose Dolphin Take Reduction Team (Team) recommended...

  3. Photobacterium piscicola sp. nov., isolated from marine fish and spoiled packed cod

    NARCIS (Netherlands)

    Figge, Marian; Cleenwerck, Ilse; van Uijen, Astrid; de Vos, Paul; Huys, Geert; Robertson, Lesley

    2014-01-01

    Five isolates from marine fish (W3T, WM, W1S, S2 and S3) and three isolates misclassified as Photobacterium phosphoreum, originating from spoiled modified atmosphere packed stored cod (NCIMB 13482 and NCIMB 13483) and the intestine of skate (NCIMB 192), were subjected to a polyphasic taxonomic study

  4. EVALUATION OF TOTAL MERCURY CONTENT IN MUSCLE TISSUE OF MARINE FISH AND ANIMALS

    Directory of Open Access Journals (Sweden)

    Daniel Bajčan

    2013-02-01

    Full Text Available Nowdays, a degree of contamination by heavy metals can be observed in the environment. Heavy metals have serious effects on all living organisms because they can accumulate in lethal or sublethal concentrations in the various parts of food chain and so they can cause different health problems like cardiovascular and cancer diseases. Marine fish and animals are one of the bigges source of mercury in human food. Therefore this work is focused to the rate of mercury content in muscle tisuues of marine fish and animals. We analyzed mainly frozen or otherwise preserved marine fish and animals that were purchased in retail network in Slovakia. Mercury content in samples was analyzed by cold vapor AAS with mercury analyser AMA254. The contents of mercury in analysed samples were in the interval 0.0057 – 0,697 mg.kg-1. Our results shows, that no analyzed samples of marine fish and animals had over-limit concetration of Hg, so they are safe for human nutrition.

  5. Screening for viral hemorrhagic septicemia virus in marine fish along the Norwegian coastal line.

    Directory of Open Access Journals (Sweden)

    Nina Sandlund

    Full Text Available Viral hemorrhagic septicemia virus (VHSV infects a wide range of marine fish species. To study the occurrence of VHSV in wild marine fish populations in Norwegian coastal waters and fjord systems a total of 1927 fish from 39 different species were sampled through 5 research cruises conducted in 2009 to 2011. In total, VHSV was detected by rRT-PCR in twelve samples originating from Atlantic herring (Clupea harengus, haddock (Melanogrammus aeglefinus, whiting (Merlangius merlangus and silvery pout (Gadiculus argenteus. All fish tested positive in gills while four herring and one silvery pout also tested positive in internal organs. Successful virus isolation in cell culture was only obtained from one pooled Atlantic herring sample which shows that today's PCR methodology have a much higher sensitivity than cell culture for detection of VHSV. Sequencing revealed that the positive samples belonged to VHSV genotype Ib and phylogenetic analysis shows that the isolate from Atlantic herring and silvery pout are closely related. All positive fish were sampled in the same area in the northern county of Finnmark. This is the first detection of VHSV in Atlantic herring this far north, and to our knowledge the first detection of VHSV in silvery pout. However, low prevalence of VHSV genotype Ib in Atlantic herring and other wild marine fish are well known in other parts of Europe. Earlier there have been a few reports of disease outbreaks in farmed rainbow trout with VHSV of genotype Ib, and our results show that there is a possibility of transfer of VHSV from wild to farmed fish along the Norwegian coast line. The impact of VHSV on wild fish is not well documented.

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

    Directory of Open Access Journals (Sweden)

    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

  7. Marine fish community structure and habitat associations on the Canadian Beaufort shelf and slope

    Science.gov (United States)

    Majewski, Andrew R.; Atchison, Sheila; MacPhee, Shannon; Eert, Jane; Niemi, Andrea; Michel, Christine; Reist, James D.

    2017-03-01

    Marine fishes in the Canadian Beaufort Sea have complex interactions with habitats and prey, and occupy a pivotal position in the food web by transferring energy between lower- and upper-trophic levels, and also within and among habitats (e.g., benthic-pelagic coupling). The distributions, habitat associations, and community structure of most Beaufort Sea marine fishes, however, are unknown thus precluding effective regulatory management of emerging offshore industries in the region (e.g., hydrocarbon development, shipping, and fisheries). Between 2012 and 2014, Fisheries and Oceans Canada conducted the first baseline survey of offshore marine fishes, their habitats, and ecological relationships in the Canadian Beaufort Sea. Benthic trawling was conducted at 45 stations spanning 18-1001 m depths across shelf and slope habitats. Physical oceanographic variables (depth, salinity, temperature, oxygen), biological variables (benthic chlorophyll and integrated water-column chlorophyll) and sediment composition (grain size) were assessed as potential explanatory variables for fish community structure using a non-parametric statistical approach. Selected stations were re-sampled in 2013 and 2014 for a preliminary assessment of inter-annual variability in the fish community. Four distinct fish assemblages were delineated on the Canadian Beaufort Shelf and slope: 1) Nearshore-shelf: 50 and ≤200 m depths, 3) Upper-slope: ≥200 and ≤500 m depths, and 4) Lower-slope: ≥500 m depths. Depth was the environmental variable that best explained fish community structure, and each species assemblage was spatially associated with distinct aspects of the vertical water mass profile. Significant differences in the fish community from east to west were not detected, and the species composition of the assemblages on the Canadian Beaufort Shelf have not changed substantially over the past decade. This community analysis provides a framework for testing hypotheses regarding the trophic

  8. Marine protected areas facilitate parasite populations among four fished host species of central Chile.

    Science.gov (United States)

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan

    2013-11-01

    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance.

  9. Avoiding conflicts and protecting coral reefs: Customary management benefits marine habitats and fish biomass

    KAUST Repository

    Campbell, Stuart J.

    2012-10-01

    Abstract One of the major goals of coral reef conservation is to determine the most effective means of managing marine resources in regions where economic conditions often limit the options available. For example, no-take fishing areas can be impractical in regions where people rely heavily on reef fish for food. In this study we test whether coral reef health differed among areas with varying management practices and socio-economic conditions on Pulau Weh in the Indonesian province of Aceh. Our results show that gear restrictions, in particular prohibiting the use of nets, were successful in minimizing habitat degradation and maintaining fish biomass despite ongoing access to the fishery. Reef fish biomass and hard-coral cover were two- to eight-fold higher at sites where fishing nets were prohibited. The guiding principle of the local customary management system, Panglima Laot, is to reduce conflict among community members over access to marine resources. Consequently, conservation benefits in Aceh have arisen from a customary system that lacks a specific environmental ethic or the means for strong resource-based management. Panglima Laot includes many of the features of successful institutions, such as clearly defined membership rights and the opportunity for resource users to be involved in making, enforcing and changing the rules. Such mechanisms to reduce conflict are the key to the success of marine resource management, particularly in settings that lack resources for enforcement. © 2012 Fauna & Flora International.

  10. Severe Inbreeding and Small Effective Number of Breeders in a Formerly Abundant Marine Fish

    Science.gov (United States)

    O'Leary, Shannon J.; Hice, Lyndie A.; Feldheim, Kevin A.; Frisk, Michael G.; McElroy, Anne E.; Fast, Mark D.; Chapman, Demian D.

    2013-01-01

    In contrast to freshwater fish it is presumed that marine fish are unlikely to spawn with close relatives due to the dilution effect of large breeding populations and their propensity for movement and reproductive mixing. Inbreeding is therefore not typically a focal concern of marine fish management. We measured the effective number of breeders in 6 New York estuaries for winter flounder (Pseudopleuronectes americanus), a formerly abundant fish, using 11 microsatellite markers (6–56 alleles per locus). The effective number of breeders for 1–2 years was remarkably small, with point estimates ranging from 65–289 individuals. Excess homozygosity was detected at 10 loci in all bays (FIS = 0.169–0.283) and individuals exhibited high average internal relatedness (IR; mean = 0.226). These both indicate that inbreeding is very common in all bays, after testing for and ruling out alternative explanations such as technical and sampling artifacts. This study demonstrates that even historically common marine fish can be prone to inbreeding, a factor that should be considered in fisheries management and conservation plans. PMID:23762473

  11. Severe inbreeding and small effective number of breeders in a formerly abundant marine fish.

    Directory of Open Access Journals (Sweden)

    Shannon J O'Leary

    Full Text Available In contrast to freshwater fish it is presumed that marine fish are unlikely to spawn with close relatives due to the dilution effect of large breeding populations and their propensity for movement and reproductive mixing. Inbreeding is therefore not typically a focal concern of marine fish management. We measured the effective number of breeders in 6 New York estuaries for winter flounder (Pseudopleuronectes americanus, a formerly abundant fish, using 11 microsatellite markers (6-56 alleles per locus. The effective number of breeders for 1-2 years was remarkably small, with point estimates ranging from 65-289 individuals. Excess homozygosity was detected at 10 loci in all bays (FIS = 0.169-0.283 and individuals exhibited high average internal relatedness (IR; mean = 0.226. These both indicate that inbreeding is very common in all bays, after testing for and ruling out alternative explanations such as technical and sampling artifacts. This study demonstrates that even historically common marine fish can be prone to inbreeding, a factor that should be considered in fisheries management and conservation plans.

  12. Long-term comparison of the fish community in a Costa Rican rocky shore marine reserve.

    Science.gov (United States)

    Myers, Mark C; Wagner, Jonathan; Vaughan, Christopher

    2011-03-01

    Despite their role in supporting diverse marine fish communities, tropical rocky shores and reefs have attracted less research and fewer targeted conservation efforts compared to coral reefs. We studied fish community composition in Playa Blanca Marine Reserve (9 degrees 40' N - 84 degrees 40' W), a rocky shore site on the central Pacific coast of Costa Rica. We conducted visual surveys of fishes along six strip transects soon after the area was designated a marine reserve in 1995, then again in 2006 following an eleven-year period of complete protection. We recorded a total of 31 406 sightings of 72 species from 30 families. Pomacentrids (42.5%), labrids (16.6%) and haemulids (14.8%) dominated the community, accounting for > 70% of total fish abundance. In comparison to other sites in the region, the fish community was more similar to one reported from Bahia Honda, Panama (7 degrees 50' N - 81 degrees 35 W) than from the geographically more proximate Culebra Bay, Costa Rica (10 degrees 45' N - 85 degrees 43 W). Sixty-one species from 26 families were recorded in 1995; sixty-nine species from 28 families in 2006. Our results suggest that the Playa Blanca Marine Reserve is fulfilling its conservation role. Average fish abundance, species richness and Shannon's index of community diversity were greater in 2006 than 1995, and fish community composition varied significantly within each transect among years. Much of the change in community composition among years resulted from spatial and temporal variation in the abundance of a few dominant species, including Abudefduf troschelli, Thalassoma lucasanum, Chromis atrilobata, and Stegastes flavilatus/acapulcoensis. Of the 48 species/species groups recorded in both years, 37 (77%) were more abundant in 2006 than 1995, and several species recorded as uncommon or rare in 1995 were more frequent and abundant in 2006. Fish community composition and the abundance of some species changed in the reserve over time, but further

  13. Climate induced increases in species richness of marine fishes

    NARCIS (Netherlands)

    Hiddink, J.G.; Hofstede, ter R.

    2008-01-01

    Climate change has been predicted to lead to changes in local and regional species richness through species extinctions and latitudinal ranges shifts. Here, we show that species richness of fish in the North Sea, a group of ecological and socio-economical importance, has increased over a 22-year per

  14. Alien marine fishes deplete algal biomass in the Eastern Mediterranean.

    Science.gov (United States)

    Sala, Enric; Kizilkaya, Zafer; Yildirim, Derya; Ballesteros, Enric

    2011-02-22

    One of the most degraded states of the Mediterranean rocky infralittoral ecosystem is a barren composed solely of bare rock and patches of crustose coralline algae. Barrens are typically created by the grazing action of large sea urchin populations. In 2008 we observed extensive areas almost devoid of erect algae, where sea urchins were rare, on the Mediterranean coast of Turkey. To determine the origin of those urchin-less 'barrens', we conducted a fish exclusion experiment. We found that, in the absence of fish grazing, a well-developed algal assemblage grew within three months. Underwater fish censuses and observations suggest that two alien herbivorous fish from the Red Sea (Siganus luridus and S. rivulatus) are responsible for the creation and maintenance of these benthic communities with extremely low biomass. The shift from well-developed native algal assemblages to 'barrens' implies a dramatic decline in biogenic habitat complexity, biodiversity and biomass. A targeted Siganus fishery could help restore the macroalgal beds of the rocky infralittoral on the Turkish coast.

  15. Alien marine fishes deplete algal biomass in the Eastern Mediterranean.

    Directory of Open Access Journals (Sweden)

    Enric Sala

    Full Text Available One of the most degraded states of the Mediterranean rocky infralittoral ecosystem is a barren composed solely of bare rock and patches of crustose coralline algae. Barrens are typically created by the grazing action of large sea urchin populations. In 2008 we observed extensive areas almost devoid of erect algae, where sea urchins were rare, on the Mediterranean coast of Turkey. To determine the origin of those urchin-less 'barrens', we conducted a fish exclusion experiment. We found that, in the absence of fish grazing, a well-developed algal assemblage grew within three months. Underwater fish censuses and observations suggest that two alien herbivorous fish from the Red Sea (Siganus luridus and S. rivulatus are responsible for the creation and maintenance of these benthic communities with extremely low biomass. The shift from well-developed native algal assemblages to 'barrens' implies a dramatic decline in biogenic habitat complexity, biodiversity and biomass. A targeted Siganus fishery could help restore the macroalgal beds of the rocky infralittoral on the Turkish coast.

  16. From Farming to Fishing: Marine Resource Conservation and a New ...

    African Journals Online (AJOL)

    diversify their livelihoods, many coastal farmers are now also ... carry blocks from the quarry in Timboni, and bicycle taxis. Mombasa and Kilifi ... landing site, also known as Bandarini, and Uyombo proper which lies inland and is an agricultural area. The fishing ...... Capacity of Fisher Folk to Implement Beach. Management ...

  17. As multiple fish species in large marine ecosystems are harvested ...

    African Journals Online (AJOL)

    CMPTMAC10

    culling to increase fish available for human harvesting ... species to develop positive surplus production invari- ... Whole-ecosystem foodweb models, specifically the dynamic model ECOSIM, contain specific ... of younger animals, would unrealistically overestimate ..... sidered to have sufficient weight to have reproductive.

  18. Impacts of fishing low-trophic level species on marine ecosystems.

    Science.gov (United States)

    Smith, Anthony D M; Brown, Christopher J; Bulman, Catherine M; Fulton, Elizabeth A; Johnson, Penny; Kaplan, Isaac C; Lozano-Montes, Hector; Mackinson, Steven; Marzloff, Martin; Shannon, Lynne J; Shin, Yunne-Jai; Tam, Jorge

    2011-08-26

    Low-trophic level species account for more than 30% of global fisheries production and contribute substantially to global food security. We used a range of ecosystem models to explore the effects of fishing low-trophic level species on marine ecosystems, including marine mammals and seabirds, and on other commercially important species. In five well-studied ecosystems, we found that fishing these species at conventional maximum sustainable yield (MSY) levels can have large impacts on other parts of the ecosystem, particularly when they constitute a high proportion of the biomass in the ecosystem or are highly connected in the food web. Halving exploitation rates would result in much lower impacts on marine ecosystems while still achieving 80% of MSY.

  19. Conservation physiology of marine fishes: state of the art and prospects for policy

    DEFF Research Database (Denmark)

    McKenzie, David J.; Axelsson, Michael; Chabot, Denis;

    2016-01-01

    The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes...... is the limited knowledge base; international collaboration is needed to study the environmental physiology of a wider range of species. Multifactorial field and laboratory studies on biomarkers hold promise to relate ecophysiology directly to habitat quality and population status. The 'Fry paradigm' could have...... broad applications for conservation physiology research if it provides a universal mechanism to link physiological function with ecological performance and population dynamics of fishes, through effects of abiotic conditions on aerobic metabolic scope. The available data indicate, however...

  20. Arctic marine fishes and their fisheries in light of global change.

    Science.gov (United States)

    Christiansen, Jørgen S; Mecklenburg, Catherine W; Karamushko, Oleg V

    2014-02-01

    In light of ocean warming and loss of Arctic sea ice, harvested marine fishes of boreal origin (and their fisheries) move poleward into yet unexploited parts of the Arctic seas. Industrial fisheries, already in place on many Arctic shelves, will radically affect the local fish species as they turn up as unprecedented bycatch. Arctic marine fishes are indispensable to ecosystem structuring and functioning, but they are still beyond credible assessment due to lack of basic biological data. The time for conservation actions is now, and precautionary management practices by the Arctic coastal states are needed to mitigate the impact of industrial fisheries in Arctic waters. We outline four possible conservation actions: scientific credibility, 'green technology', legitimate management and overarching coordination.

  1. Global marine protected areas do not secure the evolutionary history of tropical corals and fishes.

    Science.gov (United States)

    Mouillot, D; Parravicini, V; Bellwood, D R; Leprieur, F; Huang, D; Cowman, P F; Albouy, C; Hughes, T P; Thuiller, W; Guilhaumon, F

    2016-01-12

    Although coral reefs support the largest concentrations of marine biodiversity worldwide, the extent to which the global system of marine-protected areas (MPAs) represents individual species and the breadth of evolutionary history across the Tree of Life has never been quantified. Here we show that only 5.7% of scleractinian coral species and 21.7% of labrid fish species reach the minimum protection target of 10% of their geographic ranges within MPAs. We also estimate that the current global MPA system secures only 1.7% of the Tree of Life for corals, and 17.6% for fishes. Regionally, the Atlantic and Eastern Pacific show the greatest deficit of protection for corals while for fishes this deficit is located primarily in the Western Indian Ocean and in the Central Pacific. Our results call for a global coordinated expansion of current conservation efforts to fully secure the Tree of Life on coral reefs.

  2. Effects of Changes in Food Supply at the Time of Sex Differentiation on the Gonadal Transcriptome of Juvenile Fish. Implications for Natural and Farmed Populations

    Science.gov (United States)

    Díaz, Noelia; Ribas, Laia; Piferrer, Francesc

    2014-01-01

    Background Food supply is a major factor influencing growth rates in animals. This has important implications for both natural and farmed fish populations, since food restriction may difficult reproduction. However, a study on the effects of food supply on the development of juvenile gonads has never been transcriptionally described in fish. Methods and Findings This study investigated the consequences of growth on gonadal transcriptome of European sea bass in: 1) 4-month-old sexually undifferentiated fish, comparing the gonads of fish with the highest vs. the lowest growth, to explore a possible link between transcriptome and future sex, and 2) testis from 11-month-old juveniles where growth had been manipulated through changes in food supply. The four groups used were: i) sustained fast growth, ii) sustained slow growth, iii) accelerated growth, iv) decelerated growth. The transcriptome of undifferentiated gonads was not drastically affected by initial natural differences in growth. Further, changes in the expression of genes associated with protein turnover were seen, favoring catabolism in slow-growing fish and anabolism in fast-growing fish. Moreover, while fast-growing fish took energy from glucose, as deduced from the pathways affected and the analysis of protein-protein interactions examined, in slow-growing fish lipid metabolism and gluconeogenesis was favored. Interestingly, the highest transcriptomic differences were found when forcing initially fast-growing fish to decelerate their growth, while accelerating growth of initially slow-growing fish resulted in full transcriptomic convergence with sustained fast-growing fish. Conclusions Food availability during sex differentiation shapes the juvenile testis transcriptome, as evidenced by adaptations to different energy balances. Remarkably, this occurs in absence of major histological changes in the testis. Thus, fish are able to recover transcriptionally their testes if they are provided with enough food

  3. Effects of changes in food supply at the time of sex differentiation on the gonadal transcriptome of juvenile fish. Implications for natural and farmed populations.

    Directory of Open Access Journals (Sweden)

    Noelia Díaz

    Full Text Available Food supply is a major factor influencing growth rates in animals. This has important implications for both natural and farmed fish populations, since food restriction may difficult reproduction. However, a study on the effects of food supply on the development of juvenile gonads has never been transcriptionally described in fish.This study investigated the consequences of growth on gonadal transcriptome of European sea bass in: 1 4-month-old sexually undifferentiated fish, comparing the gonads of fish with the highest vs. the lowest growth, to explore a possible link between transcriptome and future sex, and 2 testis from 11-month-old juveniles where growth had been manipulated through changes in food supply. The four groups used were: i sustained fast growth, ii sustained slow growth, iii accelerated growth, iv decelerated growth. The transcriptome of undifferentiated gonads was not drastically affected by initial natural differences in growth. Further, changes in the expression of genes associated with protein turnover were seen, favoring catabolism in slow-growing fish and anabolism in fast-growing fish. Moreover, while fast-growing fish took energy from glucose, as deduced from the pathways affected and the analysis of protein-protein interactions examined, in slow-growing fish lipid metabolism and gluconeogenesis was favored. Interestingly, the highest transcriptomic differences were found when forcing initially fast-growing fish to decelerate their growth, while accelerating growth of initially slow-growing fish resulted in full transcriptomic convergence with sustained fast-growing fish.Food availability during sex differentiation shapes the juvenile testis transcriptome, as evidenced by adaptations to different energy balances. Remarkably, this occurs in absence of major histological changes in the testis. Thus, fish are able to recover transcriptionally their testes if they are provided with enough food supply during sex

  4. Trophic behaviour of juvenile reef fishes inhabiting interlinked mangrove-seagrass habitats in offshore mangrove islets

    Science.gov (United States)

    Mangroves are essential fish habitats acting as shelters and nurseries, but the relative contribution of mangrove resources to fish diets relies on site-specific context and fish life history stage. Stable isotope (δ13C, δ15N) and gut-content analyses were used to investigate siz...

  5. Marine reserves and reproductive biomass: a case study of a heavily targeted reef fish.

    Science.gov (United States)

    Taylor, Brett M; McIlwain, Jennifer L; Kerr, Alexander M

    2012-01-01

    Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself) is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochastic fluctuations in recruitment of heavily harvested stocks. Optimal strategies for managing spawner biomass are well developed for temperate systems, yet remain uncertain for tropical fisheries, where the danger of collapse from recruitment overfishing looms largest. In this study, we explored empirically and through modeling, the role of marine reserves in maximizing spawner biomass of a heavily exploited reef fish, Lethrinus harak around Guam, Micronesia. On average, spawner biomass was 16 times higher inside the reserves compared with adjacent fished sites. Adult density and habitat-specific mean fish size were also significantly greater. We used these data in an age-structured population model to explore the effect of several management scenarios on L. harak demography. Under minimum-size limits, unlimited extraction and all rotational-closure scenarios, the model predicts that preferential mortality of larger and older fish prompt dramatic declines in spawner biomass and the proportion of male fish, as well as considerable declines in total abundance. For rotational closures this occurred because of the mismatch between the scales of recovery and extraction. Our results highlight how alternative management scenarios fall short in comparison to marine reserves in preserving reproductively viable fish populations on coral reefs.

  6. Marine reserves and reproductive biomass: a case study of a heavily targeted reef fish.

    Directory of Open Access Journals (Sweden)

    Brett M Taylor

    Full Text Available Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochastic fluctuations in recruitment of heavily harvested stocks. Optimal strategies for managing spawner biomass are well developed for temperate systems, yet remain uncertain for tropical fisheries, where the danger of collapse from recruitment overfishing looms largest. In this study, we explored empirically and through modeling, the role of marine reserves in maximizing spawner biomass of a heavily exploited reef fish, Lethrinus harak around Guam, Micronesia. On average, spawner biomass was 16 times higher inside the reserves compared with adjacent fished sites. Adult density and habitat-specific mean fish size were also significantly greater. We used these data in an age-structured population model to explore the effect of several management scenarios on L. harak demography. Under minimum-size limits, unlimited extraction and all rotational-closure scenarios, the model predicts that preferential mortality of larger and older fish prompt dramatic declines in spawner biomass and the proportion of male fish, as well as considerable declines in total abundance. For rotational closures this occurred because of the mismatch between the scales of recovery and extraction. Our results highlight how alternative management scenarios fall short in comparison to marine reserves in preserving reproductively viable fish populations on coral reefs.

  7. DNA Barcoding Identifies Argentine Fishes from Marine and Brackish Waters

    Science.gov (United States)

    Mabragaña, Ezequiel; Díaz de Astarloa, Juan Martín; Hanner, Robert; Zhang, Junbin; González Castro, Mariano

    2011-01-01

    Background DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. Methodology/Principal Findings Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species), and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org). Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125) examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. Conclusions/Significance This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha taxonomy, barcodes provide

  8. The Role of Seagrasses and Kelps in Marine Fish Support

    Science.gov (United States)

    2006-02-01

    harbor greater concentrations of fishes than do unvegetated habitats (Heck et al. 1989, 1997; Edgar and Shaw 1995; Jordan et al. 1996; Jenkins et al...Jeffrey, R. (ed). (1976). “A preliminary inventory of the biota of Padilla Bay,” Huxley College, Department of Biology, Western Washington University...Research Board of Canada 18:203-220. Jordan , F., Bartolini, M., Nelson, C., Patterson, P. E., and Soulen, H. L. (1996). “Risk of predation affects

  9. ELECTRON MICROSCOPE EVIDENCE OF VIRUS INFECTION IN CULTURED MARINE FISH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Electron microscope investigation on the red sea bream (Pagrosomus major), bastard halibut (Paralichthys olivaceus) and stone flounder (Kareius bicoloratus) in North China revealed virus infection in the bodies of the dead and diseased fish. These viruses included the lymphocystis disease virus (LDV), parvovirus, globular virus, and a kind of baculavirus which was not discovered and reported before and is now tentatively named baculavirus of stone flounder (Kareius bicoloratus).

  10. DNA barcoding identifies Argentine fishes from marine and brackish waters.

    Directory of Open Access Journals (Sweden)

    Ezequiel Mabragaña

    Full Text Available BACKGROUND: DNA barcoding has been advanced as a promising tool to aid species identification and discovery through the use of short, standardized gene targets. Despite extensive taxonomic studies, for a variety of reasons the identification of fishes can be problematic, even for experts. DNA barcoding is proving to be a useful tool in this context. However, its broad application is impeded by the need to construct a comprehensive reference sequence library for all fish species. Here, we make a regional contribution to this grand challenge by calibrating the species discrimination efficiency of barcoding among 125 Argentine fish species, representing nearly one third of the known fauna, and examine the utility of these data to address several key taxonomic uncertainties pertaining to species in this region. METHODOLOGY/PRINCIPAL FINDINGS: Specimens were collected and morphologically identified during crusies conducted between 2005 and 2008. The standard BARCODE fragment of COI was amplified and bi-directionally sequenced from 577 specimens (mean of 5 specimens/species, and all specimens and sequence data were archived and interrogated using analytical tools available on the Barcode of Life Data System (BOLD; www.barcodinglife.org. Nearly all species exhibited discrete clusters of closely related haplogroups which permitted the discrimination of 95% of the species (i.e. 119/125 examined while cases of shared haplotypes were detected among just three species-pairs. Notably, barcoding aided the identification of a new species of skate, Dipturus argentinensis, permitted the recognition of Genypterus brasiliensis as a valid species and questions the generic assignment of Paralichthys isosceles. CONCLUSIONS/SIGNIFICANCE: This study constitutes a significant contribution to the global barcode reference sequence library for fishes and demonstrates the utility of barcoding for regional species identification. As an independent assessment of alpha

  11. Effects of near-future ocean acidification, fishing, and marine protection on a temperate coastal ecosystem.

    Science.gov (United States)

    Cornwall, Christopher E; Eddy, Tyler D

    2015-02-01

    Understanding ecosystem responses to global and local anthropogenic impacts is paramount to predicting future ecosystem states. We used an ecosystem modeling approach to investigate the independent and cumulative effects of fishing, marine protection, and ocean acidification on a coastal ecosystem. To quantify the effects of ocean acidification at the ecosystem level, we used information from the peer-reviewed literature on the effects of ocean acidification. Using an Ecopath with Ecosim ecosystem model for the Wellington south coast, including the Taputeranga Marine Reserve (MR), New Zealand, we predicted ecosystem responses under 4 scenarios: ocean acidification + fishing; ocean acidification + MR (no fishing); no ocean acidification + fishing; no ocean acidification + MR for the year 2050. Fishing had a larger effect on trophic group biomasses and trophic structure than ocean acidification, whereas the effects of ocean acidification were only large in the absence of fishing. Mortality by fishing had large, negative effects on trophic group biomasses. These effects were similar regardless of the presence of ocean acidification. Ocean acidification was predicted to indirectly benefit certain species in the MR scenario. This was because lobster (Jasus edwardsii) only recovered to 58% of the MR biomass in the ocean acidification + MR scenario, a situation that benefited the trophic groups lobsters prey on. Most trophic groups responded antagonistically to the interactive effects of ocean acidification and marine protection (46%; reduced response); however, many groups responded synergistically (33%; amplified response). Conservation and fisheries management strategies need to account for the reduced recovery potential of some exploited species under ocean acidification, nonadditive interactions of multiple factors, and indirect responses of species to ocean acidification caused by declines in calcareous predators. © 2014 Society for Conservation Biology.

  12. The complex early life history of a marine estuarine-opportunist fish species, Solea turbynei (Soleidae from temperate South Africa

    Directory of Open Access Journals (Sweden)

    Nadine A. Strydom

    2015-06-01

    Full Text Available The early life history stages and ecology of Solea turbynei, a marine estuarine-opportunist species, is described from nursery areas in Algoa Bay, South Africa. Early life history stages were collected over multiple years from known nursery habitats using plankton, fyke and larval seine nets. The larvae are described using morphometric measurements, meristic counts and pigmentation based on 29 individuals. Solea turbynei is differentiated from other Soleidae by the small size at flexion (3-4 mm, low myomere count and presence of two characteristic blotches of pigment on the dorsal fin. This species has a unique early life history strategy in that the larvae progressively span nearshore, surf zone and estuarine habitats with ontogeny. Abundance of preflexion stages peaks in summer in nearshore waters, indicative of peak spawning period but preflexion larvae are present throughout the year, indicating protracted spawning by adults. At flexion stage, larvae utilize surf zones where metamorphosis and settlement takes place. Early juveniles migrate into the sandy lower reaches of estuaries, after which fish take up residency to adulthood. Warm water is important for larval growth and survival in the nearshore, while turbidity shows a positive relationship with recruitment into estuarine nurseries.

  13. Evaluation of species-specific dissimilarities in two marine fish species: mercury accumulation as a function of metal levels in consumed prey.

    Science.gov (United States)

    Mieiro, C L; Coelho, J P; Pacheco, M; Duarte, A C; Pereira, M E

    2012-07-01

    The aim of this research was to compare mercury (Hg) accumulation (total and organic) and tissue distribution in two marine fish species with contrasting feeding tactics. Thus, juvenile specimens of European sea bass and Golden grey mullet were surveyed in an estuary historically affected by Hg discharges. Total Hg was preferentially accumulated in intestine, muscle, and liver, whereas gills and brain presented the lowest Hg levels observed in both species. Significant differences between species were only verified for muscle, with D. labrax's levels being greater than L. aurata's. Muscle accounted for >87% of the Hg relative tissue burden, whereas liver did not exceed 11%. Organic Hg accumulation occurred mainly in liver and muscle, with D. labrax evidencing significantly greater loads. Moreover, organic Hg in consumed prey items was also significantly greater in D. labrax. Accumulation of organic Hg in liver, intestine, and muscle seemed to vary as a function of the consumed prey items contamination, suggesting fish feeding strategies as the dominant factor determining metal accumulation. For both fish species, a stable ratio was observed between Hg increments from the reference to the contaminated site, possibly indicating that the organic Hg content of diet may regulate the internal levels of this contaminant. Thus, this ratio might prove to be a useful contamination predictor tool in early life stages of fish.

  14. Mercury exposure and source tracking in distinct marine-caged fish farm in southern China.

    Science.gov (United States)

    Xu, Xiaoyu; Wang, Wen-Xiong

    2017-01-01

    Coasts of South China have experienced an unprecedented growth in its marine-caged fish industry. We analyzed mercury concentrations and stable mercury isotope ratios in fourteen fish species from two cage-cultured farms in Southern China. Total mercury concentrations of all species were lower than the human health screening values, but the human exposures through consumption of several carnivorous fish exceeded the USEPA's reference dose. Isotopic compositions in the sediment (δ(202)Hg: -1.45‰ to -1.23‰; Δ(199)Hg: -0.04‰ to -0.01‰) suggested that mercury in these farms were from coal combustion and industrial inputs. Commercial food pellets and fresh fish viscera provided the major sources of methylmercury to the farmed fish and dominated their mercury isotopic signatures. Non-carnivorous fish presented lower δ(202)Hg and Δ(199)Hg values than the carnivorous fish. Using a mixing model, we demonstrated that the majority of mercury in non-carnivorous species came from pellets and in carnivorous fish came from combined diets of pellets and viscera. Meanwhile, methylmercury concentrations and % methylmercury in the fish were positively correlated with δ(202)Hg values but not with Δ(199)Hg values, mainly because fish eating similar feeds maintained similar Δ(199)Hg values. Environmental influences of cage farming such as fish feces and uneaten viscera that continuously provide organic mercury to the environments need to be considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Bioactive phthalate from marine Streptomyces ruber EKH2 against virulent fish pathogens

    Directory of Open Access Journals (Sweden)

    Khouloud Mohamed Barakat

    2015-01-01

    Full Text Available Marine Streptomyces ruber EKH2 isolated from sediments of Bardawil Lake, Egypt, was found as a promising strain for producing bioactive metabolite(s working against some virulent fish pathogens. Some biochemical and morphological characterizations of marine S. ruber EKH2 were carried out. Cell free culture showed activities against the tested pathogens ranging from 15 to 30 mm. Optimized conditions for maximum activities were observed at neutrality and temperature 28 °C against the tested strains. Two grams of the ethyl acetate crude extract from 10 L culture supernatant was chromatographically separated into three fractions and bioassayed. One major antibacterial compound was separated exhibiting MIC average 12.5 μg/ml. Phthalic acid was structurally suggested on the basis of gas chromatography–mass spectrum (GC–MS and infrared spectrum (IR. Phthalate activities were compared with known standard antibiotics used in fish therapy and found to be superior. A slight toxicity of phthalate against brine shrimp (LC50 = 2800 μg/ml was observed. Dealing with pan-drug resistant bacteria in fish therapy, this study confirmed that marine S. ruber EKH2 is potentially used for extracting phthalic acid as a novel bioactive and non-toxic agent for treating bacterial fish infections.

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

    KAUST Repository

    Garrido, S.

    2015-11-24

    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.

  17. A locomotor innovation enables water-land transition in a marine fish.

    Directory of Open Access Journals (Sweden)

    Shi-Tong Tonia Hsieh

    Full Text Available BACKGROUND: Morphological innovations that significantly enhance performance capacity may enable exploitation of new resources and invasion of new ecological niches. The invasion of land from the aquatic realm requires dramatic structural and physiological modifications to permit survival in a gravity-dominated, aerial environment. Most fishes are obligatorily aquatic, with amphibious fishes typically making slow-moving and short forays on to land. METHODOLOGY/PRINCIPAL FINDINGS: Here I describe the behaviors and movements of a little known marine fish that moves extraordinarily rapidly on land. I found that the Pacific leaping blenny, Alticus arnoldorum, employs a tail-twisting movement on land, previously unreported in fishes. Focal point behavioral observations of Alticus show that they have largely abandoned the marine realm, feed and reproduce on land, and even defend terrestrial territories. Comparisons of these blennies' terrestrial kinematic and kinetic (i.e., force measurements with those of less terrestrial sister genera show A. arnoldorum move with greater stability and locomotor control, and can move away more rapidly from impending threats. CONCLUSIONS/SIGNIFICANCE: My results demonstrate that axial tail twisting serves as a key innovation enabling invasion of a novel marine niche. This paper highlights the potential of using this system to address general evolutionary questions about water-land transitions and niche invasions.

  18. Impact of air gun noise on the behaviour of marine fish and squid.

    Science.gov (United States)

    Fewtrell, J L; McCauley, R D

    2012-05-01

    In this study various species of captive marine fish and one species of squid were exposed to the noise from a single air gun. Six trials were conducted off the coast of Western Australia with each trial using a different noise exposure regime. Noise levels received by the animals ranged between 120 and 184 dB re 1 μPa(2).s (SEL). Behavioural observations of the fish and squid were made before, during and after air gun noise exposure. Results indicate that as air gun noise levels increase, fish respond by moving to the bottom of the water column and swimming faster in more tightly cohesive groups. Significant increases in alarm responses were observed in fish and squid to air gun noise exceeding 147-151 dB re 1 μPa SEL. An increase in the occurrence of alarm responses was also observed as noise level increased.

  19. Effects of marine protected areas on overfished fishing stocks with multiple stable states.

    Science.gov (United States)

    Takashina, Nao; Mougi, Akihiko

    2014-01-21

    Marine protected areas (MPAs) have attracted much attention as a tool for sustainable fisheries management, restoring depleted fisheries stocks and maintaining ecosystems. However, even with total exclusion of fishing effort, depleted stocks sometimes show little or no recovery over a long time period. Here, using a mathematical model, we show that multiple stable states may hold the key to understanding the tendency for fisheries stocks to recover because of MPAs. We find that MPAs can have either a positive effect or almost no effect on the recovery of depleted fishing stocks, depending on the fish migration patterns and the fishing policies. MPAs also reinforce ecological resilience, particularly for migratory species. In contrast to previous reports, our results show that MPAs have small or sometimes negative effects on the recovery of sedentary species. Unsuitable MPA planning might result in low effectiveness or even deterioration of the existing condition. © 2013 Elsevier Ltd. All rights reserved.

  20. Marine dock pilings foster diverse, native cryptobenthic fish assemblages across bioregions.

    Science.gov (United States)

    Brandl, Simon J; Casey, Jordan M; Knowlton, Nancy; Duffy, James Emmett

    2017-09-01

    Anthropogenic habitats are increasingly prevalent in coastal marine environments. Previous research on sessile epifauna suggests that artificial habitats act as a refuge for nonindigenous species, which results in highly homogenous communities across locations. However, vertebrate assemblages that live in association with artificial habitats are poorly understood. Here, we quantify the biodiversity of small, cryptic (henceforth "cryptobenthic") fishes from marine dock pilings across six locations over 35° of latitude from Maine to Panama. We also compare assemblages from dock pilings to natural habitats in the two southernmost locations (Panama and Belize). Our results suggest that the biodiversity patterns of cryptobenthic fishes from dock pilings follow a Latitudinal Diversity Gradient (LDG), with average local and regional diversity declining sharply with increasing latitude. Furthermore, a strong correlation between community composition and spatial distance suggests distinct regional assemblages of cryptobenthic fishes. Cryptobenthic fish assemblages from dock pilings in Belize and Panama were less diverse and had lower densities than nearby reef habitats. However, dock pilings harbored almost exclusively native species, including two species of conservation concern absent from nearby natural habitats. Our results suggest that, in contrast to sessile epifaunal assemblages on artificial substrates, artificial marine habitats can harbor diverse, regionally characteristic assemblages of vertebrates that follow macroecological patterns that are well documented for natural habitats. We therefore posit that, although dock pilings cannot function as a replacement for natural habitats, dock pilings may provide cost-effective means to preserve native vertebrate biodiversity, and provide a habitat that can be relatively easily monitored to track the status and trends of fish biodiversity in highly urbanized coastal marine environments.

  1. The community structure of over-wintering larval and small juvenile fish in a large estuary

    DEFF Research Database (Denmark)

    Munk, Peter; Cardinale, Massimiliano; Casini, Michele

    2014-01-01

    the larval and early juvenile stages. In order to give more insight into the communities of the overwintering ichthyoplankton in estuarine areas, we examine an annual series of observations from a standard survey carried out 1992–2010. Species differences and annual variability in distributions...

  2. Water temperature and fish growth: otoliths predict growth patterns of a marine fish in a changing climate.

    Science.gov (United States)

    Rountrey, Adam N; Coulson, Peter G; Meeuwig, Jessica J; Meekan, Mark

    2014-08-01

    Ecological modeling shows that even small, gradual changes in body size in a fish population can have large effects on natural mortality, biomass, and catch. However, efforts to model the impact of climate change on fish growth have been hampered by a lack of long-term (multidecadal) data needed to understand the effects of temperature on growth rates in natural environments. We used a combination of dendrochronology techniques and additive mixed-effects modeling to examine the sensitivity of growth in a long-lived (up to 70 years), endemic marine fish, the western blue groper (Achoerodus gouldii), to changes in water temperature. A multi-decadal biochronology (1952-2003) of growth was constructed from the otoliths of 56 fish collected off the southwestern coast of Western Australia, and we tested for correlations between the mean index chronology and a range of potential environmental drivers. The chronology was significantly correlated with sea surface temperature in the region, but common variance among individuals was low. This suggests that this species has been relatively insensitive to past variations in climate. Growth increment and age data were also used in an additive mixed model to predict otolith growth and body size later this century. Although growth was relatively insensitive to changes in temperature, the model results suggested that a fish aged 20 in 2099 would have an otolith about 10% larger and a body size about 5% larger than a fish aged 20 in 1977. Our study shows that species or populations regarded as relatively insensitive to climate change could still undergo significant changes in growth rate and body size that are likely to have important effects on the productivity and yield of fisheries.

  3. Shrinking of fishes exacerbates impacts of global ocean changes on marine ecosystems

    Science.gov (United States)

    Cheung, William W. L.; Sarmiento, Jorge L.; Dunne, John; Frölicher, Thomas L.; Lam, Vicky W. Y.; Deng Palomares, M. L.; Watson, Reg; Pauly, Daniel

    2013-03-01

    Changes in temperature, oxygen content and other ocean biogeochemical properties directly affect the ecophysiology of marine water-breathing organisms. Previous studies suggest that the most prominent biological responses are changes in distribution, phenology and productivity. Both theory and empirical observations also support the hypothesis that warming and reduced oxygen will reduce body size of marine fishes. However, the extent to which such changes would exacerbate the impacts of climate and ocean changes on global marine ecosystems remains unexplored. Here, we employ a model to examine the integrated biological responses of over 600 species of marine fishes due to changes in distribution, abundance and body size. The model has an explicit representation of ecophysiology, dispersal, distribution, and population dynamics. We show that assemblage-averaged maximum body weight is expected to shrink by 14-24% globally from 2000 to 2050 under a high-emission scenario. About half of this shrinkage is due to change in distribution and abundance, the remainder to changes in physiology. The tropical and intermediate latitudinal areas will be heavily impacted, with an average reduction of more than 20%. Our results provide a new dimension to understanding the integrated impacts of climate change on marine ecosystems.

  4. Lost at sea: ocean acidification undermines larval fish orientation via altered hearing and marine soundscape modification.

    Science.gov (United States)

    Rossi, Tullio; Nagelkerken, Ivan; Pistevos, Jennifer C A; Connell, Sean D

    2016-01-01

    The dispersal of larvae and their settlement to suitable habitat is fundamental to the replenishment of marine populations and the communities in which they live. Sound plays an important role in this process because for larvae of various species, it acts as an orientational cue towards suitable settlement habitat. Because marine sounds are largely of biological origin, they not only carry information about the location of potential habitat, but also information about the quality of habitat. While ocean acidification is known to affect a wide range of marine organisms and processes, its effect on marine soundscapes and its reception by navigating oceanic larvae remains unknown. Here, we show that ocean acidification causes a switch in role of present-day soundscapes from attractor to repellent in the auditory preferences in a temperate larval fish. Using natural CO2 vents as analogues of future ocean conditions, we further reveal that ocean acidification can impact marine soundscapes by profoundly diminishing their biological sound production. An altered soundscape poorer in biological cues indirectly penalizes oceanic larvae at settlement stage because both control and CO2-treated fish larvae showed lack of any response to such future soundscapes. These indirect and direct effects of ocean acidification put at risk the complex processes of larval dispersal and settlement. © 2016 The Author(s).

  5. Genome analysis of Betanodavirus from cultured marine fish species in Malaysia.

    Science.gov (United States)

    Ransangan, Julian; Manin, Benny Obrain

    2012-04-23

    Betanodavirus is the causative agent of the viral nervous necrosis (VNN) or viral encephalopathy and retinopathy disease in marine fish. This disease is responsible for most of the mass mortalities that occurred in marine fish hatcheries in Malaysia. The genome of this virus consists of two positive-sense RNA molecules which are the RNA1 and RNA2. The RNA1 molecule contains the RdRp gene which encodes for the RNA-dependent RNA polymerase and the RNA2 molecule contains the Cp gene which encodes for the viral coat protein. In this study, total RNAs were extracted from 32 fish specimens representing the four most cultured marine fish species in Malaysia. The fish specimens were collected from different hatcheries and aquaculture farms in Malaysia. The RNA1 was successfully amplified using three pairs of overlapping PCR primers whereas the RNA2 was amplified using a pair of primers. The nucleotide analysis of RdRp gene revealed that the Betanodavirus in Malaysia were 94.5-99.7% similar to the RGNNV genotype, 79.8-82.1% similar to SJNNV genotype, 81.5-82.4% similar to BFNNV genotype and 79.8-80.7% similar to TPNNV genotype. However, they showed lower similarities to FHV (9.4-14.2%) and BBV (7.2-15.7%), respectively. Similarly, the Cp gene revealed that the viruses showed high nucleotide similarity to RGNNV (95.9-99.8%), SJNNV (72.2-77.4%), BFNNV (80.9-83.5%), TPNNV (77.2-78.1%) and TNV (75.1-76.5%). However, as in the RdRp gene, the coat protein gene was highly dissimilar to FHV (3.0%) and BBV (2.6-4.1%), respectively. Based on the genome analysis, the Betanodavirus infecting cultured marine fish species in Malaysia belong to the RGNNV genotype. However, the phylogenetic analysis of the genes revealed that the viruses can be further divided into nine sub-groups. This has been expected since various marine fish species of different origins are cultured in Malaysia.

  6. Evidence for protection of targeted reef fish on the largest marine reserve in the Caribbean

    Directory of Open Access Journals (Sweden)

    Fabián Pina-Amargós

    2014-02-01

    Full Text Available Marine reserves can restore fish abundance and diversity in areas impacted by overfishing, but the effectiveness of reserves in developing countries where resources for enforcement are limited, have seldom been evaluated. Here we assess whether the establishment in 1996 of the largest marine reserve in the Caribbean, Gardens of the Queen in Cuba, has had a positive effect on the abundance of commercially valuable reef fish species in relation to neighboring unprotected areas. We surveyed 25 sites, including two reef habitats (reef crest and reef slope, inside and outside the marine reserve, on five different months, and over a one-and-a-half year period. Densities of the ten most frequent, highly targeted, and relatively large fish species showed a significant variability across the archipelago for both reef habitats that depended on the month of survey. These ten species showed a tendency towards higher abundance inside the reserve in both reef habitats for most months during the study. Average fish densities pooled by protection level, however, showed that five out of these ten species were at least two-fold significantly higher inside than outside the reserve at one or both reef habitats. Supporting evidence from previously published studies in the area indicates that habitat complexity and major benthic communities were similar inside and outside the reserve, while fishing pressure appeared to be homogeneous across the archipelago before reserve establishment. Although poaching may occur within the reserve, especially at the boundaries, effective protection from fishing was the most plausible explanation for the patterns observed.

  7. DNA barcoding for species assignment: the case of Mediterranean marine fishes.

    Directory of Open Access Journals (Sweden)

    Monica Landi

    Full Text Available BACKGROUND: DNA barcoding enhances the prospects for species-level identifications globally using a standardized and authenticated DNA-based approach. Reference libraries comprising validated DNA barcodes (COI constitute robust datasets for testing query sequences, providing considerable utility to identify marine fish and other organisms. Here we test the feasibility of using DNA barcoding to assign species to tissue samples from fish collected in the central Mediterranean Sea, a major contributor to the European marine ichthyofaunal diversity. METHODOLOGY/PRINCIPAL FINDINGS: A dataset of 1278 DNA barcodes, representing 218 marine fish species, was used to test the utility of DNA barcodes to assign species from query sequences. We tested query sequences against 1 a reference library of ranked DNA barcodes from the neighbouring North East Atlantic, and 2 the public databases BOLD and GenBank. In the first case, a reference library comprising DNA barcodes with reliability grades for 146 fish species was used as diagnostic dataset to screen 486 query DNA sequences from fish specimens collected in the central basin of the Mediterranean Sea. Of all query sequences suitable for comparisons 98% were unambiguously confirmed through complete match with reference DNA barcodes. In the second case, it was possible to assign species to 83% (BOLD-IDS and 72% (GenBank of the sequences from the Mediterranean. Relatively high intraspecific genetic distances were found in 7 species (2.2%-18.74%, most of them of high commercial relevance, suggesting possible cryptic species. CONCLUSION/SIGNIFICANCE: We emphasize the discriminatory power of COI barcodes and their application to cases requiring species level resolution starting from query sequences. Results highlight the value of public reference libraries of reliability grade-annotated DNA barcodes, to identify species from different geographical origins. The ability to assign species with high precision from DNA

  8. Conventional and unconventional antimicrobials from fish, marine invertebrates and micro-algae.

    Science.gov (United States)

    Smith, Valerie J; Desbois, Andrew P; Dyrynda, Elisabeth A

    2010-04-14

    All eukaryotic organisms, single-celled or multi-cellular, produce a diverse array of natural anti-infective agents that, in addition to conventional antimicrobial peptides, also include proteins and other molecules often not regarded as part of the innate defences. Examples range from histones, fatty acids, and other structural components of cells to pigments and regulatory proteins. These probably represent very ancient defence factors that have been re-used in new ways during evolution. This review discusses the nature, biological role in host protection and potential biotechnological uses of some of these compounds, focusing on those from fish, marine invertebrates and marine micro-algae.

  9. Conventional and Unconventional Antimicrobials from Fish, Marine Invertebrates and Micro-algae

    Directory of Open Access Journals (Sweden)

    Valerie J. Smith

    2010-04-01

    Full Text Available All eukaryotic organisms, single-celled or multi-cellular, produce a diverse array of natural anti-infective agents that, in addition to conventional antimicrobial peptides, also include proteins and other molecules often not regarded as part of the innate defences. Examples range from histones, fatty acids, and other structural components of cells to pigments and regulatory proteins. These probably represent very ancient defence factors that have been re-used in new ways during evolution. This review discusses the nature, biological role in host protection and potential biotechnological uses of some of these compounds, focusing on those from fish, marine invertebrates and marine micro-algae.

  10. The use of juvenile Solea solea as sentinel in the marine platform of the Ebre Delta: in vitro interaction of emerging contaminants with the liver detoxification system.

    Science.gov (United States)

    Crespo, Marina; Solé, Montserrat

    2016-10-01

    Juveniles of Solea solea were sampled during the spring season in three consecutive years at a marine site by the mouth of the Ebre river. The aim was to assess if the extractive works from the toxic load upstream the river could be reflected on the health status of the fish living at the immediate sea. The biomarkers selected for the in vivo field study are commonly used as indicators of chemical exposures. They include activities of energy metabolism: lactate dehydrogenase (LDH) and citrate synthase (CS); neurotoxicity: cholinesterases (ChE); xenobiotic metabolism: cytochrome P450 (CYP)-dependent: EROD and BFCOD, carboxylesterase (CbE), glutathione S-transferase (GST) and uridine diphosphate glucuronyltransferase (UDPGT); and oxidative stress parameters such as catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPX) as well as levels of lipid peroxidation (LPO). These biomarkers were mostly analysed in liver but also in gills and muscle depending on their particular tissue distribution and role. A complementary in vitro approach was also sought to see the capacity of common emerging contaminants (pharmaceuticals and personal care products; PPCPs) to interact with the liver microsomal detoxification system of the fish (EROD, BFCOD and CbE activities). The results indicated that in fish sampled in 2015 there was an enhancement in detoxification parameters (EROD, BFCOD and gill GR), muscular ChEs and gill CS, but a decrease in CbE activity and a marked oxidative stress situation (increased LPO and decreased CAT activity). Also, 4 out of the 10 PPCPs tested in vitro were able to interact with the CYP3A4 (BFCOD) enzymatic system while the lipid regulators simvastatin and fenofibrate inhibited CbE activity, as it occurs in higher vertebrates. The in vivo results support the use of a multibiomarker approach when assessing the disturbances due to chemical exposures, not only spatially but also over time, once the influence of other variables has been

  11. Preference of early juveniles of a coral reef fish for distinct lagoonal microhabitats is not related to common measures of structural complexity

    NARCIS (Netherlands)

    Grol, M.G.G.; Nagelkerken, I.; Bosch, N.; Meesters, H.W.G.

    2011-01-01

    Coral reef populations of a variety of fish and invertebrate species are replenished by individuals that use inshore coastal habitats as temporary juvenile habitats. These habitats vary greatly in their architecture, and different characteristics of structure could play a role in their selection and

  12. Beyond marine reserves: exploring the approach of selecting areas where fishing is permitted, rather than prohibited.

    Directory of Open Access Journals (Sweden)

    Natalie C Ban

    Full Text Available BACKGROUND: Marine populations have been declining at a worrying rate, due in large part to fishing pressures. The challenge is to secure a future for marine life while minimizing impacts on fishers and fishing communities. METHODS AND PRINCIPAL FINDINGS: Rather than selecting areas where fishing is banned -- as is usually the case with spatial management -- we assess the concept of designating areas where fishing is permitted. We use spatial catch statistics for thirteen commercial fisheries on Canada's west coast to determine the minimum area that would be needed to maintain a pre-ascribed target percentage of current catches. We found that small reductions in fisheries yields, if strategically allocated, could result in large unfished areas that are representative of biophysical regions and habitat types, and have the potential to achieve remarkable conservation gains. CONCLUSIONS: Our approach of selecting fishing areas instead of reserves could help redirect debate about the relative values that society places on conservation and extraction, in a framework that could gain much by losing little. Our ideas are intended to promote discussions about the current status quo in fisheries management, rather than providing a definitive solution.

  13. Biodiversity inventories and conservation of the marine fishes of Bootless Bay, Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Drew Joshua A

    2012-08-01

    Full Text Available Abstract Background The effective management and conservation of biodiversity is predicated on clearly defined conservation targets. Species number is frequently used as a metric for conservation prioritization and monitoring changes in ecosystem health. We conducted a series of synoptic surveys focusing on the fishes of the Bootless Bay region of Papua New Guinea to generate a checklist of fishes of the region. Bootless Bay lies directly south of Port Moresby, the capital of Papua New Guinea, and experiences the highest human population density of any marine area in the country. Our checklist will set a baseline against which future environmental changes can be tracked. Results We generated a checklist of 488 fish species in 72 families found in Bootless Bay during a two-week sampling effort. Using incident-based methods of species estimation, we extrapolate there to be approximately 940 fish species in Bootless Bay, one of the lowest reported numbers in Papua New Guinea. Conclusions Our data suggest that the Bootless Bay ecosystem of Papua New Guinea, while diverse in absolute terms, has lower fish biodiversity compared to other shallow marine areas within the country. These differences in faunal diversity are most likely a combination of unequal sampling effort as well as biophysical factors within Bootless Bay compounded by historical and/or contemporary anthropogenic disturbances.

  14. An evaluation of underlying mechanisms for “fishing down marine food webs”

    Institute of Scientific and Technical Information of China (English)

    DING Qi; CHEN Xinjun; YU Wei; TIAN Siquan; CHEN Yong

    2016-01-01

    Since the concept of “fishing down marine food webs” was first proposed in 1998, mean trophic level of fisheries landings (MTL) has become one of the most widely used indicators to assess the impacts of fishing on the integrity of marine ecosystem and guide the policy development by many management agencies. Recent studies suggest that understanding underlying causes for changes in MTL is vital for an appropriate use of MTL as an indicator of fishery sustainability. Based on the landing data compiled by Food and Agriculture Organization (FAO) and trophic information of relevant species in Fishbase, we evaluated MTL trends in 14 FAO fishing areas and analyzed catches of upper and lower trophic level groups under different trends of MTL and found that both the cases of a recovered MTL trend and a generally increasing MTL trend could be accompanied by decreasing catches of lower trophic level species. Further, community structure and exploitation history should be considered in using MTL after excluding species with trophic levels lower than 3.25 to distinguish “fishing-through” from “fishing-down”. We conclude that MTL used as an indicator to measure fishery sustainability can benefit from a full consideration of both upper and lower trophic level species and masking effects of community structure and exploitation history.

  15. Effect of neem extract against the bacteria isolated from marine fish.

    Science.gov (United States)

    Dhayanithi, N B; Kumar, T T Ajith; Kathiresan, K

    2010-07-01

    Marine ornamental fishes are exceedingly valuable due to their high demand in domestic and international markets. There is a growing global interest to rear the fishes in captivity. But problem due to bacteria and fungi are the major hitch in captive condition. Since, the use of antibiotics is banned, an attempt was made to ascertain in vitro assay of the neem leaves extract against the bacterial pathogens isolated from infected fishes. Bacterial strains isolated from infected regions of the clown fishes Amphiprion sebae and A. ocellaris were identified as Aeromonas hydrophila, Enterobacter sp., E. coli, Pseudomonas aeruginosa, Proteus sp., Streptococcus sp., Vibrio cholerae, V. alginolyticus, V. parahaemolyticus and Yersinia enterocolitica. Ethanol and methanol extracts were highly inhibitory to the bacterial isolates when compared to other solvents. Ethanol extracts exhibited low minimum inhibitory concentration (75-250 microg ml(-1)) as compared to other extracts. The present finding revealed that the neem leaf extract significantly reduces the bacterial pathogens and their infection in marine ornamental fishes.

  16. Comparison of heavy metal concentration of some marine fishes from Black and Aegean Seas

    Directory of Open Access Journals (Sweden)

    Makedonski Lubomir

    2015-06-01

    Full Text Available Major part of healthy human diet consist of marine fish and seafood products. And it is not surprising that there are numerous studies based on metal accumulation in various fish species. Fish may also be used for heavy metal monitoring programs of marine environments due to their easy sampling, sample preparation and chemical analysis. Concentrations of lead, cadmium, nickel, copper, manganese, zinc, iron, chromium, total mercury and total arsenic were determined in edible part of two commercially valuable fish Greek aquaculture species European sea bass (Dicentrarchus labrax and gilthead sea bream (Sparus aurata purchased from Bulgarian market during 2011. The concentration of metals was measured by atomic absorption spectrophotometry (AAS. The concentration of the heavy metals in examined fish species ranged as follow: Pb 0.008 - 0.013; Cd 0.0017 - 0.022; Ni 0.007 - 0.012; Cu 0.054 - 0.115; Mn 0.043 - 0.09; Zn 0.14 - 0.15; Fe 0.17 - 0.19; Cr 0.05 - 0.07; Hg 0.11 - 0.13; As 1.6 - 1.8 mg kg-1 wet weight, respectively.

  17. Literature review of the concentration ratios of selected radionuclides in freshwater and marine fish

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Klopfer, D.C.

    1986-09-01

    Concentration ratios (CR's) used for modeling the uptake and food chain transport of radionuclides in fish have usually been conservative; that is, at the high end of reported values. This practice ensures that the dose to the consumer of contaminated fish will not be underestimated. In many models, however, conservative values have been used for all variables that have any uncertainty associated with them. As a result the dose to the consumer is overestimated. Realistic CR values need to be developed to establish model parameters that will accurately reflect tissue burdens in fish and resulting dose rates to consumers. This report reviews and summarizes published literature on the uptake and distribution of stable and radioactive isotopes of 26 elements. Based on this review, we have made recommendations on CR values to be used for modeling the accumulation of radionuclides in fish. Our recommendations are compared with CR values reported in other publications. A generic discussion of abiotic and biotic factors that influence CR values is provided so that CR values may be adjusted based on site-specific characteristics of the fishes habitat. Recommended CR values for freshwater fish and for marine fish are listed. Although this report emphasizes radionuclides, it is applicable to stable elements as well.

  18. Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda).

    Science.gov (United States)

    Ogawa, K

    2015-01-01

    Mariculture is a rapidly developing industrial sector. Generally, fish are maintained in net cages with high density. Cage culture systems allow uncontrolled flow of sea water containing potentially infectious stages of fish parasites. In such culture conditions, prevention of such parasitic infections is difficult for parasites with life cycles that complete within culture sites, among which monogeneans and blood flukes are the most important platyhelminthes. Intense monogenean infections induce respiratory and osmo-regulatory dysfunctions. A variety of control measures have been developed, including freshwater bath treatment and chemotherapy. The potential to control monogenean infections through selective breeding, modified culture techniques to avoid infection, and general fish health management are discussed. It should be noted that mariculture conditions have provided some host-specific monogeneans with a chance to expand their host ranges. Blood flukes sometimes induce mass mortality among farmed fish. In-feed administration of praziquantel is the best solution to treat infected fish. Some cases are described that show how international trade in marine fish has resulted in the spread of hitherto unknown parasites into indigenous farmed and wild fish.

  19. [Stoichiometry of cytochromes and oxygen tension in skeletal muscles of marine fish].

    Science.gov (United States)

    Soldatov, A A; Parfenova, I A

    2014-01-01

    The character of oxygen tension distribution and peculiarities of cytochromes stoichiometry in skeletal muscles of bottom and pelagic species of marine fish were compared. It is shown, that the limitation of muscle activity increases the number of hypoxic zones in the muscle tissue. The mitochondrial electron-transporting chain then obtain the uncompensated type of organization, expressed in the increase of the share of the terminal complex aa3 on the background of general reduction of cytochromes content in the muscles. The reaction is of an adaptive character and can be implemented by pelagic fish species in conditions of experimental hypokinesia.

  20. Marine fronts are important fishing areas for demersal species at the Argentine Sea (Southwest Atlantic Ocean)

    Science.gov (United States)

    Alemany, Daniela; Acha, Eduardo M.; Iribarne, Oscar O.

    2014-03-01

    The high primary and secondary production associated with frontal systems attract a diversity of organisms due to high prey availability; this is why a strong relationship between fronts and pelagic fisheries has been shown worldwide. In the Argentine Sea, demersal resources are the most important, both in economical and in ecological sense; so we hypothesize that fronts are also preferred fishing areas for demersal resources. We evaluated the relationship between spatial distribution of fishing effort and oceanographic fronts, analyzing three of the most important frontal systems located in the Argentine Sea: the shelf-break front, the southern Patagonia front and the mid-shelf front. Individual vessel satellite monitoring system data (VMS; grouped by fleet type: ice-trawlers, freezer-trawlers and jigging fleet) were studied and fishing events were identified. Fishing events per area were used as a proxy of fishing effort and its spatial distribution by fleet type was visualized and analyzed with Geographic Information Systems. Oceanographic fronts were defined using polygons based on satellite chlorophyll amplitude values, and the percentage of fishing events within each polygon was calculated. Results showed a positive association between fronts and fishing activities of the different fleets, which suggests the aggregation of target species in these zones. The coupling of the freezer-trawler and jigging fleets (that operate on lower trophic level species; Macruronus magellanicus and Illex argentinus respectively) with fronts was higher than the ice-trawler fleet, targeting species of higher trophic level (Merluccius hubbsi). Marine fronts represent important fishing areas, even for demersal resources, as the distribution of fishing fleets and fishing effort are positively associated with frontal zones.

  1. Impacts of electromagnetic fields associated with marine and hydrokinetic surrogate technologies on fish movements and behaviors.

    Energy Technology Data Exchange (ETDEWEB)

    Claisse, Jeremy T. [Vantuna Research Group, Los Angeles, CA (United States); Pondella, Daniel J. [Vantuna Research Group, Los Angeles, CA (United States); Williams, Chelsea M. [Vantuna Research Group, Los Angeles, CA (United States); Zahn, Laurel A. [Vantuna Research Group, Los Angeles, CA (United States); Williams, Jonathan P. [Vantuna Research Group, Los Angeles, CA (United States)

    2015-09-30

    Marine and hydrokinetic energy (MHK) and offshore wind devices are being developed and deployed in U.S. and international waters. Electric current flowing through subsea transmission cables associated with these devices will generate electromagnetic fields (EMF), which may interact with, and potentially impact, marine fishes. Some marine fishes can detect electric and/or magnetic fields and use them to navigate, orientate, and sense prey, mates and predators. Over the past five years there have been multiple comprehensive reviews and studies evaluating the potential vulnerability of marine fishes to EMF produced by MHK devices. Most documented effects involve sub-lethal behavioral responses of individual fish when in close proximity to EMF (e.g., fish being repelled by or attracted to fields). These reviews reach conclusions that the current state of research on this topic is still in its infancy and evaluations of potential impacts are associated with great uncertainty. A variety of MHK technologies are likely to be considered for deployment offshore of the Hawaiian Islands, and there is a need to be able to better predict and assess potential associated environmental impacts. The goal of this study was to provide a complementary piece to these previous reviews (e.g., Normandeau et al. 2011) by focusing on marine fish species in the Hawaii region. We compiled the relevant available information, then prioritized fish species as candidates for various paths of future research. To address this, we first developed a list of Hawaii Region Focal Species, which included fishes that are more likely to be sensitive to EMF. We then compiled species-specific information available in the literature on their sensitivity to EMF, as well as life history, movement and habitat use information that could inform an analysis of their likelihood of encountering EMF from subsea cables associated with MHK devices. Studies have only documented EMF sensitivity in 11 of the marine fish

  2. Comparative allometry growth of some marine fish digenetic trematodes

    Directory of Open Access Journals (Sweden)

    A. Saad-Fares

    1992-01-01

    Full Text Available Allometric growth variation was compared for Plagioporus idoneus, Lepocreadium pegorchis, Opecoeloides furcatus, Bacciger israelensis, Aphanurus stossichi and Parahurleytrema trachinoti collected from East Mediterranean fishes. The pharynx, the oral and the ventral sucker diameters always showed a negative allometry. The other parameters tested were variable with the species. We study the effects of some environmental factors: the influence of the host species is analysed in Plagioporus idoneous, wich parasitizes Oblada melanura, Diplodus sargus and D. vulgaris and in Lepocreadium pegorchis, wich parasitizes Pagellus erythrinus, Lithognathus mormyrus and Spicara smaris; the influence of the microhabitat and the intensity of infection is analysed in Bacciger israelensis and Aphanurus stossichi, both parasites of Boops boops. We report significant differences with the host species, for the allometric growth of the testes; the effect of the microhabitat was revealed by the hindbody allometric value; no significant difference was detected in relation with the intensity of infection.

  3. Egg Development of the Ussurian Bullhead Fish, Leiocassis ussuriensis (Pisces: Bagridae) and Morphological Development of Its Larvae and Juveniles.

    Science.gov (United States)

    Park, Jae-Min; Yim, Hu-Sun; Lee, Yong-Sik; Kim, Heung-Yun; Han, Kyeong-Ho

    2015-12-01

    This study was examined the ovogenesis of Ussurian bullhead, Leiocassis ussuriensis and the morphological development of its larvae and juveniles and to use the results as basic information for the preservation of species and resource enhancement. For artificial egg collection, human chorionic gonadotropin (HCG) was injected at a rate of 10 IU per gram of fish weight. During breeding period, water temperature maintained at 24.5~26.5°C (mean 25.0±0.05°C). The process of ovogenesis reached the two-cell stage in 50 minutes after fertilization. In 73 hours of fertilization the movement of the embryoid body became active state and the larvae began to hatch from the tail through the oolemma. Length of prelarvae were 6.33~6.50 mm long (mean 6.40±0.06 mm) just after hatching having yolk with their mouth not opened. After thirty eight days of hatching, juveniles were 30.6∼32.5 mm long (mean 31.5±0.65 mm). The color was dark yellowish brown throughout the entire body, and the number of caudal fin rays developed to thirty six perfectly.

  4. Lead bioaccumulation and toxicity in tissues of economically fish species from river and marine water.

    Science.gov (United States)

    Askary Sary, Abolfazl; Mohammadi, Maryam

    2012-07-01

    Bioaccumulation of lead was determined in muscle and liver of Barbus xanthopterus, Liza abu, Barbus grypus, Acanthopagrus latus, Platycephalus indicus, Otolithes ruber exposed to lead contaminated river and marine in Khouzestan. Significant variations in metal values were evaluated using student's t test at p fish, liver was polluted in comparison with muscle and high level was in B. xanthopterus (2.80 mg kg(-1) wet weight) except for B. grypus in Karkhe River (1.73 mg kg(-1)wet weight). In marine fish, muscle was contaminated than liver and high level was in O. ruber (47.18 mg kg(-1)wet weight) except for O. ruber in Mahshahr seaport (17.85 mg kg(-1) wet weight).

  5. Density-dependent changes in effective area occupied for sea-bottom-associated marine fishes

    DEFF Research Database (Denmark)

    Thorson, James T.; Rindorf, Anna; Gao, Jin

    2016-01-01

    The spatial distribution of marine fishes can change for many reasons, including density-dependent distributional shifts. Previous studies show mixed support for either the proportional-density model (PDM; no relationship between abundance and area occupied, supported by ideal-free distribution...... marine regions, to determine whether the BM or PDM provides a better description for sea-bottom-associated fishes. We fit a spatio-temporal model and estimate changes in effective area occupied and abundance, and combine results to estimate the average abundance–area relationship as well as variability...... for every 10% abundance increase) followed by Pleuronectiformes and Scorpaeniformes, and the Eastern Bering Sea shows a strong relationship between abundance and area occupied relative to other regions. We conclude that the BM explains a small but important portion of spatial dynamics for sea...

  6. Copper uptake kinetics and regulation in a marine fish after waterborne copper acclimation

    Energy Technology Data Exchange (ETDEWEB)

    Dang Fei; Zhong Huan [AMCE and Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [AMCE and Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2009-09-14

    The uptake kinetics and regulation of copper in a marine predatory fish, the black sea bream Acanthopagrus schlegeli after acclimation to waterborne Cu were examined, using radiotracer techniques. The dissolved Cu uptake followed a linear pattern during the time of exposure, and the calculated uptake rate constant was 6.24 L kg{sup -1} day{sup -1}. The efflux rate constant was 0.091 day{sup -1} following dietary uptake of Cu, and the dietary assimilation efficiency (AE) of Cu varied between 1.7% and 10.9% after the fish were fed with three types of prey (oysters, clams and brine shrimp). After the fish were acclimated at a nominal concentration of 50 {mu}g Cu L{sup -1} for 14 days, the Cu uptake rate and efflux rate constant did not change significantly, but the Cu body concentrations and metallothionein (MT) concentrations in fish tissues increased significantly. Subcellular Cu distributions were also modified. Significant MT induction was observed in response to increased Cu tissue concentrations, indicating that MT rather than the uptake kinetics may play a primary role in Cu regulation during waterborne Cu acclimation in this marine fish. Moreover, the high Cu efflux may also be important in Cu regulation during long-term exposure. Our modeling calculations indicated that dietary uptake was likely to be the main route for Cu bioaccumulation in the fish, and the relative contribution of waterborne and dietary uptake depended on the bioconcentration factor (BCF) of the prey and ingestion rate of fish.

  7. Conservation and Ecology of Marine Forage Fishes--Proceedings of a Research Symposium, September 2012

    Science.gov (United States)

    Liedtke, Theresa; Gibson, Caroline; Lowry, Dayv; Fagergren, Duane

    2013-01-01

    Locally and globally, there is growing recognition of the critical roles that herring, smelt, sand lance, eulachon, and other forage fishes play in marine ecosystems. Scientific and resource management entities throughout the Salish Sea, agree that extensive information gaps exist, both in basic biological knowledge and parameters critical to fishery management. Communication and collaboration among researchers also is inadequate. Building on the interest and enthusiasm generated by recent forage fish workshops and symposia around the region, the 2012 Research Symposium on the Conservation and Ecology of Marine Forage Fishes was designed to elucidate practical recommendations for science and policy needs and actions, and spur further collaboration in support for the precautionary management of forage fish. This dynamic and productive event was a joint venture of the Northwest Straits Commission Forage Fish Program, U.S. Geological Survey (USGS), Washington Department of Fish and Wildlife (WDFW), and The Puget Sound Partnership. The symposium was held on September 12–14, 2012, at the University of Washington, Friday Harbor Laboratories campus. Sixty scientists, graduate students, and fisheries policy experts convened; showcasing ongoing research, conservation, and management efforts targeting forage fish from regional and national perspectives. The primary objectives of this event were to: (1) review current research and management related to marine forage fish species; and (2) identify priority science and policy needs and actions for Washington, British Columbia, and the entire West Coast. Given the diversity of knowledge, interests, and disciplines surrounding forage fish on both sides of the international border, the organizing committee made a concerted effort to contact many additional experts who, although unable to attend, provided valuable insights and ideas to the symposium structure and discussions. The value of the symposium format was highlighted in

  8. Coral reef fish species survey data GIS from the Florida Keys National Marine Sanctuary (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida...

  9. NODC Standard Format Marine Fish and Shellfish Surveys (F123) Data (1948-1992) (NCEI Accession 0014195)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data type contains data from field sampling of marine fish and shellfish. The data derive from analyses of midwater or bottom tow catches and provide...

  10. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    OpenAIRE

    Kok, Judith E.; Graham, Nicholas Anthony James; Mia O Hoogenboom

    2016-01-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes (Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reef...

  11. Some philometrid nematodes (Philometridae), including four new species of Philometra, from marine fishes off New Caledonia

    OpenAIRE

    Moravec, F.; Justine, Jean-Lou

    2008-01-01

    Examinations of marine fishes off New Caledonia, South Pacific, carried out in 2003-2006, yielded some nematodes of the genus Philometra Costa, 1845, including the following three new species: P. cyanopodi sp. nov. (males and subgravid females) and P. lethrini sp. nov. (males and subgravid females) from the gonads of Epinephelus cyanopodus (Richardson) (Serranidae) and Lethrinus genivittatus Valenciennes (Lethrinidae), respectively, and P. lagocephali sp. nov. (gravid female) from the abdomin...

  12. Propensity of marine reserves to reduce the evolutionary effects of fishing in a migratory species

    OpenAIRE

    Dunlop, E.S.; Baskett, M. L.; M. Heino; Dieckmann, U.

    2009-01-01

    Evolutionary effects of fishing can have unwanted consequences diminishing a fishery's value and sustainability. Reserves, or no-take areas, have been proposed as a management tool for reducing fisheries-induced selection, but their effectiveness for migratory species has remained unexplored. Here we develop an eco-genetic model to predict the effects of marine reserves on fisheries-induced evolution under migration. To represent a stock that undergoes an annual migration between feeding and ...

  13. Ontogeny and physiology of the digestive system of marine fish larvae

    OpenAIRE

    Zambonino, Jose-luis; Gisbert, E; C. Sarasquete; Navarro, I.; Gutiérrez, J.; Cahu, Chantal

    2008-01-01

    The ontogeny of the digestive tract of marine fish larvae has been the subject of many studies these last twenty years. Beyond the scientific interest for such animal species, particularly for developmental aspects, most of these studies aimed to come up with the expectations of commercial hatcheries by reducing the bottlenecks in larvae culture and weaning processes (switch from live preys to compound diet feeding sequence). Consequently, the profile and dietary adaptation of digestive enzym...

  14. EVALUATION OF TOTAL MERCURY CONTENT IN MUSCLE TISSUE OF MARINE FISH AND ANIMALS

    OpenAIRE

    Daniel Bajčan; Július Árvay; Janette Musilová

    2013-01-01

    Nowdays, a degree of contamination by heavy metals can be observed in the environment. Heavy metals have serious effects on all living organisms because they can accumulate in lethal or sublethal concentrations in the various parts of food chain and so they can cause different health problems like cardiovascular and cancer diseases. Marine fish and animals are one of the bigges source of mercury in human food. Therefore this work is focused to the rate of mercury content in muscle tisuues of ...

  15. Asymmetric connectivity of spawning aggregations of a commercially important marine fish using a multidisciplinary approach

    Directory of Open Access Journals (Sweden)

    Adrian Munguia-Vega

    2014-08-01

    Full Text Available Understanding patterns of larval dispersal is key in determining whether no-take marine reserves are self-sustaining, what will be protected inside reserves and where the benefits of reserves will be observed. We followed a multidisciplinary approach that merged detailed descriptions of fishing zones and spawning time at 17 sites distributed in the Midriff Island region of the Gulf of California with a biophysical oceanographic model that simulated larval transport at Pelagic Larval Duration (PLD 14, 21 and 28 days for the most common and targeted predatory reef fish, (leopard grouper Mycteroperca rosacea. We tested the hypothesis that source–sink larval metapopulation dynamics describing the direction and frequency of larval dispersal according to an oceanographic model can help to explain empirical genetic data. We described modeled metapopulation dynamics using graph theory and employed empirical sequence data from a subset of 11 sites at two mitochondrial genes to verify the model predictions based on patterns of genetic diversity within sites and genetic structure between sites. We employed a population graph describing a network of genetic relationships among sites and contrasted it against modeled networks. While our results failed to explain genetic diversity within sites, they confirmed that ocean models summarized via graph and adjacency distances over modeled networks can explain seemingly chaotic patterns of genetic structure between sites. Empirical and modeled networks showed significant similarities in the clustering coefficients of each site and adjacency matrices between sites. Most of the connectivity patterns observed towards downstream sites (Sonora coast were strictly asymmetric, while those between upstream sites (Baja and the Midriffs were symmetric. The best-supported gene flow model and analyses of modularity of the modeled networks confirmed a pulse of larvae from the Baja Peninsula, across the Midriff Island region

  16. POPs and stable isotopes in bird and forage fish tissues - Persistent organic pollutant levels in juvenile salmonids, forage fish and their avian predators from Puget Sound and the outer WA coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project is examining contaminant loads of fish prey species of a resident marine bird (Rhinoceros Auklet) breeding in inland waters (Puget Sound) and in the...

  17. Dispersal patterns of coastal fish: implications for designing networks of marine protected areas.

    Directory of Open Access Journals (Sweden)

    Antonio Di Franco

    Full Text Available Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus using otolith chemistry. At a large spatial scale (∼200 km we investigated natal origin of fish and at a smaller scale (∼30 km we assessed "site fidelity" (i.e. post-settlement dispersal until recruitment. Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas.

  18. Dispersal patterns of coastal fish: implications for designing networks of marine protected areas.

    Science.gov (United States)

    Di Franco, Antonio; Gillanders, Bronwyn M; De Benedetto, Giuseppe; Pennetta, Antonio; De Leo, Giulio A; Guidetti, Paolo

    2012-01-01

    Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment) dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus) using otolith chemistry. At a large spatial scale (∼200 km) we investigated natal origin of fish and at a smaller scale (∼30 km) we assessed "site fidelity" (i.e. post-settlement dispersal until recruitment). Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply) to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas.

  19. Marine reserves: long-term protection is required for full recovery of predatory fish populations.

    Science.gov (United States)

    Russ, Garry R; Alcala, Angel C

    2004-03-01

    No-take marine reserves are advocated widely as a potential solution to the loss of marine biodiversity and ecosystem structure, and to over-fishing. We assess the duration of protection required for unfished populations of large predatory reef fish to attain natural states. We have monitored two marine reserves at Sumilon and Apo Islands, Philippines, regularly for 17 years (1983-2000). The biomass of large predatory fish was still increasing exponentially after 9 and 18 years of protection at Sumilon and Apo reserves, respectively. There was little evidence that the rate of accumulation of biomass inside the reserves was slowing down even after so many years of protection. This suggests that the length of time to full recovery will be considerable. We made two assumptions in order to estimate this period. Firstly, that biomass growth will follow the logistic model. Secondly, the conservative assumption that biomass had already attained 90% of the local carrying capacity of the environments in the reserves. We conclude that the time required for full recovery will be 15 and 40 years at Sumilon and Apo reserves, respectively. Such durations of recovery appear consistent with known life history characteristics of these fish, and with empirical data on recovery rates of heavily exploited fish stocks. By the time the full fisheries or ecosystem benefits from such reserves are apparent, human populations and impacts will have doubled in much of the developing world. Thus, networks of such reserves need to be implemented immediately. Furthermore, the management mechanisms for the reserves need to be successful over timescales of human generations.

  20. Nanosilver-marine fungal chitosan as antibiotic synergizers against sepsis fish bacteria

    Directory of Open Access Journals (Sweden)

    Khouloud Mohamed Barakat

    2016-01-01

    Full Text Available Background and Objectives: Mortality is highly variable within population of cultured fish due to virulent bacteria causing fish septicemia. The use of nano-silver marine fungal chitosan as antibiotic synergisers could be an alternative in the treatment of sepsis fish pathogens.Materials and Methods: Different bulk chitosan solutions were prepared from the mycelia of four marine fungi (Aspergillus terreus, Aspergillus flavipes, Tricoderma hamatum and Fennellia flavipes and used as capping agents for silver nanoparticles. In vitro, the antibacterial activity of these preparations was determined against nine fish-sepsis causing bacteria, alone and in combination with nine antibiotics of choice used in aquaculture. Prepared fungal chitosans (CsF were characterized by yield of chistosan obtained, degree of deacetylation and viscosity.Results and Conclusion: The maximum yield of chitosan (28% was obtained from Aspergillus terreus. A. terreus chitosan (CsF, silver nanoparticles (AgNPs and chitosan-silver nanoparticles (CsF-AgNPs showed maximum activity at the minimum inhibitory concentrations average (MICAVG 27.2, 18.2 and 7.9 μg/ml, respectively. Combination of CsF –AgNPs with amikacin (Ak and rifampicin (RD reduced the MIC values by 96 and 94%, respectively, with fractional inhibitory concentration index (FICI = 0.42 and 0.50 as synergistic effect. It is promising to use CsF-AgNPs as enhancing agent in combination with antibiotics for fish sepsis therapy.Keywords: Marine fungal chitosan, nanosilver, bacterial sepsis, antibiotics, synergy

  1. Association of marine archaea with the digestive tracts of two marine fish species

    NARCIS (Netherlands)

    Maarel, Marc J.E.C. van der; Artz, Rebekka R.E.; Haanstra, Rene; Forney, Larry J.

    Recent studies have shown that archaea which were always thought to live under strict anoxic or extreme environmental conditions are also present in cold, oxygenated seawater, soils, the digestive tract of a holothurian deep-sea-deposit feeder, and a marine sponge, In this study we show, by using

  2. Simulating Blade-Strike on Fish passing through Marine Hydrokinetic Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Romero Gomez, Pedro DJ; Richmond, Marshall C.

    2014-06-16

    The study reported here evaluated the occurrence, frequency, and intensity of blade strike of fish on an axial-flow marine hydrokinetic turbine by using two modeling approaches: a conventional kinematic formulation and a proposed Lagrangian particle- based scheme. The kinematic model included simplifying assumptions of fish trajectories such as distribution and velocity. The proposed method overcame the need for such simplifications by integrating the following components into a computational fluid dynamics (CFD) model: (i) advanced eddy-resolving flow simulation, (ii) generation of ambient turbulence based on field data, (iii) moving turbine blades in highly transient flows, and (iv) Lagrangian particles to mimic the potential fish pathways. The test conditions to evaluate the blade-strike probability and fish survival rate were: (i) the turbulent environment, (ii) the fish size, and (iii) the approaching flow velocity. The proposed method offered the ability to produce potential fish trajectories and their interaction with the rotating turbine. Depending upon the scenario, the percentile of particles that registered a collision event ranged from 6% to 19% of the released sample size. Next, by using a set of experimental correlations of the exposure-response of living fish colliding with moving blades, the simulated collision data were used as input variables to estimate the survival rate of fish passing through the operating turbine. The resulting survival rates were greater than 96% in all scenarios, which is comparable to or better than known survival rates for conventional hydropower turbines. The figures of strike probability and mortality rate were amplified by the kinematic model. The proposed method offered the advantage of expanding the evaluation of other mechanisms of stress and injury on fish derived from hydrokinetic turbines and related devices.

  3. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities

    Science.gov (United States)

    Williamson, David H; Ceccarelli, Daniela M; Evans, Richard D; Jones, Geoffrey P; Russ, Garry R

    2014-01-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery. PMID:24634720

  4. Large-scale assessment of Mediterranean marine protected areas effects on fish assemblages.

    Science.gov (United States)

    Guidetti, Paolo; Baiata, Pasquale; Ballesteros, Enric; Di Franco, Antonio; Hereu, Bernat; Macpherson, Enrique; Micheli, Fiorenza; Pais, Antonio; Panzalis, Pieraugusto; Rosenberg, Andrew A; Zabala, Mikel; Sala, Enric

    2014-01-01

    Marine protected areas (MPAs) were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS) and thermophilic species (ThS) is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1) MPAs are numerous, 2) fishing has affected species and ecosystems, and 3) the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP), partially-protected MPAs (IP) and fished areas (F) at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators), but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide.

  5. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities.

    Science.gov (United States)

    Williamson, David H; Ceccarelli, Daniela M; Evans, Richard D; Jones, Geoffrey P; Russ, Garry R

    2014-02-01

    Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery.

  6. Large-scale assessment of Mediterranean marine protected areas effects on fish assemblages.

    Directory of Open Access Journals (Sweden)

    Paolo Guidetti

    Full Text Available Marine protected areas (MPAs were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS and thermophilic species (ThS is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1 MPAs are numerous, 2 fishing has affected species and ecosystems, and 3 the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP, partially-protected MPAs (IP and fished areas (F at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators, but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide.

  7. Temperature and resource availability may interactively affect over-wintering success of juvenile fish in a changing climate.

    Directory of Open Access Journals (Sweden)

    Jakob Brodersen

    Full Text Available The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus was affected by the physiologically relatively small (2-5 °C changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC, under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2 °C affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task.

  8. Ascaridoid parasites infecting in the frequently consumed marine fishes in the coastal area of China: A preliminary investigation.

    Science.gov (United States)

    Zhao, Wen-Ting; Lü, Liang; Chen, Hui-Xia; Yang, Yue; Zhang, Lu-Ping; Li, Liang

    2016-04-01

    Marine fishes represent the important components of the diet in the coastal areas of China and they are also natural hosts of various parasites. However, to date, little is known about the occurrence of ascaridoid parasites in the frequently consumed marine fishes in China. In order to determine the presence of ascaridoid parasites in the frequently consumed marine fishes in the coastal town Huizhou, Guangdong Province, China, 211 fish representing 45 species caught from the South China Sea (off Daya Gulf) were examined. Five species of ascaridoid nematodes at different developmental stages were detected in the marine fishes examined herein, including third-stage larva of Anisakis typica (Diesing, 1860), third and fourth-stage larvae of Hysterothylacium sp. IV-A of Shamsi, Gasser & Beveridge, 2013, adult and third-stage larvae of Hysterothylacium zhoushanense Li, Liu & Zhang, 2014, adults and third-stage larvae of Raphidascaris lophii (Wu, 1949) and adults of Raphidascaris longispicula Li, Liu & Zhang, 2012. The overall prevalence of infection is 18.0%. Of them, Hysterothylacium sp. IV-A with the highest prevalence (17.5%) and intensity (mean=14.6) of infection was the predominant species. The prevalence and intensity of A. typica were very low (1/211 of marine fish infected with an intensity of one parasite per fish). The morphological and molecular characterization of all nematode species was provided. A cladistic analysis based on ITS sequence was constructed in order to determine the phylogenetic relationships of these ascaridoid parasites obtained herein. The present study provided important information on the occurrence and diagnosis of ascaridoid nematodes in the commercially important marine fishes from the South China Sea. The low level of infection and the species composition of ascaridoid nematodes seem to indicate the presence of low risk of human anisakidosis when local population consumed these marine fishes examined herein.

  9. Variation in Nutritive Composition of Two Commercially Important Marine Fin Fishes

    Directory of Open Access Journals (Sweden)

    R. Kanagalakshmi

    2012-01-01

    Full Text Available The chemical compositions of fishes vary and are closely related to feed intake, migratory swimming and sexual changes in connection with spawning. The nutritive composition of many marine, estuarine and fresh water fishes were determined and have been implemented in fish consumption. Nutritive composition of Dussumieria acuta and Sardinella brachysoma were not yet determined and the present study was dealt with these fishes. Fatty acids, Vitamins (fat soluble and water soluble and Minerals were quantified. Palmitic acid showed its higher level in both species (5.78 and 3.89% in D. acuta and S. brachysoma, respectively. Water-soluble vitamins were higher in D. acuta and fat-soluble vitamins showed higher percentage availability in S. brachysoma. Calcium was the predominant mineral in both fishes and can be consumed by humans for bone strength. The finding has proved with strong evidence that both the fishes undertaken for the present study are rich in most of the nutrients essential for proper health maintenance of humans.

  10. Comparison of Bioavailability and Biotransformation of Inorganic and Organic Arsenic to Two Marine Fish.

    Science.gov (United States)

    Zhang, Wei; Wang, Wen-Xiong; Zhang, Li

    2016-03-01

    Dietary uptake could be the primary route of arsenic (As) bioaccumulation in marine fish, but the bioavailability of inorganic and organic As remains elusive. In this study, we investigated the trophic transfer and bioavailability of As in herbivorous rabbitfish Siganus fuscescens and carnivorous seabass Lateolabrax japonicus. Rabbitfish were fed with one artificial diet or three macroalgae, whereas seabass were fed with one artificial diet, one polychaete, or two bivalves for 28 days. The six spiked fresh prey diets contained different proportions of inorganic As [As(III) and As(V)] and organic As compounds [methylarsenate (MMA), dimethylarsenate (DMA), and arsenobetaine (AsB)], and the spiked artificial diet mainly contained As(III) or As(V). We demonstrated that the trophic transfer factors (TTF) of As in both fish were negatively correlated with the concentrations of inorganic As in the diets, while there was no relationship between TTF and the AsB concentrations in the diets. Positive correlation was observed between the accumulated As concentrations and the AsB concentrations in both fish, suggesting that organic As compounds (AsB) were more trophically available than inorganic As. Furthermore, the biotransformation ability of seabass was higher than that in rabbitfish, which resulted in higher As accumulation in seabass than in rabbitfish. Our study demonstrated that different prey with different inorganic/organic As proportions resulted in diverse bioaccumulation of total As in different marine fish.

  11. The origins of intensive marine fishing in medieval Europe: the English evidence.

    Science.gov (United States)

    Barrett, James H.; Locker, Alison M.; Roberts, Callum M.

    2004-01-01

    The catastrophic impact of fishing pressure on species such as cod and herring is well documented. However, the antiquity of their intensive exploitation has not been established. Systematic catch statistics are only available for ca.100 years, but large-scale fishing industries existed in medieval Europe and the expansion of cod fishing from the fourteenth century (first in Iceland, then in Newfoundland) played an important role in the European colonization of the Northwest Atlantic. History has demonstrated the scale of these late medieval and post-medieval fisheries, but only archaeology can illuminate earlier practices. Zooarchaeological evidence shows that the clearest changes in marine fishing in England between AD 600 and 1600 occurred rapidly around AD 1000 and involved large increases in catches of herring and cod. Surprisingly, this revolution predated the documented post-medieval expansion of England's sea fisheries and coincided with the Medieval Warm Period--when natural herring and cod productivity was probably low in the North Sea. This counterintuitive discovery can be explained by the concurrent rise of urbanism and human impacts on freshwater ecosystems. The search for 'pristine' baselines regarding marine ecosystems will thus need to employ medieval palaeoecological proxies in addition to recent fisheries data and early modern historical records. PMID:15590590

  12. Bioconcentration and Elimination of the Dithiocarbamate Fungicide Polycarbamate in Marine Teleost Fish and Polychaete.

    Science.gov (United States)

    Hano, Takeshi; Ohkubo, Nobuyuki; Kono, Kumiko; Tanaka, Hiroyuki

    2015-09-01

    We evaluated the bioconcentration and elimination of polycarbamate, a popular antifoulant classified as a dithiocarbamate fungicide, in a marine teleost fish, mummichog (Fundulus heteroclitus), and a polychaete (Perinereis nuntia). Following polycarbamate exposure and depuration, the calculated bioconcentration factor (BCF) and elimination rate constant (k2) were 3.1 and 0.17 day(-1) in fish and 1.5-7.8 and 0.13-0.18 day(-1) in the polychaete, indicating that the fungicide has low bioconcentration potential in both organisms. Given the BCF of 3.1, the permissible environmental concentration level of polycarbamate in water was calculated to be 6.1 µg L(-1) to satisfy the threshold pesticide residue levels in fish permitted by law, which is far below the permissible levels in Hiroshima Bay, Japan. Therefore, we consider that the current polycarbamate contamination level in terms of bioconcentration is not likely to be an alarming issue in coastal environments.

  13. Ordinary and Extraordinary Movement Behaviour of Small Resident Fish within a Mediterranean Marine Protected Area.

    Directory of Open Access Journals (Sweden)

    Eneko Aspillaga

    Full Text Available It is important to account for the movement behaviour of fishes when designing effective marine protected areas (MPAs. Fish movements occur across different spatial and temporal scales and understanding the variety of movements is essential to make correct management decisions. This study describes in detail the movement patterns of an economically and commercially important species, Diplodus sargus, within a well-enforced Mediterranean MPA. We monitored horizontal and vertical movements of 41 adult individuals using passive acoustic telemetry for up to one year. We applied novel analysis and visualization techniques to get a comprehensive view of a wide range of movements. D. sargus individuals were highly territorial, moving within small home ranges ( 50 m, where they aggregated to spawn. This study advances our understanding about the functioning of an established MPA and provides important insights into the biology and management of a small sedentary species, suggesting the relevance of rare but important fish behaviours.

  14. Meta-analysis of carrying capacity and abundance-area relationships in marine fish species

    DEFF Research Database (Denmark)

    Mantzouni, Irene

    fish produced by spawners in a given year which subsequently grow and survive to become vulnerable to fishing gear) have reacted to temperature fluctuations, and in particular to extremes of temperature, throughout the north Atlantic. Meta-analytical methods based on effect sizes were employed......Knowledge on the carrying capacity and the abundance-area relationships of fish is critical to evaluate the impacts of exploitation and climate on the sustainability and also the recovery potential of the populations. Of particular interest is climate change, inducing major consequences...... for population dynamics and life histories of marine biota as it progresses in the 21st century. In the present PhD project, a variety of meta-analytic methods was employed to statistically combine data across the north Atlantic distributions of 3 commercially and ecologically important species; cod (Gadus...

  15. The Role of Biophysical Parameters in the Antilipopolysaccharide Activities of Antimicrobial Peptides from Marine Fish

    Directory of Open Access Journals (Sweden)

    Ramamourthy Gopal

    2014-03-01

    Full Text Available Numerous antimicrobial peptides (AMPs from marine fish have been identified, isolated and characterized. These peptides act as host defense molecules that exert antimicrobial effects by targeting the lipopolysaccharide (LPS of Gram-negative bacteria. The LPS-AMP interactions are driven by the biophysical properties of AMPs. In this review, therefore, we will focus on the physiochemical properties of AMPs; that is, the contributions made by their sequences, net charge, hydrophobicity and amphipathicity to their mechanism of action. Moreover, the interactions between LPS and fish AMPs and the structure of fish AMPs with LPS bound will also be discussed. A better understanding of the biophysical properties will be useful in the design of AMPs effective against septic shock and multidrug-resistant bacterial strains, including those that commonly produce wound infections.

  16. Juvenile thresher shark habitat suitability model for Channel Islands National Marine Sanctuary Biogeographic Assessment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Sanctuary Program (NMSP) updates and revises the management plans for each of its 13 sanctuaries. This process, which is open to the public,...

  17. Forage fish interactions: A symposium on creating the tools for ecosystem-based management of marine resources

    DEFF Research Database (Denmark)

    Peck, M.A.; Neuenfeldt, Stefan; Essington, V.M.

    2014-01-01

    Forage fish (FF) have a unique position within marine foodwebs and the development of sustainable harvest strategies for FF will be a critical step in advancing and implementing the broader, ecosystem-based management of marine systems. In all, 70 scientists from 16 nations gathered for a symposium...

  18. Forage Fish Interactions: a symposium on "Creating the tools for ecosystem-based management of marine resources

    NARCIS (Netherlands)

    Peck, M.A.; Neuenfeldt, S.; Essington, T.E.; Dickey-Collas, M.

    2014-01-01

    Forage fish (FF) have a unique position within marine foodwebs and the development of sustainable harvest strategies for FF will be a critical step in advancing and implementing the broader, ecosystem-based management of marine systems. In all, 70 scientists from 16 nations gathered for a symposium

  19. Evaluating genetic traceability methods for captive-bred marine fish and their applications in fisheries management and wildlife forensics

    DEFF Research Database (Denmark)

    Bylemans, Jonas; Maes, Gregory E.; Diopere, Eveline

    2016-01-01

    Growing demands for marine fish products is leading to increased pressure on already depleted wild populations and a rise in aquaculture production. Consequently, more captive-bred fish are released into the wild through accidental escape or deliberate releases. The increased mixing of captive...... the implementation of a case-by-case strategy when choosing the best method....

  20. Assessing the state of pelagic fish communities within an ecosystem approach and the European Marine Strategy Framework Directive

    NARCIS (Netherlands)

    Shephard, S.; Rindorf, A.; Dickey-Collas, M.; Hintzen, N.T.; Farnsworth, K.; Reid, D.G.

    2014-01-01

    Pelagic fish are key elements in marine foodwebs and thus comprise an important part of overall ecosystem health. We develop a suite of ecological indicators that track pelagic fish community state and evaluate state of specific objectives against Good Environmental Status (GES) criteria. Indicator

  1. Age determination and validation studies of marine fishes: do deep-dwellers live longer?

    Science.gov (United States)

    Cailliet, G M; Andrews, A H; Burton, E J; Watters, D L; Kline, D E; Ferry-Graham, L A

    2001-04-01

    Age determination and validation studies on deep-water marine fishes indicate they are difficult to age and often long-lived. Techniques for the determination of age in individual fish includes growth-zone analysis of vertebral centra, fin rays and spines, other skeletal structures, and otoliths (there are three sets of otoliths in most bony fish semicircular canals, each of which is made of calcium carbonate). Most have regular increments deposited as the fish (and its semicircular canals) grows. The most commonly used otolith for age determination is the largest one called the sagitta. Age validation techniques include: (1) tag-recapture, often combined with oxytetracycline injection and analysis in growth-zones of bone upon recapture; (2) analysis of growth-zones over time; and (3) radiometric approaches utilizing a known radioactive decay series as an independent chronometer in otoliths from bony fishes. We briefly summarize previous studies using these three validation approaches and present results from several of our radiometric studies on deep-water, bony fishes recently subjected to expanding fisheries. Radiometric age validation results are presented for four species of scorpaenid fishes (the bank, Sebastes rufus, and bocaccio, S. paucispinis, rockfishes, and two thornyhead species, Sebastolobus altivelis and S. alascanus). In addition, our analysis of scorpaenids indicates that longevity increases exponentially with maximum depth of occurrence. The reason that the deep-water forms of scorpaenid fishes are long-lived is uncertain. Their longevity, however, may be related to altered physiological processes relative to environmental parameters like low temperature, high pressures, low light levels, low oxygen, and poor food resources.

  2. 2010-2015 Juvenile fish ecology in the Nisqually River Delta and Nisqually Reach Aquatic Reserve

    Science.gov (United States)

    Hodgson, Sayre; Ellings, Christopher S.; Rubin, Steve P.; Hayes, Michael C.; Duval, Walker; Grossman, Eric E.

    2017-01-01

    The return of tidal inundation to over 750 acres of the U. S. Fish and Wildlife Service Billy Frank Jr. Nisqually National Wildlife Refuge (NNWR) in fall of 2009 was the crowning moment in the effort to protect and restore the Nisqually Delta. The Nisqually NWR project complemented three earlier restoration projects completed by the Nisqually Indian Tribe (Tribe) on tribal property to restore over 900 acres of the estuary, representing the largest estuary restoration project in the Pacific Northwest and one of the most significant advances to date towards the recovery of Puget Sound (USFWS 2005). In 2011 the Washington Department of Natural Resources (WADNR established the over 14000 acre Nisqually Reach Aquatic Reserve (Reserve), complementing the protection and restoration successes in the Nisqually Delta. The Reserve includes all state-owned aquatic lands around Anderson, Ketron and Eagle islands and part of McNeil Island (Figure 1, WDNR 2011). The Reserve also includes a diverse assemblage of nearshore and offshore habitats important to resident and migratory fish including federal endangered species act listed fish like Chinook salmon (Oncorynchus tshawytscha) and steelhead (O. mykiss). Studies in the Nisqually Estuary (Ellings and Hodgson 2007, David et al. 2014, Ellings et al. 2016) and South Puget Sound (Duffy 2003) have summarized fish use of the area. However, the fish ecology of the reserve had not been systematically surveyed. The Tribe, U.S. Geological Survey (USGS), NNWR, Nisqually River Foundation (NRF), and others are currently conducting a multi-year, interdisciplinary, hypothesis-based research and monitoring study investigating the impact of delta restoration on estuarine processes, habitat structures, and functions. Our interdisciplinary monitoring framework enables us to link key estuarine processes with habitat development and biological response at multiple scales across the restored footprint, reference marshes, and throughout the Nisqually

  3. Vast assembly of vocal marine mammals from diverse species on fish spawning ground.

    Science.gov (United States)

    Wang, Delin; Garcia, Heriberto; Huang, Wei; Tran, Duong D; Jain, Ankita D; Yi, Dong Hoon; Gong, Zheng; Jech, J Michael; Godø, Olav Rune; Makris, Nicholas C; Ratilal, Purnima

    2016-03-17

    Observing marine mammal (MM) populations continuously in time and space over the immense ocean areas they inhabit is challenging but essential for gathering an unambiguous record of their distribution, as well as understanding their behaviour and interaction with prey species. Here we use passive ocean acoustic waveguide remote sensing (POAWRS) in an important North Atlantic feeding ground to instantaneously detect, localize and classify MM vocalizations from diverse species over an approximately 100,000 km(2) region. More than eight species of vocal MMs are found to spatially converge on fish spawning areas containing massive densely populated herring shoals at night-time and diffuse herring distributions during daytime. We find the vocal MMs divide the enormous fish prey field into species-specific foraging areas with varying degrees of spatial overlap, maintained for at least two weeks of the herring spawning period. The recorded vocalization rates are diel (24 h)-dependent for all MM species, with some significantly more vocal at night and others more vocal during the day. The four key baleen whale species of the region: fin, humpback, blue and minke have vocalization rate trends that are highly correlated to trends in fish shoaling density and to each other over the diel cycle. These results reveal the temporospatial dynamics of combined multi-species MM foraging activities in the vicinity of an extensive fish prey field that forms a massive ecological hotspot, and would be unattainable with conventional methodologies. Understanding MM behaviour and distributions is essential for management of marine ecosystems and for accessing anthropogenic impacts on these protected marine species.

  4. Analysis of reproductive patterns of fishes from three Large Marine Ecosystems

    Directory of Open Access Journals (Sweden)

    Isaac eTrindade-Santos

    2015-06-01

    Full Text Available Fish reproductive biology plays an important role for fishery management, especially in developing countries. The aim of this study was to compile all available information and analyze reproduction patterns of marine fishes in three Large Marine Ecosystems (LMEs: North, East, and South Brazil Shelves. We tested the hypothesis that the onset and duration of spawning season differ among these three LMEs; compared the ratio between length at first maturity and asymptotic length with the global trend observed; analyzed sex ratios; and tested whether females allocate more energy into reproduction than males. The following data were compiled from published sources and ‘grey’ literature: sex ratio, spawning season, gonadosomatic indices (GSI, and length at first maturity (Lm. The reproductive load was estimated as Lm/L∞. The median extension of the spawning season in the North, East, and South Brazil Shelves were 6.5, 6.0 and 5.0 months, respectively, with higher frequency during austral summer in South Brazil. Marine fishes from these three LMEs can be grouped in summer and non-summer spawners. About ninety six percent of the cases the reproductive load was between 0.3 and 0.8, which is slightly shifted toward smaller values, compared with the global range of 0.4-0.9. Gonadosomatic indices for females were higher. Contrary to some expectations, there is seasonality in the reproduction of tropical fishes. However, seasonality is stronger in southern populations. Size at first maturity is not efficiently used as a tool for fisheries management in the ecosystems analyzed.

  5. Geographic coupling of juvenile and adult habitat shapes spatial population dynamics of a coral reef fish

    NARCIS (Netherlands)

    Huijbers, C.M.; Nagelekerken, I.; Debrot, A.O.; Jongejans, E.

    2013-01-01

    Marine spatial population dynamics are often addressed with a focus on larval dispersal, without taking into account movement behavior of individuals in later life stages. Processes occurring during demersal life stages may also drive spatial population dynamics if habitat quality is perceived diffe

  6. The co-distribution of seabirds and their juvenile fish prey in Baffin Bay

    DEFF Research Database (Denmark)

    LeBlanc, Mathieu; Mosbech, Anders; Fortier, Louis

    LeBlanc, Mathieu (1) (mathieu.leblanc.10@ulaval.ca), A. Mosbech (2) and L. Fortier (1). (1) Takuvik and Québec-Océan, Department of Biology, Université Laval, Québec, Canada. (2) Department of Bioscience - Arctic Environment, Aarhus University, Roskilde, Denmark. In arctic marine ecosystems, arctic...

  7. Risk assessment of residual DDTs in freshwater and marine fish cultivated around the Pearl River Delta, China.

    Science.gov (United States)

    Leung, S Y; Kwok, C K; Nie, X P; Cheung, K C; Wong, M H

    2010-02-01

    Six species of freshwater fish collected from 10 fishponds in Shunde and Zhongshan, China, four species of marine fishes collected from different mariculture farms [four in Hong Kong (Tung Lung Chau, Ma Wan, Cheung Chau and Kat O) and two in mainland China (Daya Bay and Shenzhen)] together with feed (both trash fish and commercial pellets) and sediment were analyzed for DDTs. Total DDTs in freshwater fish flesh decreased in the order of: carnivores [1742 microg/kg lipid weight (l.w.)] > herbivores (165 microg/kg, l.w.) > omnivores (42.5 microg/kg, l.w.), with the highest concentration detected in mandarin fish (Siniperca chuatsi) (2641 microg/kg, l.w.). For marine fish, snubnose pompano (Trachinotus blochii) and orange-spotted grouper (Epinephelus coioides) collected in Ma Wan contained elevated levels of total DDTs (2590 and 2034 microg/kg l.w., respectively). Trash fish used in both freshwater and marine fish farms contained significantly higher levels (86.5-641 microg/kg l.w.) (p culture in order to lower the level of residual DDTs in fish muscle.

  8. Are we predicting the actual or apparent distribution of temperate marine fishes?

    Directory of Open Access Journals (Sweden)

    Jacquomo Monk

    Full Text Available Planning for resilience is the focus of many marine conservation programs and initiatives. These efforts aim to inform conservation strategies for marine regions to ensure they have inbuilt capacity to retain biological diversity and ecological function in the face of global environmental change--particularly changes in climate and resource exploitation. In the absence of direct biological and ecological information for many marine species, scientists are increasingly using spatially-explicit, predictive-modeling approaches. Through the improved access to multibeam sonar and underwater video technology these models provide spatial predictions of the most suitable regions for an organism at resolutions previously not possible. However, sensible-looking, well-performing models can provide very different predictions of distribution depending on which occurrence dataset is used. To examine this, we construct species distribution models for nine temperate marine sedentary fishes for a 25.7 km(2 study region off the coast of southeastern Australia. We use generalized linear model (GLM, generalized additive model (GAM and maximum entropy (MAXENT to build models based on co-located occurrence datasets derived from two underwater video methods (i.e. baited and towed video and fine-scale multibeam sonar based seafloor habitat variables. Overall, this study found that the choice of modeling approach did not considerably influence the prediction of distributions based on the same occurrence dataset. However, greater dissimilarity between model predictions was observed across the nine fish taxa when the two occurrence datasets were compared (relative to models based on the same dataset. Based on these results it is difficult to draw any general trends in regards to which video method provides more reliable occurrence datasets. Nonetheless, we suggest predictions reflecting the species apparent distribution (i.e. a combination of species distribution and the

  9. Distribution of selected heavy metals in skin and muscle of five tropical marine fishes.

    Science.gov (United States)

    Singh, J G; Chang-Yen, I; Stoute, V A; Chatergoon, L

    1991-01-01

    An investigation was carried out to determine the effect of tissue type, tissue location and size of fish on the heavy metal levels of five species of fish found in the marine environment of the tropical island of Trinidad. The study was conducted with the fish species Lutjanus synagris, Micropogon furnieri, Cynoscion leiarchus, Caranx hippos and Scomberomorus brasiliensis, and focused on the muscle and skin tissues of the fillet of these fish. The metals Fe, Zn, Cu, Ni, Pb, Cd and Cr were analysed by atomic absorption spectrophotometry after acid digestion of the tissues, but only Fe, Zn and Cu were detected. Skin tissue showed elevated levels of metals in comparison with muscle tissue, and significant differences in metal levels with respect to tissue location in skin, and varying effects of size on both muscle and skin metal levels in the different species, were found. These results emphasize the need for careful sampling of tissue in these fish species if reliable data on heavy metal levels are to be generated.

  10. A first sighting report of six fishes from the Mahatma Gandhi Marine National Park, South Andaman, India

    Directory of Open Access Journals (Sweden)

    Kamla Devi

    2015-09-01

    Full Text Available From the fish and fisheries point of view, the Andaman and Nicobar islands are the  most interesting and fascinating owing to a diversity of ichthyofauna occurring in the varied marine habitats, such as  mangroves, creeks, rocky beaches, extensive sandy beaches, muddy shores, coral reefs, etc. During a recent underwater survey around different islands inside the Mahatma Gandhi Marine National Park (MGMNP, Wandoor, South Andaman six new records of marine fishes belonging to the families Apogonidae, Labridae and Scaridae, were reported as a new record from the Andaman and Nicobar Islands. This paper deals with the morphological features, habitats and distribution of these fishes from this Marine National Park. 

  11. A first sighting report of six fishes from the Mahatma Gandhi Marine National Park, South Andaman, India

    Directory of Open Access Journals (Sweden)

    Kamla Devi

    2015-09-01

    Full Text Available From the fish and fisheries point of view, the Andaman and Nicobar islands are the  most interesting and fascinating owing to a diversity of ichthyofauna occurring in the varied marine habitats, such as  mangroves, creeks, rocky beaches, extensive sandy beaches, muddy shores, coral reefs, etc. During a recent underwater survey around different islands inside the Mahatma Gandhi Marine National Park (MGMNP, Wandoor, South Andaman six new records of marine fishes belonging to the families Apogonidae, Labridae and Scaridae, were reported as a new record from the Andaman and Nicobar Islands. This paper deals with the morphological features, habitats and distribution of these fishes from this Marine National Park. 

  12. Density-dependent changes in effective area occupied for sea-bottom-associated marine fishes.

    Science.gov (United States)

    Thorson, James T; Rindorf, Anna; Gao, Jin; Hanselman, Dana H; Winker, Henning

    2016-10-12

    The spatial distribution of marine fishes can change for many reasons, including density-dependent distributional shifts. Previous studies show mixed support for either the proportional-density model (PDM; no relationship between abundance and area occupied, supported by ideal-free distribution theory) or the basin model (BM; positive abundance-area relationship, supported by density-dependent habitat selection theory). The BM implies that fishes move towards preferred habitat as the population declines. We estimate the average relationship using bottom trawl data for 92 fish species from six marine regions, to determine whether the BM or PDM provides a better description for sea-bottom-associated fishes. We fit a spatio-temporal model and estimate changes in effective area occupied and abundance, and combine results to estimate the average abundance-area relationship as well as variability among taxa and regions. The average relationship is weak but significant (0.6% increase in area for a 10% increase in abundance), whereas only a small proportion of species-region combinations show a negative relationship (i.e. shrinking area when abundance increases). Approximately one-third of combinations (34.6%) are predicted to increase in area more than 1% for every 10% increase in abundance. We therefore infer that population density generally changes faster than effective area occupied during abundance changes. Gadiformes have the strongest estimated relationship (average 1.0% area increase for every 10% abundance increase) followed by Pleuronectiformes and Scorpaeniformes, and the Eastern Bering Sea shows a strong relationship between abundance and area occupied relative to other regions. We conclude that the BM explains a small but important portion of spatial dynamics for sea-bottom-associated fishes, and that many individual populations merit cautious management during population declines, because a compressed range may increase the efficiency of harvest.

  13. Temperate marine reserves enhance targeted but not untargeted fishes in multiple no-take MPAs.

    Science.gov (United States)

    Tetreault, Irene; Ambrose, Richard F

    2007-12-01

    Although many papers report the effects of no-take marine protected areas (MPAs or reserves), scientifically rigorous empirical studies are rare, particularly for temperate reef fishes. We evaluated the responses of fish populations to protection from fishing in reserves by comparing densities and sizes inside and outside of five no-take reserves in southern California, USA. Our results are robust because we compared responses across multiple rocky-reef reserves in two different years and controlled for possible site differences by (a) ensuring that habitat characteristics were the same inside and outside reserves, and (b) sampling species that are not targeted, which would not be expected to have a direct response to fishing. We compared fish density and size and calculated biomass and egg production across all five sites. Fishes targeted by recreational and/or commercial fisheries consistently exhibited increases in mean density (150%), size (30%), biomass (440%), and egg production (730%) inside reserves. Reserve effects were greatest for legal-sized targeted fishes: significantly greater densities were found exclusively inside reserves for targeted species (580%), the largest size classes existed only inside reserves, and mean biomass was 1000% higher. These responses were unlikely to have been caused by habitat differences because there were no significant differences in habitat characteristics between reserve and control locations. Densities of non-targeted species did not differ between reserve and non-reserve locations, further supporting the conclusions that differences in targeted species between reserve and control locations were due to harvesting rather than site-specific effects. Although MPAs cannot replace traditional fisheries management, the concentration of increased biomass and egg production is a unique MPA benefit that serves both reserves and fisheries. Scientifically rigorous studies that include multiple reserves, such as this study, are

  14. Derelict fishing gear in Chesapeake Bay, Virginia: spatial patterns and implications for marine fauna.

    Science.gov (United States)

    Bilkovic, Donna Marie; Havens, Kirk; Stanhope, David; Angstadt, Kory

    2014-03-15

    Derelict fishing gear is a source of mortality for target and non-target marine species. A program employing commercial watermen to remove marine debris provided a novel opportunity to collect extensive spatially-explicit information for four consecutive winters (2008-2012) on the type, distribution, and abundance of derelict fishing gear and bycatch in Virginia waters of Chesapeake Bay. The most abundant form of derelict gear recovered was blue crab pots with almost 32,000 recovered. Derelict pots were widely distributed, but with notable hotspot areas, capturing 40 species and over 31,000 marine organisms. The target species, blue crab, experienced the highest mortality from lost pots with an estimated 900,000 animals killed each year, a potential annual economic loss to the fishery of $300,000. Important fishery species were captured and killed in derelict pots including Atlantic croaker and black sea bass. While some causes of gear loss are unavoidable, others can be managed to minimize loss.

  15. Quantifying Barotrauma Risk to Juvenile Fish during Hydro-turbine Passage

    Energy Technology Data Exchange (ETDEWEB)

    Richmond, Marshall C.; Serkowski, John A.; Ebner, Laurie L.; Sick, Mirjam; Brown, Richard S.; Carlson, Thomas J.

    2014-03-15

    We introduce a method for hydro turbine biological performance assessment (BioPA) to bridge the gap between field and laboratory studies on fish injury and turbine engineering design. Using this method, a suite of biological performance indicators is computed based on simulated data from a computational fluid dynamics (CFD) model of a proposed hydro turbine design. Each performance indicator is a measure of the probability of exposure to a certain dose of an injury mechanism. If the relationship between the dose of an injury mechanism (stressor) and frequency of injury (dose-response) is known from laboratory or field studies, the likelihood of fish injury for a turbine design can be computed from the performance indicator. By comparing the values of the indicators from various turbine designs, engineers and biologists can identify the more-promising designs and operating conditions to minimize hydraulic conditions hazardous to passing fish. In this paper, the BioPA method is applied to estimate barotrauma induced mortal injury rates for Chinook salmon exposed to rapid pressure changes in Kaplan-type hydro turbines. Following the description of the general method, application of the BioPA to estimate the probability of mortal injury from exposure to rapid decompression is illustrated using a Kaplan hydro turbine at the John Day Dam on the Columbia River in the Pacific Northwest region of the USA. The estimated rates of mortal injury increased from 0.3% to 1.7% as discharge through the turbine increased from 334 to 564 m3/s for fish assumed to be acclimated to a depth of 5 m. The majority of pressure nadirs occurred immediately below the runner blades, with the lowest values in the gap at the blade tips and just below the leading edge of the blades. Such information can help engineers focus on problem areas when designing new turbine runners to be more fish-friendly than existing units.

  16. Ambient radioactivity monitoring V: Marine environment, fish and marine organisms; Ueberwachung der Umweltradioaktivitaet V: Meer, Fische und Meeresorganismen

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, C. [Bundesamt fuer Seeschiffahrt und Hydrographie, Hamburg (Germany); Kanisch, G. [Bundesforschungsanstalt fuer Fischerei, Hamburg (Germany). Lab. fuer Radiooekologie der Gewaesser

    1996-12-31

    The sea, originally thought to have an almost unlimited capacity of uptake of pollutants due to its water volumes available for dilution, was shown by growing insight into the physical, chemical and ecologic interdependencies to be a sensitive ecosystem. Its limits to cope with growing pollution are increasingly becoming clear, and this is a particular reason to perform radioactivity monitoring of the sea water, as radioactivity is transferred to the marine organisms. Organisms selected for monitoring are fish and crustaceans. (orig.) [Deutsch] Das Meer, urspruenglich wegen seiner Groesse und Verduennungskapazitaet fuer Schadstoffe als fast unbegrenzt aufnahmefaehig angesehen, erwies sich mit wachsender Einsicht in die physikalischen, chemischen und oekologischen Zusammenhaenge zunehmend als empfindliches System. Die Grenzen seiner Belastbarkeit werden immer deutlicher, ein besonderer Grund fuer die Ueberwachung auch der Radioaktivitaetskonzentration im Meerwasser, die sich ja auch auf die Meeresbewohner uebertraegt. Zu den zu ueberwachenden Organismen zaehlen Fische sowie Krusten- und Schalentiere. (orig.)

  17. Determination of polychlorinated biphenyls in marine fish obtained from tsunami-stricken areas of Japan.

    Science.gov (United States)

    Uekusa, Yoshinori; Takatsuki, Satoshi; Tsutsumi, Tomoaki; Akiyama, Hiroshi; Matsuda, Rieko; Teshima, Reiko; Hachisuka, Akiko; Watanabe, Takahiro

    2017-01-01

    We determined the polychlorinated biphenyl (PCB) congeners in 101 marine fish obtained from tsunami-stricken areas following the Great East Japan Earthquake in 2011. In particular, to determine the degree of PCB contamination in the fish, we investigated the concentration of total PCB (∑PCB) and the proportions of 209 individual PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry. The ∑PCB concentration was 1.7-33 ng/g in fat greenling (n = 29), 0.44-25 ng/g in flounder (n = 36), and 1.6-86 ng/g in mackerel (n = 36), all values being much lower than the provisional regulatory limit in Japan. In the congener analysis, tetra-, penta-, hexa-, and hepta-chlorinated PCB congeners dominated in all samples (comprising over 86% of the ∑PCB). The proportions of the chlorinated PCB congeners were similar to the contamination patterns derived from Kanechlor in the environment, implying that the marine fish were not contaminated with fresh PCBs.

  18. Commented checklist of marine fishes from the Galicia Bank seamount (NW Spain).

    Science.gov (United States)

    Bañon, Rafael; Arronte, Juan Carlos; Rodriguez-Cabello, Cristina; Piñeiro, Carmen-Gloria; Punzon, Antonio; Serrano, Alberto

    2016-01-21

    A commented checklist containing 139 species of marine fishes recorded at the Galician Bank seamount is presented. The list is based on nine prospecting and research surveys carried out from 1980 to 2011 with different fishing gears. The ichthyofauna list is diversified in 2 superclasses, 3 classes, 20 orders, 62 families and 113 genera. The largest family is Macrouridae, with 9 species, followed by Moridae, Stomiidae and Sternoptychidae with 7 species each. The trachichthyd Hoplostethus mediterraneus and the morid Lepidion lepidion were the most abundant species. Biogeographically, the Atlantic group, with 113 species (81.3%) is the best represented, followed by the Lusitanian one with 17 species (12.2%). Data on species abundance, as number of individuals caught, size and depth are reported. Habitat, distribution and vulnerability status are commented. Moreover, biometric data and meristic counts are also reported for several species. The results obtained showing a high fish biodiversity and a sensible number of threatened species, strongly support the future declaration of the Galicia Bank as a Marine Protected Area.

  19. Deep-water longline fishing has reduced impact on Vulnerable Marine Ecosystems.

    Science.gov (United States)

    Pham, Christopher K; Diogo, Hugo; Menezes, Gui; Porteiro, Filipe; Braga-Henriques, Andreia; Vandeperre, Frederic; Morato, Telmo

    2014-04-29

    Bottom trawl fishing threatens deep-sea ecosystems, modifying the seafloor morphology and its physical properties, with dramatic consequences on benthic communities. Therefore, the future of deep-sea fishing relies on alternative techniques that maintain the health of deep-sea ecosystems and tolerate appropriate human uses of the marine environment. In this study, we demonstrate that deep-sea bottom longline fishing has little impact on vulnerable marine ecosystems, reducing bycatch of cold-water corals and limiting additional damage to benthic communities. We found that slow-growing vulnerable species are still common in areas subject to more than 20 years of longlining activity and estimate that one deep-sea bottom trawl will have a similar impact to 296-1,719 longlines, depending on the morphological complexity of the impacted species. Given the pronounced differences in the magnitude of disturbances coupled with its selectivity and low fuel consumption, we suggest that regulated deep-sea longlining can be an alternative to deep-sea bottom trawling.

  20. Growth of angel fish Pterophyllum scalare [Gunther, 1862] juveniles fed inert diets

    Directory of Open Access Journals (Sweden)

    M. García-Ulloa

    2005-01-01

    Full Text Available Se investigó el crecimiento, conversión alimenticia (FCR, sobrevivencia y resistencia al estrés de juveniles del pez ángel Pterophyllum scalare, alimentados con diferentes dietas inertes (quistes decapsulados de Artemia DAC, hojuelas comerciales CF, pelets comerciales CP y una dieta comercial iniciadora para tilapia CSDT. Las dietas fueron estudiadas con tres réplicas y la ración alimenticia fue ajustada al 8% de la biomasa total. Los peces pesaron 0.44 g en promedio, al inicio. Las dietas mostraron un efecto significativo sobre el crecimiento de los peces desde la primera biometría. Después de 45 días de cultivo, los peces alimentados con DAC mostraron los valores promedio más altos en la longitud estándar, peso húmedo y crecimiento específico (3.64 ± 0.07 cm, 3.19 ± 0.24 g y 4.36 % peso corporal/ día, respectivamente, comparado con el resto de los tratamientos. El FCR fluctuó desde 1.26 ± 0.01 para el grupo DAC, hasta 2.01 ± 0.17 para la dieta CP, mostrando diferencias significativas (P < 0.05 entre los tratamientos. La sobrevivencia fue similar para todas las dietas. Los peces alimentados con DAC mostraron la mayor resistencia al estrés comparado con el resto de los tratamientos. Aunque la dieta DAC mejoró el crecimiento de los juveniles del pez ángel, se requieren de estudios posteriores para identificar algunos factores (biología nutricional, técnicas y estrategias de alimentación asociados a su mejor uso económico

  1. Species-specific impacts of a small marine reserve on reef fish production and fishing productivity in the Turks and Caicos Islands

    OpenAIRE

    Tupper, M.H.; Rudd, M.A.

    2002-01-01

    Marine reserves are widely considered to potentially benefit reef fisheries through emigration, yet the empirical basis for predicting the extent of this for small reserves is weak. The effects of fishing pressure and habitat on biomass and catch per unit effort (CPUE) of three species of exploited reef fish were studied at South Caicos, Turks and Caicos Islands. Distribution and abundance of hogfish (Lachnolaimus maximus) and white margate (Haemulon album) were inversely correlated with cove...

  2. Acetylcholine produces contraction mediated by cyclooxigenase pathway in arterial vessels in the marine fish (Isacia conceptionis

    Directory of Open Access Journals (Sweden)

    FA. Moraga

    Full Text Available Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh is blocked with indomethacin in intertidal fish (G. laevifrons. Our objective was to characterize the cholinergic pathway in several artery vessels of the I. conceptionis. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using doses response curves (DRC for Ach (10–13 to 10–3 M, and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high sensitivity only in efferente branchial artery and low sensibility in all vessels. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results corroborate previous results observed in intertidal species that contraction induced by acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

  3. Ascertaining the potential effects of temperature on growth, survival and feeding of different juvenile clown ifsh

    Institute of Scientific and Technical Information of China (English)

    Vishwas Rao Methari; Mohideen Abdul Badhul Haq; Chinna Raja; Sheik Mohamed

    2015-01-01

    Objective:To determine the physiological and ecological responses of marine ornamental fishes to the change of water temperature with its potential effects on the growth, survival and feeding in clown fish. Methods: Three different sea anemone fish (Premnas biaculeatus, Amphiprion clarkii, Amphiprion akallopisos) were reared in confinement at water temperatures of 26, 28, 30, 32, and 34 oC using thermostat and they were maintained up to the marketable size, and growth, survival and feeding were evaluated during the experimental period. Results: The results illustrated that water temperature influenced the physiological performance of juveniles of three different sea anemone fish significantly. The growth and survival rates of juveniles of three different clown fish significantly increased with the increase of water temperature from 26 oC to 34 oC (P Conclusions:This study deliberately reveals that the physiological response of juveniles of clown fish as the change of water temperature and substantiated that water temperature influenced juvenile growth, survival and feeding significantly. This study also put forward that the reduced growth, survival and feeding of juveniles at lower temperature which have ecological impacts on clown fish juveniles in settlement and population replacement in the wild.

  4. Researchers evaluate low-energy recirculating system for inland production of marine finfish juveniles

    Science.gov (United States)

    The low-energy recirculating aquaculture system consists of nine separate modules which utilize the double drain fish culture tank paired to a moving bed biofilter. The nine fiberglass tanks are five feet in diameter and normal water depth is about three feet for a total tank volume of approximately...

  5. Development of a new multiple sampling trawl with autonomous opening/closing net control system for sampling juvenile pelagic fish

    Science.gov (United States)

    Oozeki, Yoshioki; Hu, Fuxiang; Tomatsu, Chiaki; Kubota, Hiroshi

    2012-03-01

    A new multiple layer sampling trawl with an autonomous net opening/closing control system was developed to sample pelagic juvenile fish quantitatively. The new trawl system, based on the Matsuda-Oozeki-Hu Trawl (MOHT), has a rigid-frame 3.3 m high and 2.35 m wide and five nets of 11.0 m length with a rectangular mouth of 2.22 m×1.81 m (4 m2 mouth area; large-scale prototype). A cambered V-shape depressor is hung below the frame and two bridles are attached at the midpoint of the side frames. A net-release controller is used, which not only controls the net release mechanism but also records the net depth, temperature and flow rate during net towing. The controller sends stored command signals to the net release mechanism as depth settings and/or time settings and does not require any commands from the surface through a conducting cable or by acoustic signals. Two other models were constructed before the construction of the large-scale prototype, which are a small-scale prototype (2 m2 mouth area) for testing the net release mechanism and a 1/4-scale model of the large-scale prototype for flume tank tests. Flume tank tests with the 1/4-scale model showed that the frame leaned forward at a tilt angle from 5 to 15 degrees at towing speeds from 0.8 to 1.4 m s-1. Opened nets closed smoothly and sequentially nets were completely opened when the trigger was released by the command. Net depth rarely changed even during changes in towing speed. Sea trials both by the small-scale and the large-scale prototype demonstrated the same towing characteristics expected from the flume tank tests. The newly developed multiple layer opening/closing MOHT (MOC-MOHT) is considered to be suitable for quantitative layer sampling of juvenile fish.

  6. Yolo Bypass Juvenile Salmon Utilization Study 2016—Summary of acoustically tagged juvenile salmon and study fish release, Sacramento River, California

    Science.gov (United States)

    Liedtke, Theresa L.; Hurst, William R.

    2017-09-12

    The Yolo Bypass is a flood control bypass in Sacramento Valley, California. Flood plain habitats may be used for juvenile salmon rearing, however, the potential value of such habitats can be difficult to evaluate because of the intermittent nature of inundation events. The Yolo Bypass Juvenile Salmon Utilization Study (YBUS) used acoustic telemetry to evaluate the movements and survival of juvenile salmon adjacent to and within the Yolo Bypass during the winter of 2016. This report presents numbers, size data, and release data (times, dates, and locations) for the 1,197 acoustically tagged juvenile salmon released for the YBUS from February 21 to March 18, 2016. Detailed descriptions of the surgical implantation of transmitters are also presented. These data are presented to support the collaborative, interagency analysis and reporting of the study findings.

  7. Effects of zebra mussel (Dreissena polymorpha) density on the survival and growth of juvenile fathead minnows (Pimephales promelas): Implications for North American river fishes

    Science.gov (United States)

    Jennings, Cecil A.

    1996-01-01

    I used replicated 37.8 1 aquaria in a factorial design (four densities of zebra mussel, Dreissena polymorpha; two hydrologic regimes) to determine if the survival or growth of juvenile fathead minnows (Pimephales promelas) was affected by the density of zebra mussel or by the retention time of the test system. None of the fathead minnows died during the 30-d experiment. However, growth of fathead minnows was lower (P0.05). These laboratory results suggest that juvenile fish survival will not be affected by low to moderate densities of mussels (0-3000 m super(-2)) but fish growth might be adversely affected at moderate densities of mussels (e.g., 3000 m super(-2)).

  8. Decadal regime shift linkage between global marine fish landings and atmospheric planetary wave forcing

    Science.gov (United States)

    Powell, A. M., Jr.; Xu, J.

    2015-04-01

    This investigation focuses on a global forcing mechanism for decadal regime shifts and their subsequent impacts. The proposed global forcing mechanism is that the global atmospheric planetary waves can lead to changes in the global surface air-sea conditions and subsequently fishery changes. In this study, the five decadal regime shifts (1956-1957, 1964-1965, 1977-1978, 1988-1989, and 1998-1999) in the most recent 59-year period (1950-2008) have been identified based on Student t tests and their association with global marine ecosystem change has been discussed. Changes in the three major oceanic (Pacific, Atlantic, and Indian) ecosystems will be explored with the goal of demonstrating the linkage between stratospheric planetary waves and the ocean surface forcing that leads to fisheries impacts. The global forcing mechanism is described with a top-down approach to help the multidisciplinary audience follow the analysis. Following previous work, this analysis addresses how changes in the atmospheric planetary waves may influence the vertical wind structure, surface wind stress, and their connection with the global ocean ecosystems based on a coupling of the atmospheric regime shifts with the decadal regime shifts determined from marine life changes. The multiple decadal regime shifts related to changes in marine life are discussed using the United Nations Food and Agriculture Organization's (FAO) global fish capture data (catch/stock). Analyses are performed to demonstrate that examining the interactions between the atmosphere, ocean, and fisheries is a plausible approach to explaining decadal climate change in the global marine ecosystems and its impacts. The results show a consistent mechanism, ocean wind stress, responsible for marine shifts in the three major ocean basins. Changes in the planetary wave pattern affect the ocean wind stress patterns. A change in the ocean surface wind pattern from longwave (relatively smooth and less complex) to shorter

  9. Decadal regime shift linkage between global marine fish landings and atmospheric planetary wave forcing

    Directory of Open Access Journals (Sweden)

    A. M. Powell Jr.

    2014-08-01

    Full Text Available This investigation focuses on a global forcing mechanism for decadal regime shifts and their subsequent impacts. The proposed global forcing mechanism is the global atmospheric planetary waves that can lead to changes in the global surface air–sea conditions and subsequently fishery changes. In this study, the five decadal regime shifts (1956–1957, 1964–1965, 1977–1978, 1988–1989, and 1998–1999 in the recent 59 years (1950–2008 have been identified based on student t tests and their association with global marine ecosystem change has been discussed. Changes in the three major oceanic (Pacific, Atlantic and Indian ecosystems will be explored with the goal of demonstrating the linkage between stratospheric planetary waves and the ocean surface forcing that leads to fisheries impacts. Due to the multidisciplinary audience, the global forcing mechanism is described from a top-down approach to help the multidisciplinary audience follow the analysis. Following previous work, this analysis addresses how changes in the atmospheric planetary waves may influence the vertical wind structure, surface wind stress, and their connection with the global ocean ecosystems based on a coupling of the atmospheric regime shifts with the decadal regime shifts determined from marine life changes. The multiple decadal regime shifts related to changes in marine life are discussed using the United Nations Food and Agriculture Organization's (FAO global fish capture data (catch/stock. Analyses are performed to demonstrate the interactions between the atmosphere, ocean, and fisheries are a plausible approach to explaining decadal climate change in the global marine ecosystems and its impacts. The results show a consistent mechanism, ocean wind stress, responsible for marine shifts in the three major ocean basins. Changes in the planetary wave pattern affect the ocean wind stress patterns. A change in the ocean surface wind pattern from long wave (relatively

  10. Effects of different modified diets on growth, digestive enzyme activities and muscle compositions in juvenile Siamese fighting fish (Betta splendens Regan, 1910)

    OpenAIRE

    Thongprajukaew, Karun; Kovitvadhi, Uthaiwan; Kovitvadhi, Satit; Somsueb, Pisamai; Torrissen, Krisna Rungruangsak

    2011-01-01

    The effects of four modified diets (gamma-irradiated, microwave-irradiated, probiotic-supplemented and carbohydrase-supplemented diets) were studied on digestive enzyme specific activities and growth performance quality of juvenile Siamese fighting fish (Betta splendens Regan, 1910) during 2 weeks of critical and intensive rearing period. The modified procedures did not change biochemical compositions and gross energy of diets, but generally resulted in relatively higher in vitro ...

  11. Foraging preferences influence microplastic ingestion by six marine fish species from the Texas Gulf Coast.

    Science.gov (United States)

    Peters, Colleen A; Thomas, Peyton A; Rieper, Kaitlyn B; Bratton, Susan P

    2017-07-11

    This study evaluated the influence of foraging preferences on microplastic ingestion by six marine fish species from the Texas Gulf Coast. A total of 1381 fish were analyzed and 42.4% contained ingested microplastic, inclusive of fiber (86.4%), microbead (12.9% %), and fragment (<1.0%) forms. Despite a substantial overlap in diet, ordination of ingested prey items clustered samples into distinctive species groupings, reflective of the foraging gradient among species. Orthopristis chrysoptera displayed the lowest overall frequency of microplastic ingestion and the most distinctive ordination grouping, indicating their selective invertebrate foraging preferences. Cluster analysis of O. chrysoptera most closely classified microplastic with the ingestion of benthic invertebrates, whereas the ingestion of microplastic by all other species most closely classified with the ingestion of vegetation and shrimp. O. chrysoptera, as selective invertebrate foragers, are less likely to ingest microplastics than species exhibiting generalist foraging preferences and methods of prey capture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Classification accuracy of algorithms for blood chemistry data for three aquaculture-affected marine fish species.

    Science.gov (United States)

    Coz-Rakovac, R; Topic Popovic, N; Smuc, T; Strunjak-Perovic, I; Jadan, M

    2009-11-01

    The objective of this study was determination and discrimination of biochemical data among three aquaculture-affected marine fish species (sea bass, Dicentrarchus labrax; sea bream, Sparus aurata L., and mullet, Mugil spp.) based on machine-learning methods. The approach relying on machine-learning methods gives more usable classification solutions and provides better insight into the collected data. So far, these new methods have been applied to the problem of discrimination of blood chemistry data with respect to season and feed of a single species. This is the first time these classification algorithms have been used as a framework for rapid differentiation among three fish species. Among the machine-learning methods used, decision trees provided the clearest model, which correctly classified 210 samples or 85.71%, and incorrectly classified 35 samples or 14.29% and clearly identified three investigated species from their biochemical traits.

  13. Morphometric and molecular descriptions of three new species of Hysterothylacium (Nematoda: Raphidascarididae) from Australian marine fish.

    Science.gov (United States)

    Shamsi, S

    2017-09-01

    Three new species of Hysterothylacium Ward & Magath, 1917, including H. australe, H. kajikiae and H. brucei, from Australian marine fish are described and illustrated by light microscopy followed by genetic characterization of their first and second internal transcribed spacers (ITS-1 and ITS-2, respectively). This is the first study reporting ITS sequence data for adult Hysterothylacium spp. in Australia, which provides an insight into the identification of some of the Hysterothylacium larval types. Alignment of ITS sequences of these species with Hysterothylacium larval types previously reported in Australia showed that fourth-stage Hysterothylacium larval type XI from Seriola lalandi and third-stage Hysterothylacium larval type X from Sphyraene novae-hollandiae are identical with ITS sequences of H. australe, suggesting that these fish are natural intermediate/paratenic hosts of H. australe.

  14. Bioactive substances from marine fishes, shrimps, and algae and their functions: present and future.

    Science.gov (United States)

    Yu, Ping; Gu, Huifen

    2015-01-01

    Marine fishes, shrimps, and algae have many important bioactive substances, such as peptides, unsaturated fatty acids, polysaccharides, trace elements, and natural pigments. The introduction of these substances contributes to a significant improvement in developing them in final processed products. In fact, the knowledge of these bioactive substances has experienced a rapid increase in the past 20 years and prompted the relevant technological revolution with a decisive contribution to the final application. The purpose of this review was to introduce critically and comprehensively the present knowledge of these bioactive substances and pointed out their future developmental situation.

  15. De-eutrophication of effluent wastewater from fish aquaculture by using marine green alga Ulva pertusa

    Institute of Scientific and Technical Information of China (English)

    刘建国; 王增福; 林伟

    2010-01-01

    The de-eutrophication abilities and characteristics of Ulva pertusa, a marine green alga, were investigated in Qingdao Yihai Hatchery Center from spring to summer in 2005 by analyzing the dynamic changes in NH+4, NOˉ3, NO2ˉ as well as the total dissolved inorganic nitrogen (DIN). The results show that the effluent wastewater produced by fish aquaculture had typical eutrophication levels with an average of 34.3 μmol L-1 DIN. This level far exceeded the level IV quality of the national seawater standard and c...

  16. Quantifying fish assemblages in large, offshore marine protected areas: an Australian case study.

    Directory of Open Access Journals (Sweden)

    Nicole A Hill

    Full Text Available As the number of marine protected areas (MPAs increases globally, so does the need to assess if MPAs are meeting their management goals. Integral to this assessment is usually a long-term biological monitoring program, which can be difficult to develop for large and remote areas that have little available fine-scale habitat and biological data. This is the situation for many MPAs within the newly declared Australian Commonwealth Marine Reserve (CMR network which covers approximately 3.1 million km2 of continental shelf, slope, and abyssal habitat, much of which is remote and difficult to access. A detailed inventory of the species, types of assemblages present and their spatial distribution within individual MPAs is required prior to developing monitoring programs to measure the impact of management strategies. Here we use a spatially-balanced survey design and non-extractive baited video observations to quantitatively document the fish assemblages within the continental shelf area (a multiple use zone, IUCN VI of the Flinders Marine Reserve, within the Southeast marine region. We identified distinct demersal fish assemblages, quantified assemblage relationships with environmental gradients (primarily depth and habitat type, and described their spatial distribution across a variety of reef and sediment habitats. Baited videos recorded a range of species from multiple trophic levels, including species of commercial and recreational interest. The majority of species, whilst found commonly along the southern or south-eastern coasts of Australia, are endemic to Australia, highlighting the global significance of this region. Species richness was greater on habitats containing some reef and declined with increasing depth. The trophic breath of species in assemblages was also greater in shallow waters. We discuss the utility of our approach for establishing inventories when little prior knowledge is available and how such an approach may inform future

  17. Extraordinary aggressive behavior from the giant coral reef fish, Bolbometopon muricatum, in a remote marine reserve.

    Directory of Open Access Journals (Sweden)

    Roldan C Muñoz

    Full Text Available Human impacts to terrestrial and marine communities are widespread and typically begin with the local extirpation of large-bodied animals. In the marine environment, few pristine areas relatively free of human impact remain to provide baselines of ecosystem function and goals for restoration efforts. Recent comparisons of remote and/or protected coral reefs versus impacted sites suggest remote systems are dominated by apex predators, yet in these systems the ecological role of non-predatory, large-bodied, highly vulnerable species such as the giant bumphead parrotfish (Bolbometopon muricatum has received less attention. Overfishing of Bolbometopon has lead to precipitous declines in population density and avoidance of humans throughout its range, contributing to its status as a candidate species under the U. S. Endangered Species Act and limiting opportunities to study unexploited populations. Here we show that extraordinary ecological processes, such as violent headbutting contests by the world's largest parrotfish, can be revealed by studying unexploited ecosystems, such as the coral reefs of Wake Atoll where we studied an abundant population of Bolbometopon. Bolbometopon is among the largest of coral reef fishes and is a well known, charismatic species, yet to our knowledge, no scientific documentation of ritualized headbutting exists for marine fishes. Our observations of aggressive headbutting by Bolbometopon underscore that remote locations and marine reserves, by inhibiting negative responses to human observers and by allowing the persistence of historical conditions, can provide valuable opportunities to study ecosystems in their natural state, thereby facilitating the discovery, conservation, and interpretation of a range of sometimes remarkable behavioral and ecological processes.

  18. Small Marine Protected Areas in Fiji Provide Refuge for Reef Fish Assemblages, Feeding Groups, and Corals

    Science.gov (United States)

    Pires, Mathias M.; Guimarães, Paulo Roberto; Hoey, Andrew S.; Hay, Mark E.

    2017-01-01

    The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (reef organisms is largely decoupled from local adult reproduction. We examined the structure of fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5–0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3–6 times greater, and macroalgal browsing was 3–5 times greater in MPAs than in non-MPAs. On average, MPAs had 260–280% as much coral cover and only 5–25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs. PMID:28122006

  19. Variability in growth and condition of juvenile common two-banded sea bream (Diplodus vulgaris)

    OpenAIRE

    Vicente, Patrícia Nunes, 1980-

    2015-01-01

    Tese de mestrado. Biologia (Ecologia Marinha). Universidade de Lisboa, Faculdade de Ciências, 2015 The objective of this study was to assess the variability in condition for juvenile common two-banded sea bream Diplodus vulgaris in nursery areas of the main Portuguese estuaries using several individual condition indices. Estuaries and coastal lagoons play an important role for juveniles of marine fish because they offer areas with high availability of food, high water temperature and lower...

  20. Terrestrial and marine trophic pathways support young-of-year growth in a nearshore Arctic fish

    Science.gov (United States)

    von Biela, Vanessa R.; Zimmerman, Christian E.; Cohn, Brian R.; Welker, Jeffrey M.

    2013-01-01

    River discharge supplies nearshore communities with a terrestrial carbon source that is often reflected in invertebrate and fish consumers. Recent studies in the Beaufort Sea have documented widespread terrestrial carbon use among invertebrates, but only limited use among nearshore fish consumers. Here, we examine the carbon source and diet of rapidly growing young-of-year Arctic cisco (Coregonus autumnalis) using stable isotope values (δ13C and δ15N) from muscle and diet analysis (stomach contents) during a critical and previously unsampled life stage. Stable isotope values (δ15N and δ13C) may differentiate between terrestrial and marine sources and integrate over longer time frames (weeks). Diet analysis provides species-specific information, but only from recent foraging (days). Average δ13C for all individuals was −25.7 ‰, with the smallest individuals possessing significantly depleted δ13C values indicative of a stronger reliance of terrestrial carbon sources as compared to larger individuals. Average δ15N for all individuals was 10.4 ‰, with little variation among individuals. As fish length increased, the proportion of offshore Calanus prey and neritic Mysis prey increased. Rapid young-of-year growth in Arctic cisco appears to use terrestrial carbon sources obtained by consuming a mixture of neritic and offshore zooplankton. Shifts in the magnitude or phenology of river discharge and the delivery of terrestrial carbon may alter the ecology of nearshore fish consumers.

  1. The importance of the marine ornamental reef fish trade in the wider Caribbean.

    Science.gov (United States)

    Bruckner, A W

    2005-05-01

    The marine ornamental fish trade began in the 1930s in Sri Lanka, spread to Hawaii and the Philippines in the 1950s, and expanded to a multi-million dollar industry in the 1970s with fisheries established throughout the tropical Pacific, Indian and Atlantic Oceans. Currently, 45 countries supply global markets an estimated 14-30 million fish annually, with an import value of US$28-44 million. The largest suppliers are Indonesia and the Philippines, followed by Brazil, Maldives, Vietnam, Sri Lanka and Hawaii. In the tropical Western Atlantic, 16 countries have export fisheries, including the U.S. (Florida and Puerto Rico). The U.S. is the world's largest buyer, followed by the European Union and Japan. The global trade consists of over 1400 species of reef fishes, of which only about 25 are captive bred on a commercial scale. Damselfish, anemonefish, and angelfish constitute over 50% of the global volume; butterflyfish, wrasses, blennies, gobies, triggerfish, filcfish, hawkfishes, groupers and basselets account for 31% of the trade, and the remaining 16% is represented by 33 families. The most important fishes from the Caribbean are angelfish (six species), seahorses (two species), royal gramma, jawfish, queen triggerfish, redlip blenny, puddingwife, bluehead wrasse, and blue chromis. The Caribbean currently supplies a small percentage of the global trade in marine ornamental species, but ornamental fisheries in this region represent important emerging industries. It is critical that effective ornamental fishery management plans and regulations are developed and enforced, and fishery-dependent and fishery-independent data are collected and utilized in decision making processes to ensure sustainable ornamental fisheries throughout the region.

  2. Trophic level stability-inducing effects of predaceous early juvenile fish in an estuarine mesocosm study.

    Directory of Open Access Journals (Sweden)

    Ryan J Wasserman

    Full Text Available BACKGROUND: Classically, estuarine planktonic research has focussed largely on the physico-chemical drivers of community assemblages leaving a paucity of information on important biological interactions. METHODOLOGY/PRINCIPAL FINDINGS: Within the context of trophic cascades, various treatments using in situ mesocosms were established in a closed estuary to highlight the importance of predation in stabilizing estuarine plankton abundances. Through either the removal (filtration or addition of certain planktonic groups, five different trophic systems were established. These treatments contained varied numbers of trophic levels and thus different "predators" at the top of the food chain. The abundances of zooplankton (copepod and polychaete, ciliate, micro-flagellate, nano-flagellate and bacteria were investigated in each treatment, over time. The reference treatment containing apex zooplanktivores (early juvenile mullet and plankton at natural densities mimicked a natural, stable state of an estuary. Proportional variability (PV and coefficient of variation (CV of temporal abundances were calculated for each taxon and showed that apex predators in this experimental ecosystem, when compared to the other systems, induced stability. The presence of these predators therefore had consequences for multiple trophic levels, consistent with trophic cascade theory. CONCLUSIONS/SIGNIFICANCE: PV and CV proved useful indices for comparing stability. Apex predators exerted a stabilizing pressure through feeding on copepods and polychaetes which cascaded through the ciliates, micro-flagellates, nano-flagellates and bacteria. When compared with treatments without apex predators, the role of predation in structuring planktonic communities in closed estuaries was highlighted.

  3. Physiological Assessment and Behavioral Interaction of Wild and Hatchery Juvenile Salmonids : The Relationship of Fish Size and Growth to Smoltification in Spring Chinook Salmon.

    Energy Technology Data Exchange (ETDEWEB)

    Beckman, Brian R.; Larsen, Donald A.; Lee-Pawlak, Beeda; Dickhoff, Walton W.

    1996-10-01

    Experiments were performed to determine the relative influence of size and growth rate on downstream migratory disposition and physiology in yearling spring chinook salmon (Oncorhynchus tshawtscha) smolts. A group of juvenile chinook salmon was size graded into small and large categories with half the fish in each group reared at an elevated temperature, resulting in four distinct treatment groups: Large Warm (LW), Large Cool (LC), Small Warm (SW), and Small Cool (SC). Fish from warm-water treatment groups displayed significantly higher growth rates than cool-water groups. Fish were tagged and released into a natural creek where downstream movement was monitored. For each of the two releases, fish that migrated past a weir within the first 5 days postrelease had significantly higher spring growth rates than fish that did not migrate within that period. Significant differences in length for the same fish were only found in the second release. Also for the second release, fish from the warm water treatment groups were recovered in higher proportions than fish from cool water groups. The results indicate that increased growth rate in the spring has a positive relation to downstream migratory disposition. Furthermore, there is a relation between smolt size and migration; however, this relation is weaker than that found between growth rate and migration.

  4. Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2002 Data Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.S. [Westslope Fisheries, Cranbrook, BC, Canada

    2003-03-01

    The Wigwam River bull trout (Salvelinus confluentus) and fish habitat monitoring program is a trans-boundary initiative implemented by the British Columbia Ministry of Water, Land, and Air Protection (MWLAP), in cooperation with Bonneville Power Administration (BPA). The Wigwam River is an important fisheries stream located in southeastern British Columbia that supports healthy populations of both bull trout and Westslope cutthroat trout (Figure 1). This river has been characterized as the single most important bull trout spawning stream in the Kootenay Region (Baxter and Westover 2000, Cope 1998). In addition, the Wigwam River supports some of the largest Westslope cutthroat trout (Oncorhynchus clarki lewisi) in the Kootenay Region. These fish are highly sought after by anglers (Westover 1999a, 1999b). Bull trout populations have declined in many areas of their range within Montana and throughout the northwest including British Columbia. Bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Center (Cannings 1993) and although there are many healthy populations of bull trout in the East Kootenay they remain a species of special concern. Bull trout in the United States portion of the Columbia River were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. The upper Kootenay River is within the Kootenai sub-basin of the Mountain Columbia Province, one of the eleven Eco-provinces that make up the Columbia River Basin. MWLAP applied for and received funding from BPA to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. This task is one of many that were undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00).

  5. Wigwam River Juvenile Bull Trout and Fish Habitat Monitoring Program : 2000 Data Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.S.; Morris, K.J.

    2001-03-01

    The Wigwam River bull trout (Salvelinus confluentus) and fish habitat monitoring program is a trans-boundary initiative implemented by the British Columbia Ministry of Environment, Lands and Parks (MOE), in cooperation with Bonneville Power Administration (BPA). The Wigwam River is an important fisheries stream located in southeastern British Columbia that supports healthy populations of both bull trout and Westslope cutthroat trout (Figure 1.1). This river has been characterized as the single most important bull trout spawning stream in the Kootenay Region (Baxter and Westover 2000, Cope 1998). In addition, the Wigwam River supports some of the largest Westslope cutthroat trout (Oncorhynchus clarki lewisi) in the Kootenay Region. These fish are highly sought after by anglers (Westover 1999a, 1999b). Bull trout populations have declined in many areas of their range within Montana and throughout the northwest including British Columbia. Bull trout were blue listed as vulnerable in British Columbia by the B.C. Conservation Data Center (Cannings 1993) and although there are many healthy populations of bull trout in the East Kootenays they remain a species of special concern. Bull trout in the United States portion of the Columbia River were listed as threatened in 1998 under the Endangered Species Act by the U.S. Fish and Wildlife Service. The upper Kootenay River is within the Kootenai sub-basin of the Mountain Columbia Province, one of the eleven Eco-provinces that make up the Columbia River Basin. MOE applied for and received funding from BPA to assess and monitor the status of wild, native stocks of bull trout in tributaries to Lake Koocanusa (Libby Reservoir) and the upper Kootenay River. This task is one of many that was undertaken to ''Monitor and Protect Bull Trout for Koocanusa Reservoir'' (BPA Project Number 2000-04-00).

  6. Quantifying the trade in marine ornamental fishes into Switzerland and an estimation of imports from the European Union

    Directory of Open Access Journals (Sweden)

    Monica V. Biondo

    2017-07-01

    Full Text Available Millions of marine ornamental fishes are traded every year. Today, over half of the known nearly 4000 coral reef fish species are in trade with poor or no monitoring and demand is increasing. This study investigates their trade into and through Switzerland by analyzing import documents for live animals. In 2009, 151 import declarations with attached species lists for marine ornamental fishes from non-EU countries totaled 28 356 specimens. The 62% of the fishes remaining in Switzerland, comprised 440 marine species from 45 families, the rest transited to EU and non-EU countries. Despite the recognized large trade volume for the European region, due to bilateral agreements, no data is collected for imports from the EU. However, inferred data shows that more than 200 000 marine ornamental fishes could be imported into Switzerland every year and an unknown quantity re-exported. As biggest import region, it is therefore safe to assume, that the European region is importing at least as many marine ornamental fishes as the US. There is no adequate data-collecting system known to be in place in any country for monitoring this trade. The EU Trade Control and Expert System (TRACES to monitor animal diseases could be adjusted to gather compulsory information for the EU and Switzerland. More than half of the species imported into Switzerland are not assessed by the IUCN and therefore marked as ‘not evaluated’ on the Red List. Overall, 70% of all known coral reef fish species have not been evaluated. If coral reef fishes are threatened or endangered due to large, possibly unsustainable numbers traded, it may be rational to monitor the trade in these species through the Convention on International Trade of Endangered Species (CITES.

  7. Lethal effects of elevated pH and ammonia on juveniles of neotropical fish Colosoma macropomum (Pisces, Caracidae).

    Science.gov (United States)

    de Croux, Parma; Julieta, Maria; Loteste, Alicia

    2004-01-01

    Ammonia is the main nitrogenous waste material excreted by gills, then is oxided first to nitrite and then to nitrate. The proportion of ionized-un-ionized ammonia depends on pH and temperature, when this variables increase in a solution containing ammonia the equation goes to left, so the proportion of NH3 increases and the solution becomes more toxic. The purpose of this study was to investigate the acute lethal effects of elevated pH and ammonia on tambaqui juveniles. With a constant ammonia concentration of 5.0 mg/l NH3, there was no mortality a pH of 6.0 (control) and 7.0; but was of 10-20% a pH of 8.0 and 100% at 9.0. The lethal effects of elevated pH and un-ionized ammonia should be recognized as a potential factor contributing to the variable success of tambaqui production ponds, but this species is highly resistant in comparison with other freshwater fish.

  8. Species-specific impacts of a small marine reserve on reef fish production and fishing productivity in the Turks and Caicos Islands

    NARCIS (Netherlands)

    Tupper, M.H.; Rudd, M.A.

    2002-01-01

    Marine reserves are widely considered to potentially benefit reef fisheries through emigration, yet the empirical basis for predicting the extent of this for small reserves is weak. The effects of fishing pressure and habitat on biomass and catch per unit effort (CPUE) of three species of exploited

  9. Toxic Marine Puffer Fish in Thailand Seas and Tetrodotoxin They Contained

    Directory of Open Access Journals (Sweden)

    Hisao Kurazono

    2011-10-01

    Full Text Available A total of 155 puffers caught from two of Thailand’s seas, the Gulf of Siam and the Andaman seas, during April to July 2010 were included in this study. Among 125 puffers from the Gulf of Siam, 18 were Lagocephalus lunaris and 107 were L. spadiceus which were the same two species found previously in 2000–2001. Thirty puffers were collected from the Andaman seas, 28 Tetraodon nigroviridis and two juvenile Arothron reticularis; the two new species totally replaced the nine species found previously in 1992–1993. Conventional mouse bioassay was used to determine the toxicity in all fish tissue extracts, i.e., liver, reproductive tissue, digestive tissue and muscle. One of each of the species L. lunaris and L. spadiceus (5.56 and 0.93%, respectively were toxic. All 28 T. nigroviridis and 2 A. reticularis (100% from the Andaman seas were toxic. The toxicity scores in T. nigroviridis tissues were much higher than in the respective tissues of the other three fish species. Liquid chromatography/tandem mass spectrometry (LC-MS/MS revealed that the main toxic principle was tetrodotoxin (TTX. This study is the first to report TTX in L. spadiceus. Our findings raised a concern for people, not only Thais but also inhabitants of other countries situated on the Andaman coast; consuming puffers of the Andaman seas is risky due to potential TTX intoxication.

  10. Fossil-based comparative analyses reveal ancient marine ancestry erased by extinction in ray-finned fishes.

    Science.gov (United States)

    Betancur-R, Ricardo; Ortí, Guillermo; Pyron, Robert Alexander

    2015-05-01

    The marine-freshwater boundary is a major biodiversity gradient and few groups have colonised both systems successfully. Fishes have transitioned between habitats repeatedly, diversifying in rivers, lakes and oceans over evolutionary time. However, their history of habitat colonisation and diversification is unclear based on available fossil and phylogenetic data. We estimate ancestral habitats and diversification and transition rates using a large-scale phylogeny of extant fish taxa and one containing a massive number of extinct species. Extant-only phylogenetic analyses indicate freshwater ancestry, but inclusion of fossils reveal strong evidence of marine ancestry in lineages now restricted to freshwaters. Diversification and colonisation dynamics vary asymmetrically between habitats, as marine lineages colonise and flourish in rivers more frequently than the reverse. Our study highlights the importance of including fossils in comparative analyses, showing that freshwaters have played a role as refuges for ancient fish lineages, a signal erased by extinction in extant-only phylogenies.

  11. Five new species of philometrid nematodes (Philometridae) from marine fishes off Java, Indonesia.

    Science.gov (United States)

    Moravec, Frantisek; Walter, Thorsten; Yuniar, Asri Trisnani

    2012-06-01

    Based on light and scanning electron microscopical studies, the following five species of the Philometridae (Nematoda: Dracunculoidea) are described from female specimens collected from marine fishes off the southwestern coast of Java, Indonesia: Philometra lobotidis sp. n. from the abdominal cavity of the Atlantic tripletail Lobotes surinamensis (Bloch) (Lobotidae, Perciformes); Philometra javaensis sp. n. from the abdominal cavity of the immaculate puffer Arothron immaculatus (Bloch et Schneider) (Tetraodontidae, Tetraodontiformes); Philometra psettoditis sp. n. from the musculature of the Indian spiny turbot Psettodes erumei (Bloch et Schneider) (Psettodidae, Pleuronectiformes); Philometroides indonesiensis sp. n. from the musculature of the hound needlefish Tylosurus crocodilus crocodilus (Péron et Lesueur) (Belonidae, Beloniformes); and Philometroides trichiuri sp. n. from the dorsal fin of the largehead hairtail Trichiurus lepturus Linnaeus (type host) and the savalai hairtail Lepturacanthus savala (Cuvier) (both Trichiuridae, Perciformes). All these new species are distinguished from their congeners parasitizing marine fishes by morphological (mainly the shape and structure of the cephalic and caudal ends and of the oesophagus) and biometrical features. Besides previously known Philometra pellucida (Jägerskiöld, 1893) and Philometra ocularis Moravec, Ogawa, Suzuki, Miyazaki et Donai, 2002, they are the only nominal philometrid species recorded from Indonesian waters.

  12. Evaluation of the global impacts of mitigation on persistent, bioaccumulative and toxic pollutants in marine fish

    Directory of Open Access Journals (Sweden)

    Lindsay T. Bonito

    2016-01-01

    Full Text Available Although persistent, bioaccumulative and toxic pollutants (PBTs are well-studied individually, their distribution and variability on a global scale are largely unknown, particularly in marine fish. Using 2,662 measurements collected from peer-reviewed literature spanning 1969–2012, we examined variability of five classes of PBTs, considering effects of geography, habitat, and trophic level on observed concentrations. While we see large-scale spatial patterning in some PBTs (chlordanes, polychlorinated biphenyls, habitat type and trophic level did not contribute to significant patterning, with the exception of mercury. We further examined patterns of change in PBT concentration as a function of sampling year. All PBTs showed significant declines in concentration levels through time, ranging from 15–30% reduction per decade across PBT groups. Despite consistent evidence of reductions, variation in pollutant concentration remains high, indicating ongoing consumer risk of exposure to fish with pollutant levels exceeding EPA screening values. The temporal trends indicate that mitigation programs are effective, but that global levels decline slowly. In order for monitoring efforts to provide more targeted assessments of risk to PBT exposure, these data highlight an urgent need for improved replication and standardization of pollutant monitoring protocols for marine finfish.

  13. Antagonistic activity of marine sponge associated Streptomyces sp. against isolated fish pathogens

    Directory of Open Access Journals (Sweden)

    G. Palani Selvan

    2012-10-01

    Full Text Available Objective: To investigate the antibacterial potential of the marine actinomycetes isolated from sponge samples. Methods: Thirty six marine sponge samples were collected from Palk Strait and further used for actinomycetes isolation by using serial dilution. The antibacterial activity was carried out by using cross streak assay method. Moreover, most potential strain also subjected to MIC and MBC techniques and the isolated potential strain was identified by molecular tools. Results: The maximum counts (26 x 102 CFU/g were observed in the month of May and minimum counts (1 x 102 CFU/g were noticed in April. A total of 21 actinomycetes were isolated and their antibacterial potential was assessed by using cross streak method. Among the 21 actinomycetes, the ACT-21 showed sensitivity against all the isolated fish pathogens. Further, the MIC and MBC results reveal that, the ACT-21 showed sensitivity at the concentration ranged between 500 毺 g/ mL-1 500 毺 g/mL. The phylogenetic analysis suggested that, the potential isolate ACT-21 (accession no: JF899543 showed maximum similarity index (>98% with Streptomyces sp. Conclusions: It is concluded from present study that, the crude extracts of sponge associated actinomycetes could be used as an effective antibacterial agent for the management of disease free fish culture system.

  14. Seaweed, fish and Crustaceans as bioindicators for {sup 99}Tc released to marine environment[Radioecology

    Energy Technology Data Exchange (ETDEWEB)

    Jerpetjoen, A.; Oughton, D.; Skipperud, l. [Norwegian Univ. of Life Sciences, Dept. of Plant and Environmental Sciences, Aas (Norway)

    2006-04-15

    Along the Norwegian coast, {sup 99}Tc discharged from nuclear installations is found in seaweed, Crustaceans and fish. The activity concentrations of {sup 99}Tc in seaweed peaked around July 2002, giving a concentration ratio (CF) for the stems up to 121 m{sup 3}/Kg. The CF in different marine organisms differs between species, and within species; however, the CF is found to be highest for lobster, 4210 and 3755 m{sup 3}/Kg in the Irish Sea and 68 to 158 m{sup 3}/Kg along the Norwegian coast. {sup 99}Tc activity concentrations in Crabs from the Norwegian coast ranged from 0.12 to 0.61 Bq/kg giving CF's in Crab ranging from 0.24 to 1.22 m{sup 3}/Kg. Salmon filet collected from Norwegian fish farms showed CF levels ranging from 0.21 to 1.39 m{sup 3}/Kg, whereas Herring showed CF values of 0.08 and 0.16 m{sup 3}/Kg. Overall the data varies a lot, which is a problem when measuring natural organisms. Habitat, growth, and eating habits are among many different factors influencing the uptake of {sup 99}Tc. Further investigation on CF and how {sup 99}Tc are obtained by different species in the marine environment, and also different organs of the organisms, is needed. (au)

  15. Purification, Characterization and Antitumor Activities of a New Protein from Syngnathus acus, an Officinal Marine Fish

    Directory of Open Access Journals (Sweden)

    Ying Peng

    2011-12-01

    Full Text Available Discovery and development of new antitumor agents from abundant marine fish are attracting an increasing interest. In the present study, we extracted and purified a novel antitumor protein Syngnathusin from the whole body of Syngnathus acus L., a precious marine fish traditionally used for tumors. Syngnathusin was comprised of 16 kinds of amino acids, mainly acidic amino acids. Its molecular weight was 67.3 kDa and its isoelectric point was 4.57. The N-terminal amino acid sequence of Syngnathusin was determined to be Lys-Arg-Asp-Leu-Gly-Phe-Val-Asp-Glu-Ile-Ser-Ala-His-Tyr and showed no significant homology with the known proteins. Syngnathusin could significantly inhibit the growth of A549 and CCRF-CEM cells. However, the obvious proliferation inhibition against human non-tumor cell lines was not observed. Flow cytometry, morphologic assessment and comet assay revealed that Syngnathusin could induce apoptosis in A549 and CCRF-CEM cells and strongly cooperated with MTX. Syngnathusin could inhibit the growth of S180 tumor transplanted in mice. Syngnathusin may be developed as a novel, selective and effective antineoplastic agent.

  16. Purification, characterization and antitumor activities of a new protein from Syngnathus acus, an officinal marine fish.

    Science.gov (United States)

    Wang, Mengyue; Nie, Yuxiao; Peng, Ying; He, Fen; Yang, Jingyu; Wu, Chunfu; Li, Xiaobo

    2012-01-01

    Discovery and development of new antitumor agents from abundant marine fish are attracting an increasing interest. In the present study, we extracted and purified a novel antitumor protein Syngnathusin from the whole body of Syngnathus acus L., a precious marine fish traditionally used for tumors. Syngnathusin was comprised of 16 kinds of amino acids, mainly acidic amino acids. Its molecular weight was 67.3 kDa and its isoelectric point was 4.57. The N-terminal amino acid sequence of Syngnathusin was determined to be Lys-Arg-Asp-Leu-Gly-Phe-Val-Asp-Glu-Ile-Ser-Ala-His-Tyr and showed no significant homology with the known proteins. Syngnathusin could significantly inhibit the growth of A549 and CCRF-CEM cells. However, the obvious proliferation inhibition against human non-tumor cell lines was not observed. Flow cytometry, morphologic assessment and comet assay revealed that Syngnathusin could induce apoptosis in A549 and CCRF-CEM cells and strongly cooperated with MTX. Syngnathusin could inhibit the growth of S180 tumor transplanted in mice. Syngnathusin may be developed as a novel, selective and effective antineoplastic agent.

  17. Factors affecting the bioaccessibility of methylmercury in several marine fish species.

    Science.gov (United States)

    He, Mei; Wang, Wen-Xiong

    2011-07-13

    Bioaccessibility refers to the maximum bioavailability of pollutant ingested with food, and its measurements can lead to a more accurate risk assessment as compared to the measurements of total concentrations of pollutant in food. This study examined the factors affecting the bioaccessibility of methylmercury (MeHg) in nine species of marine fish with an aim to identify ways of reducing MeHg bioaccessibility. MeHg bioaccessibility without any treatment in the nine species of marine fish ranged from 16.0 to 67.7%. Steaming, grilling, and frying reduced MeHg bioaccessibility by 29.4-77.4% for rabbitfish and 74.6-95.8% for grouper. Co-consumption of phytochemical-rich foods such as green tea decreased the bioaccessibility of MeHg by 72.2% for rabbitfish and 74.0% for grouper, whereas meso-2,3-dimercaptosuccinic acid increased it by 39.2-108% for rabbitfish and 45.3-75.7% for grouper. The bioaccessibilities of both MeHg and inorganic mercury were independent of the total Hg concentration and the exposure route (dietary vs dissolved). In eight of the nine species studied, bioaccessibility was negatively correlated with the extent to which MeHg was partitioned into the metal-rich granule fraction and the trophically available fraction. It was positively correlated with partitioning into the cellular debris fraction. This study demonstrated the important control of subcellular distribution in MeHg bioaccessibility.

  18. Three novel myxobolid species of genera Henneguya and Myxobolus (Myxosporea: Bivalvulida) from marine fish in Japan.

    Science.gov (United States)

    Li, Yang-Chun; Sato, Hiroshi; Kamata, Yoichi; Ohnishi, Takahiro; Sugita-Konishi, Yoshiko

    2012-08-01

    Myxosporean genera Henneguya and Myxobolus (Bivalvulida: Myxobolidae) are closely related in morphology and molecular phylogeny, speciose with approximately 1,000 nominal species. The majority of them are recorded from freshwater fish worldwide, and few are known from marine fish. In this study, three myxobolid spp. are described from marine fish around Japan. Two novel Henneguya spp., Henneguya ogawai sp. n. and Henneguya yokoyamai sp. n., are described from two black sea breams (Acanthopagrus schlegelii) fished in the Inland Sea (Setonaikai), Japan. Plasmodia of the former species were localized in the esophageal or intestinal wall, and those of the latter species were in the wall of the gall bladder and peritoneum. Spore development in plasmodia of these two species was synchronous. The spore body of H. ogawai sp. n. was 11.0 (8.9-12.2) μm in length, 6.9 (6.3-7.5) μm in width, 5.9 (5.2-6.6) μm in thickness, with a bifurcated caudal process of equal length, 10.0 (8.4-12.7) μm long; total spore length, 21.1 (19.2-23.4) μm. It contained two polar capsule, 4.3 (3.8-5.2) × 1.9 (1.4-2.3) μm. The spore body of H. yokoyamai sp. n. was 11.0 (10.1-13.7) μm in length, 7.1 (6.6-7.5) μm in width, and 5.6 (4.5-6.4) μm in thickness, with a bifurcated caudal process of equal length, 14.1 (10.8-17.0) μm long; total spore length, 25.0 (21.9-29.2) μm. It contained two polar capsules, 3.7 (3.1-4.2) × 2.0 (1.8-2.4) μm. A novel Myxobolus sp., Myxobolus machidai sp. n., is described from a spotted knifejaw (Oplegnathus punctatus) fished in the Sea of Japan, off Shimonoseki, Yamaguchi Prefecture, Japan. Plasmodia were embedded in the esophageal wall. Its round spore was small in size, 9.0 (8.1-9.4) μm in length, 7.8 (7.5-8.3) μm in width, and 5.5 (5.1-6.0) μm in thickness. It contained two polar capsules, 3.5 (3.2-3.8) × 2.3 (2.2-2.5) μm. Spore development in a plasmodium was asynchronous. Nucleotide sequencing of the small

  19. Refugia of marine fish in the Northeast Atlantic during the Last Glacial Maximum: concordant assessment from archaeozoology and palaeotemperature reconstructions

    Directory of Open Access Journals (Sweden)

    A. J. Kettle

    2010-07-01

    Full Text Available Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM ca. 21 ka ago show evidence of very different species ranges compared to the present. We show how an ecological niche model (ENM based on palaeoclimatic reconstructions of sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results indicate that the ranges of marine fish species that are now in Northwestern Europe were almost completely displaced southward from the modern distribution. Significantly, there is strong evidence that there was an invasion of fish of current economic importance into the Western Mediterranean through the Straits of Gibraltar, where they were exploited by Palaeolithic human populations. There has been much recent interest in the marine glacial refugia to understand how the ranges of the economically important fish species will be displaced with the future climate warming. Recent ENM studies have suggested that species ranges may not have been displaced far southward during the coldest conditions of the LGM. However, archaeozoological evidence and LGM ocean temperature reconstructions indicate that there were large range changes, and certain marine species were able invade the Western Mediterranean. These findings are important for ongoing studies of molecular ecology that aim to assess marine glacial refugia from the genetic structure of living populations, and they pose questions about the genetic identity of vanished marine populations during the LGM. The research presents a challenge for future archaeozoological work to verify palaeoclimatic reconstructions and delimit the glacial refugia.

  20. Ecophysiology of marine fish recruitment: A conceptual framework for understanding interannual variability

    Science.gov (United States)

    Neill, William H.; Miller, John M.; Van Der Veer, Henk W.; Winemiller, Kirk O.

    Present data and our application of logic do not permit confident rejection of the null hypothesis: Interannual variation in recruitment of marine fishes (typified by certain flatfishes) is independent of ecophysiological factors. Our inability to reject this hypothesis reflects not its likely validity, but rather a lack of conceptual structure and appropriate data for realistic evaluation of alternative hypotheses. Therefore, in this paper, we set aside as presently intractable the problem of understanding in any generalizable way the specific effects of environment on interannual variation in marine fish recruitment. Instead, we return to a conceptual scheme first proposed almost 50 years ago by F.E.J. Fry for considering effects of environmental factors on the physiology of fishes. We first extend this scheme to population-level responses, including recruitment, and then even further, to community/ecosystem-level responses. Fry supposed that all of environment can be resolved into five classes of physiological effects—controlling (which set the pace of metabolism), limiting (which constrain maximum metabolism), lethal (which completely interdict metabolism), masking (which increase obligatory metabolic work), and directive (which release and unload metabolism by guiding enviroregulatory responses). We suggest that corresponding effects can be recognized at the levels both of population and community/ecosystem. The key analogy is that environment operates on individuals through metabolism, on populations through recruitment, and on communities/ecosystems through abiotic and biotic diversification. In the context of marine-fish populations, we propose that scope for population increase is the difference between maximum and maintenance recruitment to the spawning stock. Maintenance recruitment is the product of critical spawner density and spawner mortality rate; this product varies with environment as the resultant of controlling effects on the metabolism of

  1. The impact of fish and the commercial marine harvest on the ocean iron cycle.

    Directory of Open Access Journals (Sweden)

    Allison R Moreno

    Full Text Available Although iron is the fourth most abundant element in the Earth's crust, bioavailable iron limits marine primary production in about one third of the ocean. This lack of iron availability has implications in climate change because the removal of carbon dioxide from the atmosphere by phytoplankton requires iron. Using literature values for global fish biomass estimates, and elemental composition data we estimate that fish biota store between 0.7-7 × 10(11 g of iron. Additionally, the global fish population recycles through excretion between 0.4-1.5 × 10(12 g of iron per year, which is of a similar magnitude as major recognized sources of iron (e.g. dust, sediments, ice sheet melting. In terms of biological impact this iron could be superior to dust inputs due to the distributed deposition and to the greater solubility of fecal pellets compared to inorganic minerals. To estimate a loss term due to anthropogenic activity the total commercial catch for 1950 to 2010 was obtained from the Food and Agriculture Organization of the United Nations. Marine catch data were separated by taxa. High and low end values for elemental composition were obtained for each taxonomic category from the literature and used to calculate iron per mass of total harvest over time. The marine commercial catch is estimated to have removed 1-6 × 10(9 g of iron in 1950, the lowest values on record. There is an annual increase to 0.7-3 × 10(10 g in 1996, which declines to 0.6-2 × 10(10 g in 2010. While small compared to the total iron terms in the cycle, these could have compounding effects on distribution and concentration patterns globally over time. These storage, recycling, and export terms of biotic iron are not currently included in ocean iron mass balance calculations. These data suggest that fish and anthropogenic activity should be included in global oceanic iron cycles.

  2. Experiments for possible hydroacoustic discrimination of free-swimming juvenile gadoid fish by analysis of broadband pulse spectra as well as 3D fish position form video images and split beam acoustics

    DEFF Research Database (Denmark)

    Lundgren, Bo; Nielsen, J. Rasmus

    2002-01-01

    , alignment of acoustic and optical-reference frames, and automatic position-fitting of fish models to manually marked fix-points on fish images. The software also performs Fourier spectrum analysis and pulse-shape analysis of broad-bandwidth echoes. Therefore, several measurement series on free......Measurements were made of the broad-bandwidth (80–220 kHz) acoustic backscattering from free-swimming juvenile gadoids at various orientations and positions in an acoustic beam, under controlled conditions. The experimental apparatus consisted of a stereo-video camera system, a broad...... were estimated from stereo-images captured synchronously when broad-bandwidth echoes were received from passing fish. Fish positions were also estimated from data collected with a synchronized split-beam echosounder. Software was developed for image analysis and modelling, including calibration...

  3. Marine and inland fishes of St. Croix, U. S. Virgin Islands: an annotated checklist

    Science.gov (United States)

    Smith-Vaniz, William F.; Jelks, Howard L.

    2014-01-01

    An historical account is given for the ichthyological research at St. Croix, U. S. Virgin Islands, followed by an annotated list of 544 species of mostly marine shore fishes known or reported from the island to depths of 200 m. Color photographs are included for 103 of these species. Collections made at Buck Island Reef National Monument with the ichthyocide rotenone in 2001 and 2005 increased the known ichthyofauna by about 80 species. The rational for inclusion of each species in the checklist is given, with remarks for those species for which additional documentation or voucher specimens are needed. Reports of species known or presumed to have been based on misidentifications are discussed. Of the total marine fish fauna of the island, 404 species (75%) are restricted to the western Atlantic Ocean, (223 of these species are essentially Caribbean endemics that do not occur south of the Amazon River outflow), and no St. Croix endemic species are known. An additional 17 species (3.2%) also occur at mid-Atlantic islands, 57 species (10.6 %) are limited to both sides of the Atlantic Ocean, and 40 species (7.4%) have circumtropical distributions. The four most species-rich families are the Gobiidae (47 species), Serranidae (groupers and sea basses, 41), Labridae (wrasses and parrotfishes, 31), and Labrisomidae (scaly blennies, 27). Literature reports of Mosquitofish, Gambusia sp., from St. Croix apparently were based on misidentifications of a different introduced poeciliid genus. Four species of the amphidromus goby genus Sicydium occur in St. Croix inland waters, together with three established introduced species (one cichlid and two poeciliids). Also included are one catfish (Ictaluridae) and three sunfishes (Centrarchidae) known only from ponds. The Lionfish, Pterois volitans, the only introduced marine species, was first reported from St. Croix in 2008 and is now common despite control efforts.

  4. The antioxidant effects of complexes of tilapia fish skin collagen and different marine oligosaccharides

    Science.gov (United States)

    Ren, Shuwen; Li, Jing; Guan, Huashi

    2010-12-01

    An excess of reactive oxygen species (ROS) leads to a variety of chronic health problems. As potent antioxidants, marine bioactive extracts containing oligosaccharides and peptides have been extensively studied. Recently, there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries. However, only few studies are available on the antioxidant activities of such complexes, in terms of their ROS scavenging capability. In this study, we combined different marine oligosaccharides (isolated and purified) with collagen peptides derived from tilapia fish skin, and evaluated the antioxidant activity of the marine peptide-oligosaccharide complexes vis-à-vis the activity of their original component molecules. Biochemical and cellular assays were performed to measure the scavenging effects on 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide radicals, and to evaluate the influences on the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of malondialdehyde (MDA) in UV-induced photoaging models. The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components. Among the 11 complexes tested, two complexes, namely MA1000+CP and κ-ca3000+CP, turned out to be highly effective antioxidants. Although the detailed mechanisms of this improved scavenging ability are not fully understood, this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical, cosmetics and food industries.

  5. Tracking Three-Dimensional Fish Behavior with a New Marine Acoustic Telemetry System

    Science.gov (United States)

    Brosnan, Ian G.; McGarry, Louise P.; Greene, Charles H.; Steig, Tracey W.; Johnston, Samuel V.; Ehrenberg, John E.

    2015-01-01

    The persistent monitoring capability provided by acoustic telemetry systems allows us to study behavior, movement, and resource selection of mobile marine animals. Current marine acoustic telemetry systems are challenged by localization errors and limits in the number of animals that can be tracked simultaneously. We designed a new system to provide detection ranges of up to 1 km, to reduce localization errors to less than 1 m, and to increase to 500 the number of unique tags simultaneously tracked. The design builds on HTIs experience of more than a decade developing acoustic telemetry systems for freshwater environments. A field trial of the prototype system was conducted at the University of Washingtons Friday Harbor Marine Laboratory (Friday Harbor, WA). Copper rockfish (Sebastes caurinus) were selected for field trials of this new system because their high site-fidelity and small home ranges provide ample opportunity to track individual fish behavior while testing our ability to characterize the movements of a species of interest to management authorities.

  6. THE ENVIRONMENTAL IMPACTS OF MARINE FISH CAGE FARMS IN THE EASTERN ADRIATIC

    Directory of Open Access Journals (Sweden)

    Ivan Katavić

    2003-12-01

    Full Text Available Mariculture in Croatia could play a more important role in development of rural communities along coastline. However, by increase of fish farming, public concern over environmental issues has been raised, and the need for more responsible mariculture development and management has been asked. There are opportunities and challenges for effectively integrating mariculture into coastal zone management with equal rights and obligations. This is primarily because of its social and economic mission consisting in preventing de-population of rural coastal areas and islands and meeting the growing needs of tourist market for seafood. Although intensive mariculture production is accused of producing negative environmental effects, many of these effects still need to be scientifically documented. The effect of nitrogen and phosphorous releases from farmed fish faeces or uneaten food is not of significant issues for marine ecosystem, and it is generally of little importance compared to the inflow of nutrients from other coastal sources. The impact on sediment and benthic communities is mainly local and short-term ones, and depends on the number and extent of the farms and their location. Recovery of some benthic communities after the cessation of farming activities may be delayed over several years (i. e. Posidonia beds due to the accumulated organic matter. Bluefin tuna farming if not properly located and managed might cause pollution problems, either from uneaten feed and metabolic waste or from harvesting and processing the fish. In most cases the problem comes from smell pollution during the summer time and the oily water surface that may be widespread much outside of the farm areas. It will be important for sustainable development of Croatian mariculture to offer a healthy and good quality product in the quantities required by the market, while not degrading the marine environment.

  7. Persistent organic pollutants in marine fish from Yongxing Island, South China Sea: levels, composition profiles and human dietary exposure assessment.

    Science.gov (United States)

    Sun, Yu-Xin; Hao, Qing; Xu, Xiang-Rong; Luo, Xiao-Jun; Wang, Shuai-Long; Zhang, Zai-Wang; Mai, Bi-Xian

    2014-03-01

    Little data is available on the bioaccumulation of persistent organic pollutants (POPs) in marine organisms from South China Sea (SCS). Five marine fish species were collected from Yongxing Island, SCS to investigate the presence of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). PBDEs, PCBs, and DDTs concentrations ranged from 2.0-117, 6.3-199, and 9.7-5831 ng g(-1) lw, respectively. In general, contaminants measured in this study were at the lower end of the global range. Concentrations of PBDEs and PCBs were significantly correlated in fish samples, implying that PBDEs are as prevalent as PCBs in Yongxing Island. Among the five fish species studied, yellow striped goatfish had the highest concentrations of PBDEs, PCBs, and DDTs, probably attributed to its different living and feeding habits. The contaminant distribution pattern indicated that agrochemical source is more important than industrial source in Yongxing Island, SCS. The average estimated daily intakes of PBDEs, PCBs, and DDTs via fish consumption by local residents in the coastal areas of South China ranged from 1.42-5.91, 3.20-13.3, and 8.08-33.6 ng d(-1), which were lower than those in previous studies, suggesting that consumption of marine fish in Yongxing Island, SCS, might not subject local residents to significant health risk as far as POPs are concerned. This is the first study to report the occurrence of POPs in marine biota from SCS.

  8. Developmental and Morphological Characteristics of Embryo, Larval, Juvenile, and Young Fish, Chromileptes altivelis%驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼形态观察

    Institute of Scientific and Technical Information of China (English)

    张梦淇; 陈超; 李炎璐; 贾瑞锦; 于宏; 梁友; 蔡春有; 庞尊方

    2014-01-01

    Artificial breeding of Chromileptes altivelis is difficult to marine fishing, and related studies on C. altivelis are limited. The present study investigated the embryonic and morphological development of larval, juvenile and young fish of C. altivelis using microscope, anatomical lens and digital camera. The morphological features and the time of development stages were described. The results showed that the embryonic development of C. altivelis was divided into five stages:cleavage stage, blastula stage, gastrula stage, neurula stage, and organogenesis stage. The embryonic development requires 27 h 25 min under the following condition in the sea water at 25−26℃ and salinity of 30. The post embryonic development of C. altivelis was divided into larval stage, juvenile stage and young fish stage based on the features of the yolk-sac, finfold, second dorsal fin spine, pelvic fin spine, scale, and body color. The larval stage was further classified into early larvae and late larvae based on the existence of the yolk-sac or not. The embryos developed into prelarvae in 2 days under water environment with temperature between 22 and 26℃, salinity between 29 and 31, DO≥5 mg/L. The yolk-sac of larvae disappeared and the postlarvae began at day 3. The larvae started to develop to juveniles at day 31. The juveniles completed metamorphosis and became young fish at day 57. The growth and configuration of the second spine of dorsal fin and the first spine of ventral fin were the most obvious changes during early development of C. altivelis. This study provides information for the propagation, seed culture and morphological identification of grouper fish.%对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25−26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育

  9. Speciation of Gram-positive bacteria in fresh and ambient-stored sub-tropical marine fish.

    Science.gov (United States)

    Al Bulushi, Ismail M; Poole, Susan E; Barlow, Robert; Deeth, Hilton C; Dykes, Gary A

    2010-03-31

    This study identified Gram-positive bacteria in three sub-tropical marine fish species; Pseudocaranx dentex (silver trevally), Pagrus auratus (snapper) and Mugil cephalus (sea mullet). It further elucidated the role played by fish habitat, fish body part and ambient storage on the composition of the Gram-positive bacteria. A total of 266 isolates of Gram-positive bacteria were identified by conventional biochemical methods, VITEK, PCR using genus- and species-specific primers and/or 16S rRNA gene sequencing. The isolates were found to fall into 13 genera and 30 species. In fresh fish, Staphylococcus epidermidis and Micrococcus luteus were the most frequent isolates. After ambient storage, S. epidermidis, S. xylosus and Bacillus megaterium were no longer present whereas S. warneri, B. sphaericus, Brevibacillus borstelensis, Enterococcus faecium and Streptococcus uberis increased in frequency. Micrococcus luteus and S. warneri were the most prevalent isolates from P. dentex, while E. faecium and Strep. uberis were the most frequent isolates from P. auratus and M. cephalus. With respect to different parts of the fish body, E. faecium, Strep. uberis and B. sphaericus were the most frequent isolates from the muscles, E. faecium, Strep. uberis from the gills and M. luteus from the gut. This study showed a diversity of Gram-positive bacteria in sub-tropical marine fish; however, their abundance was affected by fish habitat, fish body part and ambient storage.

  10. Peripatric differentiation among adjacent marine lake and lagoon populations of a coastal fish, Sphaeramia orbicularis (Apogonidae, Perciformes, Teleostei).

    Science.gov (United States)

    Gotoh, Ryo O; Sekimoto, Hidekatsu; Chiba, Satoru N; Hanzawa, Naoto

    2009-08-01

    The effect of geographical isolation on speciation, particularly within short geographical ranges, is poorly understood among marine organisms. Focusing on marine lakes of the Palau Islands, we investigated the effect of geographical isolation on Sphaeramia orbicularis, a coastal fish inhabiting marine lakes and lagoons. We collected a total of 157 individuals from three meromictic marine lakes and three lagoon sites, and analyzed the genetic diversity and differentiation of the populations based on complete sequences of the mitochondrial control region (824 bp). The analyses show that the genetic diversity of marine lake populations is much lower than that of lagoon populations. Moreover, a mismatch distribution analysis suggests that marine lake populations have experienced a decrease followed by a rapid expansion of their population size. These results reveal that marine lake populations have experienced severe founder and/or bottleneck events during the last thousand to tens of thousand years. Pairwise Phi(ST )values ranged from 0.531 to 0.848 between marine lake and lagoon populations and from 0.429 to 0.870 among marine lake populations, indicating a high degree of genetic differentiation. We speculate that such peripatric differentiation between marine lake and lagoon populations was caused by a small number of individuals colonizing the lakes from the lagoon (founder event) followed by repetitive bottleneck events, such as those generated by the El Niño-Southern Oscillation (ENSO). So far, such high genetic divergences in extremely short geographical ranges (approximately 150-250 m) have scarcely been reported for marine organisms. We suggest that the marine lake is one of the good model of geographical isolation in marine organisms and each marine lake population is in the early stages of speciation.

  11. Propensity of marine reserves to reduce the evolutionary effects of fishing in a migratory species.

    Science.gov (United States)

    Dunlop, Erin S; Baskett, Marissa L; Heino, Mikko; Dieckmann, Ulf

    2009-08-01

    Evolutionary effects of fishing can have unwanted consequences diminishing a fishery's value and sustainability. Reserves, or no-take areas, have been proposed as a management tool for reducing fisheries-induced selection, but their effectiveness for migratory species has remained unexplored. Here we develop an eco-genetic model to predict the effects of marine reserves on fisheries-induced evolution under migration. To represent a stock that undergoes an annual migration between feeding and spawning grounds, we draw model parameters from Atlantic cod (Gadus morhua) in the northern part of its range. Our analysis leads to the following conclusions: (i) a reserve in a stock's feeding grounds, protecting immature and mature fish alike, reduces fisheries-induced evolution, even though protected and unprotected population components mix on the spawning grounds; (ii) in contrast, a reserve in a stock's spawning grounds, protecting only mature fish, has little mitigating effects on fisheries-induced evolution and can sometimes even exacerbate its magnitude; (iii) evolutionary changes that are already underway may be difficult to reverse with a reserve; (iv) directly after a reserve is created or enlarged, most reserve scenarios result in yield losses; and (v) timescale is very important: short-term yield losses immediately after a reserve's creation can give way to long-term gains.

  12. Ordinary and Extraordinary Movement Behaviour of Small Resident Fish within a Mediterranean Marine Protected Area.

    Science.gov (United States)

    Aspillaga, Eneko; Bartumeus, Frederic; Linares, Cristina; Starr, Richard M; López-Sanz, Àngel; Díaz, David; Zabala, Mikel; Hereu, Bernat

    2016-01-01

    It is important to account for the movement behaviour of fishes when designing effective marine protected areas (MPAs). Fish movements occur across different spatial and temporal scales and understanding the variety of movements is essential to make correct management decisions. This study describes in detail the movement patterns of an economically and commercially important species, Diplodus sargus, within a well-enforced Mediterranean MPA. We monitored horizontal and vertical movements of 41 adult individuals using passive acoustic telemetry for up to one year. We applied novel analysis and visualization techniques to get a comprehensive view of a wide range of movements. D. sargus individuals were highly territorial, moving within small home ranges (sargus presented a sheltering behaviour, moving to more protected places to avoid the disturbance. Second, during the spawning season they made excursions to deep areas (> 50 m), where they aggregated to spawn. This study advances our understanding about the functioning of an established MPA and provides important insights into the biology and management of a small sedentary species, suggesting the relevance of rare but important fish behaviours.

  13. Occurrence of tumour (odontoma) in marine fish Sphyraena jello from the southeast coast of India.

    Science.gov (United States)

    Vijayakumar, R; Gopalakrishnan, A; Raja, K; Sinduja, K

    2014-02-04

    We examined the occurrence of odontoma in the marine fish Sphyraena jello sourced from 3 different landing centers (Cuddalore, Parangipettai and Nagapattinam) in Tamil Nadu (southeast India). A total of 19783 fishes were examined for odontoma presence, of which 2393 were affected with odontoma. The overall prevalence was 12.1% among the 3 stations. Fish landed at Parangipettai showed the highest peak prevalence of odontoma (16.8%) during the pre-monsoon, followed by Nagapatinam (9.1%) during summer 2011. The tumour lengths in premaxilla, supermaxilla and dentary bone were 1.1-3.6, 1.4-5.9 and 1.2-4.1 cm, respectively, and tumour widths were 0.3-1.9, 0.7-3.1 and 0.5-1.9 cm. Higher prevalence (0.206%) of tongue tumour along with odontoma was observed at Nagapattinam whereas it was lower (0.162%) at Cuddalore. Odontoma histopathology showed dense fibrous tissue with fine teeth roots. TEM analysis showed virus-like particles associated with odontoma. Radiography of the odontoma showed that the tumour masses were bony in nature and tissues were merged with upper and lower jaw.

  14. Why pair? Evidence of aggregative mating in a socially monogamous marine fish (Siganus doliatus, Siganidae).

    Science.gov (United States)

    Fox, Rebecca J; Bellwood, David R; Jennions, Michael D

    2015-09-01

    Many species live in stable pairs, usually to breed and raise offspring together, but this cannot be assumed. Establishing whether pairing is based on mating, or an alternative cooperative advantage, can be difficult, especially where species show no obvious sexual dimorphism and where the act of reproduction itself is difficult to observe. In the tropical marine fishes known as rabbitfish (Siganidae), half of extant species live in socially monogamous, territorial pairs. It has been assumed that partnerships are for mating, but the reproductive mode of pairing rabbitfish is currently unconfirmed. Using passive acoustic telemetry to track movements of fishes belonging to one such species (Siganus doliatus), we provide the first evidence that paired adult fish undertake highly synchronized migrations with multiple conspecifics on a monthly cycle. All tagged individuals migrated along the same route in three consecutive months and were absent from home territories for 2-3 days just after the new moon. The timing and directionality of migrations suggest that S. doliatus may form spawning aggregations, offering the potential for exposure to multiple reproductive partners. The finding raises fundamental questions about the basis of pairing, mate choice and partnership longevity in this family.

  15. Potential interactions between diadromous fishes of U.K. conservation importance and the electromagnetic fields and subsea noise from marine renewable energy developments.

    Science.gov (United States)

    Gill, A B; Bartlett, M; Thomsen, F

    2012-07-01

    The considerable extent of construction and operation of marine renewable energy developments (MRED) within U.K. and adjacent waters will lead, among other things, to the emission of electromagnetic fields (EMF) and subsea sounds into the marine environment. Migratory fishes that respond to natural environmental cues, such as the Earth's geomagnetic field or underwater sounds, move through the same waters that the MRED occupy, thereby raising the question of whether there are any effects of MRED on migratory fishes. Diadromous species, such as the Salmonidae and Anguillidae, which undertake large-scale migrations through coastal and offshore waters, are already significantly affected by other human activities leading to national and international conservation efforts to manage any existing threats and to minimize future concerns, including the potential effect of MRED. Here, the current state of knowledge with regard to the potential for diadromous fishes of U.K. conservation importance to be affected by MRED is reviewed. The information on which to base the review was found to be limited with respect to all aspects of these fishes' migratory behaviour and activity, especially with regards to MRED deployment, making it difficult to establish cause and effect relationships. The main findings, however, were that diadromous species can use the Earth's magnetic field for orientation and direction finding during migrations. Juveniles of anadromous brown trout (sea trout) Salmo trutta and close relatives of S. trutta respond to both the Earth's magnetic field and artificial magnetic fields. Current knowledge suggests that EMFs from subsea cables may interact with migrating Anguilla sp. (and possibly other diadromous fishes) if their movement routes take them over the cables, particularly in shallow water (fishes are likely to encounter EMFs from subsea cables either during the adult movement phases of life or their early life stages during migration within shallow

  16. Rearing diet may determine fish restocking success: a case study of hatchery-reared juvenile meagre, Argyrosomus regius

    National Research Council Canada - National Science Library

    Gil, María Del Mar; Palmer, Miquel; Hernández, María Dolores; Grau, Amalia; Durán, Juana; García García, Benjamín; Jover, Miguel; Pastor, Elena

    2015-01-01

    .... In this study, different rearing protocols were compared using meagre juveniles (Argyrosomus regius), which are presently the target of a restocking programme conducted in the Balearic Islands...

  17. Binding and movement of silver in the intestinal epithelium of a marine teleost fish, the European flounder (Platichthys flesus)

    DEFF Research Database (Denmark)

    Hogstrand, C.; Wood, C. M.; Bury, N.R.

    2002-01-01

    The intestine has been indicated as a site of waterborne silver toxicity in marine fish and chronic effects at the intestine have been observed at concentrations far below acutely toxic level. Thus, models of silver toxicity to marine fish need to consider the intestine as a biotic ligand. The pr...

  18. Monitor and Protect Wigwam River Bull Trout for Koocanusa Reservoir; Skookumchuck Creek Juvenile Bull Trout and Fish Habitat Monitoring Program, Annual Report 2002.

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R.

    2003-06-01

    The Skookumchuck Creek juvenile bull trout (Salvelinus confluentus) and fish habitat-monitoring program is a co-operative initiative of the British Columbia Ministry of Water, Land, and Air Protection and Bonneville Power Administration. This project was commissioned in planning for fish habitat protection and forest development within the Skookumchuck Creek watershed and was intended to expand upon similar studies initiated within the Wigwam River from 2000 to 2002. The broad intent is to develop a better understanding of juvenile bull trout and Westslope cutthroat trout recruitment and the ongoing hydrologic and morphologic processes, especially as they relate to spawning and rearing habitat quality. The 2002 project year represents the first year of a long-term bull trout-monitoring program with current studies focused on collecting baseline information. This report provides a summary of results obtained to date. Bull trout represented 72.4% of the catch. Fry dominated the catch because site selection was biased towards electrofishing sample sites which favored high bull trout fry capture success. The mean density of all juvenile bull trout was estimated to be 6.6 fish/100m{sup 2}. This represents one-half the densities reported for the 2002 Wigwam River enumeration program, even though enumeration of bull trout redds was an order of magnitude higher for the Wigwam River. Typically, areas with combined fry and juvenile densities greater than 1.5 fish per 100 m{sup 2} are cited as critical rearing areas. Trends in abundance appeared to be related to proximity to spawning areas, bed material size, and water depth. Cover components utilized by juvenile and adult bull trout and cutthroat trout were interstices, boulder, depth, overhead vegetation and LWD. The range of morphological stream types encompass the stable and resilient spectrum (C3(1), C3 and B3c). The Skookumchuck can be generalized as a slightly entrenched, meandering, riffle-pool, cobble dominated

  19. Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 1, Final Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Poe, Thomas P.; Rieman, Bruce E.

    1988-07-01

    In 1982 the NPPC included in its Fish and Wildlife Program a measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmonids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predation losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator: northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.

  20. Distributions of larval and juvenile/adult stages of the Antarctic myctophid fish, Electrona antarctica, off Wilkes Land in East Antarctica

    Science.gov (United States)

    Moteki, Masato; Fujii, Kentaro; Amakasu, Kazuo; Shimada, Keishi; Tanimura, Atsushi; Odate, Tsuneo

    2017-06-01

    Myctophid fish are an important component of the Southern Ocean food web because of their very high biomass. This study investigated the spatial distributions of larval and juvenile/adult stages of the Antarctic myctophid Electrona antarctica. Fish were sampled in January 2011 and 2012 on a transect along 140°E and in January 2013 along 110°E using two different opening/closing net systems. In total, 1075 specimens of E. antarctica were collected: 948 larvae, 127 juveniles/adults, and 2 in the transformation stage. Most larvae were collected at 5-200 m depth, with diel vertical migration (DVM) not apparent. Larvae were mainly distributed in the Modified Circumpolar Deep Water (-1.5 °C-2.0 °C). By contrast, an analysis of the echogram at 38 kHz and discrete depth samples implied that juveniles/adults undertook DVM except in the continental slope area (65.5°S). As the distribution of krill is limited to the cold water mass (<-1.5 °C) along the continental slope, E. antarctica and krill populations are spatially separated off Wilkes Land during summer. According to the previously estimated larval period of 30-47 days, E. antarctica may spawn in late November to December in the marginal ice zone or near the sea ice edge. This study suggests that the environment related to sea ice provides a nursery ground for early stage larvae of E. antarctica.

  1. Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 2: Supplemental Papers and Data Documentation.

    Energy Technology Data Exchange (ETDEWEB)

    Poe, Thomas P.; Rieman, Bruce E.

    1988-07-01

    In 1982 the NPPC included in its Fish and Wildlife Program measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmoids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predation losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator; northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.

  2. Survival of juvenile chinook salmon and coho salmon in the Roza Dam fish bypass and in downstream reaches of the Yakima River, Washington, 2016

    Science.gov (United States)

    Kock, Tobias J.; Perry, Russell W.; Hansen, Amy C.

    2016-12-22

    Estimates of juvenile salmon survival are important data for fishery managers in the Yakima River Basin. Radiotelemetry studies during 2012–14 showed that tagged juvenile Chinook salmon (Oncorhynchus tshawytscha) that passed through the fish bypass at Roza Dam had lower survival than fish that passed through other routes at the dam. That study also identified flow-survival relationships in the reaches between the Roza Dam tailrace and Sunnyside Dam. During 2012–14, survival also was estimated through reaches downstream of Sunnyside Dam, but generally, sample sizes were low and the estimates were imprecise. In 2016, we conducted an evaluation using acoustic cameras and acoustic telemetry to build on information collected during the previous study. The goal of the 2016 research was to identify areas where mortality occurs in the fish bypass at Roza Dam, and to estimate reach-specific survival in reaches downstream of the dam. The 2016 study included juvenile Chinook salmon and coho salmon (O. kisutch).Three acoustic cameras were used to observe fish behavior (1) near the entrances to the fish bypass, (2) at a midway point in the fish bypass (convergence vault), and (3) at the bypass outfall. In total, 504 hours of acoustic camera footage was collected at these locations. We determined that smolt-sized fish (95–170 millimeters [mm]) were present in the highest proportions at each location, but predator-sized fish (greater than 250 mm) also were present at each site. Fish presence generally peaked during nighttime hours and crepuscular periods, and was low during daytime hours. In the convergence vault, smolt-sized fish exhibited holding behavior patterns, which may explain why some fish delayed while passing through the bypass.Some of the acoustic-tagged fish were delayed in the fish bypass following release, but there was no evidence to suggest that they experienced higher mortality than fish that were released at the bypass outfall or downstream of the dam

  3. Risky business for a juvenile marine predator? Testing the influence of foraging strategies on size and growth rate under natural conditions.

    Science.gov (United States)

    Hussey, Nigel E; DiBattista, Joseph D; Moore, Jonathan W; Ward, Eric J; Fisk, Aaron T; Kessel, Steven; Guttridge, Tristan L; Feldheim, Kevin A; Franks, Bryan R; Gruber, Samuel H; Weideli, Ornella C; Chapman, Demian D

    2017-04-12

    Mechanisms driving selection of body size and growth rate in wild marine vertebrates are poorly understood, thus limiting knowledge of their fitness costs at ecological, physiological and genetic scales. Here, we indirectly tested whether selection for size-related traits of juvenile sharks that inhabit a nursery hosting two dichotomous habitats, protected mangroves (low predation risk) and exposed seagrass beds (high predation risk), is influenced by their foraging behaviour. Juvenile sharks displayed a continuum of foraging strategies between mangrove and seagrass areas, with some individuals preferentially feeding in one habitat over another. Foraging habitat was correlated with growth rate, whereby slower growing, smaller individuals fed predominantly in sheltered mangroves, whereas larger, faster growing animals fed over exposed seagrass. Concomitantly, tracked juveniles undertook variable movement behaviours across both the low and high predation risk habitat. These data provide supporting evidence for the hypothesis that directional selection favouring smaller size and slower growth rate, both heritable traits in this shark population, may be driven by variability in foraging behaviour and predation risk. Such evolutionary pathways may be critical to adaptation within predator-driven marine ecosystems. © 2017 The Author(s).

  4. Robustness of fossil fish teeth for seawater neodymium isotope reconstructions under variable redox conditions in an ancient shallow marine setting

    Science.gov (United States)

    Huck, Claire E.; van de Flierdt, Tina; Jiménez-Espejo, Francisco J.; Bohaty, Steven M.; Röhl, Ursula; Hammond, Samantha J.

    2016-03-01

    Fossil fish teeth from pelagic open ocean settings are considered a robust archive for preserving the neodymium (Nd) isotopic composition of ancient seawater. However, using fossil fish teeth as an archive to reconstruct seawater Nd isotopic compositions in different sedimentary redox environments and in terrigenous-dominated, shallow marine settings is less proven. To address these uncertainties, fish tooth and sediment samples from a middle Eocene section deposited proximal to the East Antarctic margin at Integrated Ocean Drilling Program Site U1356 were analyzed for major and trace element geochemistry, and Nd isotopes. Major and trace element analyses of the sediments reveal changing redox conditions throughout deposition in a shallow marine environment. However, variations in the Nd isotopic composition and rare earth element (REE) patterns of the associated fish teeth do not correspond to redox changes in the sediments. REE patterns in fish teeth at Site U1356 carry a typical mid-REE-enriched signature. However, a consistently positive Ce anomaly marks a deviation from a pure authigenic origin of REEs to the fish tooth. Neodymium isotopic compositions of cleaned and uncleaned fish teeth fall between modern seawater and local sediments and hence could be authigenic in nature, but could also be influenced by sedimentary fluxes. We conclude that the fossil fish tooth Nd isotope proxy is not sensitive to moderate changes in pore water oxygenation. However, combined studies on sediments, pore waters, fish teeth, and seawater are needed to fully understand processes driving the reconstructed signature from shallow marine sections in proximity to continental sources.

  5. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico). WHITE SHRIMP.

    Science.gov (United States)

    1984-09-01

    temperature (15 - 66 mm long) did not fair well in in late spring and summer affect 41-opt salinity in the Laguna Madre , distribution and reduce the size of...distri- Food habits of juvenile marine bution of postlarval brown and white fishes occupying seagrass beds in shrimp near Galveston, Texas , with the...in catches shrimp of the Gulf of Mexico. of juvenile brown and white shrimp Trans. Am. Fish . Soc. 100(3):584- in a Texas estuarine canal. Con- 586

  6. Australia’s protected area network fails to adequately protect the world’s most threatened marine fishes

    Directory of Open Access Journals (Sweden)

    Karen R. Devitt

    2015-01-01

    Full Text Available In order to maintain ecosystems and biodiversity, Australia has long invested in the development of marine and terrestrial protected area networks. Within this land- and sea-scape, northern Australia represents a global population stronghold for four species of the world’s most threatened marine fish family, the sawfishes (family Pristidae. The distribution of sawfishes across northern Australia has previously only been coarsely estimated, and the adequacy of their representation in protected areas has not been evaluated. The calculated range of each species was intersected with Australia’s marine and terrestrial protected area datasets, and targets of 10% marine and 17% inland range protection were used to determine adequacy of sawfish range protection. Marine targets have been achieved for all species, but the inland range protection targets have not been met for any species. Results indicate that further protection of inland habitats is required in order to improve sawfish protection and habitat connectivity.

  7. Interesting new record and further notes on the occurrence of marine fish in Nyamithi Pan, Ndumo Game Reserve, South Africa

    Directory of Open Access Journals (Sweden)

    R. Kyle

    2002-12-01

    Full Text Available Nyamithi Pan, situated in Ndumo Game Reserve, South Africa, is a floodplain pan near the confluence of the Usuthu and Pongolo rivers. It lies approximately 75 km from the Indian Ocean. The floodplain and its fish have been extensively surveyed (Coke & Pott 1970; Kok 1980; Merron et al 1993, 1994, 1994a, 1994b, 1994c, 1994d; Pooley 1975 and there are many records of the occurrence of marine fish in this and other pans of the Pongolo and Usuthu rivers. These are, however, usually isolated instances of individual fish being caught and attracting attention.

  8. Replacement of fish meal by poultry by-product meal, food grade, in diets for juvenile spotted rose snapper (Lutjanus guttatus

    Directory of Open Access Journals (Sweden)

    Crisantema Hernández

    2014-03-01

    Full Text Available The feasibility of replacing fish meal protein at different levels with poultry by product meal food grade (PBM-FG was assessed in diets for spotted rose snapper Lutjanus guttatus. Four diets were formulated, the control diet fish meal was used as the main protein source (FM; the other three diets had increasing levels of PBM-FG replacing 25, 50 or 75% of the fish meal protein respectively. The diets were fed close to apparent satiation, three times a day to quadruplicate groups of juvenile snapper (average body weight 11.0 ± 0.04 g. The fish were randomly distributed into groups of 15 fish in a 120 L seawater tank. The response of snapper to diets containing graded levels of fish meal was evaluated by measuring weight gain, feed efficiency, body composition, hematological parameters and apparent nutrient digestibility during a 12-week period. The replacing of the 25% of fish meal protein by PBM-FG did show a similar trend for feed efficiency and growth performance than control diet. Feed efficiency and growth performance was reduced at 75% level of fish meal protein replacement by PBM-FG, due to deficiencies of lysine and methionine. The final whole-body proximate composition did not differ among treatments. The hematological characteristics were similar among the treatments control, 25 and 50%, but the fish fed PBM-FG 75% showed the lowest levels for total protein and glucose parameters. The dietary dry matter and protein apparent digestibility coefficients (ADCs decreased with increasing dietary PBM-FG. High values for lipid ADCs were observed in all diets.

  9. 福建省主要海湾浮性鱼卵和仔稚鱼的种类组成与丰度分布%Composition of species and distribution of abundance of pelagic fish eggs, larvae and juveniles in main bays of Fujian

    Institute of Scientific and Technical Information of China (English)

    张跃平

    2011-01-01

    根据2007年8月至2009年10月期间在福建省主要海湾的调查资料,对其浮性鱼卵和仔稚鱼的种类组成与数量分布特点进行初步研究和探讨.结果表明,本调查海域共出现鱼卵和仔稚鱼68种,隶属于29科,主要是近海中上层鱼类、浅海底层鱼类和港湾河口型鱼类3个生态类型.各站鱼卵总平均丰度是497.5粒/网,仔稚鱼总平均丰度50.8个/网.优势种明显,占总量比例大;不同季节和不同海湾的种类数相差不大;数量平面分布呈现不同季节不同海湾差别较大,规律性不强,偶然性大等特点.%Many coastal constructing projects in Fujian seriously impact fishery resources in sea bays. Distributions of species and abundances of fish eggs, larvae and juveniles, which are very sensitive to environmental change, are important parameters in assessment of fishery resources; however, there are scant data at present. According to the instructions of The Specification for Marine Monitoring, part 7: Ecological survey of offshore pollution and biological monitoring, 62 stations in the main bays of Fujian were included in the survey of pelagic fish eggs, larvae and juveniles from August 2007 to October 2009. A total of 30 844 fish eggs and 3 150 larvae and juveniles were obtained. Using the survey data, the distributions of species and abundances of pelagic fish eggs, larvae and juveniles are discussed in this paper. The results show 68 species, belonging to 29 families, which can be classified into three eco-types: epipelagic and mesopelagic fish, shallow-water benthic fish, and estuarine fish. The total mean abundance of fish eggs is 497.5 ind/net, and that of larvae and juveniles is 50.8 indt/net. Dominant species account for a large proportion of the total number of individuals. The number of species is similar for different seasons and bays. The abundance distribution differs for different seasons and bays, and is irregular and random. The data can be used to guide

  10. Effect of replacing fish meal with extruded soybean meal on growth, feed utilization and apparent nutrient digestibility of juvenile white shrimp ( Litopenaeus vannamei)

    Science.gov (United States)

    Yang, Qihui; Tan, Beiping; Dong, Xiaohui; Chi, Shuyan; Liu, Hongyu

    2015-10-01

    Extruded soybean meal (ESBM) was evaluated as a protein source for partial replacement of fish meal (FM) in diets of juvenile Litopenaeus vannamei. In the control diet (Diet 1), FM protein was replaced with increasing dietary levels of ESBM (4.28%, 8.40%, 12.62%, 16.82%, and 25.26%) at 10%, 20%, 30%, 40%, and 60% levels (Diets 2 to 6, respectively). An eight-week feeding trial was conducted on 720 juvenile shrimp (0.67 g ± 0.01 g mean initial weight), and nutrient digestibility of the six diets was determined. ESBM could replace 20% of FM without causing a significant reduction in growth of shrimp, but other dietary treatments strongly affected whole body composition. Crude protein content of the whole body fed Diet 6 was significantly lower than that fed Diet 2 ( P vannamei.

  11. An unintended experiment in fisheries science: a marine area protected by war results in Mexican waves in fish numbers-at-age

    OpenAIRE

    Beare, D.J.; Hoelker, F.; Engelhard, G.H.; McKenzie, E; Reid, D. G.

    2010-01-01

    Marine protected areas (MPAs) are attaining increasing importance in the management of marine ecosystems. They are effective for conservation in tropical and subtropical areas (mainly coral and rocky reefs), but it is debated whether they are useful in the management of migratory fish stocks in open temperate regions. World War II created a large marine area within which commercial fishing was prevented for 6 years. Here we analyse scientific trawl data for three important North Sea gadoids, ...

  12. Nitrogen cycling and community structure of proteobacterial ß-subgroup ammonia-oxidizing bacteria within polluted marine fish farm sediments

    NARCIS (Netherlands)

    McCaig, A.E.; Phillips, C.B.; Stephen, J.R.; Kowalchuk, G.A.; Harvey, S.M.; Herbert, R.A.; Embley, T.M.; Prosser, J.I.

    1999-01-01

    A multidisciplinary approach was used to study the effects of pollution from a marine fish farm on nitrification rates and on the community structure of ammonia-oxidizing bacteria in the underlying sediment. Organic content, ammonium concentrations, nitrification rates, and ammonia oxidizer most-pro

  13. 36 CFR 13.1130 - Is commercial fishing authorized in the marine waters of Glacier Bay National Park?

    Science.gov (United States)

    2010-07-01

    ... authorized in the marine waters of Glacier Bay National Park? 13.1130 Section 13.1130 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Glacier Bay National Park and Preserve Commercial Fishing § 13.1130 Is...

  14. Experimental infection of rainbow trout Oncorhynchus mykiss with viral haemorrhagic septicaemia virus isolates from European marine and farmed fishes

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Slierendrecht, W.J.; King, J.A.

    2004-01-01

    The susceptibility of rainbow trout Oncorhynchus mykiss to infection with various isolates of viral haemorrhagic septicaemia virus (VHSV) was examined. A total of 8 experiments with rainbow trout ranging from 0.6 to 6.2 g was conducted for 139 isolates originating from wild marine fishes in Europ......The susceptibility of rainbow trout Oncorhynchus mykiss to infection with various isolates of viral haemorrhagic septicaemia virus (VHSV) was examined. A total of 8 experiments with rainbow trout ranging from 0.6 to 6.2 g was conducted for 139 isolates originating from wild marine fishes...... in European waters (115 isolates), farmed turbot from Scotland and Ireland (2 isolates), and farmed rainbow trout (22 isolates). The isolates were tested by immersion and/or intraperitoneal injection either as pooled or single isolates. The isolates from wild marine fishes did not cause mortality by immersion...... while some of the isolates caused mortality when injected. All VHSV isolates from farmed rainbow trout caused significant mortality by immersion. Currently, pathogenicity trials are the only way to differentiate VHSV isolates from wild marine fishes and farmed rainbow trout. The 2 farmed turbot isolates...

  15. Anthropogenic disturbance on nursery function of estuarine areas for marine species

    Science.gov (United States)

    Courrat, A.; Lobry, J.; Nicolas, D.; Laffargue, P.; Amara, R.; Lepage, M.; Girardin, M.; Le Pape, O.

    2009-01-01

    Estuaries serve as nursery grounds for many marine fish species. However increasing human activities within estuaries and surrounding areas lead to significant habitat loss for the juveniles and decrease the quality of the remaining habitats. This study is based on the data of 470 beam trawls from surveys that were conducted in 13 French estuaries for the purpose of the European Water Framework Directive. It aimed at testing the effects of anthropogenic disturbances on the nursery function of estuaries. With a multispecific approach based on ecological guilds, two fish metrics, abundance and species richness of Marine Juvenile migrant fishes, were used as proxies for the estuarine nursery function. Indices of heavy metal and organic contaminations were used to estimate anthropogenic disturbances impacting these estuaries. Fish metrics were described with statistical models that took into account: (a) sampling protocol, (b) estuarine features and (c) contamination. The results of these models showed that the fish metrics highly depend on the sampling protocol, and especially type of gear, depth and salinity, which highlights the necessity of considering such metrics at the sampling (trawl haul) scale. Densities and species richness of Marine Juvenile fishes appeared to be strongly and negatively correlated to contamination indices. These results are consistent with the hypothesis that human disturbances impact the nursery function of estuaries. Finally, the densities of Marine Juvenile migrant species appeared as a potential robust and useful fish indicator for the assessment of the ecological status of estuaries within the Water Framework Directive.

  16. The impact of United States recreational fisheries on marine fish populations.

    Science.gov (United States)

    Coleman, Felicia C; Figueira, Will F; Ueland, Jeffrey S; Crowder, Larry B

    2004-09-24

    We evaluated the commercial and recreational fishery landings over the past 22 years, first at the national level, then for populations of concern (those that are overfished or experiencing overfishing), and finally by region. Recreational landings in 2002 account for 4% of total marine fish landed in the United States. With large industrial fisheries excluded (e.g., menhaden and pollock), the recreational component rises to 10%. Among populations of concern, recreational landings in 2002 account for 23% of the total nationwide, rising to 38% in the South Atlantic and 64% in the Gulf of Mexico. Moreover, it affects many of the most-valued overfished species-including red drum, bocaccio, and red snapper-all of which are taken primarily in the recreational fishery.

  17. Phase heterogeneity in carbonate production by marine fish influences their roles in sediment generation and the inorganic carbon cycle.

    Science.gov (United States)

    Salter, Michael A; Harborne, Alastair R; Perry, Chris T; Wilson, Rod W

    2017-04-10

    Marine teleost fish are important carbonate producers in neritic and oceanic settings. However, the fates of the diverse carbonate phases (i.e., mineral and amorphous forms of CaCO3) they produce, and their roles in sediment production and marine inorganic carbon cycling, remain poorly understood. Here we quantify the carbonate phases produced by 22 Bahamian fish species and integrate these data with regional fish biomass data from The Bahamas to generate a novel platform-scale production model that resolves these phases. Overall carbonate phase proportions, ordered by decreasing phase stability, are: ~20% calcite, ~6% aragonite, ~60% high-Mg calcite, and ~14% amorphous carbonate. We predict that these phases undergo differing fates, with at least ~14% (amorphous carbonate) likely dissolving rapidly. Results further indicate that fisheries exploitation in The Bahamas has potentially reduced fish carbonate production by up to 58% in certain habitats, whilst also driving a deviation from natural phase proportions. These findings have evident implications for understanding sedimentary processes in shallow warm-water carbonate provinces. We further speculate that marked phase heterogeneity may be a hitherto unrecognised feature of fish carbonates across a wide range of neritic and oceanic settings, with potentially major implications for understanding their role in global marine inorganic carbon cycling.

  18. Concentrations of heavy metals in marine wild fishes captured from the southern sea of Korea and associated health risk assessments

    Science.gov (United States)

    Hwang, Dong-Woon; Kim, Seong-Soo; Kim, Seong-Gil; Kim, Dong-Sun; Kim, Tae-Hoon

    2017-07-01

    Concentrations of heavy metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) were determined in edible parts (muscle) of 34 marine wild fish caught from the southern sea of Korea in 2007 and 2008 in order to understand the accumulation pattern of heavy metals in wild fish and to assess the potential health risk posed by fish consumption. The highest concentrations in the muscle of 17 pelagic and 17 demersal fishes were Zn and As, respectively, while the lowest concentration in both fishes was Cd. The mean concentrations of all metals except As in wild fish were much lower than the regulatory limits for fish and fishery products applied in a number of countries. Unlike other metals, As concentration in wild fish of this study region was relatively higher than that found in other country. Estimated daily intake (EDI) of the metals was in the range of 0.05% to 22.5% of the provisional maximum tolerable daily intakes (PMTDI). Similarly, the target hazard quotient (THQ) was below 1.0 for each metal. These results imply that the consumption of the investigated wild fish do not cause significant adverse health effects.

  19. Experiments for possible hydroacoustic discrimination of free-swimming juvenile gadoid fish by analysis of broadband pulse spectra as well as 3D fish position form video images and split beam acoustics

    DEFF Research Database (Denmark)

    Lundgren, Bo; Nielsen, J. Rasmus

    2002-01-01

    Measurements were made of the broad-bandwidth (80–220 kHz) acoustic backscattering from free-swimming juvenile gadoids at various orientations and positions in an acoustic beam, under controlled conditions. The experimental apparatus consisted of a stereo-video camera system, a broad......-bandwidth echosounder and echo-processor system, a narrowband 120 kHz split-beam echosounder, a large tank, and a fishnet cage. The net cage was centred on the acoustic beams and was virtually transparent, both acoustically and optically. Accurate three-dimensional positions and angular orientations of individual fish......, alignment of acoustic and optical-reference frames, and automatic position-fitting of fish models to manually marked fix-points on fish images. The software also performs Fourier spectrum analysis and pulse-shape analysis of broad-bandwidth echoes. Therefore, several measurement series on free...

  20. Effects of partial replacement of fish meal by yeast hydrolysate on complement system and stress resistance in juvenile Jian carp (Cyprinus carpio var. Jian).

    Science.gov (United States)

    Yuan, Xiang-Yang; Liu, Wen-Bin; Liang, Chao; Sun, Cun-Xin; Xue, Yun-Fei; Wan, Zu-De; Jiang, Guang-Zhen

    2017-08-01

    A 10-week feeding trial was carried out to investigate the effects of dietary fish meal replacement by yeast hydrolysate (YH) on growth performance, complement system and stress resistance of juvenile Jian carp (Cyprinus carpio var. Jian) (initial average weight 19.44 ± 0.06 g). In the study, there were five groups: one control group was fed with a basal diet (YH0), and four treatment groups were fed with dietary fish meal replaced by 1% YH (YH1), 3% (YH3), 5% (YH5) and 7% (YH7), respectively. Each group had four replicates. At the end of feeding trial, twelve fish from each group (three fish per replicate) were randomly selected for assessing the growth and immunity. Meanwhile, 20 fish per replicate were injected by Aeromonas hydrophila. The results showed that (1) Replacement levels of YH significantly affected the growth of the fish with the highest values of weight gain (WG) occurred in fish fed YH3 diet. However, no significant difference in feed conversion ratios (FCR) was observed among all groups. (2) Pre-stressed plasma lysozyme activity, total protein and albumin contents and complement component 3 (C3) and complement component 4 (C4) levels of fish fed YH3 diet were significantly higher than those of fish fed YH0 diet. However, post-stressed immune parameters of fish in all groups were significantly lower. (3) There was a trend that the expression levels of the complement-related genes (c1r/s-A, c4-1, c3-H1, c5-1, fb/c2-A, mbl-2 and masp) initially increased and then decreased except mbl-2 and masp, with the maximum values observed in fish fed YH3 diet. Before stress, the expression levels of the inflammation-related genes (alp, il-1β and tnf-α) in the hepatopancreas and spleen of fish fed YH1 diet and YH7 diet were significant higher than that of fish fed YH0 diet. After stress, no significant difference in the expression levels of those genes was observed among all groups. These results indicated that FM replacement by YH could improve growth

  1. Development of a gene transfer system for curing of plasmids in the marine fish pathogen Vibrio salmonicida.

    Science.gov (United States)

    Valla, S; Frydenlund, K; Coucheron, D H; Haugan, K; Johansen, B; Jørgensen, T; Knudsen, G; Strøm, A

    1992-01-01

    All reported natural isolates of the marine fish pathogen Vibrio salmonicida contain plasmids, and in another marine fish pathogen, Vibrio anguillarum, it has been shown that a plasmid is important for expression of virulence by the organism. To study the function of the plasmids in V. salmonicida, we developed a gene transfer system based on the plasmid RSF1010 replicon. The gene transfer system was used to construct a plasmid-free strain, and this strain was found to behave similarly to the wild type in a fish pathogenicity test based on intraperitoneal injection of the bacteria. We were unable to detect any other phenotypic differences between the two strains. It could therefore be concluded that at least in the V. salmonicida strain tested, extrachromosomal DNA is not required for expression of virulence. Images PMID:1622274

  2. Strategies to increase the hygienic and economic value of fresh fish: Biopreservation using lactic acid bacteria of marine origin.

    Science.gov (United States)

    Gómez-Sala, Beatriz; Herranz, Carmen; Díaz-Freitas, Belén; Hernández, Pablo E; Sala, Ana; Cintas, Luis M

    2016-04-16

    In this work we describe the development of a biopreservation strategy for fresh fish based on the use of bacteriocinogenic LAB of marine origin. For this purpose, two multibacteriocinogenic LAB strains, Lactobacillus curvatus BCS35 and Enterococcus faecium BNM58, previously isolated from fish and fish products were selected owing to their capability to inhibit the growth of several fish-spoilage and food-borne pathogenic bacteria. Two commercially important fish species were chosen, young hake (Merluccius merluccius) and megrim (Lepidorhombus boscii), and the specimens were acquired at the Marín (Pontevedra, Spain) retail fish market, after one night in the chilled hold of a near-shore fishing vessel. The biopreservation potential and the application strategies of these two LAB strains were first tested at a laboratory scale, where several batches of fresh fish were inoculated with: (i) the multibacteriocinogenic LAB culture(s) as protective culture(s); and/or (ii) their cell-free culture supernatant(s) as food ingredient(s), and (iii) the lyophilized bacteriocin preparation(s) as lyophilized food ingredient(s). All batches were stored in polystyrene boxes, permanently filled with ice at 0-2 °C, for 14 days. Microbiological analyses, as well as sensorial analyses, were carried out during the biopreservation trials. Subsequently, Lb. curvatus BCS35 was selected to up-scale the trials, and combinations of the three application methods were assayed. For this purpose, this strain was grown in a semi-industrial scale fermentor (150l) in modified MRS broth, and three batches of fresh fish were inoculated with the protective culture and/or food ingredient, and stored on ice in a chilled chamber at 0-2 °C at the Marín retail fish market for 14 days. Microbiological analyses were carried out during the storage period, showing that when Lb. curvatus BCS35 culture or the corresponding cell-free culture supernatant was used as protective culture or food ingredient

  3. Effects of various feed supplements containing fish protein hydrolysate or fish processing by-products on the innate immune functions of juvenile coho salmon (oncorhynchus kisutch)

    Science.gov (United States)

    Murray, A.L.; Pascho, R.J.; Alcorn, S.W.; Fairgrieve, W.T.; Shearer, K.D.; Roley, D.

    2003-01-01

    Immunomodulators administered to fish in the diet have been shown in some cases to enhance innate immune defense mechanisms. Recent studies have suggested that polypeptide fractions found in fish protein hydrolysates may stimulate factors in fish important for disease resistance. For the current study, groups of coho salmon were reared on practical feeds that contained either fish meal (Control diet), fish meal supplemented with cooked fish by-products, or fish meal supplemented with hydrolyzed fish protein alone, or with hydrolyzed fish protein and processed fish bones. For each diet group, three replicate tanks of fish were fed the experimental diets for 6 weeks. Morphometric measurements, and serologic and cellular assays were used to evaluate the general health and immunocompetence of fish in the various feed groups. Whereas the experimental diets had no effect on the morphometric and cellular measurements, fish fed cooked by-products had increased leucocrit levels and lower hematocrit levels than fish from the other feed groups. Innate cellular responses were increased in all feed groups after feeding the four experimental diets compared with pre-feed results. Subgroups of fish from each diet group were also challenged with Vibrio anguillarum (ca. 7.71 ?? 105 bacteria ml-1) at 15??C by immersion. No differences were found in survival among the various feed groups.

  4. Polychlorinated terphenyl patterns and levels in selected marine mammals and a river fish from different continents.

    Science.gov (United States)

    Rosenfelder, Natalie; Vetter, Walter

    2014-01-01

    Polychlorinated terphenyls (PCTs) are a class of persistent organic pollutants which have been used from the 1920s to the 1980s for similar purposes as polychlorinated biphenyls (PCBs). Comparably little data was available on the PCT distribution in the environment mainly due to analytical difficulties in their determination. By means of a calculation algorithm recently developed we now studied the PCT pattern in individual marine mammal samples and one fish sample from different continents. Altogether, 97 PCTs were detected in eight samples and twelve to 66 tetra- to nonachloroterphenyl (tetra- to nonaCT) congeners were detected in individual samples. PCTs were present in all marine mammal samples which originated from four continents, but the PCT pattern was varied. TetraCTs were dominant in the sample from Africa, Australia, Spitsbergen (European Arctic) and in a sample from the Baltic Sea, heptaCTs in samples from the North Sea and octaCTs in a sample from Iceland. The abundance of sumPCTs relative to PCB 153, estimated from the GC/ECNI-MS response corrected for the degree of chlorination, ranged from 0.9 to 8.8%, corresponding with ~0.22-2.2% of the total PCB content. The highest PCT level detected was 980 mg/kg lipid in a harbour seal from the North Sea, Germany. The results from this study indicated that samples from certain areas, e.g. the North Sea may still be polluted with PCTs.

  5. New records of parasitic copepods (Crustacea, Copepoda) from marine fishes in the Argentinean Sea.

    Science.gov (United States)

    Paula, Cantatore Delfina María; Elizabeth, Braicovich Paola; Julia, Alarcos Ana; Laura, Lanfranchi Ana; Alejandra, Rossin María; Gustavo, Vales Damián; Tomás, Timi Juan

    2012-03-01

    Increasing knowledge of the biodiversity of parasitic copepods in the Argentinean Sea will provide a baseline against which changes in the distribution of marine biota can be detected. We provide new information on the distribution of 13 known species of parasitic copepods gathered from 11 species of marine fishes from Argentinean Sea, including 7 new host records and 9 new locality records. These species are: Bomolochus globiceps (Vervoort et Ramírez, 1968) and Nothobomolochus cresseyi Timi et Sardella, 1997 (Bomolochidae Sumpf, 1871); Brasilochondria riograndensis Thatcher et Pereira, 2004 (Chondracanthidae Milne Edwards, 1840); Taeniacanthus lagocephali Pearse, 1952 (Taeniacanthidae Wilson, 1911); Caligus rogercresseyi Boxshall et Bravo, 2000 and Metacaligus uruguayensis (Thomsen, 1949) (Caligidae Burmeister, 1835); Hatschekia conifera Yamaguti, 1939 (Hatschekiidae Kabata, 1979); Clavellotis pagri (Krøyer, 1863), Clavella adunca (Strøm, 1762), Clavella bowmani Kabata, 1963 and Parabrachiella amphipacifica Ho, 1982 (Lernaeopodidae Milne Edwards, 1840), and Lernanthropus leidyi Wilson, 1922 and Lernanthropus caudatus Wilson, 1922 (Lernanthropidae Kabata, 1979). A list of host species lacking parasitic copepods, for which large samples were investigated by the authors, is also provided in order to compare in future surveys.

  6. CHARACTERIZATION OF LACTATE DEHYDROGENASE ISOZYME PATTERN AND MORPHOLOGY OF THREE MARINE FISH CELL LINES

    Institute of Scientific and Technical Information of China (English)

    郭华荣; 张士璀; 李红岩; 童裳亮; 相建海

    2002-01-01

    Three continuous marine fish cell lines of FG (i. e., Hounder Gill) from flounder (Paralichthys olivaceus) gill, SPH (i. e. , Sea Perch Heart) from sea perch (Lateolabrax japonicus) heart and RSBF (i.e., Red Sea Bream Fin) from red sea bream (Pagrosomus major) fin, were characterized by lactate dehydrogenase (LDH) isozyme and morphological analysis. The LDH isozyme patterns of these three cell lines and their corresponding tissues of origin were investigated and compared. The results showed: (1) No difference was found in the LDH isozyme patterns of FG and flounder gill tissue. However, the LDH isozyme patterns of SPH and RSBF were significantly different from their corresponding tissues of origin; (2) LDH isozyme patterns of FG, SPH and RSBF were markedly different from each other and could serve as genetic markers for species identification and detection of cross contamination. Morphological change analysis of these three cell lines in comparison to their original tissues indicated that FG cells still appeared epithelioid without morphological transformation. However, morphological changes were found in SPH and RSBF compared to their original tissues. Therefore, the cellular morphology was still plastic in the relatively stable culture conditions, and it was possible that change of LDH patterns wasrelated to morphological changes of fish cells in vitro.

  7. Elevated CO2 increases energetic cost and ion movement in the marine fish intestine

    Science.gov (United States)

    Heuer, Rachael M.; Grosell, Martin

    2016-01-01

    Energetic costs associated with ion and acid-base regulation in response to ocean acidification have been predicted to decrease the energy available to fish for basic life processes. However, the low cost of ion regulation (6–15% of standard metabolic rate) and inherent variation associated with whole-animal metabolic rate measurements have made it difficult to consistently demonstrate such a cost. Here we aimed to gain resolution in assessing the energetic demand associated with acid-base regulation by examining ion movement and O2 consumption rates of isolated intestinal tissue from Gulf toadfish acclimated to control or 1900 μatm CO2 (projected for year 2300). The active marine fish intestine absorbs ions from ingested seawater in exchange for HCO3− to maintain water balance. We demonstrate that CO2 exposure causes a 13% increase of intestinal HCO3− secretion that the animal does not appear to regulate. Isolated tissue from CO2-exposed toadfish also exhibited an 8% higher O2 consumption rate than tissue from controls. These findings show that compensation for CO2 leads to a seemingly maladaptive persistent base (HCO3−) loss that incurs an energetic expense at the tissue level. Sustained increases to baseline metabolic rate could lead to energetic reallocations away from other life processes at the whole-animal level. PMID:27682149

  8. CHARACTERIZATION OF LACTATE DEHYDROGENASE ISOZYME PATTERN AND MORPHOLOGY OF THREE MARINE FISH CELL LINES

    Institute of Scientific and Technical Information of China (English)

    郭华荣; 张士璀; 李红岩; 童裳亮; 相建海

    2002-01-01

    Three continuous marine fish cell lines of FG (i.e. , Flounder Gill) from flounder (Paralichthys olivaceus) gill, SPH (i.e., Sea Perch Heart) fro m sea perch (Lateolabrax japonicus) heart and RSBF (i.e., Red Sea Bream Fin) from red se a bream (Pagrosomus major) fin, were characterized by lactate dehydrogenase (LDH) is ozyme and morphological analysis. The LDH isozyme patterns of these three cell lines and their corresponding tissues of origin were investigated and compared. The results sho wed: (1) No difference was found in the LDH isozyme patterns of FG and flounder gill tissue. However, the LDH isozyme patterns of SPH and RSBF were significantly different from their cor responding tissues of origin; (2) LDH isozyme patterns of FG, SPH and RSBF were markedly di fferent from each other and could serve as genetic markers for species identification and de tection of cross contamination. Morphological change analysis of these three cell lines in compa rison to their original tissues indicated that FG cells still appeared epithelioid without mor phological transformation. However, morphological changes were found in SPH and RSBF compa red to their original tissues. Therefore, the cellular morphology was still plastic in the relatively stable culture conditions, and it was possible that change of LDH patterns was related to morphological changes of fish cells in vitro.

  9. Evidence and population consequences of shared larval dispersal histories in a marine fish.

    Science.gov (United States)

    Shima, Jeffrey S; Swearer, Stephen E

    2016-01-01

    Larval dispersal is disproportionately important for marine population ecolgy and evolution, yet our inability to track individuals severely constrains our understanding of this key process. We analyze otoliths of a small reef fish, the common triplefin (Forsterygion lapillum), to reconstruct individual dispersal histories and address the following questions: (1) How many discrete sets of dispersal histories (dispersal cohorts) contribute to replenishment of focal populations; (2) When do dispersal cohorts converge (a metric of shared dispersal histories among cohorts); and (3) Do these patterns predict spatiotemporal variation in larval supply? We used light traps to quantify larval supply, and otolith microstructure and microchemistry (using laser ablation inductively coupled plasma mass spectrometry; LA-ICP-MS) to reconstruct daily environmental histories of individuals in their 30-d lead-up to settlement. Our results indicate that a variable number of dispersal cohorts replenish focal populations (range of 2-8, mean of 4.3, standard deviation of 2.8). Convergence times varied (from 0 to > 30 d prior to settlement), and larval supply was negatively correlated with cohort evenness but not with the number of cohorts, or when they converged, indicating disproportionately large contributions from some cohorts (i.e., sweepstakes events). Collectively, our results suggest that larval reef fishes may variably disperse in shoals, to drive local replenishment and connectivity within a metapopulation.

  10. Recovery Trends of Commercial Fish: The Case of an Underperforming Mediterranean Marine Protected Area

    Science.gov (United States)

    Marra, Stefano; Coppa, Stefania; Camedda, Andrea; Mazzoldi, Carlotta; Wrachien, Francesco; Massaro, Giorgio; de Lucia, G. Andrea

    2016-01-01

    Temporal trends in the recovery of exploited species in marine protected areas (MPAs) are useful for a proper assessment of the efficacy of protection measures. The effects of protection on the fish assemblages of the sublittoral rocky reefs in the “Penisola del Sinis-Isola di Mal di Ventre” MPA (W. Sardinia, Italy) were evaluated using a multi-year series of data. Four surveys, conducted 7, 10, 13 and 15 years after the area was designated as an MPA and carried out in the period spanning June and July, were used to estimate the abundance and biomass of commercial species. The surveys were carried out in zones with decreasing levels of fishing restrictions within the MPA (zones A, B, C) and in unprotected zones (OUT1 and OUT2), and underwater video visual census techniques were used. Protected zones only occasionally showed higher levels of abundance or biomass, and the trajectories of those metrics were not consistent across the years. In addition, the zone with the highest level of protection (zone A) never presented levels of abundance and biomass higher than those in zones B and C. This study shows that even 15 years after designation, protection has had no appreciable effect in the MPA studied. It is argued that this is emblematic of several shortcomings in the planning, regulation and enforcement frameworks of the MPA. PMID:26741959

  11. Elevated CO2 increases energetic cost and ion movement in the marine fish intestine.

    Science.gov (United States)

    Heuer, Rachael M; Grosell, Martin

    2016-09-29

    Energetic costs associated with ion and acid-base regulation in response to ocean acidification have been predicted to decrease the energy available to fish for basic life processes. However, the low cost of ion regulation (6-15% of standard metabolic rate) and inherent variation associated with whole-animal metabolic rate measurements have made it difficult to consistently demonstrate such a cost. Here we aimed to gain resolution in assessing the energetic demand associated with acid-base regulation by examining ion movement and O2 consumption rates of isolated intestinal tissue from Gulf toadfish acclimated to control or 1900 μatm CO2 (projected for year 2300). The active marine fish intestine absorbs ions from ingested seawater in exchange for HCO3(-) to maintain water balance. We demonstrate that CO2 exposure causes a 13% increase of intestinal HCO3(-) secretion that the animal does not appear to regulate. Isolated tissue from CO2-exposed toadfish also exhibited an 8% higher O2 consumption rate than tissue from controls. These findings show that compensation for CO2 leads to a seemingly maladaptive persistent base (HCO3(-)) loss that incurs an energetic expense at the tissue level. Sustained increases to baseline metabolic rate could lead to energetic reallocations away from other life processes at the whole-animal level.

  12. Social learning and acquired recognition of a predator by a marine fish.

    Science.gov (United States)

    Manassa, R P; McCormick, M I

    2012-07-01

    Predation is known to influence the distribution of behavioural traits among prey individuals, populations and communities over both evolutionary and ecological time scales. Prey have evolved mechanisms of rapidly learning the identity of predators. Chemical cues are often used by prey to assess predation risk especially in aquatic systems where visual cues are unreliable. Social learning is a method of threat assessment common among a variety of freshwater fish taxa, which incorporates chemosensory information. Learning predator identities through social learning is beneficial to naïve individuals as it eliminates the need for direct interaction with a potential threat. Although social learning is widespread throughout the animal kingdom, no research on the use of this mechanism exists for marine species. In this study, we examined the role of social learning in predator recognition for a tropical damselfish, Acanthochromis polyacanthus. This species was found to not only possess and respond to conspecific chemical alarm cues, but naïve individuals were able to learn a predators' identity from experienced individuals, the process of social learning. Fish that learned to associate risk with the olfactory cue of a predator responded with the same intensity as conspecifics that were exposed to a chemical alarm cue from a conspecific skin extract.

  13. Using environmental DNA to census marine fishes in a large mesocosm.

    Directory of Open Access Journals (Sweden)

    Ryan P Kelly

    Full Text Available The ocean is a soup of its resident species' genetic material, cast off in the forms of metabolic waste, shed skin cells, or damaged tissue. Sampling this environmental DNA (eDNA is a potentially powerful means of assessing whole biological communities, a significant advance over the manual methods of environmental sampling that have historically dominated marine ecology and related fields. Here, we estimate the vertebrate fauna in a 4.5-million-liter mesocosm aquarium tank at the Monterey Bay Aquarium of known species composition by sequencing the eDNA from its constituent seawater. We find that it is generally possible to detect mitochondrial DNA of bony fishes sufficient to identify organisms to taxonomic family- or genus-level using a 106 bp fragment of the 12S ribosomal gene. Within bony fishes, we observe a low false-negative detection rate, although we did not detect the cartilaginous fishes or sea turtles present with this fragment. We find that the rank abundance of recovered eDNA sequences correlates with the abundance of corresponding species' biomass in the mesocosm, but the data in hand do not allow us to develop a quantitative relationship between biomass and eDNA abundance. Finally, we find a low false-positive rate for detection of exogenous eDNA, and we were able to diagnose non-native species' tissue in the food used to maintain the mesocosm, underscoring the sensitivity of eDNA as a technique for community-level ecological surveys. We conclude that eDNA has substantial potential to become a core tool for environmental monitoring, but that a variety of challenges remain before reliable quantitative assessments of ecological communities in the field become possible.

  14. Shared Physiological and Molecular Responses in Marine Fish and Invertebrates to Environmental Hypoxia: Potential Biomarkers of Adverse Impacts on Marine Communities

    Science.gov (United States)

    Thomas, P.; Rahman, S.

    2016-02-01

    Knowledge of the effects of environmental exposure to hypoxia (dissolved oxygen: invertebrates is essential for accurate predictions of its chronic impacts on marine communities. Marked disruption of reproduction and its endocrine control was observed in Atlantic croaker collected from the hypoxic region in the northern Gulf of Mexico. Recent research has shown that growth and its physiological upregulation is also impaired in hypoxia-exposed marine fish. Expression of insulin-like growth factor (IGF) binding protein (IGFBP), which inhibits growth, was increased in croaker livers, whereas plasma levels of IGF, the primary regulator of growth, were decreased in snapper after hypoxia exposure. In addition, hypoxia inducible factor-1 (HIF-1), which regulates changes in metabolism during adaptation to hypoxia, was upregulated in croaker collected from hypoxic environments. Interestingly, similar changes in the expression of IGFBP and HIF-1 have been found in marine crustaceans after hypoxia exposure, suggesting these responses to hypoxia are common to marine fish and invertebrates. Preliminary field studies indicate that hypoxia exposure also causes epigenetic modifications, including increases in global DNA methylation, and that these epigenetic changes can influence reproduction and growth in croaker. Epigenetic modifications can be passed to offspring and persist in future generations no longer exposed to an environmental stressor further aggravating its long-term adverse impacts on population abundance and delaying recovery. The growing availability of complete invertebrate genomes and high-throughput DNA sequencing indicates similar epigenetic studies can now be conducted with marine invertebrates. Collectively, the results indicate that environmental hypoxia exposure disrupts major physiological functions in fish and invertebrates critical for maintenance of their populations.

  15. Absonifibula estuarina sp. n. (Monogenea: Diclidophoridae parasite of juvenile Cynoscion guatucupa (Osteichthyes from southwestern Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Cláudia Portes Santos

    2009-11-01

    Full Text Available Absonifibula estuarina sp. n. (Diclidophoridae, Absonifibulinae, is described from the gills of juvenile striped weakfish, Cynoscion guatucupa (Cuvier, from the southwestern Atlantic, Argentinean coast. This marine fish migrates to estuarine areas to spawn where exclusively juveniles are found parasitized; adult fish in marine water were never found to be parasitized by this monogenean. A. estuarina sp. n. is characterized mainly by the pedunculate clamps dissimilar in size, the shape of anterior jaw with sclerite 'a' attached to a sub-trapezoidal lamellate extension and fused to sclerites 'c' and 'd'. It differs from Absonifibula bychowskyi Lawler & Overstreet, 1976, the only known species of the genus, in the shape and arrangement of the genital corona, which is armed with six similar hooks disposed in circle and the sub-trapezoidal shape of lamellate extension ('b'. The restriction to juvenile sciaenids is a shared feature among the Absonifibulinae indicating an estuary-dependent life cycle.

  16. Fish Rejections in the Marine Aquarium Trade: An Initial Case Study Raises Concern for Village-Based Fisheries.

    Science.gov (United States)

    Militz, Thane A; Kinch, Jeff; Foale, Simon; Southgate, Paul C

    2016-01-01

    A major difficulty in managing wildlife trade is the reliance on trade data (rather than capture data) to monitor exploitation of wild populations. Collected organisms that die or are rejected before a point of sale often go unreported. For the global marine aquarium trade, identifying the loss of collected fish from rejection, prior to export, is a first step in assessing true collection levels. This study takes a detailed look at fish rejections by buyers before export using the Papua New Guinea marine aquarium fishery as a case study. Utilizing collection invoices detailing the species and quantity of fish (Actinopteri and Elasmobranchii) accepted or rejected by the exporting company it was determined that, over a six month period, 24.2% of the total fish catch reported (n = 13,886) was rejected. Of the ten most collected fish families, rejection frequency was highest for the Apogonidae (54.2%), Chaetodontidae (26.3%), and Acanthuridae (18.2%) and lowest for Labridae (6.6%) and Hemiscylliidae (0.7%). The most frequently cited reasons for rejection were fin damage (45.6% of cases), undersized fish (21.8%), and fish deemed too thin (11.1%). Despite fishers receiving feedback on invoices explaining rejections, there was no improvement in rejection frequencies over time (r = -0.33, P = 0.15) with weekly rejection frequencies being highly inconsistent (range: 2.8% to 79.4%; s = 16.3%). These findings suggest that expor