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Sample records for bluefin tuna catch

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

    PubMed

    Teo, Steven L H; Block, Barbara A

    2010-05-28

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

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  4. 76 FR 15276 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Quotas and Atlantic Tuna Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ... bluefin tuna (BFT) base quotas for all domestic fishing categories; establish BFT quota specifications for the 2011 fishing year; reinstate pelagic longline target catch requirements for retaining BFT in the...

  5. Changes in the Distribution of Atlantic Bluefin Tuna (Thunnus thynnus) in the Gulf of Maine 1979-2005

    PubMed Central

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

    2013-01-01

    The Gulf of Maine, NW Atlantic Ocean, is a productive, seasonal foraging ground for Atlantic bluefin tuna (Thunnus thynnus), but commercial landings of adult size classes were up to 40% below the allocated total allowable catch between 2004 to 2008 for the rod and reel, harpoon, and purse seine categories in the Gulf of Maine. Reduction in Atlantic bluefin tuna catches in the Gulf of Maine could represent a decline in spawning stock biomass, but given wide-ranging, complex migration patterns, and high energetic requirements, an alternative hypothesis is that their dispersal patterns shifted to regions with higher prey abundance or profitability, reducing availability to U.S. fishing fleets. This study fit generalized linear models to Atlantic bluefin tuna landings data collected from fishermen’s logbooks (1979-2005) as well as the distances between bluefin tuna schools and Atlantic herring (Clupeaharengus), a primary prey species, to test alternative hypotheses for observed shifts in Atlantic bluefin tuna availability in the Gulf of Maine. For the bluefin model, landings varied by day of year, latitude and longitude. The effect of latitude differed by day of year and the effect of longitude differed by year. The distances between Atlantic bluefin tuna schools and Atlantic herring schools were significantly smaller (p<0.05) than would be expected from a randomly distributed population. A time series of average bluefin tuna school positions was positively correlated with the average number of herring captured per tow on Georges Bank in spring and autumn surveys respectively (p<0.01, r2=0.24, p<0.01, r2=0.42). Fishermen’s logbooks contributed novel spatial and temporal information towards testing these hypotheses for the bluefin tuna fishery. PMID:24069420

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

    PubMed

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

    2013-01-01

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

  7. Sexual maturity in western Atlantic bluefin tuna

    PubMed Central

    Heinisch, Gilad; Rosenfeld, Hanna; Knapp, Jessica M.; Gordin, Hillel; Lutcavage, Molly E.

    2014-01-01

    We introduce a novel endocrine approach for assessing the unresolved matter of the timing of sexual maturation in western Atlantic bluefin tuna (ABFT), a highly migratory population whose status remains uncertain. Ratios of follicle stimulating hormone to luteinizing hormone, a sexual maturity indicator, in all ABFT ≥134 cm curved fork length (CFL) were <0.4, similar to Mediterranean spawners, indicating that western ABFT mature at considerably smaller sizes and at a much younger age than currently assumed (≥185 cm CFL). PMID:25431301

  8. 76 FR 38620 - International Fisheries; Atlantic Highly Migratory Species; Bluefin Tuna Import, Export, Re-Export

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... for Atlantic bluefin tuna fishing in the Mediterranean. NMFS advises importers to take great care with... seine vessels fishing for eastern Atlantic and Mediterranean bluefin tuna carry an ICCAT-assigned...

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

    PubMed

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

    2017-03-31

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

  10. 78 FR 36685 - Atlantic Highly Migratory Species; 2013 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... Species; 2013 Atlantic Bluefin Tuna Quota Specifications AGENCY: National Marine Fisheries Service (NMFS...: NMFS establishes 2013 quota specifications for the Atlantic bluefin tuna (BFT) fishery and closes the... Commission for the Conservation of Atlantic Tunas (ICCAT), as required by the Atlantic Tunas Convention...

  11. 75 FR 30730 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... retention limit adjustment. SUMMARY: NMFS has determined that the Atlantic tunas General category daily Atlantic bluefin tuna (BFT) retention limit should be adjusted for the June through August 2010 time...

  12. 76 FR 32086 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... retention limit adjustment. SUMMARY: NMFS has determined that the Atlantic tunas General category daily Atlantic bluefin tuna (BFT) retention limit should be adjusted for the June through August 2011 time...

  13. 76 FR 52886 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-24

    ... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... retention limit adjustment. SUMMARY: NMFS has determined that the Atlantic tunas General category daily Atlantic bluefin tuna (BFT) retention limit should be adjusted from one to three large medium or giant...

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

    PubMed

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

    2015-11-01

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

  15. A Full Lifecycle Bioenergetic Model for Bluefin Tuna

    PubMed Central

    Jusup, Marko; Klanjscek, Tin; Matsuda, Hiroyuki; Kooijman, S. A. L. M.

    2011-01-01

    We formulated a full lifecycle bioenergetic model for bluefin tuna relying on the principles of Dynamic Energy Budget theory. Traditional bioenergetic models in fish research deduce energy input and utilization from observed growth and reproduction. In contrast, our model predicts growth and reproduction from food availability and temperature in the environment. We calibrated the model to emulate physiological characteristics of Pacific bluefin tuna (Thunnus orientalis, hereafter PBT), a species which has received considerable scientific attention due to its high economic value. Computer simulations suggest that (i) the main cause of different growth rates between cultivated and wild PBT is the difference in average body temperature of approximately 6.5°C, (ii) a well-fed PBT individual can spawn an average number of 9 batches per spawning season, (iii) food abundance experienced by wild PBT is rather constant and sufficiently high to provide energy for yearly reproductive cycle, (iv) energy in reserve is exceptionally small, causing the weight-length relationship of cultivated and wild PBT to be practically indistinguishable and suggesting that these fish are poorly equipped to deal with starvation, (v) accelerated growth rate of PBT larvae is connected to morphological changes prior to metamorphosis, while (vi) deceleration of growth rate in the early juvenile stage is related to efficiency of internal heat production. Based on these results, we discuss a number of physiological and ecological traits of PBT, including the reasons for high Feed Conversion Ratio recorded in bluefin tuna aquaculture. PMID:21779352

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Abid, Noureddine; Addis, Piero; Alot, Enrique; Andrushchenko, Irene; Deguara, Simeon; Di Natale, Antonio; Gatt, Mark; Golet, Walter; Karakulak, Saadet; Kimoto, Ai; Macias, David; Saber, Samar; Santos, Miguel Neves; Zarrad, Rafik

    2015-01-01

    The compiled data for this study represents the first Atlantic and Mediterranean-wide effort to pool all available biometric data for Atlantic bluefin tuna (Thunnus thynnus) with the collaboration of many countries and scientific groups. Biometric relationships were based on an extensive sampling (over 140,000 fish sampled), covering most of the fishing areas for this species in the North Atlantic Ocean and Mediterranean Sea. Sensitivity analyses were carried out to evaluate the representativeness of sampling and explore the most adequate procedure to fit the weight-length relationship (WLR). The selected model for the WLRs by stock included standardized data series (common measurement types) weighted by the inverse variability. There was little difference between annual stock-specific round weight-straight fork length relationships, with an overall difference of 6% in weight. The predicted weight by month was estimated as an additional component in the exponent of the weight-length function. The analyses of monthly variations of fish condition by stock, maturity state and geographic area reflect annual cycles of spawning and feeding behavior. We update and improve upon the biometric relationships for bluefin currently used by the International Commission for the Conservation of Atlantic Tunas, by incorporating substantially larger datasets than ever previously compiled, providing complete documentation of sources and employing robust statistical fitting. WLRs and other conversion factors estimated in this study differ from the ones used in previous bluefin stock assessments. PMID:26505476

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2011-01-01

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

  20. Migratory movements, depth preferences, and thermal biology of Atlantic bluefin tuna.

    PubMed

    Block, B A; Dewar, H; Blackwell, S B; Williams, T D; Prince, E D; Farwell, C J; Boustany, A; Teo, S L; Seitz, A; Walli, A; Fudge, D

    2001-08-17

    The deployment of electronic data storage tags that are surgically implanted or satellite-linked provides marine researchers with new ways to examine the movements, environmental preferences, and physiology of pelagic vertebrates. We report the results obtained from tagging of Atlantic bluefin tuna with implantable archival and pop-up satellite archival tags. The electronic tagging data provide insights into the seasonal movements and environmental preferences of this species. Bluefin tuna dive to depths of >1000 meters and maintain a warm body temperature. Western-tagged bluefin tuna make trans-Atlantic migrations and they frequent spawning grounds in the Gulf of Mexico and eastern Mediterranean. These data are critical for the future management and conservation of bluefin tuna in the Atlantic.

  1. 78 FR 72584 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-03

    ... fisheries, and taking into account the protection of marine ecosystems.'' NMFS' preliminary estimate of... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National..., 2013. Emily H. Menashes, Acting Director, Office of Sustainable Fisheries, National Marine...

  2. 77 FR 28496 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ..., preserving traditional fisheries, and taking into account the protection of marine ecosystems''. Migration of... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National..., Acting Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE...

  3. 78 FR 20258 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-04

    ... traditional fisheries, and taking into account the protection of marine ecosystems.'' It is important that... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... Fisheries, National Marine Fisheries Service. BILLING CODE 3510-22-P...

  4. 78 FR 50346 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ..., preserving traditional fisheries, and taking into account the protection of marine ecosystems.'' Commercial... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National..., Acting Deputy Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING...

  5. 78 FR 77362 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ... taking into account the protection of marine ecosystems.'' For the last two years, the available January... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE 3510-22-P...

  6. 76 FR 76900 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ... opportunities, preserving traditional fisheries, and taking into account the protection of marine ecosystems... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE 3510-22-P...

  7. 77 FR 53150 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-31

    ... fisheries, and taking into account the protection of marine ecosystems.'' Commercial-sized BFT migrated to... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... Fullenkamp, Acting Deputy Director, Office of Sustainable Fisheries, National Marine Fisheries...

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

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  10. Reproductive schedules in southern bluefin tuna: are current assumptions appropriate?

    PubMed

    Evans, Karen; Patterson, Toby A; Reid, Howard; Harley, Shelton J

    2012-01-01

    Southern bluefin tuna (SBT) appear to comprise a single stock that is assumed to be both mixed across its distribution and having reproductive adults that are obligate, annual spawners. The putative annual migration cycle of mature SBT consists of dispersed foraging at temperate latitudes with migration to a single spawning ground in the tropical eastern Indian Ocean. Spawning migrations have been assumed to target two peaks in spawning activity; one in September-October and a second in February-March. SBT of sizes comparable to that of individuals observed on the spawning ground were satellite tagged in the Tasman Sea region (2003-2008) and demonstrated both migrations to the spawning grounds and residency in the Tasman Sea region throughout the whole year. All individuals undertaking apparent spawning migrations timed their movements to coincide with the second recognised spawning peak or even later. These observations suggest that SBT may demonstrate substantial flexibility in the scheduling of reproductive events and may even not spawn annually as currently assumed. Further, the population on the spawning grounds may be temporally structured in association with foraging regions. These findings provide new perspectives on bluefin population and spatial dynamics and warrant further investigation and consideration of reproductive schedules in this species.

  11. Reproductive Schedules in Southern Bluefin Tuna: Are Current Assumptions Appropriate?

    PubMed Central

    Evans, Karen; Patterson, Toby A.; Reid, Howard; Harley, Shelton J.

    2012-01-01

    Southern bluefin tuna (SBT) appear to comprise a single stock that is assumed to be both mixed across its distribution and having reproductive adults that are obligate, annual spawners. The putative annual migration cycle of mature SBT consists of dispersed foraging at temperate latitudes with migration to a single spawning ground in the tropical eastern Indian Ocean. Spawning migrations have been assumed to target two peaks in spawning activity; one in September-October and a second in February-March. SBT of sizes comparable to that of individuals observed on the spawning ground were satellite tagged in the Tasman Sea region (2003–2008) and demonstrated both migrations to the spawning grounds and residency in the Tasman Sea region throughout the whole year. All individuals undertaking apparent spawning migrations timed their movements to coincide with the second recognised spawning peak or even later. These observations suggest that SBT may demonstrate substantial flexibility in the scheduling of reproductive events and may even not spawn annually as currently assumed. Further, the population on the spawning grounds may be temporally structured in association with foraging regions. These findings provide new perspectives on bluefin population and spatial dynamics and warrant further investigation and consideration of reproductive schedules in this species. PMID:22514636

  12. 75 FR 30732 - Atlantic Highly Migratory Species; 2010 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ...-Stevens Fishery Conservation and Management Act (Magnuson- Stevens Act). DATES: Effective July 2, 2010... Species; 2010 Atlantic Bluefin Tuna Quota Specifications AGENCY: National Marine Fisheries Service (NMFS... recommendations of the International Commission for the Conservation of Atlantic Tunas (ICCAT), as required by the...

  13. Absolute abundance of southern bluefin tuna estimated by close-kin mark-recapture

    PubMed Central

    Bravington, Mark V.; Grewe, Peter M.; Davies, Campbell R.

    2016-01-01

    Southern bluefin tuna is a highly valuable, severely depleted species, whose abundance and productivity have been difficult to assess with conventional fishery data. Here we use large-scale genotyping to look for parent–offspring pairs among 14,000 tissue samples of juvenile and adult tuna collected from the fisheries, finding 45 pairs in total. Using a modified mark-recapture framework where ‘recaptures' are kin rather than individuals, we can estimate adult abundance and other demographic parameters such as survival, without needing to use contentious fishery catch or effort data. Our abundance estimates are substantially higher and more precise than previously thought, indicating a somewhat less-depleted and more productive stock. More broadly, this technique of ‘close-kin mark-recapture' has widespread utility in fisheries and wildlife conservation. It estimates a key parameter for management—the absolute abundance of adults—while avoiding the expense of independent surveys or tag-release programmes, and the interpretational problems of fishery catch rates. PMID:27841264

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

    PubMed Central

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

    2016-01-01

    Atlantic bluefin tuna are a symbol of both the conflict between preservationist and utilitarian views of top ocean predators, and the struggle to reach international consensus on the management of migratory species. Currently, Atlantic bluefin tuna are managed as an early-maturing eastern stock, which spawns in the Mediterranean Sea, and a late-maturing western stock, which spawns in the Gulf of Mexico. However, electronic tagging studies show that many bluefin tuna, assumed to be of a mature size, do not visit either spawning ground during the spawning season. Whether these fish are spawning in an alternate location, skip-spawning, or not spawning until an older age affects how vulnerable this species is to anthropogenic stressors including exploitation. We use larval collections to demonstrate a bluefin tuna spawning ground in the Slope Sea, between the Gulf Stream and northeast United States continental shelf. We contend that western Atlantic bluefin tuna have a differential spawning migration, with larger individuals spawning in the Gulf of Mexico, and smaller individuals spawning in the Slope Sea. The current life history model, which assumes only Gulf of Mexico spawning, overestimates age at maturity for the western stock. Furthermore, individual tuna occupy both the Slope Sea and Mediterranean Sea in separate years, contrary to the prevailing view that individuals exhibit complete spawning-site fidelity. Overall, this complexity of spawning migrations questions whether there is complete independence in the dynamics of eastern and western Atlantic bluefin tuna and leads to lower estimates of the vulnerability of this species to exploitation and other anthropogenic stressors. PMID:26951668

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

    PubMed

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

    2016-03-22

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

  16. 76 FR 13583 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Quotas and Atlantic Tuna Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ...., Atlantic yellowfin tuna (YFT) and swordfish) year-round with less risk of fishery interruption due to... the 2011 fishing year; reinstate pelagic longline target catch requirements for retaining BFT in the... limit adjustments, if needed, for the 2011 fishing year via Federal Register notices separate from the...

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

    DTIC Science & Technology

    2014-09-30

    Although the typical swimming speeds of bluefin tuna are 1 – 2 m/s, they can be higher during strong accelerations. The goal of the work...speeds. The question is whether laminar flow or an advanced propulsion mechanism (or both) allows them to swim at high speeds. A full-scale model...and drag reduction on the body. The typical swimming speed of bluefin tuna is 1 – 2 m/s, but it can be higher during strong accelerations. The

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

    PubMed

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

    2009-11-15

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

  19. Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California

    PubMed Central

    Madigan, Daniel J.; Baumann, Zofia; Fisher, Nicholas S.

    2012-01-01

    The Fukushima Dai-ichi release of radionuclides into ocean waters caused significant local and global concern regarding the spread of radioactive material. We report unequivocal evidence that Pacific bluefin tuna, Thunnus orientalis, transported Fukushima-derived radionuclides across the entire North Pacific Ocean. We measured γ-emitting radionuclides in California-caught tunas and found 134Cs (4.0 ± 1.4 Bq kg−1) and elevated 137Cs (6.3 ± 1.5 Bq kg−1) in 15 Pacific bluefin tuna sampled in August 2011. We found no 134Cs and background concentrations (∼1 Bq kg−1) of 137Cs in pre-Fukushima bluefin and post-Fukushima yellowfin tunas, ruling out elevated radiocesium uptake before 2011 or in California waters post-Fukushima. These findings indicate that Pacific bluefin tuna can rapidly transport radionuclides from a point source in Japan to distant ecoregions and demonstrate the importance of migratory animals as transport vectors of radionuclides. Other large, highly migratory marine animals make extensive use of waters around Japan, and these animals may also be transport vectors of Fukushima-derived radionuclides to distant regions of the North and South Pacific Oceans. These results reveal tools to trace migration origin (using the presence of 134Cs) and potentially migration timing (using 134Cs:137Cs ratios) in highly migratory marine species in the Pacific Ocean. PMID:22645346

  20. Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California.

    PubMed

    Madigan, Daniel J; Baumann, Zofia; Fisher, Nicholas S

    2012-06-12

    The Fukushima Dai-ichi release of radionuclides into ocean waters caused significant local and global concern regarding the spread of radioactive material. We report unequivocal evidence that Pacific bluefin tuna, Thunnus orientalis, transported Fukushima-derived radionuclides across the entire North Pacific Ocean. We measured γ-emitting radionuclides in California-caught tunas and found (134)Cs (4.0 ± 1.4 Bq kg(-1)) and elevated (137)Cs (6.3 ± 1.5 Bq kg(-1)) in 15 Pacific bluefin tuna sampled in August 2011. We found no (134)Cs and background concentrations (~1 Bq kg(-1)) of (137)Cs in pre-Fukushima bluefin and post-Fukushima yellowfin tunas, ruling out elevated radiocesium uptake before 2011 or in California waters post-Fukushima. These findings indicate that Pacific bluefin tuna can rapidly transport radionuclides from a point source in Japan to distant ecoregions and demonstrate the importance of migratory animals as transport vectors of radionuclides. Other large, highly migratory marine animals make extensive use of waters around Japan, and these animals may also be transport vectors of Fukushima-derived radionuclides to distant regions of the North and South Pacific Oceans. These results reveal tools to trace migration origin (using the presence of (134)Cs) and potentially migration timing (using (134)Cs:(137)Cs ratios) in highly migratory marine species in the Pacific Ocean.

  1. 77 FR 74612 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... taking into account the protection of marine ecosystems.'' Under the two-fish limit that applied in... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE 3510-22-P...

  2. 78 FR 26709 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-08

    ... Species; Atlantic Bluefin Tuna Fisheries AGENCY: National Marine Fisheries Service (NMFS), National... recreational opportunities, preserving traditional fisheries, and taking into account the protection of marine ecosystems.'' Migration of commercial-size BFT to the fishing grounds off the northeast U.S. coast...

  3. 77 FR 31546 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-29

    ... area fishery for large medium and giant Atlantic bluefin tuna (BFT) for the remainder of 2012. Fishing... rulemaking. Under Sec. 635.27(a)(3), the total amount of large medium and giant BFT (measuring 73 inches (185... December 31, 2012, landing large medium or giant BFT south of 31 00' N. lat. by vessels permitted in the...

  4. 75 FR 51182 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-19

    ... Atlantic bluefin tuna (BFT) retention limit should be adjusted from one to three large medium or giant BFT... medium and giant BFT over a range of zero to a maximum of three per vessel based on consideration of the....9 mt, and increased the default General category daily retention limit of one large medium or giant...

  5. 75 FR 33731 - Atlantic Highly Migratory Species; 2010 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 635 RIN 0648-AY77 Atlantic Highly Migratory Species; 2010 Atlantic Bluefin Tuna Quota Specifications Correction In rule document 2010-13207...

  6. Seasonal Movements, Aggregations and Diving Behavior of Atlantic Bluefin Tuna (Thunnus thynnus) Revealed with Archival Tags

    PubMed Central

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

    2009-01-01

    Electronic tags were used to examine the seasonal movements, aggregations and diving behaviors of Atlantic bluefin tuna (Thunnus thynnus) to better understand their migration ecology and oceanic habitat utilization. Implantable archival tags (n = 561) were deployed in bluefin tuna from 1996 to 2005 and 106 tags were recovered. Movement paths of the fish were reconstructed using light level and sea-surface-temperature-based geolocation estimates. To quantify habitat utilization we employed a weighted kernel estimation technique that removed the biases of deployment location and track length. Throughout the North Atlantic, high residence times (167±33 days) were identified in four spatially confined regions on a seasonal scale. Within each region, bluefin tuna experienced distinct temperature regimes and displayed different diving behaviors. The mean diving depths within the high-use areas were significantly shallower and the dive frequency and the variance in internal temperature significantly higher than during transit movements between the high-use areas. Residence time in the more northern latitude high-use areas was significantly correlated with levels of primary productivity. The regions of aggregation are associated with areas of abundant prey and potentially represent critical foraging habitats that have seasonally abundant prey. Throughout the North Atlantic mean diving depth was significantly correlated with the depth of the thermocline, and dive behavior changed in relation to the stratification of the water column. In this study, with numerous multi-year tracks, there appear to be repeatable patterns of clear aggregation areas that potentially are changing with environmental conditions. The high concentrations of bluefin tuna in predictable locations indicate that Atlantic bluefin tuna are vulnerable to concentrated fishing efforts in the regions of foraging aggregations. PMID:19582150

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

    PubMed Central

    MacKenzie, Brian R.; Mariani, Patrizio

    2012-01-01

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

  8. Canned bluefin tuna, an in vitro cardioprotective functional food potentially safer than commercial fish oil based pharmaceutical formulations.

    PubMed

    Tenore, Gian Carlo; Calabrese, Giorgio; Ritieni, Alberto; Campiglia, Pietro; Giannetti, Daniela; Novellino, Ettore

    2014-09-01

    Commercial canned fish species typical in the Italian market were evaluated for their lipid profile. Bluefin tuna samples showed the highest content in omega-3 fatty acids (n-3 PUFA) among the canned fish samples analyzed. Tests on H9C2 cardiomyocytes revealed that bluefin tuna n-3 PUFA may responsible for a significant cell protection against both physiological and doxorubicin-induced oxidative stress. Analogous tests performed by incubating cardiac cells with n-3 PUFA ethyl esters, of which most of fish oil pharmaceutical formulations (FOPF) are based, showed cytotoxicity at high doses. Our results highlighted that n-3 PUFA contents in a 50 g canned bluefin tuna portion would be almost equivalent to and potentially safer than those of 1 FOPF capsule (1000 mg)/die usually suggested for hyperlipidaemic subjects. Thus, Italian commercial canned bluefin tuna could be indicated as a functional food with potential health benefits for the prevention and care of cardiovascular disorders.

  9. Warm fish with cold hearts: thermal plasticity of excitation-contraction coupling in bluefin tuna.

    PubMed

    Shiels, H A; Di Maio, A; Thompson, S; Block, B A

    2011-01-07

    Bluefin tuna have a unique physiology. Elevated metabolic rates coupled with heat exchangers enable bluefin tunas to conserve heat in their locomotory muscle, viscera, eyes and brain, yet their hearts operate at ambient water temperature. This arrangement of a warm fish with a cold heart is unique among vertebrates and can result in a reduction in cardiac function in the cold despite the elevated metabolic demands of endothermic tissues. In this study, we used laser scanning confocal microscopy and electron microscopy to investigate how acute and chronic temperature change affects tuna cardiac function. We examined the temporal and spatial properties of the intracellular Ca2+ transient (Δ[Ca2+]i) in Pacific bluefin tuna (Thunnus orientalis) ventricular myocytes at the acclimation temperatures of 14°C and 24°C and at a common test temperature of 19°C. Acute (less than 5 min) warming and cooling accelerated and slowed the kinetics of Δ[Ca2+]i, indicating that temperature change limits cardiac myocyte performance. Importantly, we show that thermal acclimation offered partial compensation for these direct effects of temperature. Prolonged cold exposure (more than four weeks) increased the amplitude and kinetics of Δ[Ca2+]i by increasing intracellular Ca2+ cycling through the sarcoplasmic reticulum (SR). These functional findings are supported by electron microscopy, which revealed a greater volume fraction of ventricular SR in cold-acclimated tuna myocytes. The results indicate that SR function is crucial to the performance of the bluefin tuna heart in the cold. We suggest that SR Ca2+ cycling is the malleable unit of cellular Ca2+ flux, offering a mechanism for thermal plasticity in fish hearts. These findings have implications beyond endothermic fish and may help to delineate the key steps required to protect vertebrate cardiac function in the cold.

  10. Warm fish with cold hearts: thermal plasticity of excitation–contraction coupling in bluefin tuna

    PubMed Central

    Shiels, H. A.; Di Maio, A.; Thompson, S.; Block, B. A.

    2011-01-01

    Bluefin tuna have a unique physiology. Elevated metabolic rates coupled with heat exchangers enable bluefin tunas to conserve heat in their locomotory muscle, viscera, eyes and brain, yet their hearts operate at ambient water temperature. This arrangement of a warm fish with a cold heart is unique among vertebrates and can result in a reduction in cardiac function in the cold despite the elevated metabolic demands of endothermic tissues. In this study, we used laser scanning confocal microscopy and electron microscopy to investigate how acute and chronic temperature change affects tuna cardiac function. We examined the temporal and spatial properties of the intracellular Ca2+ transient (Δ[Ca2+]i) in Pacific bluefin tuna (Thunnus orientalis) ventricular myocytes at the acclimation temperatures of 14°C and 24°C and at a common test temperature of 19°C. Acute (less than 5 min) warming and cooling accelerated and slowed the kinetics of Δ[Ca2+]i, indicating that temperature change limits cardiac myocyte performance. Importantly, we show that thermal acclimation offered partial compensation for these direct effects of temperature. Prolonged cold exposure (more than four weeks) increased the amplitude and kinetics of Δ[Ca2+]i by increasing intracellular Ca2+ cycling through the sarcoplasmic reticulum (SR). These functional findings are supported by electron microscopy, which revealed a greater volume fraction of ventricular SR in cold-acclimated tuna myocytes. The results indicate that SR function is crucial to the performance of the bluefin tuna heart in the cold. We suggest that SR Ca2+ cycling is the malleable unit of cellular Ca2+ flux, offering a mechanism for thermal plasticity in fish hearts. These findings have implications beyond endothermic fish and may help to delineate the key steps required to protect vertebrate cardiac function in the cold. PMID:20667881

  11. Shift in tuna catches due to ocean warming.

    PubMed

    Monllor-Hurtado, Alberto; Pennino, Maria Grazia; Sanchez-Lizaso, José Luis

    2017-01-01

    Ocean warming is already affecting global fisheries with an increasing dominance of catches of warmer water species at higher latitudes and lower catches of tropical and subtropical species in the tropics. Tuna distributions are highly conditioned by sea temperature, for this reason and their worldwide distribution, their populations may be a good indicator of the effect of climate change on global fisheries. This study shows the shift of tuna catches in subtropical latitudes on a global scale. From 1965 to 2011, the percentage of tropical tuna in longliner catches exhibited a significantly increasing trend in a study area that included subtropical regions of the Atlantic and western Pacific Oceans and partially the Indian Ocean. This may indicate a movement of tropical tuna populations toward the poles in response to ocean warming. Such an increase in the proportion of tropical tuna in the catches does not seem to be due to a shift of the target species, since the trends in Atlantic and Indian Oceans of tropical tuna catches are decreasing. Our results indicate that as populations shift towards higher latitudes the catches of these tropical species did not increase. Thus, at least in the Atlantic and Indian Oceans, tropical tuna catches have reduced in tropical areas.

  12. Shift in tuna catches due to ocean warming

    PubMed Central

    Monllor-Hurtado, Alberto; Pennino, Maria Grazia

    2017-01-01

    Ocean warming is already affecting global fisheries with an increasing dominance of catches of warmer water species at higher latitudes and lower catches of tropical and subtropical species in the tropics. Tuna distributions are highly conditioned by sea temperature, for this reason and their worldwide distribution, their populations may be a good indicator of the effect of climate change on global fisheries. This study shows the shift of tuna catches in subtropical latitudes on a global scale. From 1965 to 2011, the percentage of tropical tuna in longliner catches exhibited a significantly increasing trend in a study area that included subtropical regions of the Atlantic and western Pacific Oceans and partially the Indian Ocean. This may indicate a movement of tropical tuna populations toward the poles in response to ocean warming. Such an increase in the proportion of tropical tuna in the catches does not seem to be due to a shift of the target species, since the trends in Atlantic and Indian Oceans of tropical tuna catches are decreasing. Our results indicate that as populations shift towards higher latitudes the catches of these tropical species did not increase. Thus, at least in the Atlantic and Indian Oceans, tropical tuna catches have reduced in tropical areas. PMID:28591205

  13. Anthropogenic and naturally-produced organobrominated compounds in bluefin tuna from the Mediterranean Sea.

    PubMed

    Pena-Abaurrea, Miren; Weijs, Liesbeth; Ramos, Lourdes; Borghesi, Nicoletta; Corsolini, Simonetta; Neels, Hugo; Blust, Ronny; Covaci, Adrian

    2009-09-01

    Anthropogenic compounds, such as polybrominated diphenyl ethers (PBDEs), together with naturally-produced organobromines, such as methoxylated PBDEs (MeO-PBDEs), polybrominated hexahydroxanthene derivatives (PBHDs), 2,4,6-tribromoanisole (TBA) and a mixed halogenated monoterpene (MHC-1), were measured in muscle from 26 farmed and wild bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea. This species is ecological attractive because of the changes of geographic habitat throughout its long lifespan which affect its feeding. PBDE concentrations were similar between tuna samples of different groups (17-149 ng g(-1) lipid weight - lw in farmed tuna, 25-219 ng g(-1)lw in longline fished tuna and 26-126 ng g(-1)lw in net-fished tuna). However, higher concentrations of naturally-produced MeO-PBDEs and PBHDs were observed in the two types of wild tuna (longline fished and net-fished) compared to farmed tuna suggesting that wild tunas come easily in contact with sources of these compounds. In all cases PBHDs presented the highest contribution to the sum of organobromines (50% in farmed tuna and >90% in wild tuna). TBA was detected at low concentrations (<6 ng g(-1)lw), while MHC-1 was found at higher concentrations (up to 42 ng g(-1)lw) in farmed tuna. The estimated daily ingestion of PBDEs from tuna was 830 ng PBDEs day(-1), regardless of the origin of the tuna. While this value is approximately 600 times lower than the minimum risk level set by the US Department of Health and Human Services, it is approximately eight times higher than the total intake of PBDEs via diet, suggesting that consumption of tuna can add considerably to the total daily intake of PBDEs.

  14. Characterization of the Boundary Layer on Full-Scale Bluefin Tuna

    NASA Astrophysics Data System (ADS)

    Amaral, Brian; Cipolla, Kimberly; Henoch, Charles

    2014-11-01

    The physics that enable tuna to cross large expanses of ocean while feeding and avoiding predators is not presently understood, and could involve complex control of turbulent boundary layer transition and drag reduction. Typical swimming speeds of Bluefin tuna are 1-2 m/s, but can be higher during strong accelerations. The goal of this work is to experimentally determine the approximate lateral location at which transition to turbulence occurs on the tuna for various speeds. The question is whether laminar flow or an advanced propulsion mechanism (or both) allows them to swim at high speeds. Uncertainties include the surface roughness of the skin, local favorable and adverse pressure gradients, and discontinuities such as the open mouth or juncture at the fins. Historically, much of the fluid mechanics work in the area of fish locomotion has focused on vortex shedding issues rather than the boundary layer. Here, the focus is obtaining information on the boundary layer characteristics of a rigid tuna model. A full scale model of a Pacific Bluefin tuna was fabricated using a mold made from an actual deceased tuna, preserving the surface features and details of the appendages. The model was instrumented with 32 wall pressure sensors and experiments performed in a tow tank. Results from flow visualization, drag and wall pressure measurements over a range of speeds and varying angles of attack will be presented.

  15. Effect of thermal acclimation on action potentials and sarcolemmal K+ channels from Pacific bluefin tuna cardiomyocytes.

    PubMed

    Galli, G L J; Lipnick, M S; Block, B A

    2009-08-01

    To sustain cardiac muscle contractility relatively independent of temperature, some fish species are capable of temporarily altering excitation-contraction coupling processes to meet the demands of their environment. The Pacific bluefin tuna, Thunnus orientalis, is a partially endothermic fish that inhabits a wide range of thermal niches. The present study examined the effects of temperature and thermal acclimation on sarcolemmal K(+) currents and their role in action potential (AP) generation in bluefin tuna cardiomyocytes. Atrial and ventricular myocytes were enzymatically isolated from cold (14 degrees C)- and warm (24 degrees C)-acclimated bluefin tuna. APs and current-voltage relations of K(+) channels were measured using the whole cell current and voltage clamp techniques, respectively. Data were collected either at the cardiomyocytes' respective acclimation temperature of 14 or 24 degrees C or at a common test temperature of 19 degrees C (to reveal the effects of acclimation). AP duration (APD) was prolonged in cold-acclimated (CA) cardiomyocytes tested at 14 degrees C compared with 19 degrees C and in warm-acclimated (WA) cardiomyocytes tested at 19 degrees C compared with 24 degrees C. This effect was mirrored by a decrease in the density of the delayed-rectifier current (I(Kr)), whereas the density of the background inward-rectifier current (I(K1)) was unchanged. When CA and WA cardiomyocytes were tested at a common temperature of 19 degrees C, no significant effects of temperature acclimation on AP shape or duration were observed, whereas I(Kr) density was markedly increased in CA cardiomyocytes. I(K1) density was unaffected in CA ventricular myocytes but was significantly reduced in CA atrial myocytes, resulting in a depolarization of atrial resting membrane potential. Our results indicate the bluefin AP is relatively short compared with other teleosts, which may allow the bluefin heart to function at cold temperatures without the necessity for thermal

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  17. Characterization and ontogenetic development of digestive enzymes in Pacific bluefin tuna Thunnus orientalis larvae.

    PubMed

    Murashita, Koji; Matsunari, Hiroyuki; Kumon, Kazunori; Tanaka, Yosuke; Shiozawa, Satoshi; Furuita, Hirofumi; Oku, Hiromi; Yamamoto, Takeshi

    2014-12-01

    The major digestive enzymes in Pacific bluefin tuna Thunnus orientalis larvae were characterized, and the physiological characteristics of the enzymes during early ontogeny were clarified using biochemical and molecular approaches. The maximum activity of trypsin (Try), chymotrypsin (Ct) and amylase (Amy) was observed at pH 6-11, 8-11 and 6-9, respectively. Maximum activity of Try, Ct and Amy occurred at 50 °C, that of lipase (Lip) was at 60 °C and that of pepsin (Pep) was at 40-50 °C. These pH and thermal profiles were similar to those for other fish species but differed from those previously reported for adult bluefin tuna. Enzyme activity for all enzymes assayed was found to decrease at high temperatures (Try, Ct, Amy and Pep: 50 °C; Lip: 40 °C), which is similar to findings for other fish species with one marked exception-increased Try activity was observed at 40 °C. Lip activity appeared to be dependent on bile salts under our assay conditions, resulting in a significant increase in activity in the presence of bile salts. Ontogenetic changes in pancreatic digestive enzymes showed similar gene expression patterns to those of other fish species, whereas marked temporal increases in enzyme activities were observed at 10-12 days post hatching (dph), coinciding with previously reported timing of the development of the pyloric caeca in bluefin tuna larvae. However, complete development of digestive function was indicated by the high pep gene expression from 19 dph, which contradicts the profile of Pep activity and previously reported development timing of the gastric gland. These findings contribute to the general knowledge of bluefin tuna larval digestive system development.

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

    NASA Astrophysics Data System (ADS)

    Walli, Andreas G.

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

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

    PubMed

    MacKenzie, Brian R; Payne, Mark R; Boje, Jesper; Høyer, Jacob L; Siegstad, Helle

    2014-08-01

    Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species in ecological isolation from others. Here, we show that a large highly migratory top predator fish species has entered a high latitude subpolar area beyond its usual range. Bluefin tuna, Thunnus thynnus Linnaeus 1758, were captured in waters east of Greenland (65°N) in August 2012 during exploratory fishing for Atlantic mackerel, Scomber scombrus Linnaeus 1758. The bluefin tuna were captured in a single net-haul in 9-11 °C water together with 6 tonnes of mackerel, which is a preferred prey species and itself a new immigrant to the area. Regional temperatures in August 2012 were historically high and contributed to a warming trend since 1985, when temperatures began to rise. The presence of bluefin tuna in this region is likely due to a combination of warm temperatures that are physiologically more tolerable and immigration of an important prey species to the region. We conclude that a cascade of climate change impacts is restructuring the food web in east Greenland waters. © 2014 John Wiley & Sons Ltd.

  20. Electronic Tagging of Atlantic Bluefin Tuna (Thunnus thynnus, L.) Reveals Habitat Use and Behaviors in the Mediterranean Sea

    PubMed Central

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

    2015-01-01

    We analyzed the movements of Atlantic tuna (Thunnus thynnus L.) in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT). Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012). Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya) using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground. PMID:25671316

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Farley, Jessica. H.; Davis, Tim L. O.; Bravington, Mark V.; Andamari, Retno; Davies, Campbell R.

    2015-01-01

    Knowledge of spawning behaviour and fecundity of fish is important for estimating the reproductive potential of a stock and for constructing appropriate statistical models for assessing sustainable catch levels. Estimates of length-based reproductive parameters are particularly important for determining potential annual fecundity as a function of fish size, but they are often difficult to estimate reliably. Here we provide new information on the reproductive dynamics of southern bluefin tuna (SBT) Thunnus maccoyii through the analysis of fish size and ovary histology collected on the spawning ground in 1993–1995 and 1999–2002. These are used to refine previous parameter estimates of spawning dynamics and investigate size related trends in these parameters. Our results suggest that the small SBT tend to arrive on the spawning ground slightly later and depart earlier in the spawning season relative to large fish. All females were mature and the majority were classed as spawning capable (actively spawning or non-spawning) with a very small proportion classed as regressing. The fraction of females spawning per day decreased with fish size, but once females start a spawning episode, they spawned daily irrespective of size. Mean batch fecundity was estimated directly at 6.5 million oocytes. Analysis of ovary histology and ovary weight data indicated that relative batch fecundity, and the duration of spawning and non-spawning episodes, increased with fish size. These reproductive parameter estimates could be used with estimates of residency time on the spawning ground as a function of fish size (if known) and demographic data for the spawning population to provide a time series of relative annual fecundity for SBT. PMID:25993276

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

    PubMed

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

    2016-10-01

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

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

    PubMed

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

    2016-04-15

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

  5. Detecting the presence-absence of bluefin tuna by automated analysis of medium-range sonars on fishing vessels.

    PubMed

    Uranga, Jon; Arrizabalaga, Haritz; Boyra, Guillermo; Hernandez, Maria Carmen; Goñi, Nicolas; Arregui, Igor; Fernandes, Jose A; Yurramendi, Yosu; Santiago, Josu

    2017-01-01

    This study presents a methodology for the automated analysis of commercial medium-range sonar signals for detecting presence/absence of bluefin tuna (Tunnus thynnus) in the Bay of Biscay. The approach uses image processing techniques to analyze sonar screenshots. For each sonar image we extracted measurable regions and analyzed their characteristics. Scientific data was used to classify each region into a class ("tuna" or "no-tuna") and build a dataset to train and evaluate classification models by using supervised learning. The methodology performed well when validated with commercial sonar screenshots, and has the potential to automatically analyze high volumes of data at a low cost. This represents a first milestone towards the development of acoustic, fishery-independent indices of abundance for bluefin tuna in the Bay of Biscay. Future research lines and additional alternatives to inform stock assessments are also discussed.

  6. Moving Cages Further Offshore: Effects on Southern Bluefin Tuna, T. maccoyii, Parasites, Health and Performance

    PubMed Central

    Kirchhoff, Nicole T.; Rough, Kirsty M.; Nowak, Barbara F.

    2011-01-01

    The effects of offshore aquaculture on SBT health (particularly parasitic infections and haematology) and performance were the main aim of this study. Two cohorts of ranched Southern Bluefin tuna (SBT) (Thunnus maccoyii) were monitored throughout the commercial season, one maintained in the traditional near shore tuna farming zone and one maintained further offshore. SBT maintained offshore had reduced mortality, increased condition index at week 6 post transfer, reduced blood fluke and sealice loads, and haematological variables such as haemoglobin or lysozyme equal to or exceeding near shore maintained fish. The offshore cohort had no Cardicola forsteri and a 5% prevalence of Caligus spp., compared to a prevalence of 85% for Cardicola forsteri and 55% prevalence for Caligus spp. near shore at 6 weeks post transfer. This study is the first of its kind to examine the effects of commercial offshore sites on farmed fish parasites, health and performance. PMID:21901129

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

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

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

    PubMed

    Alvarez-Berastegui, Diego; Ciannelli, Lorenzo; Aparicio-Gonzalez, Alberto; Reglero, Patricia; Hidalgo, Manuel; López-Jurado, Jose Luis; Tintoré, Joaquín; Alemany, Francisco

    2014-01-01

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

  12. Mercury in Pacific bluefin tuna (Thunnus orientalis):bioaccumulation and trans-Pacific Ocean migration

    USGS Publications Warehouse

    Colman, John A.; Nogueira, Jacob I.; Pancorbo, Oscar C.; Batdorf, Carol A.; Block, Barbara A.

    2015-01-01

    Pacific bluefin tuna (Thunnus orientalis) have the largest home range of any tuna species and are well known for the capacity to make transoceanic migrations. We report the measurement of mercury (Hg) concentrations in wild Pacific bluefin tuna (PBFT), the first reported with known size-of-fish and capture location. The results indicate juvenile PBFT that are recently arrived in the California Current from the western Pacific Ocean have significantly higher Hg concentrations in white muscle (0.51 ug/g wet mass, wm) than PBFT of longer California Current residency (0.41 ug/g wm). These new arrivals are also higher in Hg concentration than PBFT in farm pens (0.43 ug/g wm) that were captured on arrival in the California Current and raised in pens on locally derived feed. Analysis by direct Hg analyzer and attention to Hg by tissue type and location on the fish allowed precise comparisons of mercury among wild and captive fish populations. Analysis of migration and nearshore residency, determined through extensive archival tagging, bioaccumulation models, trophic investigations, and potential coastal sources of methylmercury, indicates Hg bioaccumulation is likely greater for PBFT juvenile habitats in the western Pacific Ocean (East China Sea, Yellow Sea) than in the eastern Pacific Ocean (California Current). Differential bioaccumulation may be a trophic effect or reflect methylmercury availability, with potential sources for coastal China (large hypoxic continental shelf receiving discharge of three large rivers, and island-arc volcanism) different from those for coastal Baja California (small continental shelf, no large rivers, spreading-center volcanism).

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

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

    PubMed

    Mladineo, I; Segvić, T; Petrić, M

    2011-01-01

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

  15. Burst Feeding of Pelagia noctiluca ephyrae on Atlantic Bluefin Tuna (Thunnus thynnus) Eggs

    PubMed Central

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

    2013-01-01

    This study investigates the predation of P. noctiluca ephyrae on Atlantic Bluefin tuna (ABFT) eggs under different experimental conditions. The specific factors considered in the experimental design were: a) water mix conditions to explore predation under two-dimensional (2D) and three-dimensional (3D) prey distributions, b) prey density to investigate the ingestion rate capacity, and c) incubation time to inspect gut saturation. The eggs and jellyfish ephyrae were collected during the 2012 ABFT spawning survey off Ibiza (Balearic Isl., Western Mediterranean). The results showed that the proportion of feeding ephyrae increased with size. The mean clearance rate of feeding ephyrae, 4.14 L h-1, was the highest ever recorded for ephyrae. Under calm conditions the eggs floated at the surface (2D spatial arrangement) and the clearance rates, at low prey densities, were at least twice those under mixed conditions (3D spatial arrangement). At high prey density, clearance rate did not differ between mix conditions, probably due to the fast gut saturation, which was reached in c.a. 15 min, as revealed by time series observations of gut contents. The fast saturation of ephyrae and their slow digestion time of approximately 18 h suggest the existence of a diel feeding periodicity. We conclude that in the Western Mediterranean, P. noctiluca ephyrae are capable of predating on ABFT eggs, a highly pulsed and spatially restricted resource that potentially switches from a 3D to a 2D configuration in the absence of wind-generated turbulence. The P. noctiluca and Atlantic Bluefin tuna egg system might represent an example of a general mechanism linking pelagic and neustonic food webs. PMID:24069335

  16. Detecting the presence-absence of bluefin tuna by automated analysis of medium-range sonars on fishing vessels

    PubMed Central

    Uranga, Jon; Arrizabalaga, Haritz; Boyra, Guillermo; Hernandez, Maria Carmen; Goñi, Nicolas; Arregui, Igor; Fernandes, Jose A.; Yurramendi, Yosu; Santiago, Josu

    2017-01-01

    This study presents a methodology for the automated analysis of commercial medium-range sonar signals for detecting presence/absence of bluefin tuna (Tunnus thynnus) in the Bay of Biscay. The approach uses image processing techniques to analyze sonar screenshots. For each sonar image we extracted measurable regions and analyzed their characteristics. Scientific data was used to classify each region into a class (“tuna” or “no-tuna”) and build a dataset to train and evaluate classification models by using supervised learning. The methodology performed well when validated with commercial sonar screenshots, and has the potential to automatically analyze high volumes of data at a low cost. This represents a first milestone towards the development of acoustic, fishery-independent indices of abundance for bluefin tuna in the Bay of Biscay. Future research lines and additional alternatives to inform stock assessments are also discussed. PMID:28152032

  17. Declining Mercury Concentrations in Bluefin Tuna Reflect Reduced Emissions to the North Atlantic Ocean.

    PubMed

    Lee, Cheng-Shiuan; Lutcavage, Molly E; Chandler, Emily; Madigan, Daniel J; Cerrato, Robert M; Fisher, Nicholas S

    2016-12-06

    Tunas are apex predators in marine food webs that can accumulate mercury (Hg) to high concentrations and provide more Hg (∼40%) to the U.S population than any other source. We measured Hg concentrations in 1292 Atlantic bluefin tuna (ABFT, Thunnus thynnus) captured in the Northwest Atlantic from 2004 to 2012. ABFT Hg concentrations and variability increased nonlinearly with length, weight, and age, ranging from 0.25 to 3.15 mg kg(-1), and declined significantly at a rate of 0.018 ± 0.003 mg kg(-1) per year or 19% over an 8-year period from the 1990s to the early 2000s. Notably, this decrease parallels comparably reduced anthropogenic Hg emission rates in North America and North Atlantic atmospheric Hg(0) concentrations during this period, suggesting that recent efforts to decrease atmospheric Hg loading have rapidly propagated up marine food webs to a commercially important species. This is the first evidence to suggest that emission reduction efforts have resulted in lower Hg concentrations in large, long-lived fish.

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

    PubMed

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

    2007-06-15

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

  19. Moving with the beat: heart rate and visceral temperature of free-swimming and feeding bluefin tuna.

    PubMed

    Clark, T D; Taylor, B D; Seymour, R S; Ellis, D; Buchanan, J; Fitzgibbon, Q P; Frappell, P B

    2008-12-22

    Owing to the inherent difficulties of studying bluefin tuna, nothing is known of the cardiovascular function of free-swimming fish. Here, we surgically implanted newly designed data loggers into the visceral cavity of juvenile southern bluefin tuna (Thunnus maccoyii) to measure changes in the heart rate (fH) and visceral temperature (TV) during a two-week feeding regime in sea pens at Port Lincoln, Australia. Fish ranged in body mass from 10 to 21 kg, and water temperature remained at 18-19 degrees C. Pre-feeding fH typically ranged from 20 to 50 beats min(-1). Each feeding bout (meal sizes 2-7% of tuna body mass) was characterized by increased levels of activity and fH (up to 130 beats min(-1)), and a decrease in TV from approximately 20 to 18 degrees C as cold sardines were consumed. The feeding bout was promptly followed by a rapid increase in TV, which signified the beginning of the heat increment of feeding (HIF). The time interval between meal consumption and the completion of HIF ranged from 10 to 24 hours and was strongly correlated with ration size. Although fH generally decreased after its peak during the feeding bout, it remained elevated during the digestive period and returned to routine levels on a similar, but slightly earlier, temporal scale to TV. These data imply a large contribution of fH to the increase in circulatory oxygen transport that is required for digestion. Furthermore, these data oppose the contention that maximum fH is exceptional in bluefin tuna compared with other fishes, and so it is likely that enhanced cardiac stroke volume and blood oxygen carrying capacity are the principal factors allowing superior rates of circulatory oxygen transport in tuna.

  20. Moving with the beat: heart rate and visceral temperature of free-swimming and feeding bluefin tuna

    PubMed Central

    Clark, T.D; Taylor, B.D; Seymour, R.S; Ellis, D; Buchanan, J; Fitzgibbon, Q.P; Frappell, P.B

    2008-01-01

    Owing to the inherent difficulties of studying bluefin tuna, nothing is known of the cardiovascular function of free-swimming fish. Here, we surgically implanted newly designed data loggers into the visceral cavity of juvenile southern bluefin tuna (Thunnus maccoyii) to measure changes in the heart rate (fH) and visceral temperature (TV) during a two-week feeding regime in sea pens at Port Lincoln, Australia. Fish ranged in body mass from 10 to 21 kg, and water temperature remained at 18–19°C. Pre-feeding fH typically ranged from 20 to 50 beats min−1. Each feeding bout (meal sizes 2–7% of tuna body mass) was characterized by increased levels of activity and fH (up to 130 beats min−1), and a decrease in TV from approximately 20 to 18°C as cold sardines were consumed. The feeding bout was promptly followed by a rapid increase in TV, which signified the beginning of the heat increment of feeding (HIF). The time interval between meal consumption and the completion of HIF ranged from 10 to 24 hours and was strongly correlated with ration size. Although fH generally decreased after its peak during the feeding bout, it remained elevated during the digestive period and returned to routine levels on a similar, but slightly earlier, temporal scale to TV. These data imply a large contribution of fH to the increase in circulatory oxygen transport that is required for digestion. Furthermore, these data oppose the contention that maximum fH is exceptional in bluefin tuna compared with other fishes, and so it is likely that enhanced cardiac stroke volume and blood oxygen carrying capacity are the principal factors allowing superior rates of circulatory oxygen transport in tuna. PMID:18755679

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

    PubMed Central

    2012-01-01

    Background Bluefin tunas are highly prized pelagic fish species representing a significant economic resource to fisheries throughout the world. Atlantic bluefin tuna (Thunnus thynnus) populations have significantly declined due to overexploitation. As a consequence of their value and population decline, T. thynnus has been the focus of considerable research effort concerning many aspects of their life history. However, in-depth understanding of T. thynnus reproductive biology is still lacking. Knowledge of reproductive physiology is a very important tool for determining effective fisheries and aquaculture management. Transcriptome techniques are proving powerful and provide novel insights into physiological processes. Construction of a microarray from T. thynnus ESTs sourced from reproductive tissues has provided an ideal platform to study the reproductive physiology of bluefin tunas. The aim of this investigation was to compare transcription profiles from the ovaries and testes of mature T. thynnus to establish sex specific variations underlying their reproductive physiology. Results Male and females T. thynnus gonad tissues were collected from the wild and histologically staged. Sub-samples of sexually mature tissues were also measured for their mRNA differential expression among the sexes using the custom microarray design BFT 4X44K. A total of 7068 ESTs were assessed for differential expression of which 1273 ESTs were significantly different (p<0.05) with >2 fold change in expression according to sex. Differential expression for 13 of these ESTs was validated with quantitative PCR. These include genes involved in egg envelope formation, hydration, and lipid transport/accumulation more highly expressed in ovaries compared with testis, while genes involved in meiosis, sperm motility and lipid metabolism were more highly expressed in testis compared with ovaries. Conclusions This investigation has furthered our knowledge of bluefin tunas reproductive biology by

  2. 76 FR 39019 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Quotas and Atlantic Tuna Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ... of available annual quota is determined by the ICCAT-recommended U.S. baseline BFT quota after... following year. At the time the proposed rule was prepared, NMFS determined that the same approach would be... other relevant factors provided under Sec. 635.27(a)(8), such as: The catches of the particular category...

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

    PubMed

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

    2015-04-01

    Following intense overfishing in the 1970s, the western stock of Atlantic bluefin tuna (Thunnus thynnus) experienced a long period of depressed abundance, which has been attributed to failure of the population to periodically produce large numbers of juveniles, the western stock mixing with the more highly exploited eastern stock (fisheries in the Northeast Atlantic Ocean and Mediterranean Sea), and regime shift in the population's ecosystem resulting in lower replacement rates. To evaluate the presence of relatively strong years of juvenile production, we analyzed age structure from a recent sample of otoliths (ear stones) collected from the western stock (2011-2013, North Carolina, U.S.A., winter fishery). Mixing levels for the recent sample were analyzed using otolith stable isotopes to test whether age structure might be biased through immigration of eastern stock bluefin tuna. Age structure from historical samples collected from United States and Canadian fisheries (1975-1981) was compared with more recent samples (1996-2007) to examine whether demographic changes had occurred to the western stock that might have disrupted juvenile production. Relatively high juvenile production occurred in 2003, 2005, and 2006. Otolith stable isotope analysis showed that these recruitments were mostly of western stock origin. However, these high recruitments were >2-fold less than historical recruitment. We found substantial age truncation in the sampled fisheries. Half the historical sample was >20 years old (mean age = 20.1 [SD 3.7]; skewness = -0.3), whereas <5% of the recent sample was >20 years old (mean age = 13.4 [SD 3.8]; skewness = 1.3). Loss of age structure is consistent with changes in fishing selectivity and trends in the stock assessment used for management. We propose that fishing, as a forcing variable, brought about a threshold shift in the western stock toward lower biomass and production, a shift that emulates the regime shift hypothesis. An abbreviated

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

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

    PubMed

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

    2016-09-22

    Atlantic bluefin tuna (Thunnus thynnus) are distributed throughout the North Atlantic and are both economically valuable and heavily exploited. The fishery is currently managed as two spawning populations, with the GOM population being severely depleted for over 20 years. In April-August of 2010, the Deepwater Horizon oil spill released approximately 4 million barrels of oil into the GOM, with severe ecosystem and economic impacts. Acute oil exposure results in mortality of bluefin eggs and larvae, while chronic effects on spawning adults are less well understood. Here we used 16 years of electronic tagging data for 66 bluefin tuna to identify spawning events, to quantify habitat preferences, and to predict habitat use and oil exposure within Gulf of Mexico spawning grounds. More than 54,000 km(2) (5%) of predicted spawning habitat within the US EEZ was oiled during the week of peak oil dispersal, with potentially lethal effects on eggs and larvae. Although the oil spill overlapped with a relatively small portion of predicted spawning habitat, the cumulative impact from oil, ocean warming and bycatch mortality on GOM spawning grounds may result in significant effects for a population that shows little evidence of rebuilding.

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

    PubMed Central

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

    2016-01-01

    Atlantic bluefin tuna (Thunnus thynnus) are distributed throughout the North Atlantic and are both economically valuable and heavily exploited. The fishery is currently managed as two spawning populations, with the GOM population being severely depleted for over 20 years. In April-August of 2010, the Deepwater Horizon oil spill released approximately 4 million barrels of oil into the GOM, with severe ecosystem and economic impacts. Acute oil exposure results in mortality of bluefin eggs and larvae, while chronic effects on spawning adults are less well understood. Here we used 16 years of electronic tagging data for 66 bluefin tuna to identify spawning events, to quantify habitat preferences, and to predict habitat use and oil exposure within Gulf of Mexico spawning grounds. More than 54,000 km2 (5%) of predicted spawning habitat within the US EEZ was oiled during the week of peak oil dispersal, with potentially lethal effects on eggs and larvae. Although the oil spill overlapped with a relatively small portion of predicted spawning habitat, the cumulative impact from oil, ocean warming and bycatch mortality on GOM spawning grounds may result in significant effects for a population that shows little evidence of rebuilding. PMID:27654709

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  10. Evaluation of Atlantic bluefin tuna reproductive potential in the western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Aranda, Guillermo; Medina, Antonio; Santos, Agustín; Abascal, Francisco J.; Galaz, Txema

    2013-02-01

    Ovarian tissue samples of Atlantic bluefin tuna (ABFT) spawners (n = 49) caught by purse seine in the Balearic Sea (western Mediterranean) were used to assess the stock reproductive characteristics. The frequency of spawning females estimated by the postovulatory follicle method was 84% and the spawning periodicity 1.2 days. Using an unbiased stereological method, the realized batch fecundity was estimated from counts of postovulatory follicles (POFs), whereas the batch fecundity of the subsequent spawn was estimated by quantification of the number of follicles containing oocytes at maturation stage (OMFs). The number of POFs was used as a reliable proxy of the realized batch fecundity, as it represents the actual number of eggs released in the last spawning event. The average relative realized batch fecundity was estimated to be approximately 48 eggs g- 1 of total body mass. While the absolute batch fecundity was isometrically related to the fork length, the relative batch fecundity was not dependent on fish size, which leads to the assumption that all length classes contribute proportionally to their size, towards the total number of eggs spawned by the broodstock. Size-related variations in the sex ratio were observed in the study area and in other Mediterranean locations; females were more abundant in mid-size classes while males predominated in large-size classes.

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

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  12. Near resonance acoustic scattering from organized schools of juvenile Atlantic bluefin tuna (Thunnus thynnus).

    PubMed

    Weber, Thomas C; Lutcavage, Molly E; Schroth-Miller, Madeline L

    2013-06-01

    Schools of Atlantic bluefin tuna (Thunnus thynnus) can exhibit highly organized spatial structure within the school. This structure was quantified for dome shaped schools using both aerial imagery collected from a commercial spotter plane and 400 kHz multibeam echo sounder data collected on a fishing vessel in 2009 in Cape Cod Bay, MA. Observations from one school, containing an estimated 263 fish within an approximately ellipsoidal volume of 1900 m(3), were used to seed an acoustic model that estimated the school target strength at frequencies between 10 and 2000 Hz. The fish's swimbladder resonance was estimated to occur at approximately 50 Hz. The acoustic model examined single and multiple scattering solutions and also a completely incoherent summation of scattering responses from the fish. Three levels of structure within the school were examined, starting with fish locations that were constrained by the school boundaries but placed according to a Poisson process, then incorporating a constraint on the distance to the nearest neighbor, and finally adding a constraint on the bearing to the nearest neighbor. Results suggest that both multiple scattering and spatial organization within the school should be considered when estimating the target strength of schools similar to the ones considered here.

  13. Muscular system in the pacific bluefin tuna Thunnus orientalis (Teleostei: Scombridae).

    PubMed

    Nakae, Masanori; Sasaki, Kunio; Shinohara, Gento; Okada, Tokihiko; Matsuura, Keiichi

    2014-02-01

    The muscular system in the Pacific bluefin tuna Thunnus orientalis is studied in detail. For the first time, a complete description of the muscular anatomy of a thunnid is provided here. Eighty-two elements including subdivisions of components of the muscular system are identified. This is less than found in a basal perciform and two other investigated scombrid species, owing mainly to the absence or fusion of pectoral, pelvic and caudal fin muscles. The absence of elements of the basal perciform pattern was most prominent in the caudal fin, which includes only the flexor dorsalis, flexor ventralis, hypochordal longitudinalis, and interradialis. In the caudal fin, the medial fan-shaped ray was identified as the first dorsal ray, judging from myological and neuroanatomical characters. The highly developed gill filament muscles in Thunnus orientalis and sheet-like rectus communis control gill ventilation. Long body muscle tendons reduce the metabolic energy needed during rapid and continuous swimming. These characters are interpreted as adaptations in the context of the oceanic life style of the species.

  14. Reconstructing transoceanic migration patterns of Pacific bluefin tuna using a chemical tracer toolbox.

    PubMed

    Madigan, Daniel J; Baumann, Zofia; Carlisle, Aaron B; Hoen, Danielle K; Popp, Brian N; Dewar, Heidi; Snodgrass, Owyn E; Block, Barbara A; Fisher, Nicholas S

    2014-06-01

    Large pelagic predators play important roles in oceanic ecosystems, and may migrate vast distances to utilize resources in different marine ecoregions. Understanding movement patterns of migratory marine animals is critical for effective management, but often challenging, due to the cryptic habitat of pelagic migrators and the difficulty of assessing past movements. Chemical tracers can partially circumvent these challenges by reconstructing recent migration patterns. Pacific bluefin tuna (Thunnus orientalis; PBFT) inhabit the western and eastern Pacific Ocean, and are in steep decline due to overfishing. Understanding age-specific eastward transpacific migration patterns can improve management practices, but these migratory dynamics remain largely unquantified. Here, we combine a Fukushima-derived radiotracer (134Cs) with bulk tissue and amino acid stable isotope analyses of PBFT to distinguish recent migrants from residents of the eastern Pacific Ocean. The proportion of recent migrants to residents decreased in older year classes, though the proportion of older PBFT that recently migrated across the Pacific was greater than previous estimates. This novel toolbox of biogeochemical tracers can be applied to any species that crosses the North Pacific Ocean.

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

    PubMed

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Jusup, Marko; Klanjšček, Tin; Matsuda, Hiroyuki

    2014-11-01

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

  18. Spawning Behaviour and Post-Spawning Migration Patterns of Atlantic Bluefin Tuna (Thunnus thynnus) Ascertained from Satellite Archival Tags

    PubMed Central

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

    2013-01-01

    Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus) was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands (years 2009-2011). All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples. PMID:24098502

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

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

    PubMed

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

    2014-04-01

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

  1. Schooling behaviour of juvenile Pacific bluefin tuna Thunnus orientalis depends on their vision development.

    PubMed

    Torisawa, S; Fukuda, H; Suzuki, K; Takagi, T

    2011-11-01

    The effects of vision development and light intensity on schooling behaviour during growth in juvenile Pacific bluefin tuna Thunnus orientalis were investigated using both behavioural and histological approaches. The schooling behaviour of three age groups [25, 40 and 55 days post hatching (dph)] of juvenile T. orinetalis were examined under various light intensities. Subsequently, schooling variables, such as the nearest neighbour distance (D(NN) ) and the separation swimming index (I(SS) ), were also measured under different light intensities. Furthermore, retinal indices of light adaptation in juvenile fish at each experimental light intensity and visual acuities in six stages (25-55 dph) of juveniles were examined histologically. During growth, the light intensity thresholds of I(SS) decreased from 5 to 0·05 lx, and D(NN) under light conditions (>300 lx) also decreased from 9·2 times the standard length (L(S) ) to 1·2 times L(S) . The thresholds of light intensities for the light adaptation of retinas in juveniles (25-55 dph) similarly decreased from 5 to 0·05 lx with growth. In addition, the visual acuities of juveniles developed from 0·04 to 0·17 with decreasing D(NN) . These data clearly indicate that the characteristics of schooling behaviour strongly correspond to the degree of vision development. Juvenile T. orinetalis also appear to be more dependent on cone rather than rod cells under low light intensity conditions, resulting in a relatively high light intensity threshold for schooling. These results suggest that juveniles can adapt to darker conditions during growth by developing improved visual capabilities.

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

    PubMed

    Takagi, Tsutomu; Tamura, Yumiko; Weihs, Daniel

    2013-11-07

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2004-11-01

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

  5. Tissue Turnover Rates and Isotopic Trophic Discrimination Factors in the Endothermic Teleost, Pacific Bluefin Tuna (Thunnus orientalis)

    PubMed Central

    Madigan, Daniel J.; Litvin, Steven Y.; Popp, Brian N.; Carlisle, Aaron B.; Farwell, Charles J.; Block, Barbara A.

    2012-01-01

    Stable isotope analysis (SIA) of highly migratory marine pelagic animals can improve understanding of their migratory patterns and trophic ecology. However, accurate interpretation of isotopic analyses relies on knowledge of isotope turnover rates and tissue-diet isotope discrimination factors. Laboratory-derived turnover rates and discrimination factors have been difficult to obtain due to the challenges of maintaining these species in captivity. We conducted a study to determine tissue- (white muscle and liver) and isotope- (nitrogen and carbon) specific turnover rates and trophic discrimination factors (TDFs) using archived tissues from captive Pacific bluefin tuna (PBFT), Thunnus orientalis, 1–2914 days after a diet shift in captivity. Half-life values for 15N turnover in white muscle and liver were 167 and 86 days, and for 13C were 255 and 162 days, respectively. TDFs for white muscle and liver were 1.9 and 1.1‰ for δ15N and 1.8 and 1.2‰ for δ13C, respectively. Our results demonstrate that turnover of 15N and 13C in bluefin tuna tissues is well described by a single compartment first-order kinetics model. We report variability in turnover rates between tissue types and their isotope dynamics, and hypothesize that metabolic processes play a large role in turnover of nitrogen and carbon in PBFT white muscle and liver tissues. 15N in white muscle tissue showed the most predictable change with diet over time, suggesting that white muscle δ15N data may provide the most reliable inferences for diet and migration studies using stable isotopes in wild fish. These results allow more accurate interpretation of field data and dramatically improve our ability to use stable isotope data from wild tunas to better understand their migration patterns and trophic ecology. PMID:23145128

  6. Global habitat preferences of commercially valuable tuna

    NASA Astrophysics Data System (ADS)

    Arrizabalaga, Haritz; Dufour, Florence; Kell, Laurence; Merino, Gorka; Ibaibarriaga, Leire; Chust, Guillem; Irigoien, Xabier; Santiago, Josu; Murua, Hilario; Fraile, Igaratza; Chifflet, Marina; Goikoetxea, Nerea; Sagarminaga, Yolanda; Aumont, Olivier; Bopp, Laurent; Herrera, Miguel; Marc Fromentin, Jean; Bonhomeau, Sylvain

    2015-03-01

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

  7. Transcriptome analysis reveals differentially expressed genes associated with germ cell and gonad development in the Southern bluefin tuna (Thunnus maccoyii).

    PubMed

    Bar, Ido; Cummins, Scott; Elizur, Abigail

    2016-03-10

    Controlling and managing the breeding of bluefin tuna (Thunnus spp.) in captivity is an imperative step towards obtaining a sustainable supply of these fish in aquaculture production systems. Germ cell transplantation (GCT) is an innovative technology for the production of inter-species surrogates, by transplanting undifferentiated germ cells derived from a donor species into larvae of a host species. The transplanted surrogates will then grow and mature to produce donor-derived seed, thus providing a simpler alternative to maintaining large-bodied broodstock such as the bluefin tuna. Implementation of GCT for new species requires the development of molecular tools to follow the fate of the transplanted germ cells. These tools are based on key reproductive and germ cell-specific genes. RNA-Sequencing (RNA-Seq) provides a rapid, cost-effective method for high throughput gene identification in non-model species. This study utilized RNA-Seq to identify key genes expressed in the gonads of Southern bluefin tuna (Thunnus maccoyii, SBT) and their specific expression patterns in male and female gonad cells. Key genes involved in the reproductive molecular pathway and specifically, germ cell development in gonads, were identified using analysis of RNA-Seq transcriptomes of male and female SBT gonad cells. Expression profiles of transcripts from ovary and testis cells were compared, as well as testis germ cell-enriched fraction prepared with Percoll gradient, as used in GCT studies. Ovary cells demonstrated over-expression of genes related to stem cell maintenance, while in testis cells, transcripts encoding for reproduction-associated receptors, sex steroids and hormone synthesis and signaling genes were over-expressed. Within the testis cells, the Percoll-enriched fraction showed over-expression of genes that are related to post-meiosis germ cell populations. Gonad development and germ cell related genes were identified from SBT gonads and their expression patterns in

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

    PubMed

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

    2013-06-15

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

  9. Empirical models to identify mechanisms driving reductions in tissue mercury concentration during culture of farmed southern bluefin tuna Thunnus maccoyii.

    PubMed

    Balshaw, S; Edwards, J W; Ross, K E; Ellis, D; Padula, D J; Daughtry, B J

    2008-12-01

    Two empirical models are presented to elucidate the mechanisms driving reductions in the mercury concentration of southern bluefin tuna (SBT) during culture. Model 1 predicts temporal fluctuations in mercury concentration in response to growth dilution. Model 2 predicts the combined effects of growth dilution and linear mercury accumulation. Model 2 was found to be the more accurate model. Over a typical farming period of 136 days, growth dilution resulted in a reduction in mean mercury concentration of SBT edible tissues from 0.51 mg/kg down to 0.33 mg/kg. Extended culture beyond 136 days resulted in an increase in mercury concentration due to the combined effects of mercury accumulation and seasonal lipid depletion. Results indicate that under current industry practice, cultured SBT can be consumed twice as frequently as that of wild caught SBT while maintaining total dietary mercury intake below national recommendations.

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

  12. 77 FR 3637 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries; General Category Fishery

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ...; closure. SUMMARY: NMFS closes the General category fishery for large medium and giant Atlantic bluefin.... Therefore, through May 31, 2012, fishing for, retaining, possessing, or landing large medium or giant BFT by... BFT fishery before landings of large medium and giant BFT exceed the available subquota....

  13. 78 FR 11788 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries; General Category Fishery

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ...; closure. SUMMARY: NMFS closes the General category fishery for large medium and giant Atlantic bluefin..., retaining, possessing, or landing large medium or giant BFT by persons aboard vessels permitted in the... large medium and giant BFT exceed the available subquota. Therefore, the AA finds good cause under 5...

  14. 77 FR 38011 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... closes the incidental Longline category northern area fishery for large medium and giant Atlantic bluefin... amount of large medium and giant BFT (measuring 73 inches (185 cm) curved fork length (CFL) or greater..., through December 31, 2012, fishing for, retaining, possessing, or landing large medium or giant BFT north...

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Bauer, Robert Klaus; Demarcq, Hervé; Brisset, Blandine

    2015-01-01

    Different dolphin and tuna species have frequently been reported to aggregate in areas of high frontal activity, sometimes developing close multi-species associations to increase feeding success. Aerial surveys are a common tool to monitor the density and abundance of marine mammals, and have recently become a focus in the search for methods to provide fisheries-independent abundance indicators for tuna stock assessment. In this study, we present first density estimates corrected for availability bias of fin whales (Balaenoptera physalus) and striped dolphins (Stenella coeruleoalba) from the Golf of Lions (GoL), compared with uncorrected estimates of Atlantic bluefin tuna (ABFT; Thunnus thynnus) densities from 8 years of line transect aerial surveys. The raw sighting data were further used to analyze patterns of spatial co-occurrence and density of these three top marine predators in this important feeding ground in the Northwestern Mediterranean Sea. These patterns were investigated regarding known species-specific feeding preferences and environmental characteristics (i. e. mesoscale activity) of the survey zone. ABFT was by far the most abundant species during the surveys in terms of schools and individuals, followed by striped dolphins and fin whales. However, when accounted for availability bias, schools of dolphins and fin whales were of equal density. Direct interactions of the species appeared to be the exception, but results indicate that densities, presence and core sighting locations of striped dolphins and ABFT were correlated. Core sighting areas of these species were located close to an area of high mesoscale activity (oceanic fronts and eddies). Fin whales did not show such a correlation. The results further highlight the feasibility to coordinate research efforts to explore the behaviour and abundance of the investigated species, as demanded by the Marine Strategy Framework Directive (MSFD). PMID:26458254

  17. Relationships between tuna catch and variable frequency oceanographic conditions

    NASA Astrophysics Data System (ADS)

    Ormaza-González, Franklin Isaac; Mora-Cervetto, Alejandra; María Bermúdez-Martínez, Raquel

    2016-08-01

    Skipjack (Katsuwunus pelamis), yellow fin (Thunnus albacares) and albacore (Thunnus alulunga) tunas landed in the Eastern Pacific Ocean (EPO) countries and Ecuador were correlated to the Indexes Oceanic El Niño (ONI) and Multivariate Enso Index (MEI). The temporal series 1983-2012, and 1977-1999 (warm Pacific Decadal Oscillation, PDO), and 2000-2012 (cold PDO) were analyzed. Linear correlation showed that at least 11 % of the total landings were associated with the MEI, with a slightly negative gradient from cold to warm conditions. When non-linear regression (n = 6), the R2 was higher up to 0.304 (MEI, r = 0.551). The correlation shows high spread from -0.5 to +0.5 for both MEI/ONI; the highest landings occurred at 0.34-0.45; both indexes suggested that at extreme values < -1.0 and > 1.1 total landings tend to decrease. Landings were associated up to 21.9 % (MEI) in 2000-2012, 1983-1999 rendered lower R2 (< 0.09); i.e., during cold PDO periods there was a higher association between landings and oceanographic conditions. For the non-linear regression (n = 6) a R2 of 0.374 (MEI) and 0.408 (ONI) were registered, for the 2000-2012, a higher R2 was observed in 1983-1999, 0.443 and 0.711 for MEI and ONI respectively, suggesting that is better to analyze split series (1983-1999, 2000-2012) than as a whole (1983-2012), due to noise produced by the transition from hot to cold PDOs. The highest landings were in the range -0.2 to 0.5 for MEI/ONI. The linear regression of skipjack landings in Ecuador gave an R2 of 0.140 (MEI) and 0.066 (ONI) and the non-linear were 0.440 and 0.183 respectively. Total landings in the EPO associated to oceanographic events of high and low frequencies could be used somehow as predictors of the high El Niño o La Niña. There is a clear evidence that tuna fish biomass are at higher levels when the PDO is on cold phase (2000-2030) and vice versa on warm phase (1980-1999). The analysis of the skipjack catch per unit effort (CPUE) on floating

  18. Comparative phylogeography of Atlantic bluefin tuna and swordfish: the combined effects of vicariance, secondary contact, introgression, and population expansion on the regional phylogenies of two highly migratory pelagic fishes.

    PubMed

    Alvarado Bremer, Jaime R; Viñas, Jordi; Mejuto, Jaime; Ely, Bert; Pla, Carles

    2005-07-01

    Comparative phylogeography has revealed remarkable patterns of concordance in the maternal phylogenies of many species. The phylogeography and historical demography of the mitochondrial control region I for 607 Atlantic bluefin tuna (Thunnus thynnus) and 275 swordfish (Xiphias gladius) were analyzed to clarify the complex phylogenetic signals in the North Atlantic-Mediterranean region where they are sympatric. Atlantic bluefin tuna mtDNA is polyphyletic, and includes rare sequences sister to Pacific bluefin tuna (Thunnus orientalis) and introgressed albacore (Thunnus alalunga) sequences. There is no geographic partitioning between Atlantic and Mediterranean samples of Atlantic bluefin tuna (Phi(ST)=0.002). In contrast, Atlantic and Mediterranean swordfish are differentiated (Phi(ST)=0.091) due to the combined effects of vicariance, secondary contact, and dissimilar regional demographic histories. Mediterranean swordfish has substantially less variation, and a more recent history (tau=2.42) than that of Atlantic swordfish (tau=7.02). In spite of the discordant phylogenetic and phylogeographic signals, the demographic history of Atlantic swordfish and Atlantic bluefin tuna (tau=7.51) suggests concordance in the timeline of population expansion. Possible scenarios of cladogenesis, expansion, and contraction, influenced by glacial cycles during the Pleistocene, are formulated.

  19. Long-term monitoring of the impact of a capture-based bluefin tuna aquaculture on water column nutrient levels in the Eastern Aegean Sea, Turkey.

    PubMed

    Aksu, Mehmet; Kaymakçi-Başaran, Asli; Egemen, Ozdemir

    2010-12-01

    Capture-based aquaculture of Atlantic bluefin tuna in the Mediterranean has been expanding rapidly but little is known about its environmental impact. In order to understand the consequences of this new sector, long-term monitoring is needed. For this purpose, we investigated the impact of a capture-based tuna farm located in the Gerence Bay (Aegean Sea) on the water column on a seasonal basis from 2005 to 2008, where in the water column, temperature, salinity, pH, dissolved oxygen, nutrients (nitrite, nitrate, ammonium, and phosphate), and chlorophyll a, in the sediment organic carbon variables were measured. Although highest nutrient concentrations were observed at the cage station as compared to the two controls in the production period, differences were not statistically significant between stations. Monitoring of physico-chemical parameters, nutrients, and chlorophyll a in water column together with organic carbon in sediment did not show detectable impact of fattening of Atlantic bluefin tuna. This was probably caused by strong currents present in the area, location of the cages away from the coast, hence high water depth, controlled feeding, and periodic presence of tuna farming activity in the study area.

  20. Computational Fluid Dynamics of the Boundary Layer Characteristics of a Pacific Bluefin Tuna

    DTIC Science & Technology

    2015-09-18

    subtracted from the cube using a Boolean operation. The same meshing procedure was employed on the surface of the cube and the meshed interface between the...advanced propulsion mechanism (or both). The issue of whether the boundary layer on a tuna swimming at typical speeds (1 to 2 body lengths/sec) is laminar...compute the approximate lateral location at which transition to turbulence occurs on the tuna for various swimming speeds, and to determine the maximum

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

    PubMed

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

    2016-04-01

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

  2. Habitat overlap between southern bluefin tuna and yellowfin tuna in the east coast longline fishery - implications for present and future spatial management

    NASA Astrophysics Data System (ADS)

    Hartog, Jason R.; Hobday, Alistair J.; Matear, Richard; Feng, Ming

    2011-03-01

    Southern bluefin tuna (SBT) are presently a quota-managed species in the multi-species eastern Australian tuna and billfish longline fishery (ETBF). Capture of SBT is regulated by quota, as is access to regions likely to contain SBT. A habitat prediction model combining data from an ocean model and pop-up satellite archival tags is used to define habitat zones based on the probability of SBT occurrence. These habitat zones are used by fishery managers to restrict access by ETBF fishers to SBT habitat during a May-November management season. The zones display a distinct seasonal cycle driven by the seasonal southward expansion and northward contraction of the East Australia Current (EAC) and as a result access by fishers to particular ocean regions changes seasonally. This species also overlaps with the commercially valuable yellowfin tuna (YFT), thus, we modified the SBT model to generate YFT habitat predictions in order to investigate habitat overlap between SBT and YFT. There is seasonal variation in the overlap of the core habitat between these two species, with overlap early (May-Jul) in the management season and habitat separation occurring towards the end (Aug-Nov). The EAC is one of the fastest warming ocean regions in the southern hemisphere. To consider the future change in distribution of these two species compared to the present and to explore the potential impact on fishers and managers of the future, we use future ocean predictions from the CSIRO Bluelink ocean model for the year 2064 to generate habitat predictions. As the ocean warms on the east coast of Australia and the EAC extends southward, our model predicts the suitable habitat for SBT and YFT will move further south. There was an increase in the overlap of SBT and YFT habitat throughout the management season, due to regional variation of each species' habitat. These results illustrate that a management tradeoff exists between restricting fisher access to SBT habitat and allowing access to YFT

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

    PubMed

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

    2017-04-01

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

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2017-12-01

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

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

    PubMed

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

    2015-01-01

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

  7. Fin Spine Bone Resorption in Atlantic Bluefin Tuna, Thunnus thynnus, and Comparison between Wild and Captive-Reared Specimens

    PubMed Central

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

    2015-01-01

    Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT) has long been considered for age estimation studies. In the present paper spine bone resorption was assessed in wild (aged 1 to 13 years) and captive-reared (aged 2 to 11 years) ABFT sampled from the Mediterranean Sea. Total surface (TS), solid surface (SS) and reabsorbed surface (RS) were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions. PMID:25751271

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

    PubMed Central

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

    2015-01-01

    The Atlantic bluefin tuna, Thunnus thynnus, is a commercially important species that has been severely over-exploited in the recent past. Although the eastern Atlantic and Mediterranean stock is now showing signs of recovery, its current status remains very uncertain and as a consequence their recovery is dependent upon severe management informed by rigorous scientific research. Monitoring of early life history stages can inform decision makers about the health of the species based upon recruitment and survival rates. Misidentification of fish larvae and eggs can lead to inaccurate estimates of stock biomass and productivity which can trigger demands for increased quotas and unsound management conclusions. Herein we used a molecular approach employing mitochondrial and nuclear genes (CO1 and ITS1, respectively) to identify larvae (n = 188) collected from three spawning areas in the Mediterranean Sea by different institutions working with a regional fisheries management organization. Several techniques were used to analyze the genetic sequences (sequence alignments using search algorithms, neighbour joining trees, and a genetic character-based identification key) and an extensive comparison of the results is presented. During this process various inaccuracies in related publications and online databases were uncovered. Our results reveal important differences in the accuracy of the taxonomic identifications carried out by different ichthyoplanktologists following morphology-based methods. While less than half of larvae provided were bluefin tuna, other dominant taxa were bullet tuna (Auxis rochei), albacore (Thunnus alalunga) and little tunny (Euthynnus alletteratus). We advocate an expansion of expertise for a new generation of morphology-based taxonomists, increased dialogue between morphology-based and molecular taxonomists and increased scrutiny of public sequence databases. PMID:26147931

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

    PubMed

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

    2015-01-01

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

  10. Front variability and surface ocean features of the presumed southern bluefin tuna spawning grounds in the tropical southeast Indian Ocean

    NASA Astrophysics Data System (ADS)

    Nieblas, Anne-Elise; Demarcq, Hervé; Drushka, Kyla; Sloyan, Bernadette; Bonhommeau, Sylvain

    2014-09-01

    The southern bluefin tuna (SBT, Thunnus maccoyii) is an ecologically and economically valuable fish. However, surprisingly little is known about its critical early life history, a period when mortality is several orders of magnitude higher than at any other life stage, and when larvae are highly sensitive to environmental conditions. Ocean fronts can be important in creating favourable spawning conditions, as they are a convergence of water masses with different properties that can concentrate planktonic particles and lead to enhanced productivity. In this study, we examine the front activity within the only region where SBT have been observed to spawn: the tropical southeast Indian Ocean between Indonesia and Australia (10°S-20°S, 105°E-125°E). We investigate front activity and its relationship to ocean dynamics and surface features of the region. Results are also presented for the entire Indian Ocean (30°N-45°S, 20°E-140°E) to provide a background context. We use an extension of the Cayula and Cornillon algorithm to detect ocean fronts from satellite images of sea surface temperature (SST) and chlorophyll-a concentration (chl-a). Front occurrence represents the probability of occurrence of a front at each pixel of an image. Front intensity represents the magnitude of the difference between the two water masses that make up a front. Relative to the rest of the Indian Ocean, both SST and chl-a fronts in the offshore spawning region are persistent in occurrence and weak in intensity. Front occurrence and intensity along the Australian coast are high, with persistent and intense fronts found along the northwest and west coasts. Fronts in the tropical southeast Indian Ocean are shown to have strong annual variability and some moderate interannual variability. SST front occurrence is found to lead the Southern Oscillation Index by one year, potentially linked to warming and wind anomalies in the Indian Ocean. The surface ocean characteristics of the offshore

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

    PubMed

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

    2016-10-02

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

  13. Levels of polychlorinated biphenyls (PCB) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in fillets of farmed Southern Bluefin Tuna (Thunnus maccoyii).

    PubMed

    Phua, Samuel T G; Ashman, Peter J; Daughtry, Ben J

    2008-10-01

    Southern Bluefin Tuna (SBT) (Thunnus maccoyii) is the only farmed tuna species in the southern hemisphere, with production centred offshore of Port Lincoln, South Australia. SBT farming is a quota-based fishery where farmers fatten wild-caught stock for subsequent sale as fresh-chilled or frozen product, mainly to Japanese markets. Fillets from wild-caught and farmed SBT were analysed and the concentration of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are reported for the first time. Time of farming was separated into two periods: a typical farming period of approximately five months and an experimental scenario that involved holding (farming) these fish for an additional 12 months. WHO-PCB and WHO-PCDD/F TEQ concentrations in fillets on a fresh weight basis at the same times and over the same periods were, 0.67-1.18pg-TEQg(-1) and 0.16-0.29pg-TEQg(-1), respectively. All WHO-PCB congeners, and only three WHO-PCDD/F congeners, were found to biomagnify during farming, after blank correction. Caution should be exercised when extrapolating these results to SBT farming as a whole because of the use of varying husbandry and feeding practices employed by different companies.

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

    PubMed

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

    2017-02-01

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

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

    PubMed

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

    2015-06-01

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

  16. Temperature-induced transcription of inflammatory mediators and the influence of Hsp70 following LPS stimulation of southern bluefin tuna peripheral blood leukocytes and kidney homogenates.

    PubMed

    Polinski, Mark; Bridle, Andrew; Nowak, Barbara

    2013-05-01

    Temperature is known to influence inflammatory signalling in mammals, but far less understood in fish. The aim of the present study was to explore the potential effects of temperature on innate immune signalling in head kidney and leukocyte populations of the economically important southern bluefin tuna through the identification and utilization of gene expression targets in vitro. Here, we identified the mRNA sequences of five potential inflammatory mediators - TNFα (1 and 2), IL-1β, IL-8, and Cox2 - and demonstrate induction of four - TNFα (2), IL-1β, IL-8, and Cox2 - following LPS stimulation of both peripheral blood leukocytes and head kidney homogenates in vitro by real-time quantitative PCR. Comparison of transcriptional expression in cultures held at 18 and 25 °C (both within the presumed natural temperature range of this heterothermic species) showed accelerated transcription of cytokines TNFα, IL-1β and IL-8 following LPS stimulation at 25 °C in both tissue types. Peak induction reached comparable levels for each transcript at both temperatures during the 24 h test period with only limited (if any) protraction in expression resulting from cold temperature (18 °C) incubation. Partial mRNA sequences were also identified for both the constitutively expressed and heat inducible chaperone proteins Hsc70 and Hsp70, and 24 h incubation at 25 °C was sufficient to induce Hsp70 transcription in leukocyte but not in head kidney cell populations. Taken together these findings suggest that temperature exerts influence in the timing but not the degree of an innate inflammatory response in bluefin tuna and that different cell populations have differential responsiveness to heat shock in this heterothermic species. Further, LPS stimulation failed to induce Hsp70 at either incubation temperature in leukocytes; whereas 25 °C incubation caused Hsp70 up-regulation in leukocytes with or without the presence of LPS. This suggests that Hsp70 does not play a

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

    PubMed

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

    2016-11-01

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

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

    PubMed

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

    2017-01-01

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

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

    PubMed Central

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

    2017-01-01

    Intentional mislabelling of seafood is a widespread problem, particularly with high-value species like tuna. In this study we examine tuna mislabelling, deliberate species substitution, types of substitution and its impact on prices. The survey covered the commercial chain, from Merca-Barna to fishmongers and restaurants in the Spanish Autonomous Community of Catalonia. To understand the geographic extent of the problem we also sampled Merca-Madrid, Europe’s biggest fish market, and Merca-Málaga for its proximity to the bluefin tuna migratory route and trap fishery. Monthly surveys were carried out over one year. The results showed a high deficiency in labelling: 75% of points of sale and 83% of restaurants did not specify the species, and in those cases the name of the species had to be asked. A total of 375 samples were analysed genetically, the largest dataset gathered in Europe so far. The identified species were Thunnus albacares, Thunnus thynnus and Thunnus obesus. Species substitution began at suppliers, with 40% of observed cases, increasing to 58% at fishmongers and 62% at restaurants. The substitution was mainly on bluefin tuna (T. thynnus), 73% of cases. At restaurants, only during the bluefin fishing season, we observed a decrease of Bluefin tuna substitution and an increase of reverse substitution revealing some illegal fishing. The effect of species substitution on species prices was relevant: T. obesus increased its price by around €12 kg-1 when it was sold as bluefin. In view of the deficiency of labelling, the abuse of generic names and the lack of the bluefin catch document, we conclude that the Spanish regulations are ineffective, highlighting the need for policy execution, and the urgent need for information campaigns to Spanish consumers. PMID:28125686

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  2. Distribution of persistent organic pollutants (POPS) IN wild Bluefin tuna (Thunnus thynnus) from different FAO capture zones.

    PubMed

    Chiesa, L M; Labella, G F; Panseri, S; Pavlovic, R; Bonacci, S; Arioli, F

    2016-06-01

    Residues of environmental contaminants in food represent a concern in food safety programs. In this study, the distribution of persistent organic pollutants (POPs) were evaluated in 79 tuna samples from FAO areas 51 (Indian Ocean), 71 (Pacific Ocean), 34 (Atlantic Ocean), and 37 (Mediterranean Sea). 6 polychlorinated biphenyls (PCBs), 16 organochlorines (OCs) and 7 polybrominated biphenyl ethers (PBDEs) were selected as representative compounds according to EFSA POPs monitoring guidelines. An analytical method, based on Accelerated Solvent Extraction (ASE), with an "in-line" clean-up step and GC-MS/MS detection, was developed, validated and applied. PCBs were detected in all FAO areas, with a prevalence of 100% for most of them. In the FAO area 37, only, all PBDEs were detected. Only 5 OCs were detected. The results showed that POPs contamination of tuna reflects FAO area contamination; in particular FAO area 37 was the most polluted. Moreover, tuna muscle was an appropriate matrix for monitoring contamination and for obtaining information about food safety.

  3. Case-control study of epidemic mortality and Cardicola forsteri-associated disease in farmed southern bluefin tuna (Thunnus maccoyii) of South Australia.

    PubMed

    Dennis, M M; Landos, M; D'Antignana, T

    2011-07-01

    Cardicola forsteri is a blood fluke that is highly prevalent among cultured southern bluefin tuna (SBT), Thunnus maccoyii, in South Australia. The role of C forsteri in annual SBT mortality outbreaks, which peak 6 to 12 weeks poststocking, is unknown. The objective of this study was to identify lesions unique to cultured SBT that died during a mortality event in 2009 and to determine the significance of C forsteri-associated lesions. Cultured SBT were sampled from 4 pontoons of a single site in Spencer Gulf that experienced a mortality epidemic that spanned 5 to 14 weeks poststocking. Study SBT comprised 7 that died during peak mortality, 27 that did not die, and 10 wild-caught (noncultured) SBT. All cultured SBT had branchitis and myocarditis due to C forsteri, whereas no life stages of C forsteri were histologically identified in any wild-caught SBT. Mortality was associated with the presence of severe branchitis (P<.005), and the odds of severe branchitis were 90 times greater for SBT that died than for SBT that were live caught during peak mortality (95% confidence interval, 5 to 1,684). In SBT that had died, no lesions other than those associated with C forsteri were of sufficient severity or physiologic significance to account for death. Other lesions common among cultured SBT included systemic granulocytic perivascular infiltrate, granulocytic gastric infiltrate, hepatic lipidosis, visceral granulomas, and branchial parasitic infestation. This study shows for the first time that a substantial proportion of poststocking mortality in cultured SBT is strongly associated with severe branchitis caused by C forsteri.

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

    NASA Astrophysics Data System (ADS)

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

    2017-07-01

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

  5. Potential impacts of climate change on the distribution of longline catches of yellowfin tuna (Thunnus albacares) in the Tasman sea

    NASA Astrophysics Data System (ADS)

    Dell, James T.; Wilcox, Chris; Matear, Richard J.; Chamberlain, Matthew A.; Hobday, Alistair J.

    2015-03-01

    The spatial distribution of living marine resources in the Tasman Sea is expected to shift due to the impacts of global climate change. Understanding the most likely future locations of valuable pelagic species will inform the sustainable harvest and management of species such as yellowfin tuna (YFT; Thunnus albacares). We estimate future upper ocean structure in the Tasman Sea, using both historical data and dynamically downscaled ocean projections for the 2060s, and apply a catch distribution model to estimate possible changes to the YFT catch in the eastern Australia domestic longline fishery. Both approaches project that locations with concentrated YFT catch in the Tasman Sea will shift poleward in response to likely climate change. By the 2060s, the core fishing areas are projected to have shifted both poleward and offshore of existing high catch areas. Shifts in the distribution and hence availability of this species may require future domestic fishing vessels to modify their fishing behaviors, which in turn may require social and economic adjustments.

  6. Identification of factors influencing shark catch and mortality in the Marshall Islands tuna longline fishery and management implications.

    PubMed

    Bromhead, D; Clarke, S; Hoyle, S; Muller, B; Sharples, P; Harley, S

    2012-04-01

    Recent average annual catches of sharks by tuna longline vessels fishing in the Republic of the Marshall Islands (RMI) are estimated to be between 1583 and 2274 t. Although 22 shark species have been recorded by the observer programme for this fishery, 80% of the annual catch comprises only five species: blue shark Prionace glauca, silky shark Carcharhinus falciformis, bigeye thresher shark Alopias superciliosus, pelagic thresher shark Alopias pelagicus and oceanic whitetip shark Carcharhinus longimanus. Wire leaders (i.e. branch lines or traces) were also used by nearly all observed vessels. Generalized additive model (GAM)-based analyses of catch rates indicated that P. glauca and A. superciliosus are caught in higher numbers when vessels fish in relatively cooler waters, at night, close to the full moon, when the 27° C thermocline is close to the surface and during El Niño conditions. In contrast, C. falciformis, A. pelagicus and C. longimanus are caught in higher numbers when shark lines are used (all three species) or hooks are set at a shallow depth (A. pelagicus and C. longimanus and, also, P. glauca). These findings are generally consistent with current knowledge of these species' habitat preferences, movement and distribution. The results of these analyses were combined with information pertaining to shark condition and fate upon capture to compare the likely effectiveness of a range of potential measures for reducing shark mortality in the longline fishery. Of the options considered, the most effective would be to combine measures that reduce the catch rate (e.g. restrictions on the use of wire leaders, shark baits and shark lines) with measures that increase survival rates after post-capture release (e.g. finning bans). © 2012 Secrtariat of the Pacific Community. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

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

    PubMed

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

    2015-08-01

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

  8. 77 FR 73969 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... member of the IATTC and to reduce overfishing of the stock. DATES: Comments must be submitted in writing... are an important step for reducing the overfishing of bluefin tuna. In 2011, NMFS determined overfishing is occurring on Pacific bluefin tuna based on stock assessment results of the...

  9. El Nino Southern Oscillation (ENSO) impact on tuna fisheries in Indian Ocean.

    PubMed

    Kumar, Palanisamy Satheesh; Pillai, Gopalakrishna N; Manjusha, Ushadevi

    2014-01-01

    El Nino Southern Oscillation (ENSO) is an important driver of interannual variations in climate and ecosystem productivity in tropical regions. However, detailed information about this important phenomenon of the Indian Ocean is scarce. Consequently, the objective of this study is to improve understanding of the impact of warm event El Nino and cool event La Nina on annual tuna landings from the Indian Ocean from 1980 to 2010. In this study, maximum tuna landings were recorded during a weak El Nino year (1456054 t in 2006) and during a weak La Nina year (1243562 t in 2000), although the lowest tuna catch was followed during the strong El Nino year (1204119 t in 2009) and during a strong La Nina year (706546 t in 1988). Validation of predicted tuna landings and SST were showing a significant positive correlation (p < 0.01) was observed all the major tuna species except Southern Bluefin Tuna. Whereas the other relationships such as sea level pressure, Wind actions; Zonal Wind (U), Meridonial Wind (V), and Scalar Wind (W) are less well-defined. In contrast with principal component analysis we find that Principal Components 1 explains 75.5% of the total variance and suggest that sea surface temperature plays a major role in determining tuna availability in the region especially during warm event El Nino years; landings in Indian Ocean tend to be optimum SST 25 to 26°C in ENSO event. Our results confirm the ENSO impact on climate, tuna abundance and production in the Indian Ocean. However, among the oceanic variables SST explained the highest deviance in generalized additive models and therefore considered the best habitat predictor in the Indian Ocean followed by sea level pressure and Winds (U, V, W).

  10. Thawing of Frozen Dressed Tuna by Microwave Heating

    NASA Astrophysics Data System (ADS)

    Tanaka, Takeo; Nagasaki, Tasuku; Takahashi, Kenji

    Large sized frozen yellowfin tuna and southern bluefin tuna in dressed form (decapitated and gutted) were thawed by microwave (915 MHz) irradiation. Temperature rise of the tuna during thawing was measured. Quality of the tuna meat before and after thawing was compared with each other using objective quality index such as degree of discoloration (met-myoglobin ratio), freshness (K1 value) and taste cornponent (K2 value). Results are as follows : (1) Both frozen tunas were thawed fairly well within as short time as 30 min without any partial over heating. (2) No changes in met-myoglobin ratio, K1 and K2 values were observed in the cases of yellow fin tuna. Slight discoloration, however, occurred in southern bluefin tuna meat during microwave thawing. This problem has been left unsolved.

  11. Tuna Cornea as Biomaterial for Cardiac Applications

    PubMed Central

    Parravicini, Roberto; Cocconcelli, Flavio; Verona, Alessandro; Parravicini, Valeriano; Giuliani, Enrico; Barbieri, Alberto

    2012-01-01

    Among available biomaterials, cornea is almost completely devoid of cells and is composed only of collagen fibers oriented in an orderly pattern, which contributes to low antigenicity. Thunnus thynnus, the Atlantic bluefin tuna, is a fish with large eyes that can withstand pressures of approximately 10 MPa. We evaluated the potential of this tuna cornea in cardiac bioimplantation. Eyes from freshly caught Atlantic bluefin tuna were harvested and preserved in a fixative solution. Sterilized samples of corneal stroma were embedded in paraffin and stained with hematoxylin and eosin, and the histologic features were studied. Physical and mechanical resistance tests were performed in comparison with bovine pericardial strips and porcine mitral valves. Corneal material was implanted subcutaneously in 7 rats, to evaluate in vivo calcification rates. Mitral valves made from tuna corneal leaflets were implanted in 9 sheep. We found that the corneal tissue consisted only of parallel collagen fibers without evidence of vascular or neural structures. In tensile strength, the tuna corneal specimens were substantially similar to bovine pericardium. After 23 days, the rat-implanted samples showed no calcium or calcium salt deposition. Hydrodynamic and fatigue testing of valve prototypes yielded acceptable functional and long-term behavioral results. In the sheep, valvular performance was stable during the 180-day follow-up period, with no instrumental sign of calcification at the end of observation. We conclude that low antigenicity and favorable physical properties qualify tuna cornea as a potential material for durable bioimplantation. Further study is warranted. PMID:22740728

  12. Tuna cornea as biomaterial for cardiac applications.

    PubMed

    Parravicini, Roberto; Cocconcelli, Flavio; Verona, Alessandro; Parravicini, Valeriano; Giuliani, Enrico; Barbieri, Alberto

    2012-01-01

    Among available biomaterials, cornea is almost completely devoid of cells and is composed only of collagen fibers oriented in an orderly pattern, which contributes to low antigenicity. Thunnus thynnus, the Atlantic bluefin tuna, is a fish with large eyes that can withstand pressures of approximately 10 MPa. We evaluated the potential of this tuna cornea in cardiac bioimplantation. Eyes from freshly caught Atlantic bluefin tuna were harvested and preserved in a fixative solution. Sterilized samples of corneal stroma were embedded in paraffin and stained with hematoxylin and eosin, and the histologic features were studied. Physical and mechanical resistance tests were performed in comparison with bovine pericardial strips and porcine mitral valves. Corneal material was implanted subcutaneously in 7 rats, to evaluate in vivo calcification rates. Mitral valves made from tuna corneal leaflets were implanted in 9 sheep. We found that the corneal tissue consisted only of parallel collagen fibers without evidence of vascular or neural structures. In tensile strength, the tuna corneal specimens were substantially similar to bovine pericardium. After 23 days, the rat-implanted samples showed no calcium or calcium salt deposition. Hydrodynamic and fatigue testing of valve prototypes yielded acceptable functional and long-term behavioral results. In the sheep, valvular performance was stable during the 180-day follow-up period, with no instrumental sign of calcification at the end of observation. We conclude that low antigenicity and favorable physical properties qualify tuna cornea as a potential material for durable bioimplantation. Further study is warranted.

  13. Thawing of Frozen Tuna Meat

    NASA Astrophysics Data System (ADS)

    Tanaka, Takeo; Nishiwaki, Kôji; Kakuda, Kitonari; Tomimatsu, Takao

    Frozen southern bluefin tuna meat discolors easily and sometimes contracts when thawed caused by thaw rigor. These phenomenon often become problematic in the transaction or handling of this kind of frozen tuna. Frozen meat blocks of southern Bluefin tuna were thawed separately by air thawing, running water thawing and microwave thawing. Changes occurring during thawing were checked for meat color by met-myoglobin ratio determination and for contract by microscopic observation. Results are as follows : (1) Discoloration scarcely occurred in the process of running water thawing (at 10°C for 50 min, or at 0°C for 6 hr). (2) No contraction was observed during thawing with running water described above and air thawing (at 18-20°C for 6 hr). (3) Discoloration and contraction seemed to be minimized, as to latently contractile blocks, when meat temperature passed through rapidly between -10°C and -5°C, and slowly (for 5-6 hr) between -5°C and -1°C. When the block was originally not contractile, discloration was minimized by rising meat temperature rapidly from -10°C to -l°C.

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

    PubMed

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

    2017-01-01

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

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

    PubMed Central

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

    2017-01-01

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

  16. 78 FR 33240 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ... the overall EPO tuna catch. The number of purse seine vessels that have landed tuna in California...; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean AGENCY: National Marine... rule. SUMMARY: NMFS is issuing regulations under the Tuna Conventions Act of 1950 to...

  17. Individual tuna trolling strategies and transmission of fishing skills in a local community of Shimokita Peninsula.

    PubMed

    Akimichi, T

    1975-12-01

    Trolling techniques and strategies of fishermen of Oma in northern Japan to catch blue-fin tunas Thunnus thynnus are described. Usage patterns of fishing devices revealed to have ecological, psychological, and social implications. Choice of fish baits depended not only on the environmental factors relevant to the ecology of fish, but also on fishermen's skills which were different among different age groups and individuals. Younger fishermen preferred live baits to dead baits or lures whereas middle-aged or older ones chose them significantly less frequently. Moreover, the combination of a bait and a line by the latter denoted particular differences and specializations in terms of fishing strategies. Large differences in tuna landings indicating individual variations of skills were apparently related to techniques of trolling gear operation. In spite of an individual-based work. alternating work exchanging baits, and gifting were important in compensating physiological and technical handicaps through fishermen's interpersonal relationships based on genealogical, generational, and neighboring bondages. The exploitative difference between the coastal and the off-shore fishing grounds, use of baits being more varied in the latter, which were lately developed area, was also referred to as a problem of transmission in a local community of technical and mental skills.

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

    PubMed

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

    2017-10-01

    Oxygen concentrations are hypothesized to decrease in many areas of the ocean as a result of anthropogenically driven climate change, resulting in habitat compression for pelagic animals. The oxygen partial pressure, pO2 , at which blood is 50% saturated (P50 ) is a measure of blood oxygen affinity and a gauge of the tolerance of animals for low ambient oxygen. Tuna species display a wide range of blood oxygen affinities (i.e., P50 values) and therefore may be differentially impacted by habitat compression as they make extensive vertical movements to forage on subdaily time scales. To project the effects of end-of-the-century climate change on tuna habitat, we calculate tuna P50 depths (i.e., the vertical position in the water column at which ambient pO2 is equal to species-specific blood P50 values) from 21st century Earth System Model (ESM) projections included in the fifth phase of the Climate Model Intercomparison Project (CMIP5). Overall, we project P50 depths to shoal, indicating likely habitat compression for tuna species due to climate change. Tunas that will be most impacted by shoaling are Pacific and southern bluefin tunas-habitat compression is projected for the entire geographic range of Pacific bluefin tuna and for the spawning region of southern bluefin tuna. Vertical shifts in P50 depths will potentially influence resource partitioning among Pacific bluefin, bigeye, yellowfin, and skipjack tunas in the northern subtropical and eastern tropical Pacific Ocean, the Arabian Sea, and the Bay of Bengal. By establishing linkages between tuna physiology and environmental conditions, we provide a mechanistic basis to project the effects of anthropogenic climate change on tuna habitats. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  19. Tuna Longline Fishing around West and Central Pacific Seamounts

    PubMed Central

    Morato, Telmo; Hoyle, Simon D.; Allain, Valerie; Nicol, Simon J.

    2010-01-01

    Background Seamounts have been identified as aggregating locations for pelagic biodiversity including tuna; however the topography and prevailing oceanography differ between seamounts and not all are important for tuna. Although a relatively common feature in oceanic ecosystems, little information is available that identifies those that are biologically important. Improved knowledge offers opportunities for unique management of these areas, which may advance the sustainable management of oceanic resources. In this study, we evaluate the existence of an association between seamounts and tuna longline fisheries at the ocean basin scale, identify significant seamounts for tuna in the western and central Pacific Ocean, and quantify the seamount contribution to the tuna longline catch. Methodology/Principal Findings We use data collected for the Western and Central Pacific Ocean for bigeye, yellowfin, and albacore tuna at the ocean basin scale. GLMs were applied to a coupled dataset of longline fisheries catch and effort, and seamount location information. The analyses show that seamounts may be associated with an annual longline combined catch of 35 thousand tonnes, with higher catch apparent for yellowfin, bigeye, and albacore tuna on 17%, 14%, and 14% of seamounts respectively. In contrast 14%, 18%, and 20% of seamounts had significantly lower catches for yellowfin, bigeye and albacore tuna respectively. Studying catch data in relation to seamount positions presents several challenges such as bias in location of seamounts, or lack of spatial resolution of fisheries data. Whilst we recognize these limitations the criteria used for detecting significant seamounts were conservative and the error in identification is likely to be low albeit unknown. Conclusions/Significance Seamounts throughout the study area were found to either enhance or reduce tuna catch. This indicates that management of seamounts is important Pacific-wide, but management approaches must take

  20. Tuna longline fishing around West and Central Pacific seamounts.

    PubMed

    Morato, Telmo; Hoyle, Simon D; Allain, Valerie; Nicol, Simon J

    2010-12-29

    Seamounts have been identified as aggregating locations for pelagic biodiversity including tuna; however the topography and prevailing oceanography differ between seamounts and not all are important for tuna. Although a relatively common feature in oceanic ecosystems, little information is available that identifies those that are biologically important. Improved knowledge offers opportunities for unique management of these areas, which may advance the sustainable management of oceanic resources. In this study, we evaluate the existence of an association between seamounts and tuna longline fisheries at the ocean basin scale, identify significant seamounts for tuna in the western and central Pacific Ocean, and quantify the seamount contribution to the tuna longline catch. We use data collected for the Western and Central Pacific Ocean for bigeye, yellowfin, and albacore tuna at the ocean basin scale. GLMs were applied to a coupled dataset of longline fisheries catch and effort, and seamount location information. The analyses show that seamounts may be associated with an annual longline combined catch of 35 thousand tonnes, with higher catch apparent for yellowfin, bigeye, and albacore tuna on 17%, 14%, and 14% of seamounts respectively. In contrast 14%, 18%, and 20% of seamounts had significantly lower catches for yellowfin, bigeye and albacore tuna respectively. Studying catch data in relation to seamount positions presents several challenges such as bias in location of seamounts, or lack of spatial resolution of fisheries data. Whilst we recognize these limitations the criteria used for detecting significant seamounts were conservative and the error in identification is likely to be low albeit unknown. Seamounts throughout the study area were found to either enhance or reduce tuna catch. This indicates that management of seamounts is important Pacific-wide, but management approaches must take account of local conditions. Management of tuna and biodiversity

  1. Biology, fishery, conservation and management of Indian Ocean tuna fisheries

    NASA Astrophysics Data System (ADS)

    Gopalakrishna Pillai, N.; Satheeshkumar, Palanisamy

    2012-12-01

    The focus of the study is to explore the recent trend of the world tuna fishery with special reference to the Indian Ocean tuna fisheries and its conservation and sustainable management. In the Indian Ocean, tuna catches have increased rapidly from about 179959 t in 1980 to about 832246 t in 1995. They have continued to increase up to 2005; the catch that year was 1201465 t, forming about 26% of the world catch. Since 2006 onwards there has been a decline in the volume of catches and in 2008 the catch was only 913625 t. The Principal species caught in the Indian Ocean are skipjack and yellowfin. Western Indian Ocean contributed 78.2% and eastern Indian Ocean 21.8% of the total tuna production from the Indian Ocean. The Indian Ocean stock is currently overfished and IOTC has made some recommendations for management regulations aimed at sustaining the tuna stock. Fishing operations can cause ecological impacts of different types: by catches, damage of the habitat, mortalities caused by lost or discarded gear, pollution, generation of marine debris, etc. Periodic reassessment of the tuna potential is also required with adequate inputs from exploratory surveys as well as commercial landings and this may prevent any unsustainable trends in the development of the tuna fishing industry in the Indian Ocean.

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

    PubMed

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

    2009-11-18

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

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

    PubMed

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

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

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

    PubMed

    Zhu, Guo-ping

    2011-08-01

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

  5. A possible explanation for the population size discrepancy in tuna (genus Thunnus) estimated from mitochondrial DNA and microsatellite data.

    PubMed

    Qiu, Fan; Kitchen, Andrew; Beerli, Peter; Miyamoto, Michael M

    2013-02-01

    A recent study using both mitochondrial DNA (mtDNA) and microsatellite data reported on a population size discrepancy in the eastern tiger salamander where the effective population size (N(e)) estimate of the former exceeded that of the latter. That study suggested, among other hypotheses, that homoplasy of microsatellite alleles is responsible for the discrepancy. In this investigation, we report 10 new cases of a similar discrepancy in five species of tuna. These cases derive from our Bayesian inferences using data from Pacific Bluefin Tuna (Thunnus orientalis) and Yellowfin Tuna (Thunnus albacares), as well as from published estimates of genetic diversity for additional populations of Yellowfin Tuna and three other tuna species. Phylogenetic character analyses of inferred genealogies of Pacific Bluefin and Yellowfin Tuna reveal similar reduced levels of mtDNA and microsatellite homoplasy. Thus, the discrepancy between inferred population sizes from mtDNA and microsatellite data in tuna is most likely not an artifact of the chosen mutation models used in the microsatellite analyses, but may reflect behavioral differences between the sexes such as female-biased philopatry and male-biased dispersal. This explanation now warrants critical testing with more local populations of tuna and with other animal and plant groups that have different life histories. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. DNA barcodes reveal species-specific mercury levels in tuna sushi that pose a health risk to consumers

    PubMed Central

    Lowenstein, Jacob H.; Burger, Joanna; Jeitner, Christian W.; Amato, George; Kolokotronis, Sergios-Orestis; Gochfeld, Michael

    2010-01-01

    Excessive ingestion of mercury—a health hazard associated with consuming predatory fishes—damages neurological, sensory-motor and cardiovascular functioning. The mercury levels found in Bigeye Tuna (Thunnus obesus) and bluefin tuna species (Thunnus maccoyii, Thunnus orientalis, and Thunnus thynnus), exceed or approach levels permissible by Canada, the European Union, Japan, the US, and the World Health Organization. We used DNA barcodes to identify tuna sushi samples analysed for mercury and demonstrate that the ability to identify cryptic samples in the market place allows regulatory agencies to more accurately measure the risk faced by fish consumers and enact policies that better safeguard their health. PMID:20410032

  7. 75 FR 64246 - Submission for OMB Review; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... monitoring program for bluefin tuna, frozen bigeye tuna, and swordfish to discourage illegal, unregulated, and unreported fishing activities as well as to further understand catches of and international trade...

  8. 76 FR 18504 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Quotas and Atlantic Tuna Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ...: Notification of public hearing. ] SUMMARY: On March 14, 2011, NMFS published a proposed rule to modify Atlantic... the comment period for this action until April 28, 2011, allowing a 45-day comment period, rescheduled... greater opportunity for public comment on the proposed rule. DATES: A hearing will be held on April...

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

    PubMed Central

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

    2009-01-01

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

  10. Exploring future scenarios for the global supply chain of tuna

    NASA Astrophysics Data System (ADS)

    Mullon, C.; Guillotreau, P.; Galbraith, E. D.; Fortilus, J.; Chaboud, C.; Bopp, L.; Aumont, O.; Kaplan, D.

    2017-06-01

    The abundance of tuna, an important top predator that ranges throughout tropical and subtropical oceans, is now largely determined by fishing activity. Fishing activity, in turn, is determined by the interaction of fish availability, fishing capacity, fishing costs and global markets for tuna products. In the face of overfishing, the continued sustainable supply of tuna is likely to require improved global governance, that would benefit from modeling frameworks capable of integrating market forces with the availability of fish in order to consider alternative future projections. Here we describe such a modeling framework, in which we develop several simple, contrasting scenarios for the development of the tuna supply chain in order to illustrate the utility of the approach for global evaluation of management strategies for tuna and other complex, stock-structured fisheries. The model includes multiple national and multi-national fishing fleets, canneries and fresh/frozen markets, and connects these to global consumers using a network of flows. The model is calibrated using recent data on fish catch, cannery and fresh/frozen production, and consumption. Scenarios explore the control on future outcomes in the global tuna fishery by representing, in a simple way, the effects of (1) climate change, (2) changes in the global demand for tuna, and (3) changes in the access to fishing grounds (marine reserves). The results emphasize the potential importance of increasing demand in provoking a global collapse, and suggest that controlling tuna production by limiting technical efficiency is a potential countermeasure. Finally we discuss the outcomes in terms of potential extensions of the scenario approach allowed by this global network model of the tuna supply chain.

  11. Accumulation pattern of butyltin compounds in dolphin, tuna, and shark collected from Italian coastal waters.

    PubMed

    Kannan, K; Corsolini, S; Focardi, S; Tanabe, S; Tatsukawa, R

    1996-07-01

    Tributyltin (TBT) and its breakdown products, mono-(MBT) and dibutyltin (DBT) were determined in bottlenose dolphin (Tursiops truncatus), bluefin tuna (Thunnus thynnus thynnus) and blue shark (Prionace glauca) collected from the Italian coast of the Mediterranean Sea in 1992-1993. Concentrations of total butyltin (BTs) in the liver of dolphin (1,200-2,200 ng/g wet wt) were an order of magnitude higher than in the blubber (48-320 ng/g wet wt). TBT was the predominant butyltin species in the blubber while DBT accounted for an higher proportion in the liver of dolphins. Butyltin concentrations in bluefin tuna were lower than those in dolphins, with TBT highest in the muscle and DBT in the liver. Concentrations of BTs in blue sharks were lower than those in dolphin and tuna, with kidney having the highest concentrations. TBT was the predominant form of butyltin derivatives in all the tissues of shark. Accumulation of butyltin compounds in liver/kidney seems to be associated with the presence of proteins such as glutathione.

  12. El Nino Southern Oscillation and Tuna in the Western Pacific

    NASA Technical Reports Server (NTRS)

    Lehodey, P.; Bertignac, M.; Hampton, J.; Lewis, A.; Picaut, J.

    1997-01-01

    Nearly 70% of the world's annual tuna harvest, currently 3.2 million tonnes, comes from the Pacific Ocean. Skipjack tuna (Katsuwonus pelamis) dominate the catch. Although skipjack are distributed in the surface mixed layer throughout the equatorial and subtropical Pacific, catches are highest in the western equatorial Pacific warm pool, a region characterized by low primary productivity rates that has the warmest surface waters of the world's oceans. Assessments of tuna stocks indicate that recent western Pacific skipjack catches approaching one million tonnes annually are sustainable. The warm pool, which is fundamental to the El Nino Southern Oscillation (ENSO) and the Earth's climate in general, must therefore also provide a habitat capable of supporting this highly productive tuna population. Here we show that apparent spatial shifts in the skipjack population are linked to large zonal displacements of the warm pool that occur during ENSO events. This relationship can be used to predict (several months in advance) the region of highest skipjack abundance, within a fishing ground extending over 6,000 km along the Equator.

  13. El Nino Southern Oscillation and Tuna in the Western Pacific

    NASA Technical Reports Server (NTRS)

    Lehodey, P.; Bertignac, M.; Hampton, J.; Lewis, A.; Picaut, J.

    1997-01-01

    Nearly 70% of the world's annual tuna harvest, currently 3.2 million tonnes, comes from the Pacific Ocean. Skipjack tuna (Katsuwonus pelamis) dominate the catch. Although skipjack are distributed in the surface mixed layer throughout the equatorial and subtropical Pacific, catches are highest in the western equatorial Pacific warm pool, a region characterized by low primary productivity rates that has the warmest surface waters of the world's oceans. Assessments of tuna stocks indicate that recent western Pacific skipjack catches approaching one million tonnes annually are sustainable. The warm pool, which is fundamental to the El Nino Southern Oscillation (ENSO) and the Earth's climate in general, must therefore also provide a habitat capable of supporting this highly productive tuna population. Here we show that apparent spatial shifts in the skipjack population are linked to large zonal displacements of the warm pool that occur during ENSO events. This relationship can be used to predict (several months in advance) the region of highest skipjack abundance, within a fishing ground extending over 6,000 km along the Equator.

  14. Incidence of three Kudoa spp., K. neothunni, K. hexapunctata, and K. thunni (Myxosporea: Multivalvulida), in Thunnus tunas distributed in the western Pacific Ocean.

    PubMed

    Kasai, Akihiro; Tsuduki, Hideaki; Jimenez, Lea Angsinco; Li, Ying-Chun; Tanaka, Shuhei; Sato, Hiroshi

    2017-04-01

    A variety of tunas of the genus Thunnus are consumed daily in Japan as sliced raw fish (sashimi and sushi). The consumption of fresh sliced raw fish, i.e., unfrozen or uncooked, can sometimes cause food poisoning that is manifested by transient diarrhea and vomiting for a single day. One of the causes of this type of food poisoning has been identified as live Kudoa septempunctata (Myxosporea: Multivalvulida) in the olive flounder (Paralichthys olivaceus). Furthermore, raw slices of fresh tunas are highly suspected to be a possible causative fish of similar food poisoning in Japan. In the present study, we conducted a survey of kudoid infections in tunas (the yellowfin tuna Thunnus albacares, the Pacific bluefin tuna Thunnus orientalis, and the longtail tuna Thunnus tonggol) fished in the western Pacific Ocean off Japan and several East Asian countries and characterized morphologically and genetically the kudoid myxospores in pseudocysts or cysts dispersed in the trunk muscles. Pseudocysts of solely Kudoa hexapunctata were identified in the Pacific bluefin tuna (four isolates), whereas in the yellowfin tuna (21 isolates) pseudocysts of Kudoa neothunni and K. hexapunctata were detected at a ratio of 15:6, respectively, in addition to cyst-forming Kudoa thunni in five yellowfin tunas. In the trunk muscles of six longtail tunas examined, pseudocysts of K. neothunni (all six fish) and K. hexapunctata (two fish) were densely dispersed. The myxospores of K. neothunni found in these longtail tunas had seven shell valves and polar capsules (SV/PC) instead of the more common six SV/PC arranged symmetrically. Nucleotide sequences of the 18S and 28S ribosomal RNA gene (rDNA), some with the internal transcribed spacer regions as well, of K. hexapunctata and K. neothunni from the three Thunnus spp., including the seven-SV/PC morphotype, were very similar to previously characterized nucleotide sequences of each species, whereas the 18S and 28S rDNA of four isolates of K. thunni

  15. Tuna comparative physiology.

    PubMed

    Graham, Jeffrey B; Dickson, Kathryn A

    2004-11-01

    Thunniform swimming, the capacity to conserve metabolic heat in red muscle and other body regions (regional endothermy), an elevated metabolic rate and other physiological rate functions, and a frequency-modulated cardiac output distinguish tunas from most other fishes. These specializations support continuous, relatively fast swimming by tunas and minimize thermal barriers to habitat exploitation, permitting niche expansion into high latitudes and to ocean depths heretofore regarded as beyond their range.

  16. A Validated Methodology for Genetic Identification of Tuna Species (Genus Thunnus)

    PubMed Central

    Viñas, Jordi; Tudela, Sergi

    2009-01-01

    Background Tuna species of the genus Thunnus, such as the bluefin tunas, are some of the most important and yet most endangered trade fish in the world. Identification of these species in traded forms, however, may be difficult depending on the presentation of the products, which may hamper conservation efforts on trade control. In this paper, we validated a genetic methodology that can fully distinguish between the eight Thunnus species from any kind of processed tissue. Methodology After testing several genetic markers, a complete discrimination of the eight tuna species was achieved using Forensically Informative Nucleotide Sequencing based primarily on the sequence variability of the hypervariable genetic marker mitochondrial DNA control region (mtDNA CR), followed, in some specific cases, by a second validation by a nuclear marker rDNA first internal transcribed spacer (ITS1). This methodology was able to distinguish all tuna species, including those belonging to the subgenus Neothunnus that are very closely related, and in consequence can not be differentiated with other genetic markers of lower variability. This methodology also took into consideration the presence of introgression that has been reported in past studies between T. thynnus, T. orientalis and T. alalunga. Finally, we applied the methodology to cross-check the species identity of 26 processed tuna samples. Conclusions Using the combination of two genetic markers, one mitochondrial and another nuclear, allows a full discrimination between all eight tuna species. Unexpectedly, the genetic marker traditionally used for DNA barcoding, cytochrome oxidase 1, could not differentiate all species, thus its use as a genetic marker for tuna species identification is questioned. PMID:19898615

  17. Global population trajectories of tunas and their relatives

    PubMed Central

    Juan-Jordá, Maria José; Mosqueira, Iago; Cooper, Andrew B.; Freire, Juan; Dulvy, Nicholas K.

    2011-01-01

    Tunas and their relatives dominate the world's largest ecosystems and sustain some of the most valuable fisheries. The impacts of fishing on these species have been debated intensively over the past decade, giving rise to divergent views on the scale and extent of the impacts of fisheries on pelagic ecosystems. We use all available age-structured stock assessments to evaluate the adult biomass trajectories and exploitation status of 26 populations of tunas and their relatives (17 tunas, 5 mackerels, and 4 Spanish mackerels) from 1954 to 2006. Overall, populations have declined, on average, by 60% over the past half century, but the decline in the total adult biomass is lower (52%), driven by a few abundant populations. The trajectories of individual populations depend on the interaction between life histories, ecology, and fishing pressure. The steepest declines are exhibited by two distinct groups: the largest, longest lived, highest value temperate tunas and the smaller, short-lived mackerels, both with most of their populations being overexploited. The remaining populations, mostly tropical tunas, have been fished down to approximately maximum sustainable yield levels, preventing further expansion of catches in these fisheries. Fishing mortality has increased steadily to the point where around 12.5% of the tunas and their relatives are caught each year globally. Overcapacity of these fisheries is jeopardizing their long-term sustainability. To guarantee higher catches, stabilize profits, and reduce collateral impacts on marine ecosystems requires the rebuilding of overexploited populations and stricter management measures to reduce overcapacity and regulate threatening trade. PMID:22143785

  18. Discrimination of Juvenile Yellowfin (Thunnus albacares) and Bigeye (T. obesus) Tunas using Mitochondrial DNA Control Region and Liver Morphology

    PubMed Central

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

    2012-01-01

    Yellowfin tuna, Thunnus albacares (Bonnaterre, 1788) and bigeye tuna, Thunnus obesus (Lowe, 1839) are two of the most economically important tuna species in the world. However, identification of their juveniles, especially at sizes less than 40 cm, is very difficult, often leading to misidentification and miscalculation of their catch estimates. Here, we applied the mitochondrial DNA control region D-loop, a recently validated genetic marker used for identifying tuna species (Genus Thunnus), to discriminate juvenile tunas caught by purse seine and ringnet sets around fish aggregating devices (FADs) off the Southern Iloilo Peninsula in Central Philippines. We checked individual identifications using the Neighbor-Joining Method and compared results with morphometric analyses and the liver phenotype. We tested 48 specimens ranging from 13 to 31 cm fork length. Morpho-meristic analyses suggested that 12 specimens (25%) were bigeye tuna and 36 specimens (75%) were yellowfin tuna. In contrast, the genetic and liver analyses both showed that 5 specimens (10%) were bigeye tuna and 43 (90%) yellowfin tuna. This suggests that misidentification can occur even with highly stringent morpho-meristic characters and that the mtDNA control region and liver phenotype are excellent markers to discriminate juveniles of yellowfin and bigeye tunas. PMID:22536417

  19. Catching Sunlight

    NASA Astrophysics Data System (ADS)

    Friedman, Alan

    Everyone knows that astronomy is done in the dark. Astronomers are creatures of the night, like vampires, sleeping during the day and working all night long to catch the faint light of their elusive prey.

  20. 76 FR 60790 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... vessels is approximated by the average number of U.S. large-scale longline vessels that have caught bigeye... place in the EPO. The proportion of the large-scale longline vessels annual bigeye tuna catches that... landed by large-scale longline vessels in 2005-2010. Large-scale longline vessels fishing in...

  1. Clean catch urine sample

    MedlinePlus

    ... specimen; Urine collection - clean catch; UTI - clean catch; Urinary tract infection - clean catch; Cystitis - clean catch ... LE, Norrby SR. Approach to the patient with urinary tract infection. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  2. Characterization of bigeye tuna habitat in the Southern Waters off Java-Bali using remote sensing data

    NASA Astrophysics Data System (ADS)

    Setiawati, Martiwi Diah; Sambah, Abu Bakar; Miura, Fusanori; Tanaka, Tasuku; As-syakur, Abd. Rahman

    2015-01-01

    Bigeye tuna (Thunnus obesus) habitat was investigated based on catch data and environmental satellite data, such as sea surface temperature (SST), sea surface chlorophyll (SSC), and sea surface height deviation (SSHD) data in the Southern Waters off Java and Bali. First, we obtained daily fish catch data and monthly satellite data for SST, SSC, and SSHD for 2006-2010. Then, we analyzed the relationship between daily catch data and satellite data by combining the statistical method of generalized additive model (GAM) and geographic information system (GIS). Seven GAM models were generated with the number of bigeye tuna as a response variable, and SST, SSC, and SSHD as predictor variables. All of the predictors of SST, SSC, and SSHD were highly significant (P < 0.001) to the number of bigeye tuna. Values of SST, SSHD, and SSC in bigeye tuna habitat ranged from 24.8 to 28.7 °C, -3 to 7 cm, and 0.05 to 0.17 mg/m3, respectively. Validation of the predicted number of bigeye tuna with the observed value was significant (P < 0.05, r2 = 0.56). SST was the most important environmental variable to the number of bigeye tuna caught, followed by SSHD and SSC.

  3. Application of the Oxidation-Reduction Potential (ORP) for Pre-grading Tuna Freshness On-board

    NASA Astrophysics Data System (ADS)

    Cheevaporanapivat, Mongkol; Sakai, Hisaharu; Mine, Yuuji; Watanabe, Manabu; Suzuki, Toru

    Application of ORP as a rapid indicator for grading tuna's freshness on the ship was studied. The long line trawling process was used for catching the sample tuna in the South Pacific Ocean. All captured sample tuna were weighed, gender identified and investigated for their mortality, then measured ORP and K value. Three species of tuna were caught: blue marlin (Makaira mazara), yellow fin tuna (Thunnus albacares), and swordfish (Xiphia gladius). Most of the fish captured were male and they had been dead after picking onboard. The measured ORP values of blue marlin varied in the range of 0.295-0.362 Volt, with pH between 5.35-5.84. Both ORP and pH of swordfish was similar to that of blue marlin. But for yellow fin tuna, the ORP value was about the same as blue marlin while its pH was significantly higher. ORP value in all species tended to increase with pH of the fish meat decrease. It is interesting that ORP value of tuna increased in correlation with K value. These results suggested that ORP and pH change, which are measured in the short time, are the effective indicators for grading tuna's freshness on-board.

  4. 76 FR 18416 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    .... Currently, the default Angling category daily retention limit of one school, large school, or small medium... for school BFT, 85.6 mt for large school/small medium BFT, and 4.3 mt for large medium/giant BFT... type, such as private vessels, headboats, or charterboats. NMFS has considered the set of criteria...

  5. 76 FR 44834 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries; Northern Area Trophy Fishery

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... closes the northern area Angling category fishery for large medium and giant (``trophy'') Atlantic... 2011 Angling category northern area subquota for large medium and giant BFT. DATES: Effective 11:30 p.m... quota of 1.4 mt of large medium and giant BFT (measuring 73 inches curved fork length or greater) to...

  6. 75 FR 41995 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ... (185 cm) curved fork length or greater) north of 39 18' N. lat. (off Great Egg Inlet, NJ) is prohibited... area, i.e., north of 39 18' N. lat. (off Great Egg Inlet, NJ) by vessels permitted in the HMS...

  7. 76 FR 74003 - Atlantic Highly Migratory Species; Adjustments to the Atlantic Bluefin Tuna General and Harpoon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-30

    ... availability of large medium and giant BFT to the fishery during the winter months. As described in the... allowed daily retention limit of large medium and giant BFT over a range from zero to a maximum of five... daily incidental retention limit of large medium BFT from two to four per vessel. This action is...

  8. 77 FR 19175 - Atlantic Highly Migratory Species; 2012 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ... public hearings in Gloucester, MA, and Silver Spring, MD, in order to provide greater opportunity for... Gloucester, MA, and a hearing will be held on April 10, 2012, from 2:30 to 4 p.m. in Silver Spring, MD... Drive, Gloucester, MA 01930. 2. Silver Spring, MD--NMFS Science Center, 1301 East-West Highway,...

  9. 77 FR 44161 - Atlantic Highly Migratory Species; 2012 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ... present their perspectives on any rule that may affect them. Another commenter requested that NMFS hold... additional reductions in the 2011 and subsequent year-classes (relative to what they would have been in...

  10. 77 FR 21015 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ... fishery management objectives of the 2006 Consolidated HMS Fishery Management Plan (Consolidated HMS FMP... the adjustment on accomplishing the objectives of the fishery management plan; Variations in seasonal... (16 U.S.C. 971 et seq.) and the Magnuson-Stevens Fishery Conservation and Management Act...

  11. 75 FR 33531 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-14

    ... BFT fishery management objectives of the 2006 Consolidated HMS Fishery Management Plan and to prevent... overfishing; effects of the adjustment on accomplishing the objectives of the fishery management plan... the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson- Stevens Act; 16 U.S.C. 1801...

  12. 75 FR 79309 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ... scheduled to revert back to the default retention limit of one large medium or giant BFT (measuring 73... default level of one large medium or giant BFT as follows: Two large medium or giant BFT for January (74 FR 68709, December 29, 2009), and three large medium or giant BFT for June through December (75 FR...

  13. 76 FR 69137 - Atlantic Highly Migratory Species; Atlantic Bluefin Tuna Fisheries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... General category daily BFT retention limit should be adjusted from three to two large medium or giant BFT...), NMFS may increase or decrease the daily retention limit of large medium and giant BFT over a range of... from the default level of one large medium or giant BFT as follows: two large medium or giant BFT for...

  14. 78 FR 21584 - Atlantic Highly Migratory Species; 2013 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... not necessary to prepare an EA for quota specifications alone (in accordance with the approach... category. This constitutes the best available information regarding the universe of permits and permit...

  15. 77 FR 15712 - Atlantic Highly Migratory Species; 2012 Atlantic Bluefin Tuna Quota Specifications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-16

    ... for the pelagic longline fleet to operate for the entire fishing year while also accounting for dead... Seine, Angling, General, Longline, and Trap categories). The 2012 BFT quota specifications are necessary... related to pelagic longline fisheries in the Northeast Distant gear restricted area (NED), is 948.7 mt...

  16. Predicting Interactions between Common Dolphins and the Pole-and-Line Tuna Fishery in the Azores

    PubMed Central

    Cruz, Maria João; Menezes, Gui; Machete, Miguel; Silva, Mónica A.

    2016-01-01

    Common dolphins (Delphinus delphis) are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998–2012) collected by observers placed aboard tuna fishing vessels. Dolphins interacted in less than 3% of the fishing events observed during the study period. The probability of dolphin interaction varied significantly between years with no evident trend over time. Generalized additive modeling results suggest that fishing duration, sea surface temperature and prey abundance in the region were the most important factors explaining common dolphin interaction. Dolphin interaction had no impact on the catches of albacore, skipjack and yellowfin tuna but resulted in significantly lower catches of bigeye tuna, with a predicted median annual loss of 13.5% in the number of fish captured. However, impact on bigeye catches varied considerably both by year and fishing area. Our work shows that rates of common dolphin interaction with the pole-and-line tuna fishery in the Azores are low and showed no signs of increase over the study period. Although overall economic impact was low, the interaction may lead to significant losses in some years. These findings emphasize the need for continued monitoring and for further research into the consequences and economic viability of potential mitigation measures. PMID:27851763

  17. Predicting Interactions between Common Dolphins and the Pole-and-Line Tuna Fishery in the Azores.

    PubMed

    Cruz, Maria João; Menezes, Gui; Machete, Miguel; Silva, Mónica A

    2016-01-01

    Common dolphins (Delphinus delphis) are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998-2012) collected by observers placed aboard tuna fishing vessels. Dolphins interacted in less than 3% of the fishing events observed during the study period. The probability of dolphin interaction varied significantly between years with no evident trend over time. Generalized additive modeling results suggest that fishing duration, sea surface temperature and prey abundance in the region were the most important factors explaining common dolphin interaction. Dolphin interaction had no impact on the catches of albacore, skipjack and yellowfin tuna but resulted in significantly lower catches of bigeye tuna, with a predicted median annual loss of 13.5% in the number of fish captured. However, impact on bigeye catches varied considerably both by year and fishing area. Our work shows that rates of common dolphin interaction with the pole-and-line tuna fishery in the Azores are low and showed no signs of increase over the study period. Although overall economic impact was low, the interaction may lead to significant losses in some years. These findings emphasize the need for continued monitoring and for further research into the consequences and economic viability of potential mitigation measures.

  18. Source levels and estimated yellowfin tuna (Thunnus albacares) detection ranges for dolphin jaw pops, breaches, and tail slaps.

    PubMed

    Finneran, J J; Oliver, C W; Schaefer, K M; Ridgway, S H

    2000-01-01

    Tuna fishers in the eastern Pacific Ocean often exploit an association between a few genus of dolphin (Stenella and Delphinus) and yellowfin tuna (Thunnus albacares) to locate and capture the tuna. Identification of a mechanism which facilitates the tuna/dolphin bond may provide a means of exploiting the bond and capturing tuna without catching dolphin. To investigate if tuna may be attracted to low-frequency sounds produced by dolphins, source levels of bottlenose dolphin (Tursiops truncatus) jaw pops, breaches, and tail slaps were experimentally measured and used to estimate the maximum range at which yellowfin could detect similar sounds produced by pelagic species. The effective acoustic stimulus to the tuna was defined as the maximum one-third-octave level between 200 and 800 Hz, the frequency range where T. albacares is most sensitive. Spherical spreading was assumed to predict transmission loss with range. Breaches and jaw pops produced maximum one-third-octave source levels between 200 and 800 Hz of 153 (+/-4) and 163 (+/-2) dB re: 1 microPa-m, respectively, which resulted in estimated detection ranges of 340-840 and 660-1040 m, respectively. Tail slaps had lower source levels [max. 141 (+/-3) dB re: 1 microPa-m] and a maximum detection range of approximately 90-180 m.

  19. 78 FR 70002 - International Fisheries; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-22

    ...; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the Eastern Pacific Ocean; Correction... rule published in the Federal Register on November 4, 2013, to close the bigeye tuna longline fishery.... SUPPLEMENTARY INFORMATION: NMFS announced that the bigeye tuna longline fishery in the Eastern Pacific Ocean...

  20. 77 FR 44592 - Atlantic Highly Migratory Species; Electronic Dealer Reporting System Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... swordfish, shark, and tunas dealers (except for dealers reporting Atlantic bluefin tuna) to report... maintain optimum yield, rebuild overfished fisheries, and prevent overfishing. Atlantic Tunas Convention... tunas dealers (except for dealers reporting Atlantic bluefin tuna) to report commercially-...

  1. [Association of the abundance and vertical distribution of tuna and beakfish in the southeast of the Caribbean sea].

    PubMed

    Eslava, Nora; González, Leo W; Gaertner, Daniel

    2003-03-01

    The longline hooks suspension depth was estimated using the Mechanic Imitation of Flexible Systems method. The vertical distribution of tunas and billfish was determined by the relative abundance index, obtained from the catch by 11 to 25 m -long longline vessels, -based at Cumaná, Venezuela, South-eastern Caribbean Sea in depths of 65 to 142 m. The CPUE was evaluated per species, according to depth. High values were found for most of the captured species in the layer from 105 to 125 m. Yellowfin tuna (Thunnus albacares) showed the highest yield (3.37 fish/100 hooks) and blue marlin (Makaira nigricans) the lowest (0.04 fish/100 hooks). However, the statistical comparison did not allow to reject the hypothesis of lack of depth efect (Kruskal-Wallis p > .05), and demonstrated a homogeneous distribution of yellowfin tuna (Thunnus albacares), albacore (Thunnus alalunga), bigeye tuna (Thunnus obesus), sailfish (Istiophorus albicans), white marlin (Tetrapturus albidus) and blue marlin (Makaira nigricans) in the water column. The conclusion is that fish concentration in the Southern border of the Caribbean Sea is possibly due to several hydroclimatic factors--which affect tuna and billfish catching--such as water temperature and dissolved oxygen concentration which limit the distribution according to depth.

  2. Assessment of the seabird community of the Mozambique Channel and its potential use as an indicator of tuna abundance

    NASA Astrophysics Data System (ADS)

    Le Corre, Matthieu; Jaquemet, Sébastien

    2005-05-01

    Tropical seabirds are known to associate with aggregations of surface dwelling predators, like tunas when feeding. Some species are even regarded as near obligate commensals of tunas. As food is one of the main factors that shape breeding strategies and determine breeding success of seabirds, it is of interest to test the hypothesis that variations in tuna abundance may have effects on foraging success and thus on breeding parameters of tropical seabirds. The Mozambique Channel is appropriate for such a study because relative tuna abundance is assessed annually (through fishery catches) and seabird populations are abundant. A regional synopsis shows that at least 3.034 million pairs of seabirds breed on islands of the Mozambique Channel, 99.3% being sooty terns. This super-abundant seabird is strongly associated with tuna and marine mammals when feeding. More than 99% of the sooty tern population of the Mozambique Channel breeds at three remote coralline islands, namely Juan de Nova (66%), Europa (25%) and Glorieuses (9%). Various breeding parameters (breeding population size, breeding time, growth rate of the chicks, daily food intake, diet) are studied at these three sites in order to investigate their relation to the marine environment (including tuna abundance). A preliminary estimate is made of the quantity of food eaten by the sooty tern population.

  3. Predicting the Distribution of Yellowfin Tuna in Philippine Waters

    NASA Astrophysics Data System (ADS)

    Perez, G. J. P.; Leonardo, E. M.

    2015-12-01

    The Philippines is considered as a major tuna producer in the Western and Central Pacific Ocean, both for domestic consumption and on industrial scale. However, with the ever-increasing demand of growing population, it has always been a challenge to achieve sustainable fishing. The creation of satellite-derived potential fishing zone maps is a technology that has been adopted by advanced countries for almost three decades already and has led to reduction in search times by up to 40%. In this study, a Generalized Additive Model (GAM) is developed to predict the distribution of the Yellowfin tuna species in seas surrounding the Philippines based on the Catch-Per-Unit-Effort (CPUE) index. Level 3 gridded chlorophyll-a and sea surface temperature from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite of the National Aeronautics and Space Administration (NASA) are the main input parameters of the model. Chlorophyll-a is linked with the presence of phytoplankton, which indicates primary productivity and suggests potential regions of fish aggregation. Fish also prefers to stay in regions where the temperature is stable, thus the sea surface temperature fronts serve as a guide to locate concentrations of fish school. Historical monthly tuna catch data from Western and Central Pacific Commissions (WCPFC) is used to train the model. The resulting predictions are converted to potential fishing zone maps and are evaluated within and beyond the historical time range of the training data used. Diagnostic tests involving adjusted R2 value, GAM residual plots and root mean square error value are used to assess the accuracy of the model. The generated maps were able to confirm locations of known tuna fishing grounds in Mindanao and other parts of the country, as well us detect their seasonality and interannual variability. To improve the performance of the model, ancillary data such as surface winds reanalysis from National Centers for

  4. Risk Factors for Seabird Bycatch in a Pelagic Longline Tuna Fishery.

    PubMed

    Gilman, Eric; Chaloupka, Milani; Peschon, John; Ellgen, Sarah

    2016-01-01

    Capture in global pelagic longline fisheries threatens the viability of some seabird populations. The Hawaii longline tuna fishery annually catches hundreds of seabirds, primarily Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses. Since seabird regulations were introduced in 2001, the seabird catch rate has declined 74%. However, over the past decade, seabird catch levels significantly increased due to significant increasing trends in both effort and nominal seabird catch rates. We modelled observer data using a spatio-temporal generalized additive mixed model with zero-inflated Poisson likelihood to determine the significance of the effect of various risk factors on the seabird catch rate. The seabird catch rate significantly increased as annual mean multivariate ENSO index values increased, suggesting that decreasing ocean productivity observed in recent years in the central north Pacific may have contributed to the increasing trend in nominal seabird catch rate. A significant increasing trend in number of albatrosses attending vessels, possibly linked to declining regional ocean productivity and increasing absolute abundance of black-footed albatrosses, may also have contributed to the increasing nominal seabird catch rate. Largest opportunities for reductions are through augmented efficacy of seabird bycatch mitigation north of 23° N where mitigation methods are required and during setting instead of during hauling. Both side vs. stern setting, and blue-dyed vs. untreated bait significantly reduced the seabird catch rate. Of two options for meeting regulatory requirements, side setting had a significantly lower seabird catch rate than blue-dyed bait. There was significant spatio-temporal and seasonal variation in the risk of seabird capture with highest catch rates in April and May and to the northwest of the main Hawaiian Islands.

  5. Risk Factors for Seabird Bycatch in a Pelagic Longline Tuna Fishery

    PubMed Central

    Gilman, Eric; Chaloupka, Milani; Peschon, John; Ellgen, Sarah

    2016-01-01

    Capture in global pelagic longline fisheries threatens the viability of some seabird populations. The Hawaii longline tuna fishery annually catches hundreds of seabirds, primarily Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses. Since seabird regulations were introduced in 2001, the seabird catch rate has declined 74%. However, over the past decade, seabird catch levels significantly increased due to significant increasing trends in both effort and nominal seabird catch rates. We modelled observer data using a spatio-temporal generalized additive mixed model with zero-inflated Poisson likelihood to determine the significance of the effect of various risk factors on the seabird catch rate. The seabird catch rate significantly increased as annual mean multivariate ENSO index values increased, suggesting that decreasing ocean productivity observed in recent years in the central north Pacific may have contributed to the increasing trend in nominal seabird catch rate. A significant increasing trend in number of albatrosses attending vessels, possibly linked to declining regional ocean productivity and increasing absolute abundance of black-footed albatrosses, may also have contributed to the increasing nominal seabird catch rate. Largest opportunities for reductions are through augmented efficacy of seabird bycatch mitigation north of 23° N where mitigation methods are required and during setting instead of during hauling. Both side vs. stern setting, and blue-dyed vs. untreated bait significantly reduced the seabird catch rate. Of two options for meeting regulatory requirements, side setting had a significantly lower seabird catch rate than blue-dyed bait. There was significant spatio-temporal and seasonal variation in the risk of seabird capture with highest catch rates in April and May and to the northwest of the main Hawaiian Islands. PMID:27192492

  6. Time-Temperature-Tolerance (T. T. T.) of On-Board Frozen Tuna During Subsequent On-Land Frozen Storage with Particular Reference to Commercial Scale Trial-II

    NASA Astrophysics Data System (ADS)

    Tanaka, Takeo; Hamamoto, Yûkichi; Nishiwaki, Kôji

    As described in the preceding paper 1), there is a demand in the tuna industry from the view point of energy saving for setting up T. T. T. of on-board frozen tuna during on-land frozen storage. Three groups of tuna being composed of three different species, yellowfin (YF), southern bluefin (SB) and bigeye (BE) tuna which had been frozen on-board commercially were further stored experimentally at -40, - 30 and -20°C. K1 value (one of freshness index for fish) and K2 value (one of taste component index for fish meat) were used as quality index for T. T. T. decision. Results are as follows : Both values of three tunas examined did not change appreciably throughout storage at any temperature of -20, - 30 and -40°C. These findings indicated that T. T. T. of YF and SB was estimated to be 6 months∗ at least, and that of BE to be 17 months∗ at least as far as it was judged on bases of K1) and K2 values. (Asterisks indicate merely the length of the experimental storage, ac tual T. T. T. therefore, must be longer).

  7. The Southern Oscillation, Hypoxia, and the Eastern Pacific Tuna Fishery

    NASA Astrophysics Data System (ADS)

    Webster, D.; Kiefer, D.; Lam, C. H.; Harrison, D. P.; Armstrong, E. M.; Hinton, M.; Luo, L.

    2012-12-01

    The Eastern Pacific tuna fishery, which is one of the world's major fisheries, covers thousands of square kilometers. The vessels of this fishery are registered in more than 30 nations and largely target bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin (T. albacores) tuna. In both the Pelagic Habitat Analysis Module project, which is sponsored by NASA, and the Fishscape project, which is sponsored by NSF, we have attempted to define the habitat of the three species by matching a 50 year time series on fish catch and effort with oceanographic information obtained from satellite imagery and from a global circulation model. The fishery time series, which was provided by the Inter-American Tropical Tuna Commission, provided spatial maps of catch and effort at monthly time steps; the satellite imagery of the region consisted of sea surface temperature, chlorophyll, and height from GHRSST, SEAWiFS, and AVISO products, and the modeled flow field at selected depths was output from ECCO-92 simulations from 1992 to present. All information was integrated and analyzed within the EASy marine geographic information system. This GIS will also provides a home for the Fishscape spatial simulation model of the coupled dynamics of the ocean, fish, fleets, and markets. This model will then be applied to an assessment of the potential ecological and economic impacts of climate change, technological advances in fleet operations, and increases in fuel costs. We have determined by application of EOF analysis that the ECCO-2 simulation of sea surface height fits well with that of AVISO imagery; thus, if driven properly by predictions of future air-sea exchange, the model should provide good estimates of circulation patterns. We have also found that strong El Nino events lead to strong recruitment of all three species and strong La Nina events lead to weak recruitment. Finally, we have found that the general spatial distribution of the Eastern Pacific fishing grounds

  8. Synthesis of underreported small-scale fisheries catch in Pacific island waters

    NASA Astrophysics Data System (ADS)

    Zeller, D.; Harper, S.; Zylich, K.; Pauly, D.

    2015-03-01

    We synthesize fisheries catch reconstruction studies for 25 Pacific island countries, states and territories, which compare estimates of total domestic catches with officially reported catch data. We exclude data for the large-scale tuna fleets, which have largely foreign beneficial ownership, even when flying Pacific flags. However, we recognize the considerable financial contributions derived from foreign access or charter fees for Pacific host countries. The reconstructions for the 25 entities from 1950 to 2010 suggested that total domestic catches were 2.5 times the data reported to FAO. This discrepancy was largest in early periods (1950: 6.4 times), while for 2010, total catches were 1.7 times the reported data. There was a significant difference in trend between reported and reconstructed catches since 2000, with reconstructed catches declining strongly since their peak in 2000. Total catches increased from 110,000 t yr-1 in 1950 (of which 17,400 t were reported) to a peak of over 250,000 t yr-1 in 2000, before declining to around 200,000 t yr-1 by 2010. This decrease is driven by a declining artisanal (small-scale commercial) catch, which was not compensated for by increasing domestic industrial (large-scale commercial) catches. The artisanal fisheries appear to be declining from a peak of 97,000 t yr-1 in 1992 to less than 50,000 t yr-1 by 2010. However, total catches were dominated by subsistence (small-scale, non-commercial) fisheries, which accounted for 69 % of total catches, with the majority missing from the reported data. Artisanal catches accounted for 22 %, while truly domestic industrial fisheries accounted for only 6 % of total catches. The smallest component is the recreational (small-scale, non-commercial and largely for leisure) sector (2 %), which, although small in catch, is likely of economic importance in some areas due to its direct link to tourism income.

  9. Bluefin autonomous underwater vehicles: Programs, systems, and acoustic issues

    NASA Astrophysics Data System (ADS)

    Bondaryk, Joseph E.

    2001-05-01

    Bluefin Robotics Corporation has been manufacturing autonomous underwater vehicles (AUVs) since spinning out of the MIT Sea Grant Laboratory in 1997. Bluefin currently makes three different diameter models of AUVs; the 9, 12, and 21, all based on the same free-flooded architecture and vectored-thrust propulsion design. Auxiliary acoustic systems include acoustic abort, ranging beacons, and acoustic modems. Vehicle navigation is aided by a downward-looking acoustic Doppler velocity logger (DVL). Sonar payloads can include: bottom profiler, side-scan sonar, SAS, forward-looking imagers (DIDSON), as well as horizontal and vertical discrete hydrophone arrays. Acoustic issues that arise include: (1) transmission of sound through the ABS plastic vehicle shell; (2) the impact of vehicle self-noise on data; (3) interoperability of sonars with other acoustic emitters present on and off the vehicle; and (4) the impact of navigation on some acoustic operations like SAS. This talk will illustrate these issues with real data collected on various Bluefin vehicles.

  10. Spatiotemporal variability in bigeye tuna ( Thunnus obesus) dive behavior in the central North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Howell, Evan A.; Hawn, Donald R.; Polovina, Jeffrey J.

    2010-07-01

    Data from 29 pop-up archival transmission (PAT) tags deployed on commercial-size bigeye tuna ( Thunnus obesus) in the central North Pacific Ocean from 4°N to 32°N were analyzed to describe variability in their dive behavior across space and time. During the day, bigeye tuna generally spent time in the 0-50 m and 300-400 m depth ranges, with spatial and temporal variability in the deep mode. At night, bigeye tuna generally inhabited the 0-100 m depth range. Three daily dive types were defined based on the percentage of time tuna spent in specific depth layers during the day. These three types were defined as shallow, intermediate, and deep and represented 24.4%, 18.8%, and 56.8% of the total number of days in the study, respectively. More shallow and intermediate dive-type behavior was found in the first half of the year, and in latitudes from 14°N to 16°N and north of 28°N. A greater amount of deep-dive behavior was found in the regions south of 10°N and between 18°N and 28°N during the third and fourth quarters of the year. Dive-type behavior also varied with oceanographic conditions, with more shallow and intermediate behavior found in colder surface waters. Intermediate and deep-dive types were pooled to reflect the depths where bigeye tuna may have potential interactions with fishing gear. A Generalized Additive Model was used to quantify the effects of time, space, and sea surface temperature on this pooled dive type. Results from the model showed that while latitude and quarter of the year were important parameters, sea surface temperature had the most significant effect on the pooled intermediate and deep-dive behavior. Model predictions indicated that the largest percentage of potential interaction would occur in the fourth quarter in the region from 18°N-20°N, which corresponds to the time and place of the highest bigeye tuna catch rates by the Hawaii-based long-line fishery. These results suggest that a model framework using these three

  11. Space Technology For Tuna Boats

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Freshly-caught tuna is stored below decks in wells cooled to about zero degrees by brine circulated through a refrigerating system. The wells formerly were insulated by cork or fiberglass, but both materials were subject to deterioration; cork, for instance, needs replacement every three years. The Campbell Machine Division of Campbell Industries, San Diego, which manufactures and repairs large boats for the commercial fishing industry, was looking for a better way to insulate tuna storage wells. Learning of the Rockwell technique, Campbell contracted for a test installation on one boat, then bought its own equipment and adopted the spray-foam procedure for their boats. The foam hardens after application. It not only is a superior insulator, it also is considerably lighter and easier to apply. Fishing industry spokesmen say that foam insulation is far more reliable, efficient and economical than prior techniques. More than 40 foam-insulated tuna boats, ranging in cost from $1 million to $4 million, have been built and sold. Principal customers are Ralston Purina's Van Camp Seafood Division and Star-Kist Inc.

  12. Evaluation of three harvest control rules for Bigeye Tuna ( Thunnus obesus) fisheries in the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Tong, Yuhe; Chen, Xinjun; Kolody, Dale

    2014-10-01

    The stock of Bigeye tuna ( Thunnus obesus) in the Indian Ocean supports an important international fishery and is considered to be fully exploited. The responsible management agency, the Indian Ocean Tuna Commission (IOTC), does not have an explicit management decision-making framework in place to prevent over-fishing. In this study, we evaluated three harvest control rules, i) constant fishing mortality (CF), from 0.2 to 0.6, ii) constant catch (CC), from 60000 to 140000 t, and iii) constant escapement (CE), from 0.3 to 0.7. The population dynamics simulated by the operating model was based on the most recent stock assessment using Stock Synthesis version III (SS3). Three simulation scenarios (low, medium and high productivity) were designed to cover possible uncertainty in the stock assessment and biological parameters. Performances of three harvest control rules were compared on the basis of three management objectives (over 3, 10 and 25 years): i) the probability of maintaining spawning stock biomass above a level that can sustain maximum sustainable yield (MSY) on average, ii) the probability of achieving average catches between 0.8 MSY and 1.0 MSY, and iii) inter-annual variability in catches. The constant escapement strategy ( CE=0.5), constant fishing mortality strategy ( F=0.4) and constant catch ( CC=80000) were the most rational among the respective management scenarios. It is concluded that the short-term annual catch is suggested at 80000 t, and the potential total allowable catch for a stable yield could be set at 120000 t once the stock had recovered successfully. All the strategies considered in this study to achieve a `tolerable' balance between resource conservation and utilization have been based around the management objectives of the IOTC.

  13. [Spatial-temporal distribution of bigeye tuna Thunnus obesus in the tropical Atlantic Ocean based on Argo data].

    PubMed

    Yang, Sheng-long; Jin, Shao-fei; Hua, Cheng-jun; Dai, Yang

    2015-02-01

    In order to analyze the correlation between spatial-temporal distribution of the bigeye tuna ( Thunnus obesus) and subsurface factors, the study explored the isothermal distribution of subsurface temperatures in the bigeye tuna fishing grounds in the tropical Atlantic Ocean, and built up the spatial overlay chart of the isothermal lines of 9, 12, 13 and 15 °C and monthly CPUE (catch per unit effort) from bigeye tuna long-lines. The results showed that the bigeye tuna mainly distributed in the water layer (150-450 m) below the lower boundary depth of thermocline. At the isothermal line of 12 °C, the bigeye tuna mainly lived in the water layer of 190-260 m, while few individuals were found at water depth more than 400 m. As to the 13 °C isothermal line, high CPUE often appeared at water depth less than 250 m, mainly between 150-230 m, while no CPUE appeared at water depth more than 300 m. The optimum range of subsurface factors calculated by frequency analysis and empirical cumulative distribution function (ECDF) exhibited that the optimum depth range of 12 °C isothermal depth was 190-260 m and the 13 °C isothermal depth was 160-240 m, while the optimum depth difference range of 12 °C isothermal depth was -10 to 100 m and the 13 °C isothermal depth was -40 to 60 m. The study explored the optimum range of subsurface factors (water temperature and depth) that drive horizontal and vertical distribution of bigeye tuna. The preliminary result would help to discover the central fishing ground, instruct fishing depth, and provide theoretical and practical references for the longline production and resource management of bigeye tuna in the Atlantic Ocean.

  14. Spatial surplus production modeling of Atlantic tunas and billfish.

    PubMed

    Carruthers, Thomas R; McAllister, Murdoch K; Taylor, Nathan G

    2011-10-01

    We formulate and simulation-test a spatial surplus production model that provides a basis with which to undertake multispecies, multi-area, stock assessment. Movement between areas is parameterized using a simple gravity model that includes a "residency" parameter that determines the degree of stock mixing among areas. The model is deliberately simple in order to (1) accommodate nontarget species that typically have fewer available data and (2) minimize computational demand to enable simulation evaluation of spatial management strategies. Using this model, we demonstrate that careful consideration of spatial catch and effort data can provide the basis for simple yet reliable spatial stock assessments. If simple spatial dynamics can be assumed, tagging data are not required to reliably estimate spatial distribution and movement. When applied to eight stocks of Atlantic tuna and billfish, the model tracks regional catch data relatively well by approximating local depletions and exchange among high-abundance areas. We use these results to investigate and discuss the implications of using spatially aggregated stock assessment for fisheries in which the distribution of both the population and fishing vary over time.

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

    PubMed

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

    2017-01-01

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

  16. Time-Temperature-Tolerance(T. T. T.) of On-Board Frozen Tuna During Subsequent On-Land Frozen Storage with Particular Reference to Commercial Scale Trial-I

    NASA Astrophysics Data System (ADS)

    Tanaka, Takeo; Takahashi, Kenji; Nishiwaki, Koji

    This study was undertaken to meet the demand of the tuna industry for the definite criterion of T. T. T. of on-board frozen tuna during on-land frozen storage, from the veiw point of energy saving. Yellowfin (YF), southern bluefin (SB) and bigeye (BE) tuna which had been frozen-stored on board in semi-dressed form, excluding gills and viscera, commercially were further stored experimentally at -40, -30 and -20°C on the premise that a target of commercial storage period was 6 months. Decision on tolerance limits was given by degree of discoloration of the meat (met-myoglobin ratio). Results are as follows : T. T. T. of YF and SB was estimated to be 6 months∗ and that of BE to be 17 months∗ at -40°C, and that of the three tunas examined to be 6 months∗ at -30°C. T. T. T. of YF and SB was estimated to be 1.5 and 4-5 months (2-3 and 5 months in the case of meat block), respectively, and that of BE to be one month at -20°C. (Asterisks indicate merely the length of the experimental storage, actual T. T. T therefore, must be longer).

  17. Catch a Star!

    NASA Astrophysics Data System (ADS)

    2006-11-01

    ESO and the European Association for Astronomy Education are launching today the 2007 edition of 'Catch a Star!', their international astronomy competition for school students. Now in its fifth year, the competition offers students the chance to win a once-in-a-lifetime trip to ESO's flagship observatory in Chile, as well as many other prizes. Students are invited to 'become astronomers' and embark on a journey to explore the Universe. ESO PR Photo 42/06 The competition includes separate categories - 'Catch a Star Researchers' and 'Catch a Star Adventurers' - to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. For the artistically minded, 'Catch a Star!' also includes an artwork competition, 'Catch a Star Artists'. "'Catch a Star!' offers a unique opportunity for students to learn more about astronomy and about the methods scientists use to discover new things about the Universe", said Douglas Pierce-Price, Education Officer at ESO. In teams, students choose an astronomical topic to study and produce an in-depth report. An important part of the project for 'Catch a Star Researchers' is to think about how ESO's telescopes or a telescope of the future can contribute to their investigations of the subject. As well as the top prize - a trip to one of ESO's observatory sites in Chile - visits to observatories in Germany, Austria and Spain, and many other prizes are also available to be won. 'Catch a Star Researchers' winners will be chosen by an international jury, and 'Catch a Star Adventurers' will be awarded further prizes by lottery. Entries for 'Catch a Star Artists' will be displayed on the web and winners chosen with the help of a public online vote. The first editions of 'Catch a Star!' have attracted several hundred entries from more than 25 countries worldwide. Previous winning entries have included "Star clusters and the structure of the Milky Way" (Budapest, Hungary), "Vega" (Acqui Terme, Italy) and "Venus

  18. 77 FR 24669 - Atlantic Highly Migratory Species; Public Conference Call Regarding Recreational Yellowfin Tuna...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... the U.S. recreational yellowfin tuna fishery and the relationship to international yellowfin tuna... tuna fishery and the relationship to international yellowfin tuna management (e.g., quota establishment...

  19. Preliminary forecasts of Pacific bigeye tuna population trends under the A2 IPCC scenario

    NASA Astrophysics Data System (ADS)

    Lehodey, P.; Senina, I.; Sibert, J.; Bopp, L.; Calmettes, B.; Hampton, J.; Murtugudde, R.

    2010-07-01

    An improved version of the spatial ecosystem and population dynamics model SEAPODYM was used to investigate the potential impacts of global warming on tuna populations. The model included an enhanced definition of habitat indices, movements, and accessibility of tuna predators to different vertically migrant and non-migrant micronekton functional groups. The simulations covered the Pacific basin (model domain) at a 2° × 2° geographic resolution. The structure of the model allows an evaluation from multiple data sources, and parameterization can be optimized by adjoint techniques and maximum likelihood using fishing data. A first such optimized parameterization was obtained for bigeye tuna ( Thunnus obesus) in the Pacific Ocean using historical catch data for the last 50 years and a hindcast from a coupled physical-biogeochemical model driven by the NCEP atmospheric reanalysis. The parameterization provided very plausible biological parameter values and a good fit to fishing data from the different fisheries, both within and outside the time period used for optimization. We then employed this model to forecast the future of bigeye tuna populations in the Pacific Ocean. The simulation was driven by the physical-biogeochemical fields predicted from a global marine biogeochemistry - climate simulation. This global simulation was performed with the IPSL climate model version 4 (IPSL-CM4) coupled to the oceanic biogeochemical model PISCES and forced by atmospheric CO 2, from historical records over 1860-2000, and under the SRES A2 IPCC scenario for the 21st century (i.e. atmospheric CO 2 concentration reaching 850 ppm in the year 2100). Potential future changes in distribution and abundance under the IPCC scenario are presented but without taking into account any fishing effort. The simulation showed an improvement in bigeye tuna spawning habitat both in subtropical latitudes and in the eastern tropical Pacific (ETP) where the surface temperature becomes optimal for

  20. Defining the Habitat of Pacific Tuna of the Eastern Tropical Pacific from Satellite Imagery, Climatologies, and a Global Circulation Model

    NASA Astrophysics Data System (ADS)

    Kiefer, D. A.; Hinton, M. G.; Armstrong, E. M.; Harrison, D. P.; Menemenlis, D.; Hu, C.

    2016-02-01

    With support from NASA's Ecological Forecasting program, we have developed a Tuna Stock Assessment Support System, which merges time series of satellite imagery, a global ocean circulation model, climatology from field surveys, and fisheries data on catch and effort. The purpose of this software is to extract information on the habitat of skipjack, bigeye, and yellowfin tuna in the Eastern Tropical Pacific. The support system is based upon a 50-year record of catch and effort from long-line and purse seine vessels provide by the Inter-American Tropical Tuna Commission. This database, which covers thousands of kilometers of ocean surface, provides monthly information at a 1 degree spatial resolution for the purse seine fleet and 5 degree resolution for the long line fishery. This data is then merged in time and space with satellite imagery of sea surface temperature, chlorophyll, and height, as well as NODC climatologies of oxygen concentration and temperature, and output from NASA's ECCO-2 global circulation model, which provides 3-dimensional simulations of water density, current velocity, mixed layer depth, and sea surface height. Our analyses have yielded a broad range of understanding of the habitat and dynamics both the fish and the fisherman. The purse seine ground, which targets younger tuna, is constrained to waters where the hypoxic layer is shallow. The longline fishery, which targets older tuna, is not constrained by the hypoxic layer and has a much larger distribution. We have characterized the preferences of each species to environmental variables including the depth of the hypoxic layer, the depth of the water column, as well as sea surface height, temperature, and chlorophyll concentration. Finally, the analyses have revealed information on local depletion by fishing, the size distribution of the schools of younger fish, and the impact of ENSO on fishing activities.

  1. Catch a Star 2008!

    NASA Astrophysics Data System (ADS)

    2007-10-01

    ESO and the European Association for Astronomy Education have just launched the 2008 edition of 'Catch a Star', their international astronomy competition for school students. Now in its sixth year, the competition offers students the chance to win a once-in-a-lifetime trip to ESO's flagship observatory in Chile, as well as many other prizes. CAS logo The competition includes separate categories - 'Catch a Star Researchers' and 'Catch a Star Adventurers' - to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. In teams, students investigate an astronomical topic of their choice and write a report about it. An important part of the project for 'Catch a Star Researchers' is to think about how ESO's telescopes such as the Very Large Telescope (VLT) or future telescopes such as the Atacama Large Millimeter/submillimeter Array (ALMA) and the European Extremely Large Telescope (E-ELT) could contribute to investigations of the topic. Students may also include practical activities such as observations or experiments. For the artistically minded, 'Catch a Star' also offers an artwork competition, 'Catch a Star Artists'. Last year, hundreds of students from across Europe and beyond took part in 'Catch a Star', submitting astronomical projects and artwork. "'Catch a Star' gets students thinking about the wonders of the Universe and the science of astronomy, with a chance of winning great prizes. It's easy to take part, whether by writing about astronomy or creating astronomically inspired artwork," said Douglas Pierce-Price, Education Officer at ESO. As well as the top prize - a trip to ESO's Very Large Telescope in Chile - visits to observatories in Austria and Spain, and many other prizes, can also be won. 'Catch a Star Researchers' winners will be chosen by an international jury, and 'Catch a Star Adventurers' will be awarded further prizes by lottery. Entries for 'Catch a Star Artists' will be displayed on the web and winners

  2. Standardization of a geo-referenced fishing data set for the Indian Ocean bigeye tuna, Thunnus obesus (1952-2014)

    NASA Astrophysics Data System (ADS)

    Wibawa, Teja A.; Lehodey, Patrick; Senina, Inna

    2017-02-01

    Geo-referenced catch and fishing effort data of the bigeye tuna fisheries in the Indian Ocean over 1952-2014 were analyzed and standardized to facilitate population dynamics modeling studies. During this 62-year historical period of exploitation, many changes occurred both in the fishing techniques and the monitoring of activity. This study includes a series of processing steps used for standardization of spatial resolution, conversion and standardization of catch and effort units, raising of geo-referenced catch into nominal catch level, screening and correction of outliers, and detection of major catchability changes over long time series of fishing data, i.e., the Japanese longline fleet operating in the tropical Indian Ocean. A total of 30 fisheries were finally determined from longline, purse seine and other-gears data sets, from which 10 longline and 4 purse seine fisheries represented 96 % of the whole historical geo-referenced catch. Nevertheless, one-third of total nominal catch is still not included due to a total lack of geo-referenced information and would need to be processed separately, accordingly to the requirements of the study. The geo-referenced records of catch, fishing effort and associated length frequency samples of all fisheries are available at doi:10.1594/PANGAEA.864154.

  3. The Tuna/Porpoise Problem: Behavioral Aspects

    ERIC Educational Resources Information Center

    Pryor, Karen; Norris, Kenneth S.

    1978-01-01

    Recent legislation has been enforced to reduce porpoise losses in the nets of tuna fishermen. This article discusses some of the behavioral causes of porpoise mortality and described solutions that may or may not work. (MA)

  4. No evidence for homeoviscous adaptation in a heterothermic tissue: tuna heat exchangers.

    PubMed

    Fudge, D S; Stevens, E D; Ballantyne, J S

    1998-09-01

    Many poikilotherms are known to adjust the membrane composition of their cells in response to a temperature change so that membrane fluidity, and therefore function, is conserved. Such compensatory changes in membrane composition are considered "homeoviscous adaptations." In this study, we examined a heterothermic tissue, the visceral rete mirabile of the bluefin tuna, for evidence of homeoviscous adaptation. We measured the proportions of phospholipid fatty acids and phospholipid head groups as a function of position along the rete thermal gradient, which has been estimated to be approximately 10 degrees C. We found no effect of position along the rete on the composition of either phospholipid fatty acids or head groups. Our results were unexpected in light of our previous demonstration of compensation of metabolic enzyme activity in the same tissue. The lack of evidence for a homeoviscous response may be due to the fluctuating nature of the thermal gradient along the visceral retia; i.e., membranes may be adapted to a eurythermal existence rather than being fine-tuned to a particular temperature.

  5. 76 FR 18653 - Atlantic Highly Migratory Species; Bluefin Tuna Bycatch Reduction in the Gulf of Mexico Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    ... the recent management history. Those details are not repeated here. ] Response to Comments During the... early summer months of March, April, May, and June. Because the experiment focused on collecting data... to the spring and early summer months of March, April, May, and June. Because the experiment focused...

  6. 76 FR 2313 - Atlantic Highly Migratory Species; Bluefin Tuna Bycatch Reduction in the Gulf of Mexico Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ... capture from the warm water. Promising research results, from an experiment (the weak hook study... context. Background and History A brief history on the management of the PLL fishery is provided below as... research experiment in this area on various PLL gear modifications to reduce sea turtle bycatch and bycatch...

  7. 78 FR 65887 - International Fisheries; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... National Oceanic and Atmospheric Administration 50 CFR Part 300 RIN 0648-XC922 International Fisheries; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the Eastern Pacific Ocean AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce...

  8. Global integration of European tuna markets

    NASA Astrophysics Data System (ADS)

    Jiménez-Toribio, Ramòn; Guillotreau, Patrice; Mongruel, Rémi

    2010-07-01

    This paper evaluates the degree of integration between the world market and the major European marketplaces of frozen and canned tuna through both vertical and horizontal price relationships. Spatial linkages are investigated horizontally in order to estimate the connection between the European market and the world-wide market on the primary stage of the value chain. One of the key results is the high level of market integration at the ex-vessel stage, and the price leadership of yellowfin tuna over skipjack tuna. The same approach is applied at the ex-factory level. Basically, the European market for final goods appears to be segmented between the Northern countries consuming low-priced canned skipjack tuna imported from Asia (mainly Thailand) and the Southern countries (Italy, Spain) processing and importing yellowfin-based products sold at higher prices. France appears to be an intermediate market where both products are consumed. The former market is found to be well integrated to the world market and can be considered to be competitive, but there is a suspicion of market power being exercised on the latter. Price relationships are therefore tested vertically between the price of frozen tuna paid by the canneries and the price of canned fish in both Italy and France. The two species show an opposite pattern in prices transmission along the value chain: price changes along the chain are far better transmitted for the “global” skipjack tuna than for the more “European” yellowfin tuna. The results are discussed, along with their implications for the fishing industry.

  9. How important are coastal fronts to albacore tuna (Thunnus alalunga) habitat in the Northeast Pacific Ocean?

    NASA Astrophysics Data System (ADS)

    Nieto, Karen; Xu, Yi; Teo, Steven L. H.; McClatchie, Sam; Holmes, John

    2017-01-01

    We used satellite sea surface temperature (SST) data to characterize coastal fronts and then tested the effects of the fronts and other environmental variables on the distribution of the albacore tuna (Thunnus alalunga) catches in the coastal areas (from the coast to 200 nm offshore) of the Northeast Pacific Ocean. A boosted regression tree (BRT) model was used to explain the spatial and temporal patterns in albacore tuna catch per unit effort (CPUE) (1988-2011), using frontal features (distance to the front and temperature gradient), and other environmental variables like SST, surface chlorophyll concentration (chlorophyll), and geostrophic currents as explanatory variables. Based on over two decades of high-resolution data, the modeled results confirmed previous findings that albacore CPUE distribution is strongly influenced by SST and chlorophyll at fishing locations, and the distance of fronts from the coast (DFRONT-COAST), albeit with substantial seasonal and interannual variation. Albacore CPUEs were higher near warm, low chlorophyll oceanic waters, and near SST fronts. We performed sequential leave-one-year-out cross-validations for all years and found that the relationships in the BRT models were robust for the entire study period. Spatial distributions of model-predicted albacore CPUE were similar to observations, but the model was unable to predict very high CPUEs in some areas. These results help to explain previously observed variability in albacore CPUE and will likely help improve international fisheries management in the face of environmental changes.

  10. 77 FR 25732 - Tuna-Tariff-Rate Quota; the Tariff-Rate Quota for Calendar Year 2012 Tuna Classifiable Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-01

    ... Year 2012 Tuna Classifiable Under Subheading 1604.14.22, Harmonized Tariff Schedule of the United... Year 2012 Tuna Classifiable under Subheading 1604.14.22, Harmonized Tariff Schedule of the United...

  11. Nitrogen catch crops

    USDA-ARS?s Scientific Manuscript database

    High costs of nitrogen (N) fertilizer and the potential for N losses to ground and surface water have resulted in increased interest in using catch crops to recover this N. Research on potatoes has shown that the amount of N lost to leaching can be as much as the amount of N removed from the field ...

  12. Structure and function of tuna tail tendons.

    PubMed

    Shadwick, Robert E; Rapoport, H Scott; Fenger, Joelle M

    2002-12-01

    The caudal tendons in tunas and other scombrid fish link myotomal muscle directly to the caudal fin rays, and thus serve to transfer muscle power to the hydrofoil-like tail during swimming. These robust collagenous tendons have structural and mechanical similarity to tendons found in other vertebrates, notably the leg tendons of terrestrial mammals. Biochemical studies indicate that tuna tendon collagen is composed of the (alpha1)(2),alpha2 heterotrimer that is typical of vertebrate Type I collagen, while tuna skin collagen has the unusual alpha1,alpha2,alpha3 trimer previously described in the skin of some other teleost species. Tuna collagen, like that of other fish, has high solubility due to the presence of an acid-labile intermolecular cross-link. Unlike collagen in mammalian tendons, no differences related to cross-link maturation were detected among tendons in tuna ranging from 0.05 to 72 kg (approx. 0.25-6 years). Tendons excised post-mortem were subjected to load cycling to determine the modulus of elasticity and resilience (mean of 1.3 GPa and 90%, respectively). These material properties compare closely to those of leg tendons from adult mammals that can function as effective biological springs in terrestrial locomotion, but the breaking strength is substantially lower. Peak tendon forces recorded during steady swimming appear to impose strains of much less than 1% of tendon length, and no more than 1.5% during bursts. Thus, the caudal tendons in tunas do not appear to function as elastic storage elements, even at maximal swimming effort.

  13. Evaluation of FAD-associated purse seine fishery reduction strategies for bigeye tuna ( Thunnus obesus) in the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Tong, Yuhe; Chen, Xinjun; Xu, Liuxiong; Chen, Yong

    2013-07-01

    In the Indian Ocean, bigeye tuna supports one of the most important fisheries in the world. This fishery mainly consists of two components: longline and purse seine fisheries. Evidence of overfishing and stock depletion of bigeye tuna calls for an evaluation of alternative management strategies. Using an age-structured operating model, parameterized with the results derived in a recent stock assessment, we evaluated the effectiveness of applying constant fishing mortality (CF) and quasi-constant fishing mortality (QCF) strategies to reduce fishing effort of purse seining with fish aggregating devices (FADs) at different rates. Three different levels of productivity accounted for the uncertainty in our understanding of stock productivity. The study shows that the results of CF and QCF are similar. Average SSB and catch during simulation years would be higher if fishing mortality of FAD-associated purse seining was reduced rapidly. The banning or rapid reduction of purse seining with FAD resulted in a mean catch, and catch in the last simulation year, higher than that of the base case in which no change was made to the purse seine fishery. This could be caused by growth overfishing by purse seine fisheries with FADs according to the per-recruit analysis. These differences would be more obvious when stock productivity was low. Transferring efforts of FAD-associated purse seining to longline fisheries is also not feasible. Our study suggests that changes are necessary to improve the performance of the current management strategy.

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

    PubMed

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

    2009-05-01

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

  15. Experiments in robotic catching

    NASA Technical Reports Server (NTRS)

    Hove, Barbara; Slotine, Jean-Jacques E.

    1991-01-01

    Real-time coordination of visual information with high-speed manipulator control is studied in the context of three-dimensional robotic catching. All path planning for the catch occurs in real-time during the half-second that the targeted object is airborne. A trajectory-matching algorithm is used that combines an observer with a varying-strength filter, an error estimator, and an initial motion algorithm. The results are demonstrated experimentally using a real-time vision system and a four-degree-of-freedom, cable-driven arm with a workspace of 4.2 m3 and speed capabilities of up to 2.0 m/s.

  16. Kounis syndrome following canned tuna fish ingestion.

    PubMed

    De Gennaro, Luisa; Brunetti, Natale Daniele; Locuratolo, Nicola; Ruggiero, Massimo; Resta, Manuela; Diaferia, Giuseppe; Rana, Michele; Caldarola, Pasquale

    2016-12-20

    Kounis syndrome (KS) is a complex of cardiovascular symptoms and signs following either allergy or hypersensitivity and anaphylactic or anaphylactoid insults. We report the case of 57-year-old man, with hypertension and history of allergy, referred for facial rash and palpitations appeared after consumption of canned tuna fish. Suddenly, the patient collapsed: electrocardiogram showed ST-elevation in inferior leads. The patient was transferred from the spoke emergency room for coronary angio, which did not show any sign of coronary atherosclerosis. A transient coronary spasm was therefore hypothesized and the final diagnosis was KS. To the best of our knowledge, this is one of the first cases of KS following the ingestion of tuna fish. KS secondary to food allergy has also been reported, and shellfish ingestion has been considered as one of the most active KS inducer foods. Canned tuna fish too is well known as an allergy inducer. Tuna fish allergy should be considered, however, within the context of scombroid food poisoning, also called histamine fish poisoning. Fish with high levels of free histidine, the enzyme substrate converted to histamine by bacterial histidine decarboxylase, are those most often implicated in scombroid poisoning. Inflammatory mediators such as histamine constitute the pathophysiologic basis of Kounis hypersensitivity-associated acute coronary syndrome. Patients with coronary risk factors, allergic reaction after food ingestion, and suspected scombroid poisoning should be therefore carefully monitored for a prompt diagnosis of possible coronary complications.

  17. Measurement of Coefficient of Thermal Expansion of Tuna Fish

    NASA Astrophysics Data System (ADS)

    Ogawa, Yutaka

    Considering that gape and heave produced during the freezing of tuna fish derive from changes in the thermophysical properties of tuna fish itself during freezing, the coefficient of linear and cubical expansion of tuna meat were measured continuously between the temperature before freezing and during freezing. The results of measurement were shown that the coefficient of thermal expansion of tuna meat displayed special temperature dependence as sudden change at the boundary temperature of freezing beginning as summarized below: 1) the coefficient of linear expansion of tuna meat were anisotropic according to the tissue and structure of the fish body, but these properties varied according to the test temperature; and 2) the coefficient of cubical expansion during freezing assumed a maximal value when tuna meat was partially frozen.

  18. A spatial ecosystem and populations dynamics model (SEAPODYM) Modeling of tuna and tuna-like populations

    NASA Astrophysics Data System (ADS)

    Lehodey, Patrick; Senina, Inna; Murtugudde, Raghu

    2008-09-01

    An enhanced version of the spatial ecosystem and population dynamics model SEAPODYM is presented to describe spatial dynamics of tuna and tuna-like species in the Pacific Ocean at monthly resolution over 1° grid-boxes. The simulations are driven by a bio-physical environment predicted from a coupled ocean physical-biogeochemical model. This new version of SEAPODYM includes expanded definitions of habitat indices, movements, and natural mortality based on empirical evidences. A thermal habitat of tuna species is derived from an individual heat budget model. The feeding habitat is computed according to the accessibility of tuna predator cohorts to different vertically migrating and non-migrating micronekton (mid-trophic) functional groups. The spawning habitat is based on temperature and the coincidence of spawning fish with presence or absence of predators and food for larvae. The successful larval recruitment is linked to spawning stock biomass. Larvae drift with currents, while immature and adult tuna can move of their own volition, in addition to being advected by currents. A food requirement index is computed to adjust locally the natural mortality of cohorts based on food demand and accessibility to available forage components. Together these mechanisms induce bottom-up and top-down effects, and intra- (i.e. between cohorts) and inter-species interactions. The model is now fully operational for running multi-species, multi-fisheries simulations, and the structure of the model allows a validation from multiple data sources. An application with two tuna species showing different biological characteristics, skipjack ( Katsuwonus pelamis) and bigeye ( Thunnus obesus), is presented to illustrate the capacity of the model to capture many important features of spatial dynamics of these two different tuna species in the Pacific Ocean. The actual validation is presented in a companion paper describing the approach to have a rigorous mathematical parameter optimization

  19. Evidence of discrete yellowfin tuna (Thunnus albacares) populations demands rethink of management for this globally important resource.

    PubMed

    Grewe, P M; Feutry, P; Hill, P L; Gunasekera, R M; Schaefer, K M; Itano, D G; Fuller, D W; Foster, S D; Davies, C R

    2015-11-23

    Tropical tuna fisheries are central to food security and economic development of many regions of the world. Contemporary population assessment and management generally assume these fisheries exploit a single mixed spawning population, within ocean basins. To date population genetics has lacked the required power to conclusively test this assumption. Here we demonstrate heterogeneous population structure among yellowfin tuna sampled at three locations across the Pacific Ocean (western, central, and eastern) via analysis of double digest restriction-site associated DNA using Next Generation Sequencing technology. The differences among locations are such that individuals sampled from one of the three regions examined can be assigned with close to 100% accuracy demonstrating the power of this approach for providing practical markers for fishery independent verification of catch provenance in a way not achieved by previous techniques. Given these results, an extended pan-tropical survey of yellowfin tuna using this approach will not only help combat the largest threat to sustainable fisheries (i.e. illegal, unreported, and unregulated fishing) but will also provide a basis to transform current monitoring, assessment, and management approaches for this globally significant species.

  20. Evidence of discrete yellowfin tuna (Thunnus albacares) populations demands rethink of management for this globally important resource

    NASA Astrophysics Data System (ADS)

    Grewe, P. M.; Feutry, P.; Hill, P. L.; Gunasekera, R. M.; Schaefer, K. M.; Itano, D. G.; Fuller, D. W.; Foster, S. D.; Davies, C. R.

    2015-11-01

    Tropical tuna fisheries are central to food security and economic development of many regions of the world. Contemporary population assessment and management generally assume these fisheries exploit a single mixed spawning population, within ocean basins. To date population genetics has lacked the required power to conclusively test this assumption. Here we demonstrate heterogeneous population structure among yellowfin tuna sampled at three locations across the Pacific Ocean (western, central, and eastern) via analysis of double digest restriction-site associated DNA using Next Generation Sequencing technology. The differences among locations are such that individuals sampled from one of the three regions examined can be assigned with close to 100% accuracy demonstrating the power of this approach for providing practical markers for fishery independent verification of catch provenance in a way not achieved by previous techniques. Given these results, an extended pan-tropical survey of yellowfin tuna using this approach will not only help combat the largest threat to sustainable fisheries (i.e. illegal, unreported, and unregulated fishing) but will also provide a basis to transform current monitoring, assessment, and management approaches for this globally significant species.

  1. Ecological metrics of biomass removed by three methods of purse-seine fishing for tunas in the eastern tropical Pacific Ocean.

    PubMed

    Gerrodette, Tim; Olson, Robert; Reilly, Stephen; Watters, George; Perrin, William

    2012-04-01

    An ecosystem approach to fisheries management is a widely recognized goal, but describing and measuring the effects of a fishery on an ecosystem is difficult. Ecological information on the entire catch (all animals removed, whether retained or discarded) of both species targeted by the fishery and nontarget species (i.e., bycatch) is required. We used data from the well-documented purse-seine fishery for tunas (Thunnus albacares, T. obesus, and Katsuwonus pelamis) in the eastern tropical Pacific Ocean to examine the fishery's ecological effects. Purse-seine fishing in the eastern tropical Pacific is conducted in 3 ways that differ in the amount and composition of target species and bycatch. The choice of method depends on whether the tunas are swimming alone (unassociated sets), associated with dolphins (dolphin sets), or associated with floating objects (floating-object sets). Among the fishing methods, we compared catch on the basis of weight, number of individuals, trophic level, replacement time, and diversity. Floating-object sets removed 2-3 times as much biomass as the other 2 methods, depending on how removal was measured. Results of previous studies suggest the ecological effects of floating-object sets are thousands of times greater than the effects of other methods, but these results were derived from only numbers of discarded animals. Management of the fishery has been driven to a substantial extent by a focus on reducing bycatch, although discards are currently 4.8% of total catch by weight, compared with global averages of 7.5% for tuna longline fishing and 30.0% for midwater trawling. An ecosystem approach to fisheries management requires that ecological effects of fishing on all animals removed by a fishery, not just bycatch or discarded catch, be measured with a variety of metrics. ©2012 Society for Conservation Biology.

  2. "Catching" Social Bias.

    PubMed

    Skinner, Allison L; Meltzoff, Andrew N; Olson, Kristina R

    2017-02-01

    Identifying the origins of social bias is critical to devising strategies to overcome prejudice. In two experiments, we tested the hypothesis that young children can catch novel social biases from brief exposure to biased nonverbal signals demonstrated by adults. Our results are consistent with this hypothesis. In Experiment 1, we found that children who were exposed to a brief video depicting nonverbal bias in favor of one individual over another subsequently explicitly preferred, and were more prone to behave prosocially toward, the target of positive nonverbal signals. Moreover, in Experiment 2, preschoolers generalized such bias to other individuals. The spread of bias observed in these experiments lays a critical foundation for understanding the way that social biases may develop and spread early in childhood.

  3. "Catch a Star !"

    NASA Astrophysics Data System (ADS)

    2002-05-01

    ESO and EAAE Launch Web-based Educational Programme for Europe's Schools Catch a star!... and discover all its secrets! This is the full title of an innovative educational project, launched today by the European Southern Observatory (ESO) and the European Association for Astronomy Education (EAAE). It welcomes all students in Europe's schools to an exciting web-based programme with a competition. It takes place within the context of the EC-sponsored European Week of Science and Technology (EWST) - 2002 . This unique project revolves around a web-based competition and is centred on astronomy. It is specifically conceived to stimulate the interest of young people in various aspects of this well-known field of science, but will also be of interest to the broad public. What is "Catch a Star!" about? [Go to Catch a Star Website] The programme features useful components from the world of research, but it is specifically tailored to (high-)school students. Younger participants are also welcome. Groups of up to four persons (e.g., three students and one teacher) have to select an astronomical object - a bright star, a distant galaxy, a beautiful comet, a planet or a moon in the solar system, or some other celestial body. Like detectives, they must then endeavour to find as much information as possible about "their" object. This information may be about the position and visibility in the sky, the physical and chemical characteristics, particular historical aspects, related mythology and sky lore, etc. They can use any source available, the web, books, newspaper and magazine articles, CDs etc. for this work. The group members must prepare a (short) summarising report about this investigation and "their" object, with their own ideas and conclusions, and send it to ESO (email address: eduinfo@eso.org). A jury, consisting of specialists from ESO and the EAAE, will carefully evaluate these reports. All projects that are found to fulfill the stipulated requirements, including a

  4. Environmental Load during the Distribution of Cultured Tuna

    NASA Astrophysics Data System (ADS)

    Sakai, Rirei; Watanabe, Manabu; Suzuki, Toru

    Tuna is the most favorite marine products for Japanese people. Most of them are consumed as Sashimi in Japan, and a half of them are imported. Cold transportation technology is essential to keep freshness of tuna during the oversea transportation. In the case of transporting tuna, ship transportation in ultra low temperature such as -60 °C is applied and also high speed transportation even by using airplane is practically used. On the other hand, it is a fact that such transportation processes of tuna are giving huge environmental load, though it has not been so much focused. Evaluation of cold transportation technologies from this environmental viewpoint must be important in the future. In this article, we compared CO2 emission during cold transportations of frozen tuna (marine transportation) and non-frozen tuna (air transportation) by using LCI analysis. As a result, CO2 emission of non-frozen tuna is found to be about four times greater than that of frozen tuna. This is due to the difference in the amount of freight per transportation of the airplane and the ship.

  5. Trouble with tuna: two cases of scombrotoxin poisoning.

    PubMed Central

    Stell, I M

    1997-01-01

    Two cases of scombrotoxin poisoning after exposure to tuna are described, the second being unusual in that tinned, rather than fresh, tuna was involved. This relatively rare condition needs to be distinguished from an allergic reaction, for which it can easily be mistaken. Images p111-a PMID:9132185

  6. Mercury in canned tuna: white versus light and temporal variation.

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2004-11-01

    There are abundant data and advisories for mercury levels in wild fish, but far fewer for commercial fish that compose a large majority of the fish most people eat. Until recently, relatively little attention has been devoted to examining mercury in canned tuna, despite its great importance in human diets. There is substantial media coverage of the benefits and risk from fish consumption, but few peer-reviewed data on canned tuna, the most commonly consumed fish in the United States. In this paper, we examine the levels of total mercury in canned tuna obtained from a New Jersey grocery store from 1998 to 2003, looking for temporal consistency within this data set and particularly for comparison with the Food and Drug Administration's 1991 study. We analyzed 168 cans individually for total mercury. All values are reported as parts per million (= microg/g) on a wet weight basis. In a subset of samples analyzed for total and inorganic mercury, the inorganic mercury was below detection levels; hence at least 89% of the mercury can be considered methylmercury. We found that white-style tuna had significantly more total mercury (mean 0.407 ppm) than light-style tuna (mean 0.118 ppm), presumably reflecting that "white" tuna is albacore, a species relatively larger than the skipjack tuna, which is commonly available as "light" or "chunk light." The maximum mercury in a can was 0.997 ppm, but 25% of white tuna samples exceeded 0.5 ppm. Data suggest a slight increase in levels since 1991, and mercury levels were significantly higher in 2001 than in other years. The mean level of mercury in white tuna (mean 0.407 ppm) was significantly higher than the mean value of 0.17 ppm currently used by the U.S. Food and Drug Administration (FDA) in its risk assessment and public information. There were no significant differences in mercury levels in tuna packed in oil compared to water. Draining contents had no effect on mercury levels, and the fluid, both oil and water, contained

  7. Total mercury in canned tuna sold in Canada in 2006.

    PubMed

    Dabeka, Robert W; Mckenzie, Arthur D; Forsyth, Donald S

    2014-01-01

    Total mercury was measured in 156 composites prepared from 936 samples of canned tuna sold in Canada in 2006. Each composite comprised a single brand. Yellowfin tuna contained the lowest concentrations, averaging 0.066 mg/kg. Skipjack tuna contained slightly higher concentrations, averaging 0.132 mg/kg. The highest average concentration was found in the Albacore tuna: mean 0.325 mg/kg, range 0.174-0.507 mg/kg. The second highest concentration among the 49 albacore composites was 0.469 mg/kg. There were 72 composites for which the type of tuna was not specified. The mercury in these averaged 0.095 mg/kg and ranged from 0.016 to 0.237 mg/kg.

  8. 76 FR 27658 - Tuna-Tariff-Rate Quota; The Tariff-Rate Quota for Calendar Year 2011 Tuna Classifiable Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-12

    ... United States consumption of tuna in airtight containers during the preceding Calendar Year. This...-rate quota is applicable to tuna entered or withdrawn from warehouse for consumption during the period... for consumption during the Calendar Year 2011, at the rate of 6 percent ad valorem under subheading...

  9. 78 FR 24430 - Tuna-Tariff Rate Quota; the Tariff-Rate Quota for Calendar Year 2013 Tuna Classifiable Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... States consumption of tuna in airtight containers during the preceding Calendar Year. This document sets... is applicable to tuna fish entered, or withdrawn from warehouse, for consumption during the period... warehouse, for consumption during the Calendar Year 2013, at the rate of 6.0 percent ad valorem under...

  10. 77 FR 22796 - Tuna-Tariff-Rate Quota; the Tariff-Rate Quota for Calendar Year 2012 Tuna Classifiable Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... United States consumption of tuna in airtight containers during the preceding Calendar Year. This...-rate quota is applicable to tuna fish entered, or withdrawn from warehouse, for consumption during the... warehouse, for consumption during the Calendar Year 2012, at the rate of 6 percent ad valorem under...

  11. Assessing Anthropogenic Impacts on Tunas, Sharks and Billfishes with Direct Observations of Human Fishers on the High Seas

    NASA Astrophysics Data System (ADS)

    Block, B.; Ferretti, F.; White, T.; De Leo, G.; Hazen, E. L.; Bograd, S. J.

    2016-12-01

    Anthropogenic impacts on marine predators have been examined within exclusive economic zones, but few data sets have enabled assessing human fishing impacts on the high seas. By combining large electronic tagging databases archiving mobile predator movements (e.g. Tagging of Pacific Pelagics, TAG A Giant, Animal Telemetry Network) with the global fishing catch and fishing effort data, from satellite tracks of vessels on the high seas (AIS), a better understanding of human use and exploitation at a global scale can be obtained. This capacity to combine the movements of mobile ocean predators (tunas, sharks, billfishes) with analyses of their human predator's behaviors, via examination of the global fishing fleet activities is unprecedented due to the new access researchers are garnering to these big satellite derived AIS databases. Global Fishing Watch is one example of such a data provider, that now makes accessible, the AIS data from the global community of maritime vessels, and has developed along with researchers new algorithms that delineate distinct types of fishing vessel behaviors (longline, purse seiner) and effort. When combined with satellite tagging data of mobile apex predators, oceanographic preferences, records of fishing fleets catches, targeted species and economic drivers of fisheries, new quantitative insights can be gained about the catch reporting of fleets, and the pelagic species targeted at a global scale. Research communities can now also examine how humans behave on the high seas, and potentially improve how fish stocks, such as tunas, billfishes, and sharks are exploited. The capacity to gather information on diverse human fishing fleets and behaviors remotely, should provide a wealth of new tools that can potentially be applied toward the resource management efforts surrounding these global fishing fleets. This type of information is essential for prioritizing regions of conservation concern for megaufauna swimming in our oceans.

  12. 78 FR 20604 - Enhanced Document Requirements To Support Use of the Dolphin Safe Label on Tuna Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-05

    ... processors, other than tuna canners, of tuna product labeled dolphin-safe; and modify the reporting... processors, other than tuna canners, of tuna product labeled dolphin- safe; and to include modifications to a... the processor indicates the tuna is eligible to be labeled dolphin-safe under 50 CFR 216.91....

  13. Increase in mercury in Pacific yellowfin tuna.

    PubMed

    Drevnick, Paul E; Lamborg, Carl H; Horgan, Martin J

    2015-04-01

    Mercury is a toxic trace metal that can accumulate to levels that threaten human and environmental health. Models and empirical data suggest that humans are responsible for a great deal of the mercury actively cycling in the environment at present. Thus, one might predict that the concentration of mercury in fish should have increased dramatically since the Industrial Revolution. Evidence in support of this hypothesis has been hard to find, however, and some studies have suggested that analyses of fish show no change in mercury concentration. By compiling and re-analyzing published reports on yellowfin tuna (Thunnus albacares) caught near Hawaii (USA) over the past half century, the authors found that the concentration of mercury in these fish currently is increasing at a rate of at least 3.8% per year. This rate of increase is consistent with a model of anthropogenic forcing on the mercury cycle in the North Pacific Ocean and suggests that fish mercury concentrations are keeping pace with current loading increases to the ocean. Future increases in mercury in yellowfin tuna and other fishes can be avoided by reductions in atmospheric mercury emissions from point sources. © 2015 SETAC.

  14. Climate change projection for the western tropical Pacific Ocean using a high-resolution ocean model: Implications for tuna fisheries

    NASA Astrophysics Data System (ADS)

    Matear, R. J.; Chamberlain, M. A.; Sun, C.; Feng, M.

    2015-03-01

    The Western Pacific Warm Pool is a region of high tuna catch, and how future climate change might impact the tuna fisheries is an important regional issue. By using a high-resolution ocean model forced by the simulated climate of the 2060s, we investigate whether enhanced spatial resolution and bias correction of the mean state could alter the climate change projection for the western tropical Pacific and examine the consequences this might have for tropical tuna distributions. For most of the physical environmental variables, enhanced resolution and bias correction had only a minor impact on the projected changes. The climate projections showed a maximum surface warming east of the Warm Pool, a shoaling of the thermocline in the Warm Pool, and an eastward expansion of the Warm Pool. In the Warm Pool, the shoaling of the thermocline raises the nutricline into the photic zone and increases phytoplankton and primary productivity, a feature that is most evident in the high-resolution model projection but also weakly present in the coarse-resolution projection. The phytoplankton and primary productivity response to climate change was where ocean model resolution produced a clear difference. With enhanced resolution, the simulation had stronger and better-defined zonal currents, which were more consistent with observations. Along the equator, the high-resolution model enabled vertical current shear mixing to generate a sub-surface phytoplankton maximum both inside and outside the Warm Pool, which is an observed phenomenon. With climate change, the enhanced-resolution model projected enhanced vertical shear mixing, increased vertical supply of nutrients to the photic zone, and increased sub-surface phytoplankton concentrations. The increase in sub-surface phytoplankton concentrations helps to offset the decline in surface phytoplankton concentrations and results in a projection of almost no change in the western tropical Pacific primary productivity. In contrast, the low

  15. Structure comparison of control region in Stromateoidei and complete mitochondrial genome of the bluefin driftfish Psenes pellucidus (Perciformes, Nomeidae).

    PubMed

    Wei, Tao; Zhang, Bo; Sun, Yuena

    2014-10-01

    In the present study, the complete mitochondrial genome of the bluefin driftfish Psenes pellucidus was determined first. The genome was 16,572 bp in length and consisted of 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes and 2 main non-coding regions. The mitochondrial genome of bluefin driftfish had common features about gene arrangement, base composition and tRNA structures compared with those of most of the bony fishes. In the control region, a termination-associated sequence, the central conserved block (CSB-F, CSB-E and CSB-D) and the conserved sequence blocks (CSB-1, CSB-2 and CSB-3) were determined. Meanwhile, the conserved motif 5'-GCCGG-3' was identified in the origin of light strand replication of bluefin driftfish. This mitogenome sequence data would play key role in phylogenetic analysis of Stromateoidei.

  16. Tuna fish diet influences cat behavior. [Elevated levels of selenium and mercury in commercial tuna fish cat food

    SciTech Connect

    Houpt, K.A.; Essick, L.A.; Shaw, E.B.; Alo, D.K.; Gilmartin, J.E.; Gutenmann, W.H.; Littman, C.B.; Lisk, D.J.

    1988-01-01

    When observed in their home cages, cats fed commercial tuna fish cat food were less active, vocalized less, and spent more time on the floor and more time eating than cats fed commercial beef cat food. There were no differences in response to human handling between the two groups. There were no differences in learning ability on a two-choice point maze or in reversal learning in the same maze between beef- and tuna-fed cats. The behavior of the groups differed in a 15-min open field test only in the number of toys contacted. Cats fed the tuna had elevated tissue levels of mercury and selenium.

  17. 50 CFR 660.17 - Catch monitors and catch monitor service providers. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries § 660.17 Catch monitors and catch monitor service providers. ...

  18. Monitoring of bisphenols in canned tuna from Italian markets.

    PubMed

    Fattore, Margherita; Russo, Giacomo; Barbato, Francesco; Grumetto, Lucia; Albrizio, Stefania

    2015-09-01

    Monitoring of food contamination from bisphenols is a necessary process for the consumers' risk assessment. A method for the quali-quantitative analysis of Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol A Diglycidyl Ether (BADGE), and Bisphenol F Diglycidyl Ether (BFDGE), by liquid chromatography with fluorescence detection (LC-FD), was performed and validated for their determination in 33 samples of tuna fish, canned in either oil or aqueous medium. Samples were collected in Italian markets. Tuna and the correspondent preservation medium were analyzed separately. Detected levels of bisphenols ranged from 19.1 to 187.0 ng/g in tuna matrix and from 6.3 to 66.9 ng/mL in oil medium. No bisphenols were found in aqueous medium. At least one of the analytes was found in 83% of the tuna samples in oil medium, whereas tuna samples in aqueous medium showed BPA alone in 67% of samples. 21% of the oil medium samples resulted positive for at least one bisphenol. On the basis of measured concentrations and general daily ingestion rate of canned tuna fish, the probable daily intake of BPA for Italian population was calculated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Measurement of Young's Modulus and Poisson's Ratio of Tuna Fish

    NASA Astrophysics Data System (ADS)

    Ogawa, Yutaka; Hagura, Yoshio

    Considering that gape and heave produced during the freezing of tuna fish derive from changes in the mechanical properties of tuna fish itself during freezing,the Poisson's ratio and Young's modulus of tuna meat were measured at the respective temperature conditions of i) no freezing,ii) partial freezing,and iii) freezing. The results of measurement were shown that the mechanical properties of tuna meat displayed temperature dependence as sudden change at the boundary temperature of freezing beginning as summarized below: 1) the mechanical properties of tuna meat were anisotropic according to the tissue and structure of the fish body,but these properties greatly varied according to the test temperature;2) the Young's modulus of non-frozen tuna meat were approximately 50 KPa,but these became an extremely large value (approximately 4 GPa) after being frozen; and 3) the Poisson's ratio decreased as the frozen water percentage increased,but these displayed an approximate value of one or more.

  20. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... catch limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ... limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ). (a... limited access scallop fishery shall be allocated 94.5 percent of the ACL specified in paragraph (a)(1)...

  1. Snow catch by conifer crowns

    Treesearch

    Donald R. Satterlund; Harold F. Haupt

    1967-01-01

    Study of interception storage of snow by two species of sapling conifers in northern Idaho revealed that cumulative snow catch follows the classical law of autocatakinetic growth, or [equation - see PDF] where I, is interception storage, e is the interception storage capacity of the tree, e is the base of the natural logarithm, k is a constant expressing the rate of...

  2. Passing and Catching in Rugby.

    ERIC Educational Resources Information Center

    Namudu, Mike M.

    This booklet contains the fundamentals for rugby at the primary school level. It deals primarily with passing and catching the ball. It contains instructions on (1) holding the ball for passing, (2) passing the ball to the left--standing, (3) passing the ball to the left--running, (4) making a switch pass, (5) the scrum half's normal pass, (6) the…

  3. Catch-22 and Property Rights

    Treesearch

    Warren A. Flick

    1998-01-01

    Almost everone knows Catch-22 situations where the inherenct logic of something creates an absurdity or self-contridiction. Author Joesph Heller's original was a military rule designed to thwart airmen from pleading insanity to escape bombing missions--the rule said any airman rational enough to want to be grounded could not possibly be insane and therefore had to...

  4. Passing and Catching in Rugby.

    ERIC Educational Resources Information Center

    Namudu, Mike M.

    This booklet contains the fundamentals for rugby at the primary school level. It deals primarily with passing and catching the ball. It contains instructions on (1) holding the ball for passing, (2) passing the ball to the left--standing, (3) passing the ball to the left--running, (4) making a switch pass, (5) the scrum half's normal pass, (6) the…

  5. The Large-Scale Deployment of Fish Aggregation Devices Alters Environmentally-Based Migratory Behavior of Skipjack Tuna in the Western Pacific Ocean

    PubMed Central

    Wang, Xuefang; Chen, Yong; Truesdell, Samuel; Xu, Liuxiong; Cao, Jie; Guan, Wenjiang

    2014-01-01

    Fish aggregation devices (FADs) have been used extensively in the tuna purse seine fishery since the 1980s. This long-term modification of natural habitat has generated discussions as to whether FADs impact movement patterns of tuna species. We examined this question using data collected from the skipjack tuna (Katsuwonus pelamis) fishery. We used the longitudinal gravitational center of catch (G) to examine temporal variability in skipjack movement in the Western and Central Pacific Ocean, and related this to El Niño Southern Oscillation (ENSO) events. We found that in most cases G for free-swimming school sets changed with the onset of ENSO events, while G for floating-object-associated school sets remained relatively constant. This suggests that skipjack exhibit distinguishable behavioral strategies in response to ENSO events: they either react by moving long distances or they associate with floating objects. There has been no previous attempt to evaluate the interaction between FADs and the environmentally-determined movement of skipjack; this study shows evidence of an interaction, which should be considered when managing skipjack populations. PMID:24849561

  6. Will a catch share for whales improve social welfare?

    PubMed

    Smith, Martin D; Asche, Frank; Bennear, Lori S; Havice, Elizabeth; Read, Andrew J; Squires, Dale

    2014-01-01

    We critique a proposal to use catch shares to manage transboundary wildlife resources with potentially high non-extractive values, and we focus on the case of whales. Because whales are impure public goods, a policy that fails to capture all nonmarket benefits (due to free riding) could lead to a suboptimal outcome. Even if free riding were overcome, whale shares would face four implementation challenges. First, a whale share could legitimize the international trade in whale meat and expand the whale meat market. Second, a legal whale trade creates monitoring and enforcement challenges similar to those of organizations that manage highly migratory species such as tuna. Third, a whale share could create a new political economy of management that changes incentives and increases costs for nongovernmental organizations (NGOs) to achieve the current level of conservation. Fourth, a whale share program creates new logistical challenges for quota definition and allocation regardless of whether the market for whale products expands or contracts. Each of these issues, if left unaddressed, could result in lower overall welfare for society than under the status quo.

  7. The effects of water depth and light on oviposition and egg cannibalism in the bluefin killifish Lucania goodei.

    PubMed

    Sandkam, B A; Fuller, R C

    2011-03-01

    This study showed that sex and depth had strong effects on egg cannibalism, whereas water clarity (clear v. tea-stained) had no effect on cannibalism or oviposition in the bluefin killifish Lucania goodei. These results are consistent with the extreme levels of iteroparity in L. goodei where females appear to spread their eggs across multiple locations and depths presumably to avoid egg predation.

  8. 75 FR 54078 - International Fisheries; Pacific Tuna Fisheries; Vessel Capacity Limit in the Purse Seine Fishery...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-03

    ... (Resolution C-02-03) to address the problem of excess capacity in the tuna purse-seine fleet operating in the... for tuna in the IATTC Convention Area. However, these vessels (class size 5 and under purse seine... satisfying its obligations under the Tuna Conventions Act and not exceeding its allotted capacity in...

  9. 76 FR 39808 - International Fisheries; Pacific Tuna Fisheries; Recommendations Adopted by the Inter-American...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... International Fisheries; Pacific Tuna Fisheries; Recommendations Adopted by the Inter-American Tropical Tuna...) to conform to recommendations adopted by the Inter- American Tropical Tuna Commission (IATTC). This..., held in September 2010, members of the IATTC adopted three recommendations. This ANPR discusses two of...

  10. 50 CFR 216.95 - Official mark for “Dolphin-safe” tuna products.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Official mark for âDolphin-safeâ tuna... AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.95 Official mark for “Dolphin-safe... Department of Commerce that may be used to label tuna products that meet the “dolphin-safe” standards...

  11. 50 CFR 216.95 - Official mark for “Dolphin-safe” tuna products.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Official mark for âDolphin-safeâ tuna... AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.95 Official mark for “Dolphin-safe... Department of Commerce that may be used to label tuna products that meet the “dolphin-safe” standards...

  12. 50 CFR 216.95 - Official mark for “Dolphin-safe” tuna products.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Official mark for âDolphin-safeâ tuna... AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.95 Official mark for “Dolphin-safe... Department of Commerce that may be used to label tuna products that meet the “dolphin-safe” standards...

  13. 50 CFR 216.95 - Official mark for “Dolphin-safe” tuna products.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Official mark for âDolphin-safeâ tuna... AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.95 Official mark for “Dolphin-safe... Department of Commerce that may be used to label tuna products that meet the “dolphin-safe” standards...

  14. 50 CFR 216.95 - Official mark for “Dolphin-safe” tuna products.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Official mark for âDolphin-safeâ tuna... AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.95 Official mark for “Dolphin-safe... Department of Commerce that may be used to label tuna products that meet the “dolphin-safe” standards...

  15. Environmental preferences of tuna and non-tuna species associated with drifting fish aggregating devices (DFADs) in the Atlantic Ocean, ascertained through fishers' echo-sounder buoys

    NASA Astrophysics Data System (ADS)

    Lopez, Jon; Moreno, Gala; Lennert-Cody, Cleridy; Maunder, Mark; Sancristobal, Igor; Caballero, Ainhoa; Dagorn, Laurent

    2017-06-01

    Understanding the relationship between environmental variables and pelagic species concentrations and dynamics is helpful to improve fishery management, especially in a changing environment. Drifting fish aggregating device (DFAD)-associated tuna and non-tuna biomass data from the fishers' echo-sounder buoys operating in the Atlantic Ocean have been modelled as functions of oceanographic (Sea Surface Temperature, Chlorophyll-a, Salinity, Sea Level Anomaly, Thermocline depth and gradient, Geostrophic current, Total Current, Depth) and DFAD variables (DFAD speed, bearing and soak time) using Generalized Additive Mixed Models (GAMMs). Biological interaction (presence of non-tuna species at DFADs) was also included in the tuna model, and found to be significant at this time scale. All variables were included in the analyses but only some of them were highly significant, and variable significance differed among fish groups. In general, most of the fish biomass distribution was explained by the ocean productivity and DFAD-variables. Indeed, this study revealed different environmental preferences for tunas and non-tuna species and suggested the existence of active habitat selection. This improved assessment of environmental and DFAD effects on tuna and non-tuna catchability in the purse seine tuna fishery will contribute to transfer of better scientific advice to regional tuna commissions for the management and conservation of exploited resources.

  16. Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu) in Captivity: Sound Structure, Context and Vocal Activity

    PubMed Central

    Radford, Craig A.; Ghazali, Shahriman M.; Montgomery, John C.; Jeffs, Andrew G.

    2016-01-01

    Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish-1 h-1) with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas. PMID:26890124

  17. Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu) in Captivity: Sound Structure, Context and Vocal Activity.

    PubMed

    Radford, Craig A; Ghazali, Shahriman M; Montgomery, John C; Jeffs, Andrew G

    2016-01-01

    Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish-1 h-1) with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas.

  18. Fishing-induced changes in adult length are mediated by skipped-spawning.

    PubMed

    Wang, Hui-Yu; Chen, Ying-Shiuan; Hsu, Chien-Chung; Shen, Sheng-Feng

    2017-01-01

    Elucidating fishing effects on fish population dynamics is a critical step toward sustainable fisheries management. Despite previous studies that have suggested age or size truncation in exploited fish populations, other aspects of fishing effects on population demography, e.g., via altering life histories and density, have received less attention. Here, we investigated the fishing effects altering adult demography via shifting reproductive trade-offs in the iconic, overexploited, Pacific bluefin tuna Thunnus orientalis. We found that, contrary to our expectation, mean lengths of catch increased over time in longline fisheries. On the other hand, mean catch lengths for purse seine fisheries did not show such increasing trends. We hypothesized that the size-dependent energetic cost of the spawning migration and elevated fishing mortality on the spawning grounds potentially drive size-dependent skipped spawning for adult tuna, mediating the observed changes in the catch lengths. Using eco-genetic individual-based modeling, we demonstrated that fishing-induced evolution of skipped spawning and size truncation interacted to shape the observed temporal changes in mean catch lengths for tuna. Skipped spawning of the small adults led to increased mean catch lengths for the longline fisheries, while truncation of small adults by the purse seines could offset such a pattern. Our results highlight the eco-evolutionary dynamics of fishing effects on population demography and caution against using demographic traits as a basis for fisheries management of the Pacific bluefin tuna as well as other migratory species. © 2016 by the Ecological Society of America.

  19. Development of functional canned and pouched tuna products added inulin for commercial production.

    PubMed

    Rueangwatcharin, U; Wichienchot, S

    2015-08-01

    Four formulas of canned tuna in spring water and tuna in mayonnaise and pouched tuna in salad cream and tuna in thousand island cream with added inulin were developed for commercial production. The effects of the addition of a prebiotic (inulin, Orafti®-HP) on the color and sensory properties of these products were studied. For inulin concentrations studied (3, 5, 7 and 10 %, w/w) caused more intensed yellow and red colors. Hedonic sensory values of tuna packed in spring water and in mayonnaise showed no significant differences (p > 0.05) among products with different inulin addition levels (3, 5, 7 and 10 %, w/w) in terms of color, flavor, sweetness and overall characteristics. However, when packed in thousand island cream, significant differences (p < 0.05) in color and overall characteristics were found when inulin was added higher than 7 %. Tuna in salad cream showed significant differences (p < 0.05) in color, flavor, sweetness and overall characteristics at higher than 7 % inulin. The panelists showed acceptable overall liking scores at upto 7 % inulin of all tuna products. The thermal sterilization process resulted in approximately 20 % decrease in final inulin content. The calculated residual fructans of finished products at shelf life of 3 years were 3.01, 2.78, 2.90 and 2.84 % for tuna in spring water, tuna in mayonnaise, tuna in thousand island and tuna in salad cream, respectively. Considering formula cost in a commercial production and the recommended daily intake (RDI) of inulin in the finished product at end of shelf life (≥3 g/d), an addition of 5 % inulin for tuna in spring water and 7 % inulin for tuna in mayonnaise, tuna in thousand island and tuna in salad cream are recommended.

  20. Occurrence of toxic metals (Hg, Cd and Pb) in fresh and canned tuna: public health implications.

    PubMed

    Storelli, Maria M; Barone, Grazia; Cuttone, Giuseppe; Giungato, Daniele; Garofalo, Rita

    2010-11-01

    Hg, Pb and Cd levels in fresh and canned tuna were determined and assessed by comparing element levels in these samples with maximum permissible limits set by European legislation. The estimated weekly intakes by human consuming both fresh and canned tuna were also evaluated for possible consumer health risks. Among tested metals, Hg had the highest concentrations, followed by Pb and Cd either in fresh tuna or canned tuna. None of the tested samples surpassed the European regulatory limits fixed for Cd and Pb, whereas 8.9% of the tuna cans and 20% of fresh tuna samples exceeded standard for Hg. The size of tuna was a determining factor of Hg burden. A high intake of Hg surpassing the toxicological reference value established by WHO, was associated with consumption of larger size tuna specimens. Also canned tuna consumption with Hg concentrations higher than 1 μg kg(-1), strongly increased the consumer exposure. In contrast, Cd and Pb weekly intakes through consumption either of fresh tuna or canned tuna did not exceed the toxicological reference values established by WHO, and consequently there was no human health risk. A continuous surveillance system of Hg content in these fishery products is crucial for consumer protection.

  1. Consequences of the historical demography on the global population structure of two highly migratory cosmopolitan marine fishes: the yellowfin tuna (Thunnus albacares) and the skipjack tuna (Katsuwonus pelamis)

    PubMed Central

    Ely, Bert; Viñas, Jordi; Alvarado Bremer, Jaime R; Black, Donna; Lucas, Luciano; Covello, Kelly; Labrie, Alexis V; Thelen, Eric

    2005-01-01

    Background Yellowfin and skipjack tuna are globally distributed in the world's tropical and sub-tropical oceans. Since little, if any, migration of these fishes occurs between the Atlantic and Indo-Pacific Oceans, one might expect to see genetic differences between sub-populations in these ocean basins. However, yellowfin and skipjack tuna have extremely large population sizes. Thus, the rate of genetic drift should be slower than that observed for other tunas. Results Low levels of genetic differentiation were observed between Atlantic and Pacific samples of yellowfin tuna. In contrast, no genetic differentiation was observed between Atlantic and Pacific samples of skipjack tuna. Conclusion Much lower levels of genetic differentiation were found among sub-populations of yellowfin tuna compared to those observed for other large tunas, probably due to the large population size of yellowfin tuna. Since skipjack tuna appear to have even larger population sizes, it is not surprising that no genetic differentiation was detected between Atlantic and Pacific samples of these fish. PMID:15725349

  2. Can catch shares prevent fisheries collapse?

    PubMed

    Costello, Christopher; Gaines, Steven D; Lynham, John

    2008-09-19

    Recent reports suggest that most of the world's commercial fisheries could collapse within decades. Although poor fisheries governance is often implicated, evaluation of solutions remains rare. Bioeconomic theory and case studies suggest that rights-based catch shares can provide individual incentives for sustainable harvest that is less prone to collapse. To test whether catch-share fishery reforms achieve these hypothetical benefits, we have compiled a global database of fisheries institutions and catch statistics in 11,135 fisheries from 1950 to 2003. Implementation of catch shares halts, and even reverses, the global trend toward widespread collapse. Institutional change has the potential for greatly altering the future of global fisheries.

  3. 5 CFR 1600.23 - Catch-up contributions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Catch-up contributions. (a) A participant may make traditional catch-up contributions or Roth catch-up... traditional catch-up contributions and Roth catch-up contributions during the same year, but the combined... contributions to his or her Roth balance from pay which is exempt from taxation under 26 U.S.C. 112. (g)...

  4. 5 CFR 1600.23 - Catch-up contributions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Catch-up contributions. (a) A participant may make traditional catch-up contributions or Roth catch-up... traditional catch-up contributions and Roth catch-up contributions during the same year, but the combined... contributions to his or her Roth balance from pay which is exempt from taxation under 26 U.S.C. 112. (g)...

  5. Radiation hydrolysate of tuna cooking juice with enhanced antioxidant properties

    NASA Astrophysics Data System (ADS)

    Choi, Jong-il; Sung, Nak-Yun; Lee, Ju-Woon

    2012-08-01

    Tuna protein hydrolysates are of increasing interest because of their potential application as a source of bioactive peptides. Large amounts of tuna cooking juice with proteins and extracts are produced during the process of tuna canning, and these cooking juice wastes cause environmental problems. Therefore, in this study, cooking juice proteins were hydrolyzed by irradiation for their utilization as functional additives. The degree of hydrolysis of tuna cooking juice protein increased from 0% to 15.1% at the absorbed doses of 50 kGy. To investigate the antioxidant activity of the hydrolysate, it was performed the ferric reducing antioxidant power (FRAP) assay, and the lipid peroxidation inhibitory and superoxide radical scavenging activities were measured. The FRAP values increased from 1470 μM to 1930 μM and IC50 on superoxide anion was decreased from 3.91 μg/mL to 1.29 μg/mL at 50 kGy. All of the antioxidant activities were increased in the hydrolysate, suggesting that radiation hydrolysis, which is a simple process that does not require an additive catalysts or an inactivation step, is a promising method for food and environmental industries.

  6. Estimating clandestine activities from partially observed processes: illegal transhipment of fish catches among vessels

    NASA Astrophysics Data System (ADS)

    Wilcox, C.; Ford, J.

    2016-12-01

    Crimes involving fishers impose significant costs on fisheries, managers and national governments. These crimes also lead to unsustainable harvesting practices, as they undermine both knowledge of the status of fisheries stocks and limits on their harvesting. One of the greatest contributors to fisheries crimes globally is transfer of fish catch among vessels, otherwise known as transshipment. While legal transshipment provides economic advantages to vessels by increasing their efficiency, illegal transshipment can allow them to avoid regulations, catch prohibited species, and fish with impunity in prohibited locations such as waters of foreign countries. Despite the presence of a number of monitoring technologies for tracking fishing vessels, transshipment is frequently done clandestinely. Here we present a statistical model for transshipment in a Southeast Asian tuna fishery. We utilize both spatial and temporal information on vessel movement patterns in a statistical model to infer unobserved transshipment events among vessels. We provide a risk analysis framework for forecasting likely transshipment events, based on our analysis of vessel movement patterns. The tools we present are widely applicable to a variety of fisheries and types of tracking data, allowing managers to more effectively screen the large volume of data tracking systems create and quickly identify suspicious behavior.

  7. Temperature sensitivity of cardiac function in pelagic fishes with different vertical mobilities: yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus), mahimahi (Coryphaena hippurus), and swordfish (Xiphias gladius).

    PubMed

    Galli, Gina L J; Shiels, Holly A; Brill, Richard W

    2009-01-01

    We measured the temperature sensitivity, adrenergic sensitivity, and dependence on sarcoplasmic reticulum (SR) Ca(2+) of ventricular muscle from pelagic fishes with different vertical mobility patterns: bigeye tuna (Thunnus obesus), yellowfin tuna (Thunnus albacares), and mahimahi (Coryphaena hippurus) and a single specimen from swordfish (Xiphias gladius). Ventricular muscle from the bigeye tuna and mahimahi exhibited a biphasic response to an acute decrease in temperature (from 26 degrees to 7 degrees C); twitch force and kinetic parameters initially increased and then declined. The magnitude of this response was larger in the bigeye tuna than in the mahimahi. Under steady state conditions at 26 degrees C, inhibition of SR Ca(2+) release and reuptake with ryanodine and thapsigargin decreased twitch force and kinetic parameters, respectively, in the bigeye tuna only. However, the initial inotropy associated with decreasing temperature was abolished by SR inhibition in both the bigeye tuna and the mahimahi. Application of adrenaline completely reversed the effects of ryanodine and thapsigargin, but this effect was diminished at cold temperatures. In the yellowfin tuna, temperature and SR inhibition had minor effects on twitch force and kinetics, while adrenaline significantly increased these parameters. Limited data suggest that swordfish ventricular muscle responds to acute temperature reduction, SR inhibition, and adrenergic stimulation in a manner similar to that of bigeye tuna ventricular muscle. In aggregate, our results show that the temperature sensitivity, SR dependence, and adrenergic sensitivity of pelagic fish hearts are species specific and that these differences reflect species-specific vertical mobility patterns.

  8. Catch shares slow the race to fish.

    PubMed

    Birkenbach, Anna M; Kaczan, David J; Smith, Martin D

    2017-04-05

    In fisheries, the tragedy of the commons manifests as a competitive race to fish that compresses fishing seasons, resulting in ecological damage, economic waste, and occupational hazards. Catch shares are hypothesized to halt the race by securing each individual's right to a portion of the total catch, but there is evidence for this from selected examples only. Here we systematically analyse natural experiments to test whether catch shares reduce racing in 39 US fisheries. We compare each fishery treated with catch shares to an individually matched control before and after the policy change. We estimate an average policy treatment effect in a pooled model and in a meta-analysis that combines separate estimates for each treatment-control pair. Consistent with the theory that market-based management ends the race to fish, we find strong evidence that catch shares extend fishing seasons. This evidence informs the current debate over expanding the use of market-based regulation to other fisheries.

  9. Storage Time and Temperature Effects on Histamine Production in Tuna Salad Preparations.

    PubMed

    McCarthy, Susan; Bjornsdottir-Butler, Kristin; Benner, Ronald

    2015-07-01

    Scombrotoxin fish poisoning (SFP), also known as histamine (Hst) poisoning, has been associated with consumption of scombroid-type fish, including tuna and tuna fish products. Preparation of commercial tuna salad contaminated with Hstproducing bacteria (HPB), combined with time-temperature abuse, can present a food safety hazard. A potential source of HPB is raw ingredients, such as celery and onions. The objectives of this study were to determine whether raw ingredients can be a source of HPB and to ascertain the effects of storage time (up to 4 days or 4 weeks) and temperature (4, 10, 18, 25, 30°C) on growth and Hst production by high-HPB (>1,000 ppm of Hst) in tuna salad preparations. Pantoea-Erwinia, Erwinia persicinus, Erwinia spp., and Enterobacter pyrinus isolated from celery in this study were used to inoculate tuna salad and tuna salad with celery or onion. HPB numbers were 0.7 to 4.3 log most probable number per g higher in the presence of celery or onion versus plain tuna salad (3:1 tuna:mayonnaise). E. pyrinus-inoculated plain tuna salad and tuna salad with celery and onion had >500 ppm of Hst after 2 days at 30°C and 4 days at 25°C. E. pyrinus-inoculated salad with celery and onion had >500 ppm of Hst after 4 days at 18°C and 2 weeks at 10°C. Raw celery can introduce HPB into tuna salad, which can cause SFP if the product is time-temperature abused. Tuna salad products must be refrigerated at ≤4°C to prevent growth and Hst production by the HPB used in this study, to protect consumers from potential SFP.

  10. Effect of different types of heat processing on chemical changes in tuna.

    PubMed

    Stephen, Nimish Mol; Jeya Shakila, R; Jeyasekaran, G; Sukumar, D

    2010-03-01

    The chemical changes in skipjack tuna (Katsuwonus pelamis) subjected to cooking, frying, canning and microwave heating were studied. Raw tuna contained an unusual fatty acid C16:3 in high proportion (29.3%) followed by C18:2, C24:1, C16:0 and C18:3. Health beneficial fatty acids, eicosapentaenoic acid (EPA) (1.67%) and docosahexaenoic acid (DHA) (2.50%), were quite low with ω-3/ω-6 ratio 0.28. The total saturated fatty acids suffered major loss in fried (70%) and canned tuna (40%) due to loss of C16:0, C14:0 and C22:0. The monounsaturated fatty acids content increased (38%) in cooked and microwave heated tuna due to C24:1. The polyunsaturated fatty acids content increased in fried (50%) and canned (25%) tuna due to the uptake of frying and filling oil, respectively during processing. The loss of health beneficial ω-3 fatty acids, EPA and DHA were minimum in cooked tuna followed by microwave heated tuna. Canning totally destroyed these fatty acids. In fried tuna, the losses of EPA and DHA were 70 and 85%, respectively. Thiobarbituric acid - reactive substances values increased in heat processed tuna. Cholesterol increased in canned and microwave heated tuna but not in cooked tuna. Reduction of cholesterol in fried tuna was due to its migration into frying oil. This study indicated that cooking and microwave heating are the better processing methods to retain the health beneficial ω-3 fatty acids in comparison to frying and canning.

  11. Reconciling fisheries catch and ocean productivity

    PubMed Central

    Stock, Charles A.; Asch, Rebecca G.; Cheung, William W. L.; Dunne, John P.; Friedland, Kevin D.; Lam, Vicky W. Y.; Sarmiento, Jorge L.; Watson, Reg A.

    2017-01-01

    Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM). After removing a small number of lightly fished ecosystems, stark interregional differences in fish catch per unit area can be explained (r = 0.79) with an energy-based model that (i) considers dynamic interregional differences in benthic and pelagic energy pathways connecting phytoplankton and fish, (ii) depresses trophic transfer efficiencies in the tropics and, less critically, (iii) associates elevated trophic transfer efficiencies with benthic-predominant systems. Model catch estimates are generally within a factor of 2 of values spanning two orders of magnitude. Climate change projections show that the same macroecological patterns explaining dramatic regional catch differences in the contemporary ocean amplify catch trends, producing changes that may exceed 50% in some regions by the end of the 21st century under high-emissions scenarios. Models failing to resolve these trophodynamic patterns may significantly underestimate regional fisheries catch trends and hinder adaptation to climate change. PMID:28115722

  12. Reconciling fisheries catch and ocean productivity.

    PubMed

    Stock, Charles A; John, Jasmin G; Rykaczewski, Ryan R; Asch, Rebecca G; Cheung, William W L; Dunne, John P; Friedland, Kevin D; Lam, Vicky W Y; Sarmiento, Jorge L; Watson, Reg A

    2017-02-21

    Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM). After removing a small number of lightly fished ecosystems, stark interregional differences in fish catch per unit area can be explained (r = 0.79) with an energy-based model that (i) considers dynamic interregional differences in benthic and pelagic energy pathways connecting phytoplankton and fish, (ii) depresses trophic transfer efficiencies in the tropics and, less critically, (iii) associates elevated trophic transfer efficiencies with benthic-predominant systems. Model catch estimates are generally within a factor of 2 of values spanning two orders of magnitude. Climate change projections show that the same macroecological patterns explaining dramatic regional catch differences in the contemporary ocean amplify catch trends, producing changes that may exceed 50% in some regions by the end of the 21st century under high-emissions scenarios. Models failing to resolve these trophodynamic patterns may significantly underestimate regional fisheries catch trends and hinder adaptation to climate change.

  13. School students "Catch a Star"!

    NASA Astrophysics Data System (ADS)

    2007-04-01

    School students from across Europe and beyond have won prizes in an astronomy competition, including the trip of a lifetime to one of the world's most powerful astronomical observatories, on a mountaintop in Chile. ESO, the European Organisation for Astronomical Research in the Southern Hemisphere, together with the European Association for Astronomy Education (EAAE), has just announced the winners of the 2007 "Catch a Star!" competition. ESO PR Photo 21/07 "Catch a Star!" is an international astronomy competition for school students, in which students are invited to 'become astronomers' and explore the Universe. The competition includes two categories for written projects on astronomical themes, to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. For the artistically minded, "Catch a Star!" also includes an astronomy-themed artwork competition. Students from 22 countries submitted hundreds of written projects and pieces of artwork. "The standard of entries was most impressive, and made the jury's task of choosing winners both enjoyable and difficult! We hope that everyone, whether or not they won a prize, had fun taking part, and learnt some exciting things about our Universe", said Douglas Pierce-Price, Education Officer at ESO. The top prize, of a week-long trip to Chile to visit the ESO Very Large Telescope (VLT) on Paranal, was won by students Jan Mestan and Jan Kotek from Gymnazium Pisek in the Czech Republic, together with their teacher Marek Tyle. Their report on "Research and Observation of the Solar Eclipse" told how they had studied solar eclipses, and involved their fellow students in observations of an eclipse from their school in 2006. The team will travel to Chile and visit the ESO VLT - one of the world's most powerful optical/infrared telescopes - where they will meet astronomers and be present during a night of observations on the 2600m high Paranal mountaintop. "It's fantastic that we will see the

  14. Responses of the red blood cells from two high-energy-demand teleosts, yellowfin tuna (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis), to catecholamines.

    PubMed

    Lowe, T E; Brill, R W; Cousins, K L

    1998-08-01

    In fishes, catecholamines increase red blood cell intracellular pH through stimulation of a sodium/proton (Na+/H+) antiporter. This response can counteract potential reductions in blood O2 carrying capacity (due to Bohr and Root effects) when plasma pH and intracellular pH decrease during hypoxia, hypercapnia, or following exhaustive exercise. Tuna physiology and behavior dictate exceptionally high rates of O2 delivery to the tissues often under adverse conditions, but especially during recovery from exhaustive exercise when plasma pH may be reduced by as much as 0.4 pH units. We hypothesize that blood O2 transport during periods of metabolic acidosis could be especially critical in tunas and the response of rbc to catecholamines elevated to an extreme. We therefore investigated the in vitro response of red blood cells from yellowfin tuna (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis) to catecholamines. Tuna red blood cells had a typical response to catecholamines, indicated by a rapid decrease in plasma pH. Amiloride reduced the response, whereas 4,4'diisothiocyanatostilbene-2,2'-disulphonic acid enhanced both the decrease in plasma pH and the increase in intracellular pH. Changes in plasma [Na+], [Cl-], and [K+] were consistent with the hypothesis that tuna red blood cells have a Na+/H+ antiporter similar to that described for other teleost red blood cells. Red blood cells from both tuna species were more responsive to noradrenaline than adrenaline. At identical catecholamine concentrations, the decrease in plasma pH was greater in skipjack tuna blood, the more active of the two tuna species. Based on changes in plasma pH, the response of red blood cells to catecholamines from both tuna species was less than that of rainbow trout (Oncorhynchus mykiss) red blood cells, but greater than that of cod (Gadus morhua) red blood cells. Noradrenaline had no measurable influence on the O2 affinity of skipjack tuna blood and only slightly increased the O2

  15. Baseline concentration of Polonium-210 ((210)Po) in tuna fish.

    PubMed

    Khan, M Feroz; Wesley, S Godwin

    2016-06-15

    Several species of tuna fish were analyzed for (210)Po content in their edible muscle tissues. This study was carried out as a part of baseline data generation around a large nuclear power plant situated at Kudankulam, southeast coast of India. The concentration of (210)Po in the muscle tissue ranged from 40.9±5.2 to 92.5±7.9Bq/kg of fresh fish, and the highest activity was recorded for the tuna Euthynnus affinis and the lowest for Auxis thazard. The committed effective dose to the local residents was calculated to be 62.7-141.8μSvyear(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Catch reconstructions reveal that global marine fisheries catches are higher than reported and declining.

    PubMed

    Pauly, Daniel; Zeller, Dirk

    2016-01-19

    Fisheries data assembled by the Food and Agriculture Organization (FAO) suggest that global marine fisheries catches increased to 86 million tonnes in 1996, then slightly declined. Here, using a decade-long multinational 'catch reconstruction' project covering the Exclusive Economic Zones of the world's maritime countries and the High Seas from 1950 to 2010, and accounting for all fisheries, we identify catch trajectories differing considerably from the national data submitted to the FAO. We suggest that catch actually peaked at 130 million tonnes, and has been declining much more strongly since. This decline in reconstructed catches reflects declines in industrial catches and to a smaller extent declining discards, despite industrial fishing having expanded from industrialized countries to the waters of developing countries. The differing trajectories documented here suggest a need for improved monitoring of all fisheries, including often neglected small-scale fisheries, and illegal and other problematic fisheries, as well as discarded bycatch.

  17. Catch reconstructions reveal that global marine fisheries catches are higher than reported and declining

    PubMed Central

    Pauly, Daniel; Zeller, Dirk

    2016-01-01

    Fisheries data assembled by the Food and Agriculture Organization (FAO) suggest that global marine fisheries catches increased to 86 million tonnes in 1996, then slightly declined. Here, using a decade-long multinational ‘catch reconstruction' project covering the Exclusive Economic Zones of the world's maritime countries and the High Seas from 1950 to 2010, and accounting for all fisheries, we identify catch trajectories differing considerably from the national data submitted to the FAO. We suggest that catch actually peaked at 130 million tonnes, and has been declining much more strongly since. This decline in reconstructed catches reflects declines in industrial catches and to a smaller extent declining discards, despite industrial fishing having expanded from industrialized countries to the waters of developing countries. The differing trajectories documented here suggest a need for improved monitoring of all fisheries, including often neglected small-scale fisheries, and illegal and other problematic fisheries, as well as discarded bycatch. PMID:26784963

  18. Convergent evolution in mechanical design of lamnid sharks and tunas.

    PubMed

    Donley, Jeanine M; Sepulveda, Chugey A; Konstantinidis, Peter; Gemballa, Sven; Shadwick, Robert E

    2004-05-06

    The evolution of 'thunniform' body shapes in several different groups of vertebrates, including whales, ichthyosaurs and several species of large pelagic fishes supports the view that physical and hydromechanical demands provided important selection pressures to optimize body design for locomotion during vertebrate evolution. Recognition of morphological similarities between lamnid sharks (the most well known being the great white and the mako) and tunas has led to a general expectation that they also have converged in their functional design; however, no quantitative data exist on the mechanical performance of the locomotor system in lamnid sharks. Here we examine the swimming kinematics, in vivo muscle dynamics and functional morphology of the force-transmission system in a lamnid shark, and show that the evolutionary convergence in body shape and mechanical design between the distantly related lamnids and tunas is much more than skin deep; it extends to the depths of the myotendinous architecture and the mechanical basis for propulsive movements. We demonstrate that not only have lamnids and tunas converged to a much greater extent than previously known, but they have also developed morphological and functional adaptations in their locomotor systems that are unlike virtually all other fishes.

  19. Biomagnifications of mercury and methylmercury in tuna and mackerel.

    PubMed

    Hajeb, P; Jinap, S; Ahmad, I

    2010-12-01

    Seawater may be contaminated by harmful substances, including toxic elements released by human activities. The present study evaluates the total mercury and methylmercury concentrations and their correlations to fish body size in longtail tuna and short-bodied mackerel from Chendring, Kuantan, at east coast and Kuala Perlis at west costs of Peninsular Malaysia during May to November 2007. Total mercury and methylmercury in muscle tissue of 69 samples of longtail tuna and short-bodied mackerel, ranged from 0.180 to 1.460 μg/g and 0.0.169-0.973 μg/g and 0.251-1.470 μg/g and 0.202-1.352, whereas the methylmercury to total mercury ratio ranged from 70% to 83%, respectively. Samples of both species from the east coast showed higher levels of mercury compared to those from west coast. In all of the locations, significant positive correlations were found between fish body weight and mercury content (R(2) > 0.470). The estimated weekly intake of total mercury and methylmercury from the consumption 66.33 g/week of short-bodied mackerel and 18.34 g/week of longtail tuna (based on local dietry survey) was found to be lower than the maximum limit of 5 and 1.5 μg/kg bodyweight established by FAO/WHO and codex, respectively.

  20. Skipjack tuna as a bioindicator of contamination by perfluorinated compounds in the oceans.

    PubMed

    Hart, Kimberly; Kannan, Kurunthachalam; Tao, Lin; Takahashi, Shin; Tanabe, Shinsuke

    2008-09-15

    Perfluorinated chemicals (PFCs) have emerged as global environmental contaminants. Studies have reported the widespread occurrence of PFCs in biota from marine coastal waters and in remote polar regions. However, few studies have reported the distribution of PFCs in biota from offshore waters and open oceans. In this study, concentrations of nine PFCs were determined in the livers of 60 skipjack tuna (Katsuwonus pelamis) collected from offshore waters and the open ocean along the Pacific Rim, including the Sea of Japan, the East China Sea, the Indian Ocean, and the Western North Pacific Ocean, during 1997-1999. At least one of the nine PFCs was found in every tuna sample analyzed. Overall, perfluorooctanesulfonate (PFOS) and perfluoroundecanoic acid (PFUnDA) were the predominant compounds found in livers of tuna at concentrations of <1-58.9 and <1-31.6 ng/g, wet wt, respectively. Long-chain perfluorocarboxylates such as perfluorodecanoic acid (PFDA) and perfluorododecanoic acid (PFDoDA) were common in the tuna livers. In livers of tuna from several offshore and open-ocean locations, concentrations of PFUnDA were greater than the concentrations of PFOS. The profiles and concentrations of PFCs in tuna livers suggest that the sources in East Asia are dominated by long-chain perfluorocarboxylates, especially PFUnDA. High concentrations of PFUnDA in tuna may indicate a shift in sources of PFCs in East Asia. The spatial distribution of PFOS in skipjack tuna reflected the concentrations previously reported in seawater samples from the Pacific and Indian Oceans, suggesting that tuna are good bioindicators of pollution by PFOS. Despite its predominance in ocean waters, PFOA was rarely found in tuna livers, indicative of the low bioaccumulation potential of this compound. Our study establishes baseline concentrations of PFCs in skipjack tuna from the oceans of the Asia-Pacific region, enabling future temporal trend studies of PFCs in oceans.

  1. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a)...

  2. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a)...

  3. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a)...

  4. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a)...

  5. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a)...

  6. Nutritional catch-up growth.

    PubMed

    Gat-Yablonski, Galia; Pando, Rakefet; Phillip, Moshe

    2013-01-01

    Malnutrition, marked by variant nutrient deficiencies, is considered a leading cause of stunted growth worldwide. In developing countries, malnutrition is caused mainly by food shortage and infectious diseases. Malnutrition may also be found in the developed world, where it is due mostly to prematurity, chronic diseases, and anorexia nervosa. In most cases, when food consumption is corrected, spontaneous catch-up (CU) growth occurs. However, CU growth is not always complete, leading to growth deficits. Therefore, it is important to understand the mechanisms that govern this process. Using a rat model of food restriction followed by refeeding, we established a nutrition-induced CU growth model. Levels of leptin and insulin-like growth factor-1 were found to significantly decrease when food was restricted and to increase already 1 day after refeeding. Gene expression analysis of the growth plate revealed that food restriction specifically affects transcription factors such as the hypoxia inducible factor-1 and its downstream targets on the one hand, and global gene expression, indicating epigenetic regulation, on the other. Food restriction also reduced the level of several microRNAs, including the chondrocyte-specific miR-140, which led to an increase in its target, SIRT1, a class III histone deacetylase. These findings may explain the global changes in gene expression observed under nutritional manipulation. We suggest that multiple levels of regulation, including transcription factors, epigenetic mechanisms, and microRNAs respond to nutritional cues and offer a possible explanation for some of the effects of food restriction on epiphyseal growth plate growth. The means whereby these components sense changes in nutritional status are still unknown. Deciphering the role of epigenetic regulation in growth may pave the way for the development of new treatments for children with growth disorders.

  7. 50 CFR 622.496 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.496 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  8. 50 CFR 622.457 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.457 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  9. 50 CFR 622.439 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.439 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  10. 50 CFR 622.439 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.439 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  11. 50 CFR 622.58 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). 622.58 Section 622.58 Wildlife and Fisheries FISHERY... Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). (a) Royal...

  12. 50 CFR 622.457 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.457 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  13. 50 CFR 622.496 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.496 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  14. 50 CFR 622.58 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). 622.58 Section 622.58 Wildlife and Fisheries FISHERY... Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). (a) Royal...

  15. Effect of survey design and catch rate estimation on total catch estimates in Chinook salmon fisheries

    USGS Publications Warehouse

    McCormick, Joshua L.; Quist, Michael C.; Schill, Daniel J.

    2012-01-01

    Roving–roving and roving–access creel surveys are the primary techniques used to obtain information on harvest of Chinook salmon Oncorhynchus tshawytscha in Idaho sport fisheries. Once interviews are conducted using roving–roving or roving–access survey designs, mean catch rate can be estimated with the ratio-of-means (ROM) estimator, the mean-of-ratios (MOR) estimator, or the MOR estimator with exclusion of short-duration (≤0.5 h) trips. Our objective was to examine the relative bias and precision of total catch estimates obtained from use of the two survey designs and three catch rate estimators for Idaho Chinook salmon fisheries. Information on angling populations was obtained by direct visual observation of portions of Chinook salmon fisheries in three Idaho river systems over an 18-d period. Based on data from the angling populations, Monte Carlo simulations were performed to evaluate the properties of the catch rate estimators and survey designs. Among the three estimators, the ROM estimator provided the most accurate and precise estimates of mean catch rate and total catch for both roving–roving and roving–access surveys. On average, the root mean square error of simulated total catch estimates was 1.42 times greater and relative bias was 160.13 times greater for roving–roving surveys than for roving–access surveys. Length-of-stay bias and nonstationary catch rates in roving–roving surveys both appeared to affect catch rate and total catch estimates. Our results suggest that use of the ROM estimator in combination with an estimate of angler effort provided the least biased and most precise estimates of total catch for both survey designs. However, roving–access surveys were more accurate than roving–roving surveys for Chinook salmon fisheries in Idaho.

  16. 76 FR 3646 - Safety Requirements and Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ...Pursuant to Section 904 of the 2010 Coast Guard Authorization Act, the Coast Guard announces the availability of a draft policy regarding distant water tuna fleet vessels manning exemption eligibility and safety requirements. We request your comments on the Safety Requirements and Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels.

  17. 76 FR 31351 - Safety Requirements and Manning Exemption Eligibility on Distant Water Tuna Fleet Vessels

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ...The Coast Guard announces the availability of Office of Vessel Activities Policy Letter 11-05 regarding Distant Water Tuna Fleet vessels manning exemption eligibility and safety requirements. This final policy clarifies the requirements to allow a distant water tuna fleet vessel to engage foreign citizens under a temporary manning exemption.

  18. Mitochondrial genome of the blackfin tuna Thunnus atlanticus Lesson, 1831 (Perciformes, Scrombidae).

    PubMed

    Márquez, Edna J; Isaza, Juan P; Alzate, Juan F

    2016-05-01

    Blackfin tuna, Thunnus atlanticus is a widespread epipelagic oceanic species in the western Atlantic. So far the mitochondrial genome of this species remained unknown, although the mitogenomes of all congeners are known. The mitochondrial genome encodes for 13 proteins, 21 tRNAs, 2 ribosomal RNAs and the gene synteny is conserved with other previously reported mitogenomes of tunas.

  19. Separation of gonadotropic fractions with different species specificities from tuna pituitaries

    SciTech Connect

    Ando, H.; Ishii, S.

    1988-05-01

    Eight different gonadotropic glycoprotein fractions were separated from the acetone-dried powder of yellow fin tuna pituitary glands by successive chromatographies on Superose 12 for gel filtration and Mono Q for anion exchange using the Pharmacia fast protein liquid chromatography system. This was preceded by preliminary separations using an ammonium sulfate precipitation method and affinity chromatography on concanavalin A-Sepharose. For biological characterization, we employed two radioreceptor assay systems, one using goby testis plasma membranes and silver carp GTH as the receptor and radioligand, respectively, and the other using testis plasma membranes of the yellow fin tuna and gonadotropin of the same species, respectively. We also employed two testicular cyclic AMP accumulation bioassay methods in vitro, one with the goby testis and the other with the mackerel testis. The least acidic fraction after Mono Q was further separated into four subfractions by rechromatography with Mono Q. They were strongly active in the tuna and mackerel assays but almost inactive in the goby assays. They were referred to as tuna-type tuna gonadotropin. In contrast, the most acidic fraction obtained after the first Mono Q was active in the goby assays but almost inactive in the tuna and mackerel assays. It was referred to as goby-type tuna gonadotropin. The intermediate fractions were active on both assays and are considered to be mixtures of tuna-type and goby-type gonadotropins. The reason for the presence of gonadotropin inactive to homologous species is discussed from the evolutionary viewpoint.

  20. Plankton Production, Fish Catch, and the Potential for Sharp Regional Catch Trends Under Climate Change

    NASA Astrophysics Data System (ADS)

    Stock, C. A.; John, J. G.; Lam, V.; Rykaczewski, R. R.; Cheung, W. W. L.; Dunne, J. P.; Asch, R. G.; Sarmiento, J. L.

    2016-02-01

    Fish catch has been related to diverse plankton metrics with often ambiguous mechanistic linkages to fish and varying degrees of spatial and temporal robustness. Proposed fish catch indicators also exhibit different patterns of variability and projected change, hindering fisheries assessments and the formulation of resilient marine resource management strategies. We combine 1) a new catch reconstruction featuring improved estimates of illegal and under-reported catch, 2) a novel high-resolution global Earth System Model (GFDL-ESM2.6) featuring 10 km ocean resolution and regionally robust patterns of carbon flow through the planktonic food web, and 3) simple fish trophodynamic considerations, and revisit the relationship between catch and planktonic food web fluxes in a more mechanistic context. Realized 20-year peak catches across globally distributed coastal regions could be well explained by the estimated planktonic production available to fish (via mesozooplankton and the flux of carbon to the benthos) after accounting for the catch trophic level (r = 0.64, r = 0.74 after removing lightly fished Australian systems). Similar skill, however, could result from models invoking high trophic efficiencies within the fish food web and a modest fraction of energy available to fish taken as catch, or low trophic efficiencies and a high fraction. Projections using either parameter combination suggest that projected regional changes in fish yields may be considerably larger than those implied from primary production.

  1. 50 CFR 660.18 - Certification and decertification procedures for catch monitors and catch monitor providers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Certification and decertification procedures for catch monitors and catch monitor providers. 660.18 Section 660.18 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF...

  2. 50 CFR 660.18 - Certification and decertification procedures for catch monitors and catch monitor providers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Certification and decertification procedures for catch monitors and catch monitor providers. 660.18 Section 660.18 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT...

  3. A resolution expressing the sense of the Senate that, at the 21st Regular Meeting of the International Commission on the Conservation of Atlantic Tunas, the United States should seek to ensure management of the eastern Atlantic and Mediterranean bluefin tuna fishery adheres to the scientific advice provided by the Standing Committee on Research and Statistics and has a high probability of achieving the established rebuilding target, pursue strengthened protections for spawning bluefin populations in the Mediterranean Sea to facilitate the recovery of the Atlantic bluefin tuna, pursue imposition of more stringent measures to ensure compliance by all Members with the International Commission for the Conservation of Atlantic Tunas' conservation and management recommendations for Atlantic bluefin tuna and other species, and ensure that United States' quotas of tuna and swordfish are not reallocated to other nations, and for other purposes.

    THOMAS, 111th Congress

    Sen. Snowe, Olympia J. [R-ME

    2009-11-09

    Senate - 11/09/2009 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

  4. A resolution expressing the sense of the Senate that, at the 21st Regular Meeting of the International Commission on the Conservation of Atlantic Tunas, the United States should seek to ensure management of the eastern Atlantic and Mediterranean bluefin tuna fishery adheres to the scientific advice provided by the Standing Committee on Research and Statistics and has a high probability of achieving the established rebuilding target, pursue strengthened protections for spawning bluefin populations in the Mediterranean Sea to facilitate the recovery of the Atlantic bluefin tuna, pursue imposition of more stringent measures to ensure compliance by all Members with the International Commission for the Conservation of Atlantic Tunas' conservation and management recommendations for Atlantic bluefin tuna and other species, and ensure that United States' quotas of tuna and swordfish are not reallocated to other nations, and for other purposes.

    THOMAS, 111th Congress

    Sen. Snowe, Olympia J. [R-ME

    2009-11-09

    11/09/2009 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (All Actions) Tracker: This bill has the status Agreed to in SenateHere are the steps for Status of Legislation:

  5. Catch shares slow the race to fish

    NASA Astrophysics Data System (ADS)

    Birkenbach, Anna M.; Kaczan, David J.; Smith, Martin D.

    2017-04-01

    In fisheries, the tragedy of the commons manifests as a competitive race to fish that compresses fishing seasons, resulting in ecological damage, economic waste, and occupational hazards. Catch shares are hypothesized to halt the race by securing each individual’s right to a portion of the total catch, but there is evidence for this from selected examples only. Here we systematically analyse natural experiments to test whether catch shares reduce racing in 39 US fisheries. We compare each fishery treated with catch shares to an individually matched control before and after the policy change. We estimate an average policy treatment effect in a pooled model and in a meta-analysis that combines separate estimates for each treatment-control pair. Consistent with the theory that market-based management ends the race to fish, we find strong evidence that catch shares extend fishing seasons. This evidence informs the current debate over expanding the use of market-based regulation to other fisheries.

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

    PubMed

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

    2013-05-01

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

  7. Spatial Patterns and Temperature Predictions of Tuna Fatty Acids: Tracing Essential Nutrients and Changes in Primary Producers.

    PubMed

    Pethybridge, Heidi R; Parrish, Christopher C; Morrongiello, John; Young, Jock W; Farley, Jessica H; Gunasekera, Rasanthi M; Nichols, Peter D

    2015-01-01

    Fatty acids are among the least understood nutrients in marine environments, despite their profile as key energy components of food webs and that they are essential to all life forms. Presented here is a novel approach to predict the spatial-temporal distributions of fatty acids in marine resources using generalized additive mixed models. Fatty acid tracers (FAT) of key primary producers, nutritional condition indices and concentrations of two essential long-chain (≥C20) omega-3 fatty acids (EFA) measured in muscle of albacore tuna, Thunnus alalunga, sampled in the south-west Pacific Ocean were response variables. Predictive variables were: location, time, sea surface temperature (SST) and chlorophyll-a (Chla), and phytoplankton biomass at time of catch and curved fork length. The best model fit for all fatty acid parameters included fish length and SST. The first oceanographic contour maps of EFA and FAT (FATscapes) were produced and demonstrated clear geographical gradients in the study region. Predicted changes in all fatty acid parameters reflected shifts in the size-structure of dominant primary producers. Model projections show that the supply and availability of EFA are likely to be negatively affected by increases in SST especially in temperate waters where a 12% reduction in both total fatty acid content and EFA proportions are predicted. Such changes will have large implications for the availability of energy and associated health benefits to high-order consumers. Results convey new concerns on impacts of projected climate change on fish-derived EFA in marine systems.

  8. Improving electrofishing catch consistency by standardizing power

    USGS Publications Warehouse

    Burkhardt, Randy W.; Gutreuter, Steve

    1995-01-01

    The electrical output of electrofishing equipment is commonly standardized by using either constant voltage or constant amperage, However, simplified circuit and wave theories of electricity suggest that standardization of power (wattage) available for transfer from water to fish may be critical for effective standardization of electrofishing. Electrofishing with standardized power ensures that constant power is transferable to fish regardless of water conditions. The in situ performance of standardized power output is poorly known. We used data collected by the interagency Long Term Resource Monitoring Program (LTRMP) in the upper Mississippi River system to assess the effectiveness of standardizing power output. The data consisted of 278 electrofishing collections, comprising 9,282 fishes in eight species groups, obtained during 1990 from main channel border, backwater, and tailwater aquatic areas in four reaches of the upper Mississippi River and one reach of the Illinois River. Variation in power output explained an average of 14.9% of catch variance for night electrofishing and 12.1 % for day electrofishing. Three patterns in catch per unit effort were observed for different species: increasing catch with increasing power, decreasing catch with increasing power, and no power-related pattern. Therefore, in addition to reducing catch variation, controlling power output may provide some capability to select particular species. The LTRMP adopted standardized power output beginning in 1991; standardized power output is adjusted for variation in water conductivity and water temperature by reference to a simple chart. Our data suggest that by standardizing electrofishing power output, the LTRMP has eliminated substantial amounts of catch variation at virtually no additional cost.

  9. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... divided as sub-ACLs between limited access vessels, limited access vessels that are fishing under a... limited access fishery sub-ACLs for fishing years 2011 through 2013 are: (A) 2011: 24,954 mt. (B) 2012: 26... catch, observer set-aside, and research set-aside, as specified in this paragraph (a). The LAGC ACLs...

  10. Comparative evaluation of light-trap catches, electric motor mosquito catches and human biting catches of Anopheles in the Three Gorges Reservoir.

    PubMed

    Duo-quan, Wang; Lin-hua, Tang; Zhen-cheng, Gu; Xiang, Zheng; Man-ni, Yang; Wei-kang, Jiang

    2012-01-01

    The mosquito sampling efficiency of light-trap catches and electric motor mosquito catches were compared with that of human biting catches in the Three Gorges Reservoir. There was consistency in the sampling efficiency between light-trap catches and human biting catches for Anopheles sinensis (r = 0.82, P<0.01) and light-trap catches were 1.52 (1.35-1.71) times that of human biting catches regardless of mosquito density (r = 0.33, P>0.01), while the correlation between electric motor mosquito catches and human biting catches was found to be not statistically significant (r = 0.43, P>0.01) and its sampling efficiency was below that of human biting catches. It is concluded that light-traps can be used as an alternative to human biting catches of Anopheles sinensis in the study area and is a promising tool for sampling malaria vector populations.

  11. Identification of five highly priced tuna species by quantitative real-time polymerase chain reaction.

    PubMed

    Liu, Shasha; Xu, Kunhua; Wu, Zhigang; Xie, Xiao; Feng, Junli

    2016-09-01

    Tunas are economically important fishery worldwide, and are often used for commercial processed production. For effective fishery management and protection of consumers' rights, it is important to develop a molecular method to identify species in canned tuna products rapidly and reliably. Here, we have developed a duplex quantitative real-time PCR (qPCR) for identification of five highly priced tuna species (Thunnus maccoyii, Thunnus obesus, Thunnus albacares, Thunnus alalunga and Katsuwonus pelamis) from processed as well as fresh fish. After amplification and sequencing of seven genetic markers commonly used for species identification, 16S rDNA and control region (CR) of mitochondrial DNA were selected as the reference gene markers for genus Thunnus and tuna species identification, respectively. Subsequently, a 73 bp fragment of 16S rDNA and 85-99 bp fragment of CR were simultaneously amplified from each target species by qPCR. The qPCR efficiency of each reaction was calculated according to the standard curves, and the method was validated by amplification DNA extracted from single or mixed tuna specimen. The developed duplex qPCR system was applied to authenticate species of 14 commercial tuna products successfully, which demonstrated it was really a useful and academic technique to identify highly priced tuna species.

  12. Behavior of Salmonella and Listeria monocytogenes in Raw Yellowfin Tuna during Cold Storage

    PubMed Central

    Liu, Chengchu; Mou, Jing; Su, Yi-Cheng

    2016-01-01

    Behavior of Salmonella and Listeria monocytogenes in raw yellowfin tuna during refrigeration and frozen storage were studied. Growth of Salmonella was inhibited in tuna during refrigerated storage, while L. monocytogenes was able to multiply significantly during refrigerated storage. Populations of Salmonella in tuna were reduced by 1 to 2 log after 12 days of storage at 5–7 °C, regardless levels of contamination. However, populations of L. monocytogenes Scott A, M0507, and SFL0404 in inoculated tuna (104–105 CFU/g) increased by 3.31, 3.56, and 3.98 log CFU/g, respectively, after 12 days of storage at 5–7 °C. Similar increases of L. monocytogenes cells were observed in tuna meat with a lower inoculation level (102–103 CFU/g). Populations of Salmonella and L. monocytogenes declined gradually in tuna samples over 84 days (12 weeks) of frozen storage at −18 °C with Salmonella Newport 6962 being decreased to undetectable level (<10 CFU/g) from an initial level of 103 log CFU/g after 42 days of frozen storage. These results demonstrate that tuna meat intended for raw consumption must be handled properly from farm to table to reduce the risks of foodborne illness caused by Salmonella and L. monocytogenes. PMID:28231111

  13. 2. CATCH BASIN, INFLOW PIPES AT CENTER, COLD FLOW LABORATORY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. CATCH BASIN, INFLOW PIPES AT CENTER, COLD FLOW LABORATORY AT LEFT, VIEW TOWARDS NORTHWEST. - Glenn L. Martin Company, Titan Missile Test Facilities, Catch Basin, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  14. Eight Ways to Catch an Insect

    ERIC Educational Resources Information Center

    Gray, Alice

    1977-01-01

    The webs of eight North American spiders are illustrated and discussed. Using these webs, the spiders are able to catch insects for their meals. Each of the webs are unique and require a different approach to the problem of food getting. (MA)

  15. Pitch-catch only ultrasonic fluid densitometer

    DOEpatents

    Greenwood, M.S.; Harris, R.V.

    1999-03-23

    The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

  16. Pitch-catch only ultrasonic fluid densitometer

    DOEpatents

    Greenwood, Margaret S.; Harris, Robert V.

    1999-01-01

    The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface.

  17. 30 CFR 57.19132 - Safety catches.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Safety catches. 57.19132 Section 57.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel...

  18. 30 CFR 57.19132 - Safety catches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Safety catches. 57.19132 Section 57.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel...

  19. 30 CFR 56.19132 - Safety catches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Safety catches. 56.19132 Section 56.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel...

  20. 30 CFR 57.19132 - Safety catches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Safety catches. 57.19132 Section 57.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel...

  1. 30 CFR 56.19132 - Safety catches.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Safety catches. 56.19132 Section 56.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel...

  2. 30 CFR 56.19132 - Safety catches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Safety catches. 56.19132 Section 56.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel...

  3. 30 CFR 57.19132 - Safety catches.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Safety catches. 57.19132 Section 57.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel...

  4. 30 CFR 56.19132 - Safety catches.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Safety catches. 56.19132 Section 56.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel...

  5. 30 CFR 56.19132 - Safety catches.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Safety catches. 56.19132 Section 56.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel...

  6. 30 CFR 57.19132 - Safety catches.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Safety catches. 57.19132 Section 57.19132 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel...

  7. Liberal Arts Catch-Up Revisited

    ERIC Educational Resources Information Center

    Goyder, John

    2014-01-01

    This paper replicates the work of Giles and Drewes from the 1990s. They showed a catch-up effect whereby graduates of liberal arts undergraduate programs, although at an early-career disadvantage compared with graduates of applied programs, had higher incomes by mid-career. Working with the Panel 5 Survey of Labour and Income Dynamics (2005-2010),…

  8. 50 CFR 660.511 - Catch restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... § 660.511 Catch restrictions. (a) All CPS harvested shoreward of the outer boundary of the EEZ (0-200... trip limit for harvesting vessels fishing in the CPS Limited Entry Zone for CPS other than live bait without a limited entry permit is 5 mt tons of all CPS finfish combined. (c)The trip limit for...

  9. 50 CFR 660.511 - Catch restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... § 660.511 Catch restrictions. (a) All CPS harvested shoreward of the outer boundary of the EEZ (0-200... trip limit for harvesting vessels fishing in the CPS Limited Entry Zone for CPS other than live bait without a limited entry permit is 5 mt tons of all CPS finfish combined. (c)The trip limit for...

  10. 50 CFR 648.71 - Catch quotas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Catch quotas. 648.71 Section 648.71 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE NORTHEASTERN UNITED STATES Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries §...

  11. 50 CFR 660.511 - Catch restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Catch restrictions. 660.511 Section 660.511 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Coastal Pelagics Fisheries...

  12. 50 CFR 660.511 - Catch restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Catch restrictions. 660.511 Section 660.511 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Coastal Pelagics Fisheries...

  13. Data Report for Catch Tank Vapor Sampling

    SciTech Connect

    NGUYEN, D.M.

    2000-09-28

    CH2M HILL Hanford Group, Inc. (CHG) is responsible for developing and maintaining the authorization basis for River Protection Project (RPP) facilities and operations. This responsibility includes closure of the Flammable Gas Unreviewed Safety Question (USQ) for waste tank ancillary equipment such as catch tanks, double-contained receiver tanks, 244-AR and 244-CR vaults, 242-S and 242-T Evaporators, and inactive miscellaneous underground storage tanks. To support closure of the Flammable Gas USQ for catch tanks, an analysis of the flammable gas hazard was performed. This document provides a summary of flammable gas data obtained from RPP active catch tanks in FY 2000. Flammable gas level measurements for each catch tank (other than 241-AX-152) are discussed on a tank-by-tank basis in Section 3.0. Conclusions based on the data are provided in Section 4.0. This section also includes recommendations that would be useful when conducting vapor sampling for other miscellaneous tanks (e.g., inactive miscellaneous underground storage tanks).

  14. Eight Ways to Catch an Insect

    ERIC Educational Resources Information Center

    Gray, Alice

    1977-01-01

    The webs of eight North American spiders are illustrated and discussed. Using these webs, the spiders are able to catch insects for their meals. Each of the webs are unique and require a different approach to the problem of food getting. (MA)

  15. Project Catch-Up. Awareness Brochure.

    ERIC Educational Resources Information Center

    Newport-Mesa Unified School District, Newport Beach, CA.

    Project Catch-Up, an ESEA Title I program, operates in Newport Beach and in Costa Mesa, California. It is said to be designed to provide remedial instruction in reading and arithmetic to underachieving children, kindergarten through sixth grade, in schools serving low socioeconomic level suburban areas. Among its key features are the following:…

  16. 50 CFR 660.511 - Catch restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Catch restrictions. 660.511 Section 660.511 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Coastal Pelagics...

  17. Book review: Methods for catching beetles

    USDA-ARS?s Scientific Manuscript database

    Beetles are the most speciose animal group and found in virtually all habitats on Earth. Methods for Catching Beetles is a comprehensive general sourcebook about where and how to collect members of this diverse group. The book makes a compelling case in its Introduction about the value of scientif...

  18. Catching the Dream Annual Report, 2002.

    ERIC Educational Resources Information Center

    Chavers, Dean, Ed.

    2002-01-01

    In 2002, Catching the Dream (CTD) provided college scholarships to 208 American Indian students as well as grants to improve education in schools that serve Native students. This annual report describes CTD's programs and activities in 2002. Contents include short descriptions of CTD's scholarship, fellowship, and internship programs; describe…

  19. Accelerating Electronic Tag Development for Tracking Free-Ranging Marine Animals at Sea

    DTIC Science & Technology

    2003-01-01

    of the tags and animals (when available), the quality of data, and performance of the tags has been carefully examined. Studies with bluefin tuna are...Additional efforts are ongoing to determine if the light data from existing records from elephant seals and bluefin tuna can be used to document...archival tags were implanted in bluefin and yellowfin tuna respectively off California and Mexico. Captive experiments at the TRCC with PAT tags lead to

  20. 75 FR 41996 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Pollock Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ... United States; Northeast Multispecies Fishery; Pollock Catch Limit Revisions AGENCY: National Marine... associated increases in pollock catch limits under the Northeast (NE) Multispecies Fishery Management Plan..., including Overfishing Levels (OFLs), Acceptable Biological Catches (ABCs), Annual Catch Limits (ACLs), ACL...

  1. Vulnerability of teleosts caught by the pelagic tuna longline fleets in South Atlantic and Western Indian Oceans

    NASA Astrophysics Data System (ADS)

    Lucena-Frédou, Flávia; Kell, Laurie; Frédou, Thierry; Gaertner, Daniel; Potier, Michel; Bach, Pascal; Travassos, Paulo; Hazin, Fábio; Ménard, Frédéric

    2017-06-01

    Productivity and Susceptibility Analysis (PSA) is a methodology for evaluating the vulnerability of a stock based on its biological productivity and susceptibility to fishing. In this study, we evaluated the vulnerability of 60 stocks of tuna, billfishes and other teleosts caught by the tuna longline fleets operating in the South Atlantic and Indian Ocean using a semi-quantitative PSA. We (a) evaluated the vulnerability of the species in the study areas; (b) compared the vulnerability of target and non-target species and oceans; (c) analyzed the sensitivity of data entry; and (d) compared the results of the PSA to other fully quantitative assessment methods. Istiophoridae exhibited the highest scores for vulnerability. The top 10 species at risk were: Atlantic Istiophorus albicans; Indian Ocean Istiompax indica; Atlantic Makaira nigricans and Thunnus alalunga; Indian Ocean Xiphias gladius; Atlantic T. albacares, Gempylus serpens, Ranzania laevis and X. gladius; and Indian Ocean T. alalunga. All species considered at high risk were targeted or were commercialized bycatch, except for the Atlantic G. serpens and R. laevis which were discarded, and may be considered as a false positive. Those species and others at high risk should be prioritized for further assessment and/or data collection. Most species at moderate risk were bycatch species kept for sale. Conversely, species classified at low risk were mostly discarded. Overall, species at high risk were overfished and/or subjected to overfishing. Moreover, all species considered to be within extinction risk (Critically Endangered, Endangered and Vulnerable) were in the high-risk category. The good concordance between approaches corroborates the results of our analysis. PSA is not a replacement for traditional stock assessments, where a stock is assessed at regular intervals to provide management advice. It is of importance, however, where there is uncertainty about catches and life history parameters, since it can

  2. [Food poisoning by scombroid fish (tuna) in a communal dining room of a company].

    PubMed

    Arnedo, A; Bellido, J; Criado, J; Pérez, R; González, F; Safont, L; Monfort, G; Calvo, C

    1989-11-25

    We report a collective tuna fish poisoning which developed on June 10, 1988, in a staff dining room in Castellón. Twenty-one people were involved (attack rate 42.9%). The major symptoms were diarrhea, abdominal pain, headache, facial flushing and oral burning. The mean duration of the symptoms was 15 hours. The ingestion of tuna fish was significantly associated with the illness (p less than 0.001) when the other foodstuffs were controlled. Tuna fish had been defrosted at room air temperature during 14 hours. The analysis of several foodstuffs (there were no tuna fish remains available) and the food handling staff did not disclose pathogens. We discuss the etiology, pathogenesis, epidemiology and control of this type of food poisoning.

  3. Modelling the impact of climate change on South Pacific albacore tuna

    NASA Astrophysics Data System (ADS)

    Lehodey, Patrick; Senina, Inna; Nicol, Simon; Hampton, John

    2015-03-01

    The potential impact of climate change under the IPCC AR4-A2 scenario (close to the AR5-RCP8.5 scenario) on south Pacific albacore tuna (Thunnus alalunga) is simulated with the Spatial Ecosystem And Population Dynamics Model (SEAPODYM) and environmental forcing variables provided by the Earth Climate model IPSL-CM4. Parameters controlling the habitat and dynamics of the population were optimized by fitting the model, using maximum likelihood, to a complete fishing data set for the historical fishing period since 1950. Albacore undertake clear seasonal migrations between feeding and spawning grounds, as evidenced by seasonal catch and size composition changes. This seasonality was well predicted by the SEAPODYM albacore simulations. The total biomass estimate of south Pacific albacore was predicted to have decreased from ~1.8 million tonnes (Mt) at the beginning of industrial fisheries in 1950 to 1.25 Mt in 2006, in good agreement with an independent estimate from stock assessment analysis. A simulation without fishing indicated an equivalent contribution of environmental variability and fishing to the historical decrease of the stock biomass. The parameterized SEAPODYM model was used to project the dynamics of the population until the end of the 21st century with an average fishing effort based on recent years. Under this fishing and climate change scenario, the population was predicted to decrease and to stabilize after 2035 just below 0.8 Mt, i.e., 55% below the initial biomass of 1960. After 2080 however, the trend was reversed when a new spawning ground emerged in the north Tasman Sea. A test simulation highlighted the sensitivity of the model results to projected dissolved oxygen concentration for which there is large uncertainty in the tropical region. A second test simulation showed that genetic selection favouring albacore with preferences for higher optimal ambient spawning temperature would maintain a reduced level of spawning in current tropical spawning

  4. An evaluation of mercury concentrations in three brands of canned tuna.

    PubMed

    Gerstenberger, Shawn L; Martinson, Adam; Kramer, Joanna L

    2010-02-01

    There is widespread concern over the presence of Hg in fish consumed by humans. While studies have been focused on determining the Hg concentration in sport fish and some commercial fish, little attention has been directed to canned tuna; it is widely held that concentrations are low. In the present study, the amount of Hg present in canned tuna purchased in Las Vegas, Nevada, USA, was examined, and the brand, temporal variation, type, and packaging medium impacts on Hg concentrations in tuna were explored. A significant (p < 0.001) brand difference was noted: Brand 3 contained higher Hg concentrations ($\\bar x$ standard deviation (SD) (0.777 +/- 0.320 ppm) than Brands 1 (0.541 +/- 0.114 ppm) and 2 (0.550 +/- 0.199 ppm). Chunk white tuna (0.619 +/- 0.212 ppm) and solid white tuna (0.576 +/- 0.178 ppm) were both significantly (p < 0.001) higher in mean Hg than chunk light tuna (0.137 +/- 0.063 ppm). No significant temporal variation was noted, and packaging had no significant effect on Hg concentration. In total, 55% of all tuna examined was above the U.S. Environmental Protection Agency's (U.S. EPA) safety level for human consumption (0.5 ppm), and 5% of the tuna exceeded the action level established by the U.S. Food and Drug Administration (U.S. FDA) (1.0 ppm). These results indicate that stricter regulation of the canned tuna industry is necessary to ensure the safety of sensitive populations such as pregnant women, infants, and children. According to the U.S. EPA reference dose of 0.1 microg/kg body weight per day and a mean Hg value of 0.619 ppm, a 25-kg child may consume a meal (75 g) of canned chunk white tuna only once every 18.6 d. Continued monitoring of the industry and efforts to reduce Hg concentrations in canned tuna are recommended. Environ.

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

    PubMed

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

    2011-12-01

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

  6. Species-diverse coral communities on an artificial substrate at a tuna farm in Amami, Japan.

    PubMed

    Hata, Hiroki; Hirabayashi, Isao; Hamaoka, Hideki; Mukai, Yoshio; Omori, Koji; Fukami, Hironobu

    2013-04-01

    Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the natural environment. In Japan, tuna-farming is conducted on coral reefs that have been damaged by mass-bleaching events and crown-of-thorns starfish (COTS) outbreaks. This study focused on the coral community on an artificial substrate of tuna-farm to reveal the possible effects of tuna-farming on the natural environment. Corals flourished on ropes suspended in the farm in the Amami Islands, southern Japan. These were moored 3 m below the sea-surface in 50-m-deep water. The coral community on the rope was analyzed and compared with those on natural substrata on two adjacent COTS-damaged reefs and with that in a protected reef. Corals were monitored throughout a year. Sixty coral species grew on the ropes, that corresponds to 27.3% of the 220 species known from Amami. The coral community was unique, dominated by massive faviid corals. On the ropes, the water temperature rarely exceeded 30.0 °C and no corals on the rope were severely bleached or covered by sedimentation during the observations. The tuna-farm infrastructure provided corals with a suitable habitat, and species-rich coral communities were established. These coral communities are an important node connecting tuna-farms and the natural environment.

  7. An Evolutionarily Conserved Long Noncoding RNA TUNA Controls Pluripotency and Neural Lineage Commitment

    PubMed Central

    Lin, Nianwei; Chang, Kung-Yen; Li, Zhonghan; Gates, Keith; Rana, Zacharia A.; Dang, Jason; Zhang, Danhua; Han, Tianxu; Yang, Chao-Shun; Cunningham, Thomas J.; Head, Steven R.; Duester, Gregg; Dong, Duc; Rana, Tariq M.

    2014-01-01

    SUMMARY Here, we generated the first genome-scale shRNA library targeting lincRNAs in the mouse. We performed an unbiased loss-of-function study in mouse embryonic stem cells (mESCs) and identified 20 novel lincRNAs involved in the maintenance of pluripotency. Among these, TUNA (Tcl1 Upstream Neuron-Associated lincRNA), was required for pluripotency and formed a complex with three RNA-binding proteins (RBPs). The TUNA–RBP complex was detected at the promoters of Nanog, Sox2, and Fgf4, and knockdown of TUNA or the individual RBPs inhibited neural differentiation of mESCs. TUNA showed striking evolutionary conservation of both sequence and central nervous system-restricted expression in vertebrates. Accordingly, knockdown of tuna in zebrafish caused impaired locomotor function, and TUNA expression in the brains of Huntington’s patients was significantly associated with disease grade. Our results suggest that the lincRNA TUNA plays a vital role in pluripotency and neural differentiation of ESCs and is associated with neurological function of adult vertebrates. PMID:24530304

  8. Heavy metals in canned tuna from Italian markets.

    PubMed

    Russo, R; Lo Voi, A; De Simone, A; Serpe, F P; Anastasio, A; Pepe, T; Cacace, D; Severino, L

    2013-02-01

    Fish is a good source of nutrients for humans but can pose a risk to human health because of the possible presence of some xenobiotics such as heavy metals and persistent organic contaminants. Constant monitoring is needed to minimize health risks and ensure product quality and consumer safety. The aim of the present study was to use atomic absorption spectrometry to determine the concentrations of some heavy metals (Hg, Pb, and Cd) in tuna packaged in different kinds of packages (cans or glass) in various countries (Italy and elsewhere). Concentrations of Cd and Hg were within the limits set by European Commission Regulation (EC) No 1881/2006 and in many samples were below the detection limit. Pb concentrations exceeded European limits in 9.8% of the analyzed samples. These results are reassuring in terms of food safety but highlighted the need to constantly monitor the concentrations of heavy metals in fish products that could endanger consumer health.

  9. Simulating energy flow in biomolecules: application to tuna cytochrome c.

    PubMed Central

    Wang, Q; Wong, C F; Rabitz, H

    1998-01-01

    By constructing a continuity equation of energy flow, one can utilize results from a molecular dynamics simulation to calculate the energy flux or flow in different parts of a biomolecule. Such calculations can yield useful insights into the pathways of energy flow in biomolecules. The method was first tested on a small system of a cluster of 13 argon atoms and then applied to the study of the pathways of energy flow after a tuna ferrocytochrome c molecule was oxidized. Initially, energy propagated faster along the direction perpendicular to the heme plane. This was due to an efficient through-bond mechanism, because the heme iron in cytochrome c was covalently bonded to a cysteine and a histidine. For the oxidation of cytochrome c, electrostatic interactions also facilitated a long-range through-space mechanism of energy flow. As a result, polar or charged groups that were further away from the oxidation site could receive energy earlier than nonpolar groups closer to the site. Another bridging mechanism facilitating efficient long-range responses to cytochrome c oxidation involved the coupling of far-off atoms with atoms that were nearer to, and interacted directly with, the oxidation site. The different characteristics of these energy transfer mechanisms defied a simple correlation between the time that the excess energy of the oxidation site first dissipated to an atom and the distance of the atom from the oxidation site. For tuna cytochrome c, all of the atoms of the protein had sensed the effects of the oxidation within approximately 40 fs. For the length scale of energy transfer considered in this study, the speed of the energy propagation in the protein was on the order of 10(5) m/s. PMID:9649368

  10. Influence of fronts on the spatial distribution of albacore tuna (Thunnus alalunga) in the Northeast Pacific over the past 30 years (1982-2011)

    NASA Astrophysics Data System (ADS)

    Xu, Yi; Nieto, Karen; Teo, Steven L. H.; McClatchie, Sam; Holmes, John

    2017-01-01

    The association of albacore tuna distribution with subtropical fronts in the Northeast Pacific was examined on seasonal and interannual scales from 1982 to 2011. Spatial analyses were performed on commercial logbook data from US and Canadian troll and pole-and-line fisheries targeting albacore tuna that were matched with corresponding satellite images from the Advanced Very High Resolution Radiometer (AVHRR). Subtropical fronts were detected by deriving sea surface temperature (SST) gradients on large basin-scales and by using an improved version of the Cayula-Cornillon frontal detection algorithm. Based on our results, we suggest that areas with high albacore catch-per-unit-effort (CPUE) tend to occur in regions with high SST gradients, such as the North Pacific Transition Zone (NPTZ) and the North American coast. Approaching the North American coast along the NPTZ, SST gradients drop off substantially around 130°W before increasing rapidly near the coast, which corresponded to a similar pattern in albacore CPUE. In the NPTZ, the centroid of albacore CPUE showed a seasonal shift northwards in summer and southwards in fall, which coincided with seasonal spatial shifts of areas with high SST gradients. A similar pattern was found on an interannual scale, with the exception of several years with limited fishery data in the NPTZ due to changes in fishery operations. A fine-scale analysis of frontal locations suggested that areas with high albacore CPUE are associated with oceanic fronts, with the highest albacore CPUEs observed within 100 km of the nearest front. In addition, albacore distribution is related to frontal strength, with the highest CPUE found near fronts with high SST gradient values in the range of 0.12-0.16 °C km-1. Integrating our findings on the influence of frontal areas on albacore distribution and abundance in the NEPO should improve the standardization model used to derive abundance indices for North Pacific albacore stock assessments.

  11. Vision Algorithms Catch Defects in Screen Displays

    NASA Technical Reports Server (NTRS)

    2014-01-01

    Andrew Watson, a senior scientist at Ames Research Center, developed a tool called the Spatial Standard Observer (SSO), which models human vision for use in robotic applications. Redmond, Washington-based Radiant Zemax LLC licensed the technology from NASA and combined it with its imaging colorimeter system, creating a powerful tool that high-volume manufacturers of flat-panel displays use to catch defects in screens.

  12. Catch-Up Growth: Basic Mechanisms.

    PubMed

    Griffin, Ian J

    2015-01-01

    The neuroendocrine model of catch-up growth has been well studied in a number of animal models. During nutritional inadequacy, which invariably precedes catch-up growth, growth hormone (GH) levels increase under the influence of the oxygenic 'hunger signal' ghrelin. This increase in GH would usually be accompanied by an increase in IGF-1. However, malnutrition also induces the nutritionally responsive proteins sirtuin 1 (SIRT1) and fibroblast growth factor 21 (FGF21) that block GH signal transduction in the liver by blocking the JAK/STAT pathway, limiting IGF-1 production. The result is that GH's action is shifted from hepatic effects to effects in other tissues (for example muscle and adipose) and shifted away from IGF-1-mediated effects and towards GH-mediated effects. Once nutrients become more available, SIRT1 and FGF21 levels, and hepatic GH sensitivity return to normal, and production of IGF-1 resumes. This shifts GH signaling away from GH-mediated effects, and towards IGF-1-mediated effects both in the liver and in other tissues. It presumably leads to greatly increased IGF-1 signaling that would have been expected without the prior episode of nutritional inadequacy. Although much work remains to be done, it does appear that ghrelin is increased in in utero and postnatal malnutrition, that elevations in ghrelin may be prolonged after malnutrition resolves, and that higher ghrelin levels are associated with increased rates of catch-up growth. Prolonged increases in circulating ghrelin and GH, combined with a rapid return in hepatic GH sensitivity would provide an elegant mechanism to drive catch-up growth after periods of nutritional insufficiency.

  13. Phenomenological and microscopic theories for catch bonds.

    PubMed

    Chakrabarti, Shaon; Hinczewski, Michael; Thirumalai, D

    2017-01-01

    Lifetimes of bound states of protein complexes or biomolecule folded states typically decrease when subject to mechanical force. However, a plethora of biological systems exhibit the counter-intuitive phenomenon of catch bonding, where non-covalent bonds become stronger under externally applied forces. The quest to understand the origin of catch-bond behavior has led to the development of phenomenological and microscopic theories that can quantitatively recapitulate experimental data. Here, we assess the successes and limitations of such theories in explaining experimental data. The most widely applied approach is a phenomenological two-state model, which fits all of the available data on a variety of complexes: actomyosin, kinetochore-microtubule, selectin-ligand, and cadherin-catenin binding to filamentous actin. With a primary focus on the selectin family of cell-adhesion complexes, we discuss the positives and negatives of phenomenological models and the importance of evaluating the physical relevance of fitting parameters. We describe a microscopic theory for selectins, which provides a structural basis for catch bonds and predicts a crucial allosteric role for residues Asn82-Glu88. We emphasize the need for new theories and simulations that can mimic experimental conditions, given the complex response of cell adhesion complexes to force and their potential role in a variety of biological contexts. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Spatial Patterns and Temperature Predictions of Tuna Fatty Acids: Tracing Essential Nutrients and Changes in Primary Producers

    PubMed Central

    Pethybridge, Heidi R.; Parrish, Christopher C.; Morrongiello, John; Young, Jock W.; Farley, Jessica H.; Gunasekera, Rasanthi M.; Nichols, Peter D.

    2015-01-01

    Fatty acids are among the least understood nutrients in marine environments, despite their profile as key energy components of food webs and that they are essential to all life forms. Presented here is a novel approach to predict the spatial-temporal distributions of fatty acids in marine resources using generalized additive mixed models. Fatty acid tracers (FAT) of key primary producers, nutritional condition indices and concentrations of two essential long-chain (≥C20) omega-3 fatty acids (EFA) measured in muscle of albacore tuna, Thunnus alalunga, sampled in the south-west Pacific Ocean were response variables. Predictive variables were: location, time, sea surface temperature (SST) and chlorophyll-a (Chla), and phytoplankton biomass at time of catch and curved fork length. The best model fit for all fatty acid parameters included fish length and SST. The first oceanographic contour maps of EFA and FAT (FATscapes) were produced and demonstrated clear geographical gradients in the study region. Predicted changes in all fatty acid parameters reflected shifts in the size-structure of dominant primary producers. Model projections show that the supply and availability of EFA are likely to be negatively affected by increases in SST especially in temperate waters where a 12% reduction in both total fatty acid content and EFA proportions are predicted. Such changes will have large implications for the availability of energy and associated health benefits to high-order consumers. Results convey new concerns on impacts of projected climate change on fish-derived EFA in marine systems. PMID:26135308

  15. Accounting for Age Uncertainty in Growth Modeling, the Case Study of Yellowfin Tuna (Thunnus albacares) of the Indian Ocean

    PubMed Central

    Dortel, Emmanuelle; Massiot-Granier, Félix; Rivot, Etienne; Million, Julien; Hallier, Jean-Pierre; Morize, Eric; Munaron, Jean-Marie; Bousquet, Nicolas; Chassot, Emmanuel

    2013-01-01

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

  16. Natural communities in catch basins in southern Rhode Island

    USGS Publications Warehouse

    Butler, M.; Ginsberg, H.S.; LeBrun, R.A.; Gettman, A.D.; Pollnak, F.

    2007-01-01

    Storm-water drainage catch basins are manmade structures that often contain water and organic matter, making them suitable environments for various organisms. We censused organisms inhabiting catch basins in southern Rhode Island in 2002 in an effort to begin to describe these communities. Catch-basin inhabitants were mostly detritivores, including annelids, arthropods, and mollusks that could withstand low oxygen levels and droughts. Our results suggest that catch-basin inhabitants were mostly washed in with rainwater, and populations increased over the summer season as biotic activity resulted in increased nutrient levels later in the summer. In contrast, mosquitoes and other Diptera larvae were abundant earlier in the summer because the adults actively sought catch basins for oviposition sites. Mosquito larvae were likely to be abundant in catch basins with shallow, stagnant water that had relatively low dissolved oxygen and pH, and relatively high total suspended solids, carbon, and nitrogen.

  17. Catch tank inhibitor addition 200-East and 200-West Areas

    SciTech Connect

    Palit, A.N.

    1996-06-21

    Reported is the study of 11 catch tanks in the 200-East Area and the 7 catch tanks in the 200-West Area listed as active. The location, capacity, material of construction, annual total accumulation, annual rain intrusion, waste transfer rate, and access for chemical injection in these tanks are documented. The present and future utilization and isolation plans for the catch tanks are established.

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

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

  19. Population assessment of tropical tuna based on their associative behavior around floating objects.

    PubMed

    Capello, M; Deneubourg, J L; Robert, M; Holland, K N; Schaefer, K M; Dagorn, L

    2016-11-03

    Estimating the abundance of pelagic fish species is a challenging task, due to their vast and remote habitat. Despite the development of satellite, archival and acoustic tagging techniques that allow the tracking of marine animals in their natural environments, these technologies have so far been underutilized in developing abundance estimations. We developed a new method for estimating the abundance of tropical tuna that employs these technologies and exploits the aggregative behavior of tuna around floating objects (FADs). We provided estimates of abundance indices based on a simulated set of tagged fish and studied the sensitivity of our method to different association dynamics, FAD numbers, population sizes and heterogeneities of the FAD-array. Taking the case study of yellowfin tuna (Thunnus albacares) acoustically-tagged in Hawaii, we implemented our approach on field data and derived for the first time the ratio between the associated and the total population. With more extensive and long-term monitoring of FAD-associated tunas and good estimates of the numbers of fish at FADs, our method could provide fisheries-independent estimates of populations of tropical tuna. The same approach can be applied to obtain population assessments for any marine and terrestrial species that display associative behavior and from which behavioral data have been acquired using acoustic, archival or satellite tags.

  20. Microbiological, sensory, and electronic nose evaluation of yellowfin tuna under various storage conditions.

    PubMed

    Du, W X; Kim, J; Cornell, J A; Huang, T; Marshall, M R; Wei, C I

    2001-12-01

    Microbiological assessment, sensory evaluation, and electronic nose (AromaScan) analysis were performed on yellowfin tuna stored at 0, 4, 10, and 22 degrees C for 0, 1, 3, 5, and 9 days. Fish color, texture, appearance, and odor were evaluated by a trained sensory panel, while aroma-odor properties were evaluated using an AromaScan. Bacterial enumeration was performed using plate count agar containing 1.5% NaCl. Tuna fillets stored at 22 degrees C for 3 days or longer had a bacterial load of over 10(7) CFU/g and were rated not acceptable for consumption (grade C) by the sensory panel. Tuna fillets stored at 4 degrees C for 9 days or 10 degrees C for over 5 days were rated as grade C products and also had a bacterial load of over 10(7) CFU/g. The change in fish quality as determined by AromaScan followed increases in microbiological counts in tuna fillets, indicating that bacterial load can serve as a useful and objective indicator of gross spoilage. Electronic nose devices can be used in conjunction with microbial counts and sensory panels to evaluate the degree of decomposition in tuna during storage.

  1. Modelling the Spatial Behaviour of a Tropical Tuna Purse Seine Fleet

    PubMed Central

    Davies, Tim K.; Mees, Chris C.; Milner-Gulland, E. J.

    2014-01-01

    Industrial tuna fisheries operate in the Indian, Atlantic and Pacific Oceans, but concerns over sustainability and environmental impacts of these fisheries have resulted in increased scrutiny of how they are managed. An important but often overlooked factor in the success or failure of tuna fisheries management is the behaviour of fishers and fishing fleets. Uncertainty in how a fishing fleet will respond to management or other influences can be reduced by anticipating fleet behaviour, although to date there has been little research directed at understanding and anticipating the human dimension of tuna fisheries. The aim of this study was to address gaps in knowledge of the behaviour of tuna fleets, using the Indian Ocean tropical tuna purse seine fishery as a case study. We use statistical modelling to examine the factors that influence the spatial behaviour of the purse seine fleet at broad spatiotemporal scales. This analysis reveals very high consistency between years in the use of seasonal fishing grounds by the fleet, as well as a forcing influence of biophysical ocean conditions on the distribution of fishing effort. These findings suggest strong inertia in the spatial behaviour of the fleet, which has important implications for predicting the response of the fleet to natural events or management measures (e.g., spatial closures). PMID:25462165

  2. Population assessment of tropical tuna based on their associative behavior around floating objects

    PubMed Central

    Capello, M.; Deneubourg, J. L.; Robert, M.; Holland, K. N.; Schaefer, K. M.; Dagorn, L.

    2016-01-01

    Estimating the abundance of pelagic fish species is a challenging task, due to their vast and remote habitat. Despite the development of satellite, archival and acoustic tagging techniques that allow the tracking of marine animals in their natural environments, these technologies have so far been underutilized in developing abundance estimations. We developed a new method for estimating the abundance of tropical tuna that employs these technologies and exploits the aggregative behavior of tuna around floating objects (FADs). We provided estimates of abundance indices based on a simulated set of tagged fish and studied the sensitivity of our method to different association dynamics, FAD numbers, population sizes and heterogeneities of the FAD-array. Taking the case study of yellowfin tuna (Thunnus albacares) acoustically-tagged in Hawaii, we implemented our approach on field data and derived for the first time the ratio between the associated and the total population. With more extensive and long-term monitoring of FAD-associated tunas and good estimates of the numbers of fish at FADs, our method could provide fisheries-independent estimates of populations of tropical tuna. The same approach can be applied to obtain population assessments for any marine and terrestrial species that display associative behavior and from which behavioral data have been acquired using acoustic, archival or satellite tags. PMID:27808175

  3. Modelling the spatial behaviour of a tropical tuna purse seine fleet.

    PubMed

    Davies, Tim K; Mees, Chris C; Milner-Gulland, E J

    2014-01-01

    Industrial tuna fisheries operate in the Indian, Atlantic and Pacific Oceans, but concerns over sustainability and environmental impacts of these fisheries have resulted in increased scrutiny of how they are managed. An important but often overlooked factor in the success or failure of tuna fisheries management is the behaviour of fishers and fishing fleets. Uncertainty in how a fishing fleet will respond to management or other influences can be reduced by anticipating fleet behaviour, although to date there has been little research directed at understanding and anticipating the human dimension of tuna fisheries. The aim of this study was to address gaps in knowledge of the behaviour of tuna fleets, using the Indian Ocean tropical tuna purse seine fishery as a case study. We use statistical modelling to examine the factors that influence the spatial behaviour of the purse seine fleet at broad spatiotemporal scales. This analysis reveals very high consistency between years in the use of seasonal fishing grounds by the fleet, as well as a forcing influence of biophysical ocean conditions on the distribution of fishing effort. These findings suggest strong inertia in the spatial behaviour of the fleet, which has important implications for predicting the response of the fleet to natural events or management measures (e.g., spatial closures).

  4. 75 FR 22418 - The Tariff-Rate Quota for Calendar Year 2010 Tuna Classifiable Under Subheading 1604.14.22...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... United States consumption of tuna in airtight containers during the preceding Calendar Year. This...-rate quota is applicable to tuna entered or withdrawn from warehouse for consumption during the period... for consumption during the Calendar Year 2010, at the rate of 6 percent ad valorem under subheading...

  5. Redox conformation changes in refined tuna cytochrome c.

    PubMed Central

    Takano, T; Dickerson, R E

    1980-01-01

    Tuna ferrocytochrome c and ferricytochrome c have been refined independently at high resolution (1.5 A and 1.8 A) to crystallographic residual errors of 17.3% and 20.8%, respectively. Small but significant conformational differences are seen surrounding a buried water molecule that is hydrogen bonded to Asn-52, Tyr-67, and Thr-78. In the oxidized state, this water molecule is 1.0 A closer to the heme and the heme has moved 0.15 A out of its heme crevice; both changes lead to a more polar microenvironment for the heme. Chemical modification studies, patterns of evolutionary conservatism, structural differences in bacterial cytochromes, and x-ray studies all agree that the "active site" for cytochrome c is bounded by lysines 8, 13,27, 72, 79, 86, and 87 (thus containing the evolutionary conservative 72-87 loop) and has the buried water molecule just below its surface and the opening of the heme crevice slightly to one side. PMID:6256733

  6. Modeling the Spatial Dynamics of International Tuna Fleets.

    PubMed

    Sun, Jenny; Hinton, Michael G; Webster, D G

    2016-01-01

    We developed an iterative sequential random utility model to investigate the social and environmental determinants of the spatiotemporal decision process of tuna purse-seine fishery fishing effort in the eastern Pacific Ocean. Operations of the fishing gear mark checkpoints in a continuous complex decision-making process. Individual fisher behavior is modeled by identifying diversified choices over decision-space for an entire fishing trip, which allows inclusion of prior and current vessel locations and conditions among the explanatory variables. Among these factors are vessel capacity; departure and arrival port; duration of the fishing trip; daily and cumulative distance travelled, which provides a proxy for operation costs; expected revenue; oceanographic conditions; and tons of fish on board. The model uses a two-step decision process to capture the probability of a vessel choosing a specific fishing region for the first set and the probability of switching to (or staying in) a specific region to fish before returning to its landing port. The model provides a means to anticipate the success of marine resource management, and it can be used to evaluate fleet diversity in fisher behavior, the impact of climate variability, and the stability and resilience of complex coupled human and natural systems.

  7. Application of transfer functions to canned tuna fish thermal processing.

    PubMed

    Ansorena, M R; del Valle, C; Salvadori, V O

    2010-02-01

    Design and optimization of thermal processing of foods need accurate dynamic models to ensure safe and high quality food products. Transfer functions had been demonstrated to be a useful tool to predict thermal histories, especially under variable operating conditions. This work presents the development and experimental validation of a dynamic model (discrete transfer function) for the thermal processing of tuna fish in steam retorts. Transfer function coefficients were obtained numerically, using commercial software of finite elements (COMSOL Multiphysics) to solve the heat transfer balance. Dependence of transfer function coefficients on the characteristic dimensions of cylindrical containers (diameter and height) and on the sampling interval is reported. A simple equation, with two empirical parameters that depends on the container dimensions, represented the behavior of transfer function coefficients with very high accuracy. Experimental runs with different size containers and different external conditions (constant and variable retort temperature) were carried out to validate the developed methodology. Performance of the thermal process simulation was tested for predicting internal product temperature of the cold point and lethality and very satisfactory results were found. The developed methodology can play an important role in reducing the computational effort while guaranteeing accuracy by simplifying the calculus involved in the solution of heat balances with variable external conditions and emerges as a potential approach to the implementation of new food control strategies leading not only to more efficient processes but also to product quality and safety.

  8. Modeling the Spatial Dynamics of International Tuna Fleets

    PubMed Central

    2016-01-01

    We developed an iterative sequential random utility model to investigate the social and environmental determinants of the spatiotemporal decision process of tuna purse-seine fishery fishing effort in the eastern Pacific Ocean. Operations of the fishing gear mark checkpoints in a continuous complex decision-making process. Individual fisher behavior is modeled by identifying diversified choices over decision-space for an entire fishing trip, which allows inclusion of prior and current vessel locations and conditions among the explanatory variables. Among these factors are vessel capacity; departure and arrival port; duration of the fishing trip; daily and cumulative distance travelled, which provides a proxy for operation costs; expected revenue; oceanographic conditions; and tons of fish on board. The model uses a two-step decision process to capture the probability of a vessel choosing a specific fishing region for the first set and the probability of switching to (or staying in) a specific region to fish before returning to its landing port. The model provides a means to anticipate the success of marine resource management, and it can be used to evaluate fleet diversity in fisher behavior, the impact of climate variability, and the stability and resilience of complex coupled human and natural systems. PMID:27537545

  9. Inshore capture-based tuna aquaculture impact on Posidonia oceanica meadows in the eastern part of the Adriatic Sea.

    PubMed

    Kružić, Petar; Vojvodić, Vjeročka; Bura-Nakić, Elvira

    2014-09-15

    Mapping and monitoring of the seagrass Posidonia oceanica in the eastern (Croatian) part of the Adriatic Sea since 2004 indicates a significant decline in meadow density in an area impacted by inshore capture-based tuna aquaculture. The density and overall condition of P. oceanica meadows impacted by tuna farms near Fulija Islet was compared to two reference sites (Iž Island and Mrtovnjak Islet). The factors with the most significant influence on P. oceanica meadows were found to be the input of organic matter originating from the cages, as well as high epiphyte biomass caused by nutrient enrichment. Significant differences in nutrient concentrations were found between the sites impacted by tuna farms (Fulija Islet) and the control stations. Shoot density of the P. oceanica meadows decreased at the stations in close vicinity to the tuna farm, which suggests that the tuna farm activity strongly affected the surrounding meadows. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Increased Throwing Accuracy Improves Children's Catching Performance in a Ball-Catching Task from the Movement Assessment Battery (MABC-2).

    PubMed

    Dirksen, Tim; De Lussanet, Marc H E; Zentgraf, Karen; Slupinski, Lena; Wagner, Heiko

    2016-01-01

    The Movement Assessment Battery for Children (MABC-2) is a functional test for identifying deficits in the motor performance of children. The test contains a ball-catching task that requires the children to catch a self-thrown ball with one hand. As the task can be executed with a variety of different catching strategies, it is assumed that the task success can also vary considerably. Even though it is not clear, whether the performance merely depends on the catching skills or also to some extent on the throwing skills, the MABC-2 takes into account only the movement outcome. Therefore, the purpose of the current study was to examine (1) to what extent the throwing accuracy has an effect on the children's catching performance and (2) to what extent the throwing accuracy influences their choice of catching strategy. In line with the test manual, the children's catching performance was quantified on basis of the number of correctly caught balls. The throwing accuracy and the catching strategy were quantified by applying a kinematic analysis on the ball's trajectory and the hand movements. Based on linear regression analyses, we then investigated the relation between throwing accuracy, catching performance and catching strategy. The results show that an increased throwing accuracy is significantly correlated with an increased catching performance. Moreover, a higher throwing accuracy is significantly correlated with a longer duration of the hand on the ball's parabola, which indicates that throwing the ball more accurately could enable the children to effectively reduce the requirements on temporal precision. As the children's catching performance and their choice of catching strategy in the ball-catching task of the MABC-2 are substantially determined by their throwing accuracy, the test evaluation should not be based on the movement outcome alone, but should also take into account the children's throwing performance. Our findings could be of particular value for the

  11. Increased Throwing Accuracy Improves Children's Catching Performance in a Ball-Catching Task from the Movement Assessment Battery (MABC-2)

    PubMed Central

    Dirksen, Tim; De Lussanet, Marc H. E.; Zentgraf, Karen; Slupinski, Lena; Wagner, Heiko

    2016-01-01

    The Movement Assessment Battery for Children (MABC-2) is a functional test for identifying deficits in the motor performance of children. The test contains a ball-catching task that requires the children to catch a self-thrown ball with one hand. As the task can be executed with a variety of different catching strategies, it is assumed that the task success can also vary considerably. Even though it is not clear, whether the performance merely depends on the catching skills or also to some extent on the throwing skills, the MABC-2 takes into account only the movement outcome. Therefore, the purpose of the current study was to examine (1) to what extent the throwing accuracy has an effect on the children's catching performance and (2) to what extent the throwing accuracy influences their choice of catching strategy. In line with the test manual, the children's catching performance was quantified on basis of the number of correctly caught balls. The throwing accuracy and the catching strategy were quantified by applying a kinematic analysis on the ball's trajectory and the hand movements. Based on linear regression analyses, we then investigated the relation between throwing accuracy, catching performance and catching strategy. The results show that an increased throwing accuracy is significantly correlated with an increased catching performance. Moreover, a higher throwing accuracy is significantly correlated with a longer duration of the hand on the ball's parabola, which indicates that throwing the ball more accurately could enable the children to effectively reduce the requirements on temporal precision. As the children's catching performance and their choice of catching strategy in the ball-catching task of the MABC-2 are substantially determined by their throwing accuracy, the test evaluation should not be based on the movement outcome alone, but should also take into account the children's throwing performance. Our findings could be of particular value for the

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

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

    SciTech Connect

    Ashraf, M.; Jaffar, M.

    1988-02-01

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

  14. US Food and Drug Administration survey of methyl mercury in canned tuna

    SciTech Connect

    Yess, J.

    1993-01-01

    Methyl mercury was determined by the US Food and Drug Administration (FDA) in 220 samples of canned tuna collected in 1991. Samples were chosen to represent different styles, colors, and packs as available. Emphasis was placed on water-packed tuna, small can size, and the highest-volume brand names. The average methyl mercury (expressed as Hg) found for the 220 samples was 0.17 ppm; the range was <0.10-0.75 ppm. Statistically, a significantly higher level of methyl mercury was found in solid white and chunk tuna. Methyl mercury level was not related to can size. None of the 220 samples had methyl mercury levels that exceeded the 1 ppm FDA action level. 11 refs., 1 tab.

  15. Validation of tsunami inundation model TUNA-RP using OAR-PMEL-135 benchmark problem set

    NASA Astrophysics Data System (ADS)

    Koh, H. L.; Teh, S. Y.; Tan, W. K.; Kh'ng, X. Y.

    2017-05-01

    A standard set of benchmark problems, known as OAR-PMEL-135, is developed by the US National Tsunami Hazard Mitigation Program for tsunami inundation model validation. Any tsunami inundation model must be tested for its accuracy and capability using this standard set of benchmark problems before it can be gainfully used for inundation simulation. The authors have previously developed an in-house tsunami inundation model known as TUNA-RP. This inundation model solves the two-dimensional nonlinear shallow water equations coupled with a wet-dry moving boundary algorithm. This paper presents the validation of TUNA-RP against the solutions provided in the OAR-PMEL-135 benchmark problem set. This benchmark validation testing shows that TUNA-RP can indeed perform inundation simulation with accuracy consistent with that in the tested benchmark problem set.

  16. Adaptive responses of tropical tuna purse-seiners under temporal regulations.

    PubMed

    Torres-Irineo, Edgar; Dreyfus-León, Michel; Gaertner, Daniel; Salas, Silvia; Marchal, Paul

    2017-02-01

    The failure to achieve fisheries management objectives has been broadly discussed in international meetings. Measuring the effects of fishery regulations is difficult due to the lack of detailed information. The yellowfin tuna fishery in the eastern Pacific Ocean offers an opportunity to evaluate the fishers' responses to temporal regulations. We used data from observers on-board Mexican purse-seine fleet, which is the main fleet fishing on dolphin-associated tuna schools. In 2002, the Inter-American Tropical Tuna Commission implemented a closed season to reduce fishing effort for this fishery. For the period 1992-2008, we analysed three fishery indicators using generalized estimating equations to evaluate the fishers' response to the closure. We found that purse-seiners decreased their time spent in port, increased their fishing sets, and maintained their proportion of successful fishing sets. Our results highlight the relevance of accounting for the fisher behaviour to understand fisheries dynamics when establishing management regulations.

  17. Trade-offs among catch, bycatch, and landed value in the American Samoa longline fishery.

    PubMed

    Watson, Jordan T; Bigelow, Keith A

    2014-08-01

    The interspecific preferences of fishes for different depths and habitats suggest fishers could avoid unwanted catches of some species while still effectively targeting other species. In pelagic longline fisheries, albacore (Thunnus alalunga) are often caught in relatively cooler, deeper water (>100 m) than many species of conservation concern (e.g., sea turtles, billfishes, and some sharks) that are caught in shallower water (<100 m). From 2007 to 2011, we examined the depth distributions of hooks for 1154 longline sets (3,406,946 hooks) and recorded captures by hook position on 2642 sets (7,829,498 hooks) in the American Samoa longline fishery. Twenty-three percent of hooks had a settled depth <100 m. Individuals captured in the 3 shallowest hook positions accounted for 18.3% of all bycatch. We analyzed hypothetical impacts for 25 of the most abundant species caught in the fishery by eliminating the 3 shallowest hook positions under scenarios with and without redistribution of these hooks to deeper depths. Distributions varied by species: 45.5% (n = 10) of green sea turtle (Chelonia mydas), 59.5% (n = 626) of shortbill spearfish (Tetrapturus angustirostris), 37.3% (n = 435) of silky shark (Carcharhinus falciformis), and 42.6% (n = 150) of oceanic whitetip shark (C. longimanus) were caught on the 3 shallowest hooks. Eleven percent (n = 20,435) of all tuna and 8.5% (n = 10,374) of albacore were caught on the 3 shallowest hooks. Hook elimination reduced landed value by 1.6-9.2%, and redistribution of hooks increased average annual landed value relative to the status quo by 5-11.7%. Based on these scenarios, redistribution of hooks to deeper depths may provide an economically feasible modification to longline gear that could substantially reduce bycatch for a suite of vulnerable species. Our results suggest that this method may be applicable to deep-set pelagic longline fisheries worldwide.

  18. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (North Atlantic). American Shad.

    DTIC Science & Technology

    1986-07-01

    overfishing . The 2865,49 2,092 Atlantic coast catches are greatest in 1929 13,95209 Chesapeake Bay (Table 7). 1930 10,373 Present Fishery 1931 11,336...rostrata), and birds. At sea, adult water teeperatures of 12 to 18 °C, or shad fall prey to seals, sharks, 54 to 64 OF (Leggett and Whitney bluefin ... tuna (Thunnus thynnus), 1972). Leim (1924) claimed that kingfish (Scomberomorus regalS), and American shad eggs hatch in 12 to 15 porpoises (Scott and

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  20. Performance variation due to stiffness in a tuna-inspired flexible foil model.

    PubMed

    Rosic, Mariel-Luisa N; Thornycroft, Patrick J M; Feilich, Kara L; Lucas, Kelsey N; Lauder, George V

    2017-01-17

    Tuna are fast, economical swimmers in part due to their stiff, high aspect ratio caudal fins and streamlined bodies. Previous studies using passive caudal fin models have suggested that while high aspect ratio tail shapes such as a tuna's generally perform well, tail performance cannot be determined from shape alone. In this study, we analyzed the swimming performance of tuna-tail-shaped hydrofoils of a wide range of stiffnesses, heave amplitudes, and frequencies to determine how stiffness and kinematics affect multiple swimming performance parameters for a single foil shape. We then compared the foil models' kinematics with published data from a live swimming tuna to determine how well the hydrofoil models could mimic fish kinematics. Foil kinematics over a wide range of motion programs generally showed a minimum lateral displacement at the narrowest part of the foil, and, immediately anterior to that, a local area of large lateral body displacement. These two kinematic patterns may enhance thrust in foils of intermediate stiffness. Stiffness and kinematics exhibited subtle interacting effects on hydrodynamic efficiency, with no one stiffness maximizing both thrust and efficiency. Foils of intermediate stiffnesses typically had the greatest coefficients of thrust at the highest heave amplitudes and frequencies. The comparison of foil kinematics with tuna kinematics showed that tuna motion is better approximated by a zero angle of attack foil motion program than by programs that do not incorporate pitch. These results indicate that open questions in biomechanics may be well served by foil models, given appropriate choice of model characteristics and control programs. Accurate replication of biological movements will require refinement of motion control programs and physical models, including the creation of models of variable stiffness.

  1. Effects of frozen storage on survival of Staphylococcus aureus and enterotoxin production in precooked tuna meat.

    PubMed

    Wu, Xulei; Su, Yi-Cheng

    2014-08-01

    This study investigated the survival of Staphylococcus aureus in precooked tuna meat for producing canned products during frozen storage (-20 ± 2 °C) as well as its growth and enterotoxin production at 35 to 37 °C after the storage. Samples (50 ± 5 g) of precooked albacore (loin, chunk, and flake) and skipjack (chunk and flake) tuna were inoculated with 5 enterotoxin-producing strains of S. aureus at a level of approximately 3.5 log CFU/g and individually packed in a vacuum bag after 3 h incubation at 35 to 37 °C. Vacuum-packed samples were stored in a freezer (-20 ± 2 °C) for 4 wk. The frozen samples were then thawed in 37 °C circulating water for 2 h and incubated at 35 to 37 °C for 22 h. Populations of S. aureus in all precooked tuna samples decreased slightly (<0.7 log CFU/g) after 4 wk of storage at -20 ± 2 °C, but increased rapidly once the samples were thawed and held at 35 to 37 °C. Total S. aureus counts in albacore and skipjack samples increased by greater than 3 log CFU/g after 6 and 8 h of exposure to 35 to 37 °C, respectively. All samples became spoiled after 10 h of exposure to 35 to 37 °C, while no enterotoxin was detected in any samples. However, enterotoxins were detected in albacore loin and other samples after 12 and 24 h of incubation at 35 to 37 °C, respectively. Frozen precooked tuna meat should be used for producing canned tuna within 6 to 8 h of thawing to avoid product spoilage and potential enterotoxin production by S. aureus in contaminated precooked tuna meat.

  2. U.S. Tuna Fisheries: a trifecta of sustainable practices at odds with climate change mitigation

    NASA Astrophysics Data System (ADS)

    McKuin, B.; Campbell, J. E.

    2016-12-01

    Environmental concerns have given rise to eco-label initiatives in the seafood industry and a shift to more sustainable fishing practices in the U.S. Currently, the greenhouse gas emissions of fisheries are being considered in the sustainability criteria of the consumer advocacy group Seafood Watch. We looked at sustainable practices employed by U.S. tuna fisheries and find the term "sustainably sourced" changes when climate forcing is added to the criteria. Specifically, there are three sustainable practices at odds with climate change mitigation: 1) the use of selective fishing gear reduces bycatch but increases fuel use; 2) fishing within exclusive economic zones is more equitable to coastal fishermen, and allows the high seas to serve as an ecological bank, but fishing within these regions means fisheries are subject to more stringent fuel sulfur laws thereby diminishing the cooling effects of sulfate aerosols and increasing climate forcing; and 3) removing sulfur from fuels improves air quality but there are added emissions from the refinery process. We used ship registry data, historical sulfur levels in fuels, gear-specific fishery fuel use data collected from the literature, historical gear-specific tuna landings data, and a range of global warming potentials to estimate the climate forcing of U.S. tuna fisheries over the last fifteen years. We found that for tuna caught within exclusive economic zones, the net fuel-related climate forcing has more than doubled over the last fifteen years. We also normalized the fuel-related climate forcing results to a unit of tuna protein and compared these results to other farmed sources of protein. We found that tuna caught within exclusive economic zones has the highest climate impact of all land-based protein sources considered, with the exception of beef. Our results can inform policy makers and consumer advocacy groups which is an important step in communicating the climate impact of dietary choices to consumers.

  3. 50 CFR 665.211 - Total Allowable Catch (TAC) limit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Total Allowable Catch (TAC) limit. 665.211... Fisheries § 665.211 Total Allowable Catch (TAC) limit. (a) TAC limits will be set annually for the fishing... Administrator shall publish a notice indicating the annual TAC limit in the Federal Register by August 31...

  4. Project Catch-Up. Analysis and Selection Kit.

    ERIC Educational Resources Information Center

    Newport-Mesa Unified School District, Newport Beach, CA.

    Project Catch-Up is an ESEA Title I reading and math laboratory project for kindergarten through sixth-grade students, operating in Southern California's Newport-Mesa Unified School District. Its philosophy is that students having difficulty in reading and math can catch up with other students. Teachers take responsibility for the achievement…

  5. School climate and the institutionalization of the CATCH program.

    PubMed

    Parcel, Guy S; Perry, Cheryl L; Kelder, Steven H; Elder, John P; Mitchell, Paul D; Lytle, Leslie A; Johnson, Carolyn C; Stone, Elaine J

    2003-08-01

    School climate refers to various physical and psychosocial structures that shape schools' social and physical environments. The Child and Adolescent Trial for Cardiovascular Health (CATCH) study provided an opportunity to study how aspects of school climate are associated with continued implementation of the CATCH program. Nutrient analysis of menus, observations of physical education (PE) classes, and teacher and staff self-reports were used to measure CATCH program components. Results of this study indicate that aspects of school climate were associated with continued implementation of the CATCH classroom component but not the CATCH food service or PE components. These findings have implications for how we plan for the progression of innovative school health promotion programs from the initial trial stage to institutionalization. Measures of school climate may be useful in determining a school's readiness to adopt and implement an innovative health promotion curriculum.

  6. Nutritionally-Induced Catch-Up Growth

    PubMed Central

    Gat-Yablonski, Galia; Phillip, Moshe

    2015-01-01

    Malnutrition is considered a leading cause of growth attenuation in children. When food is replenished, spontaneous catch-up (CU) growth usually occurs, bringing the child back to its original growth trajectory. However, in some cases, the CU growth is not complete, leading to a permanent growth deficit. This review summarizes our current knowledge regarding the mechanism regulating nutrition and growth, including systemic factors, such as insulin, growth hormone, insulin- like growth factor-1, vitamin D, fibroblast growth factor-21, etc., and local mechanisms, including autophagy, as well as regulators of transcription, protein synthesis, miRNAs and epigenetics. Studying the molecular mechanisms regulating CU growth may lead to the establishment of better nutritional and therapeutic regimens for more effective CU growth in children with malnutrition and growth abnormalities. It will be fascinating to follow this research in the coming years and to translate the knowledge gained to clinical benefit. PMID:25594438

  7. NC CATCH: Advancing Public Health Analytics.

    PubMed

    Studnicki, James; Fisher, John W; Eichelberger, Christopher; Bridger, Colleen; Angelon-Gaetz, Kim; Nelson, Debi

    2010-01-01

    The North Carolina Comprehensive Assessment for Tracking Community Health (NC CATCH) is a Web-based analytical system deployed to local public health units and their community partners. The system has the following characteristics: flexible, powerful online analytic processing (OLAP) interface; multiple sources of multidimensional, event-level data fully conformed to common definitions in a data warehouse structure; enabled utilization of available decision support software tools; analytic capabilities distributed and optimized locally with centralized technical infrastructure; two levels of access differentiated by the user (anonymous versus registered) and by the analytical flexibility (Community Profile versus Design Phase); and, an emphasis on user training and feedback. The ability of local public health units to engage in outcomes-based performance measurement will be influenced by continuing access to event-level data, developments in evidence-based practice for improving population health, and the application of information technology-based analytic tools and methods.

  8. Visual factors in hitting and catching.

    PubMed

    Regan, D

    1997-12-01

    To hit or catch an approaching ball, it is necessary to move a bat or hand to the right place at the right time. The performance of top sports players is remarkable: positional errors of less than 5 cm and temporal errors of less than 2 or 3 ms are reliably maintained. There are three schools of thought about how this is achieved. One holds that predictive visual information about where the ball will be at some future instance (when) is used to achieve the hit or catch. The second holds that the bat or hand is moved to the correct position by exploiting some relation between visual information and the required movement. The third focuses on the use of prior knowledge to supplement inadequate visual information. For a rigid spherical ball travelling at constant speed along or close to the line of sight, the retinal images contain both binocular and monocular correlates of the ball's instantaneous direction of motion in depth. Also, the retinal images contain both binocular and monocular information about time of arrival. Humans can unconfound and use this visual information, but they are unable to estimate the absolute distance of the ball or its approach speed other than crudely. In cricket, this visual inadequacy allows a slow bowler to cause the batsman to misjudge where the ball will hit the ground. Such a bowler uses a three-pronged strategy: first, to deliver the ball in such a way as to prevent the batsman from obtaining the necessary visual information until it is too late to react; secondly, to force the batsman to rely entirely on inadequate retinal image information; thirdly, to allow the batsman to learn a particular relationship between the early part of the ball's flight and the point where the ball hits the ground, and then to change the relationship with such skill that the batsman does not detect the change.

  9. Fish and robot dancing together: bluefin killifish females respond differently to the courtship of a robot with varying color morphs.

    PubMed

    Phamduy, P; Polverino, G; Fuller, R C; Porfiri, M

    2014-09-01

    The experimental integration of bioinspired robots in groups of social animals has become a valuable tool to understand the basis of social behavior and uncover the fundamental determinants of animal communication. In this study, we measured the preference of fertile female bluefin killifish (Lucania goodei) for robotic replicas whose aspect ratio, body size, motion pattern, and color morph were inspired by adult male killifish. The motion of the fish replica was controlled via a robotic platform, which simulated the typical courtship behavior observed in killifish males. The positional preferences of females were measured for three different color morphs (red, yellow, and blue). While variation in preference was high among females, females tend to spend more time in the vicinity of the yellow painted robot replicas. This preference may have emerged because the yellow robot replicas were very bright, particularly in the longer wavelengths (550–700 nm) compared to the red and blue replicas. These findings are in agreement with previous observations in mosquitofish and zebrafish on fish preference for artificially enhanced yellow pigmentation.

  10. Relationship of hand length to catching performance by children in kindergarten to grade 2.

    PubMed

    Loovis, E Michael; Butterfield, Stephen A

    2003-06-01

    This study examined the relationship between hand length and catching performance by 257 children (142 boys, 115 girls) in Grades K-2. Children's catching performance was determined by the number of successful catches (0-5) when a small ball was tossed underhand from 10 ft. Specifically, the children were tested on the qualitative aspects of catching, i.e., form, and catching accuracy, i.e., successful catching. Hand length was measured by standard anthropometric technique. A multiple regression analysis showed age, sex, and hand length contributed significantly (p = .001) to catching accuracy and catching form. Implications for instruction and further research are offered.

  11. Trophic position increases with thermocline depth in yellowfin and bigeye tuna across the Western and Central Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Houssard, Patrick; Lorrain, Anne; Tremblay-Boyer, Laura; Allain, Valérie; Graham, Brittany S.; Menkes, Christophe E.; Pethybridge, Heidi; Couturier, Lydie I. E.; Point, David; Leroy, Bruno; Receveur, Aurore; Hunt, Brian P. V.; Vourey, Elodie; Bonnet, Sophie; Rodier, Martine; Raimbault, Patrick; Feunteun, Eric; Kuhnert, Petra M.; Munaron, Jean-Marie; Lebreton, Benoit; Otake, Tsuguo; Letourneur, Yves

    2017-05-01

    Estimates of trophic position are used to validate ecosystem models and understand food web structure. A consumer's trophic position can be estimated by the stable nitrogen isotope values (δ15N) of its tissue, once the baseline isotopic variability has been accounted for. Our study established the first data-driven baseline δ15N isoscape for the Western and Central Pacific Ocean using particulate organic matter. Bulk δ15N analysis on 1039 muscle tissue of bigeye and yellowfin tuna were conducted together with amino acid compound-specific δ15N analysis (AA-CSIA) on a subset of 21 samples. Both particulate organic matter and tuna bulk δ15N values varied by more than 10‰ across the study area. Fine-scaled trophic position maps were constructed and revealed higher tuna trophic position (by ∼1) in the southern latitudes compared to the equator. AA-CSIA confirmed these spatial patterns for bigeye and, to a lesser extent, yellowfin tuna. Using generalized additive models, spatial variations of tuna trophic positions were mainly related to the depth of the 20°C isotherm, a proxy for the thermocline behavior, with higher tuna trophic position estimates at greater thermocline depths. We hypothesized that a deeper thermocline would increase tuna vertical habitat and access to mesopelagic prey of higher trophic position. Archival tagging data further suggested that the vertical habitat of bigeye tuna was deeper in the southern latitudes than at the equator. These results suggest the importance of thermocline depth in influencing tropical tuna diet, which affects their vulnerability to fisheries, and may be altered by climate change.

  12. Reconciling catch differences from multiple fishery independent gill net surveys

    USGS Publications Warehouse

    Kraus, Richard T.; Vandergoot, Christopher; Kocovsky, Patrick M.; Rogers, Mark W.; Cook, H. Andrew; Brenden, Travis O.

    2017-01-01

    Fishery independent gill net surveys provide valuable demographic information for population assessment and resource management, but relative to net construction, the effects of ancillary species, and environmental variables on focal species catch rates are poorly understood. In response, we conducted comparative deployments with three unique, inter-agency, survey gill nets used to assess walleye Sander vitreus in Lake Erie. We used an information-theoretic approach with Akaike’s second-order information criterion (AICc) to evaluate linear mixed models of walleye catch as a function of net type (multifilament and two types of monofilament netting), mesh size (categorical), Secchi depth, temperature, water depth, catch of ancillary species, and interactions among selected variables. The model with the greatest weight of evidence showed that walleye catches were positively associated with potential prey and intra-guild predators and negatively associated with water depth and temperature. In addition, the multifilament net had higher average walleye catches than either of the two monofilament nets. Results from this study both help inform decisions about proposed gear changes to stock assessment surveys in Lake Erie, and advance our understanding of how multispecies associations explain variation in gill net catches. Of broader interest to fishery-independent gill net studies, effects of abiotic variables and ancillary species on focal specie’s catch rates were small in comparison with net characteristics of mesh size or twine type.

  13. Gender Transformations and Colonial Displacements in Laura Antillano's "Tuna de mar"

    ERIC Educational Resources Information Center

    Reid, Alana

    2015-01-01

    This paper examines the trajectories of two characters in Laura Antillano's short story, "Tuna de mar" (1991), as they navigate interrelated systems of power and attempt to position themselves closer to, or further away from, the margins. Set in the late eighteenth century, the tale features a female protagonist who escapes prostitution…

  14. Tomato and tuna: a test for language-free assessment of action understanding.

    PubMed

    Danek, Amory H; Gade, Miriam; Lunardelli, Alberta; Rumiati, Raffaella I

    2013-12-01

    We introduce a novel test that allows pictorial, nonverbal assessment of action understanding. Focusing on action goals and the sequential nature of actions, the "Tomato and Tuna Test" tests whether exposure to the accomplished goal of an action is sufficient to infer the preceding action. This aspect has rarely been addressed in conventional paradigms. We used the Tomato and Tuna Test in conjunction with another task, the Kissing and Dancing Test, to detect action understanding deficits in 11 patients (mean age 72 ± 6 years) with chronic brain lesions ± aphasia. We compared their performance to an age- and education-matched control group and to 15 young controls (mean age 24 ± 3 years). To investigate the influence of language deficits on test performance, we compared the scores of our patients with and without aphasia. Our patients were less accurate than the matched controls on the Tomato and Tuna Test, though not slower. The Kissing and Dancing Test did not differentiate between patients and matched controls. Young controls performed better than patients on both tests. We found no performance differences between our aphasic and nonaphasic patients, confirming our assumption that both tests measure action understanding without requiring intact language abilities. We recommend the "Tomato and Tuna Test" as a new nonverbal measure of action understanding that can reveal subtle deficits.

  15. Probing local thermal stabilities of bovine, horse, and tuna ferricytochromes c at pH 7.

    PubMed

    Filosa, A; English, A M

    2000-08-01

    Correlation between the flexibility of the Met80 loop (residues 75-86) and the local stabilities of native ferricytochromes c from horse, bovine, and tuna was examined. By monitoring the heme bands versus temperature, absorption changes associated with altered ligation in the alkaline isomers were observed. In addition, the intensity of the 695-nm absorption band, which is associated with the heme-crevice stability, decreased with increasing temperature and exhibited biphasic temperature dependence, with transition temperatures (Tc) at 35 degrees C in tuna c, 55 degrees C in horse c, and 58 C in bovine c. Since the heme crevice plays a key role in the thermal stabilities of cytochromes c, their susceptibility to proteolytic attack was examined as a function of temperature. Proteolytic digestion, which requires local conformational instability, revealed that the local stabilities of the cytochromes follow the order: bovine > horse > tuna, and increased digestion occurred at temperatures close to the 695-nm Tc for each protein. This is consistent with the actual substitution of the Met80 ligand above the 695-nm Tc, which is reflected in the thermodynamic parameters for the two phases. Also, tuna c, unlike horse and bovine c, exhibits different 695-nm (35 degrees C) and Soret (approximately 46 degrees C) Tc values, but its local stability is controlled by the transition detected at 695 nm. The combined spectroscopic and proteolysis results clearly indicate that the flexibility of the Met80 loop determines the local stability of cytochromes c.

  16. Determination of histamine in canned tuna by molecularly imprinted polymers-surface enhanced Raman spectroscopy.

    PubMed

    Gao, Fang; Grant, Edward; Lu, Xiaonan

    2015-12-11

    We introduce a rapid, cost effective and reliable approach to determine histamine level in canned tuna. Molecularly imprinted polymers (MIPs) were synthesized as artificial antibodies towards histamine by utilizing the interaction between histamine and a functional monomer (methacrylic acid) to impress specific binding sites on polymer particles after polymerization. Polyvinyl chloride (PVC) was used to immobilize the MIPs, yielding a MIPs-PVC film that functioned as a recognition element to specifically separate histamine from tuna extract. A gold colloid solution served both as an eluting solvent to extract histamine from MIPs-PVC film and furnish a substrate for surface enhanced Raman spectroscopy (SERS) detection of histamine signals. Principal component analysis together with a partial least square regression (PLSR) model (R(2) = 0.947, RMSECV = 3.526) verified the reliability of MIPs-PVC-SERS approach for the detection and spectral analysis of histamine. Linear regression models were also constructed to relate the intensity of different histamine SERS bands with the corresponding spiking levels. One such model (using a band at 1576 cm(-1)) performed slightly better in predicting histamine content in tuna than the PLSR model. We conclude that our new MIPs-PVC-SERS approach can rapidly and reliably determine histamine at levels from 3 to 90 ppm in canned tuna meat.

  17. Examining dolphin hydrodynamics provides clues to calf-loss during tuna fishing

    PubMed Central

    Moore, Pete

    2004-01-01

    A combination of mathematical modeling and direct observation of the swimming behavior of dolphin mother-calf pairs has shown how the calf can gain much of the energy required for swimming if it is positioned correctly relative to the mother, a situation that may be disrupted during the chases that result from tuna-fishing practices. PMID:15132739

  18. Reproductive biology of yellowfin tuna T. albacares in the west-central Indian Ocean

    NASA Astrophysics Data System (ADS)

    Zhu, Guoping; Xu, Liuxiong; Zhou, Yingqi; Song, Liming

    2008-08-01

    Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese longliners during 2003, 2004 and 2005, which is a part of Chinese Tuna Fishery Scientific Observer Program (CTFSOP). The reproductive biology has been investigated. A total of 1 023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59, and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is estimated at 113.77 cm for female and 120.20 cm for male, whereas maturation rate is 0.066 cm-1 for female and 0.091 cm-1 for male. Sex ratio by length class indicates that the proportion of male is higher than female’s along with size increasing; for instance, in the group of the body length longer than 145 cm, some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically, yellowfin tuna has a significant seasonal reproduction.

  19. 78 FR 2273 - Canned Tuna Deviating From Identity Standard; Temporary Permit for Market Testing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-10

    ... HUMAN SERVICES Food and Drug Administration Canned Tuna Deviating From Identity Standard; Temporary Permit for Market Testing AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food... Sea International (the applicant). We are announcing that we have issued a temporary permit to...

  20. 40 CFR 408.140 - Applicability; description of the tuna processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the tuna processing subcategory. 408.140 Section 408.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY...

  1. 40 CFR 408.140 - Applicability; description of the tuna processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the tuna processing subcategory. 408.140 Section 408.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY...

  2. 40 CFR 408.140 - Applicability; description of the tuna processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the tuna processing subcategory. 408.140 Section 408.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY...

  3. 40 CFR 408.140 - Applicability; description of the tuna processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the tuna processing subcategory. 408.140 Section 408.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY...

  4. 40 CFR 408.140 - Applicability; description of the tuna processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the tuna processing subcategory. 408.140 Section 408.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY...

  5. 76 FR 74747 - Western and Central Pacific Fisheries for Highly Migratory Species; 2011 Bigeye Tuna Longline...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... Fisheries for Highly Migratory Species; 2011 Bigeye Tuna Longline Fishery Closure AGENCY: National Marine... through arrangements with U.S. vessels with permits issued under the Fishery Management (now ``Ecosystem.... Risenhoover, Director, Office of Sustainable Fisheries, National Marine Fisheries Service. BILLING CODE 3510...

  6. Gender Transformations and Colonial Displacements in Laura Antillano's "Tuna de mar"

    ERIC Educational Resources Information Center

    Reid, Alana

    2015-01-01

    This paper examines the trajectories of two characters in Laura Antillano's short story, "Tuna de mar" (1991), as they navigate interrelated systems of power and attempt to position themselves closer to, or further away from, the margins. Set in the late eighteenth century, the tale features a female protagonist who escapes prostitution…

  7. Genomic Differentiation and Demographic Histories of Atlantic and Indo-Pacific Yellowfin Tuna (Thunnus albacares) Populations

    PubMed Central

    Damerau, Malte; Matschiner, Michael; Jentoft, Sissel

    2017-01-01

    Recent developments in the field of genomics have provided new and powerful insights into population structure and dynamics that are essential for the conservation of biological diversity. As a commercially highly valuable species, the yellowfin tuna (Thunnus albacares) is intensely exploited throughout its distribution in tropical oceans around the world, and is currently classified as near threatened. However, conservation efforts for this species have so far been hampered by limited knowledge of its population structure, due to incongruent results of previous investigations. Here, we use whole-genome sequencing in concert with a draft genome assembly to decipher the global population structure of the yellowfin tuna, and to investigate its demographic history. We detect significant differentiation of Atlantic and Indo-Pacific yellowfin tuna populations as well as the possibility of a third diverged yellowfin tuna group in the Arabian Sea. We further observe evidence for past population expansion as well as asymmetric gene flow from the Indo-Pacific to the Atlantic. PMID:28419285

  8. Formation of biogenic amine in mayonnaise, herring and tuna fish salad by lactobacilli.

    PubMed

    Leuschner, R G; Hammes, W P

    1999-05-01

    The effect of amino acid decarboxylase-positive lactobacilli in mayonnaise, herring and tuna fish salads on formation of biogenic amines (BA) was investigated. Commercial mayonnaise was inoculated with either of five amine-forming lactobacilli which were selected as model contaminants: Lactobacillus curvatus LTH 975 and LTH 1859 (cadaverine, putrescine, tyramine and phenylethylamine producing), L. delbrueckii LTH 1260 (tyramine and phenylethylamine forming) and L. buchneri LTH 1388 and LTH 661 (histamine forming). Low concentrations of tyramine (4.5 ppm) were detected and an addition of precursor amino acids resulted in an increase of amine concentrations to 40 ppm putrescine, 16.5 ppm tyramine and 5.5 ppm cadaverine. Herring and tuna fish salads were inoculated either with L. curvatus LTH 975 or L. Buchneri LTH 1388. In tuna fish salad 1 ppm putrescine, 3 ppm cadaverine, 7 ppm histamine and 28 ppm tyramine were found after 4 days when L. curvatus was added. In the corresponding herring salad putrescine (14 ppm), cadaverine (11.5 ppm), histamine (17 ppm) and tyramine (72 ppm) were detected. Fish salads containing L. buchneri displayed histamine concentrations of 900 ppm in tuna and 670 ppm in herring salad, respectively. Eight lactic acid bacteria and five yeasts, isolates from spoiled delicatessen salads and ingredients, were not able to form putrescine, cadaverine, histamine, tyramine or phenylethylamine.

  9. 50 CFR 635.24 - Commercial retention limits for sharks, swordfish, and BAYS tunas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... storage of silky sharks, oceanic whitetip sharks, and scalloped, smooth, and great hammerhead sharks is... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Commercial retention limits for sharks... Management Measures § 635.24 Commercial retention limits for sharks, swordfish, and BAYS tunas. The...

  10. 50 CFR 635.24 - Commercial retention limits for sharks, swordfish, and BAYS tunas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... storage of silky sharks, oceanic whitetip sharks, and scalloped, smooth, and great hammerhead sharks is... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Commercial retention limits for sharks... Management Measures § 635.24 Commercial retention limits for sharks, swordfish, and BAYS tunas. The...

  11. Consumers' preferences toward techniques for improving manual catching of poultry.

    PubMed

    Delezie, E; Verbeke, W; De Tavernier, J; Decuypere, E

    2006-11-01

    Growing interest in ameliorating animal welfare has prompted numerous studies that compare various aspects of manual and mechanical catching. In general, mechanical catching has been adopted as a realistic alternative for manual catching. The success of a catching machine as an alternative for manual catching does not only depend on its practical applicability, but also on its acceptance by "the general public." In the history of technological change, public perception of new technologies has often been ambivalent. Against this background, it is important to know how consumers perceive the production methods. This paper provides an evaluation of the preferences for catching methods by "society" to investigate whether there is a shift in preference due to the confrontation with video segments and the potential effect of awareness and importance attached to animal welfare on preference. Data were gathered through a questionnaire-based survey, including 450 respondents, performed in Belgium. For this study, the data indicated that when subjects were provided information concerning catching methods of broilers, they liked the technology much more. However, for those respondents without prior awareness of both catching methods or with high importance attached to animal welfare, giving information could not convince them of the advantage of using a mechanical catching machine. It is obvious that preference varies with the awareness and experience of the respondents. Future research should move forward from simple assessments of consumer concerns about the technologies and focus more directly on questions and issues related to the consumer's expected bottlenecks of these technologies. In this way, working at a better understanding can directly influence the acceptance of these technologies.

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

    PubMed

    Drevnick, Paul E; Brooks, Barbara A

    2017-05-01

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

  13. One-step triplex-polymerase chain reaction assay for the authentication of yellowfin (Thunnus albacares), bigeye (Thunnus obesus), and skipjack (Katsuwonus pelamis) tuna DNA from fresh, frozen, and canned tuna samples.

    PubMed

    Michelini, Elisa; Cevenini, Luca; Mezzanotte, Laura; Simoni, Patrizia; Baraldini, Mario; De Laude, Luca; Roda, Aldo

    2007-09-19

    A one-step triplex-polymerase chain reaction (PCR)-based assay was developed to discriminate between three tuna species, Thunnus albacares, Thunnus obesus, and Katsuwonus pelamis, even in highly processed food samples such as canned or cooked tuna. Diagnostic nucleotides were identified by direct sequencing and alignment of part of the mitochondrial cytochrome b gene of 30 authenticated exemplars, which allowed us to evaluate intraspecific variation and the genetic distance between three tuna species. The assay relies on a one-step triplex-PCR reaction in which in a single tube species-specific amplification products are generated only in the presence of the correct template nucleic acid and the species of origin of the DNA is indicated by the distinctive size of the PCR product. The identification of tuna species can be performed with a good accuracy, low cost, and with potential automation for large-scale high-throughput screenings in small in-house laboratories.

  14. Catch-up Growth: Cellular and Molecular Mechanisms

    PubMed Central

    Finkielstain, GP; Lui, JC; Baron, J

    2012-01-01

    In mammals, after a period of growth inhibition, body growth often does not just return to a normal rate but actually exceeds the normal rate, resulting in catch-up growth. Recent evidence suggests that catch-up growth occurs because growth-inhibiting conditions delay progression of the physiological mechanisms that normally cause body growth to slow and cease with age. As a result, following the period of growth inhibition, tissues retain a greater proliferative capacity than normal, and therefore grow more rapidly than normal for age. There is evidence that this mechanism contributes both to catch-up growth in terms of body length, which involves proliferation in the growth plate, and to catch-up growth in terms of organ mass, which involves proliferation in multiple non-skeletal tissues. PMID:23428687

  15. 1. VIEW EAST, COMPONENTS TEST LABORATORY SHOWING CATCH BASINS, TURBINE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW EAST, COMPONENTS TEST LABORATORY SHOWING CATCH BASINS, TURBINE TESTING AREA, AND PUMP TESTING TOWER. - Marshall Space Flight Center, East Test Area, Components Test Laboratory, Huntsville, Madison County, AL

  16. 76 FR 71469 - Western and Central Pacific Fisheries for Highly Migratory Species; 2011 Bigeye Tuna Longline...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ... in the western and central Pacific Ocean as a result of the fishery reaching the 2011 catch limit... in the western and central Pacific Ocean is managed, in part, under the Western and Central Pacific... Western and Central Pacific Ocean (Convention Area). NMFS monitored the retained catches of bigeye...

  17. Oligonucleotide indexing of DNA barcodes: identification of tuna and other scombrid species in food products

    PubMed Central

    2010-01-01

    Background DNA barcodes are a global standard for species identification and have countless applications in the medical, forensic and alimentary fields, but few barcoding methods work efficiently in samples in which DNA is degraded, e.g. foods and archival specimens. This limits the choice of target regions harbouring a sufficient number of diagnostic polymorphisms. The method described here uses existing PCR and sequencing methodologies to detect mitochondrial DNA polymorphisms in complex matrices such as foods. The reported application allowed the discrimination among 17 fish species of the Scombridae family with high commercial interest such as mackerels, bonitos and tunas which are often present in processed seafood. The approach can be easily upgraded with the release of new genetic diversity information to increase the range of detected species. Results Cocktail of primers are designed for PCR using publicly available sequences of the target sequence. They are composed of a fixed 5' region and of variable 3' cocktail portions that allow amplification of any member of a group of species of interest. The population of short amplicons is directly sequenced and indexed using primers containing a longer 5' region and the non polymorphic portion of the cocktail portion. A 226 bp region of CytB was selected as target after collection and screening of 148 online sequences; 85 SNPs were found, of which 75 were present in at least two sequences. Primers were also designed for two shorter sub-fragments that could be amplified from highly degraded samples. The test was used on 103 samples of seafood (canned tuna and scomber, tuna salad, tuna sauce) and could successfully detect the presence of different or additional species that were not identified on the labelling of canned tuna, tuna salad and sauce samples. Conclusions The described method is largely independent of the degree of degradation of DNA source and can thus be applied to processed seafood. Moreover, the

  18. Heat resistance of histamine-producing bacteria in irradiated tuna loins.

    PubMed

    Enache, Elena; Kataoka, Ai; Black, D Glenn; Weddig, Lisa; Hayman, Melinda; Bjornsdottir-Butler, Kristin

    2013-09-01

    Consumption of foods high in biogenic amines leads to an illness known as histamine, or scombrotoxin, poisoning. The illness is commonly associated with consumption of fish with high levels of histamine ( $ 500 ppm). The objective of this study was to determine and compare the heat resistance of five histamine-producing bacteria in irradiated albacore tuna loins. Heat-resistance parameters (D- and z-values) were determined for Morganella morganii, Raoultella planticola, Hafnia alvei, and Enterobacter aerogenes. D- or z-values were not determined for Photobacterium damselae, which was the most heat-sensitive organism in this study. P. damselae declined > 5.9 log CFU/g after a heat treatment of 50°C for 10 min, 54°C for 3 min, and 56°C for 0.5 min. M. morganii was the most heat-resistant histamine-producing bacteria in albacore tuna loins, followed by E. aerogenes, H. alvei, and R. planticola. M. morganii and E. aerogenes had the highest D(50°C), 49.7 ± 17.57 and 51.8 ± 17.38 min, respectively. In addition, M. morganii had the highest D-values for all other temperatures (54, 56, and 58°C) tested. D- and zvalues were also determined for M. morganii in skipjack tuna. While no significant (P > 0.05) difference was observed between D(54°C) and D(56°C) of M. morganii in either albacore or skipjack tuna, the D(58°C) (0.4 ± 0.17 min) was significantly lower (P < 0.05) in skipjack than in albacore (0.9 ± 0.24 min). The z-values for all organisms tested were in the range of 3.2 to 3.8°C. This study suggests that heat treatment designed to control M. morganii in tuna loins is sufficient for controlling histamine-producing bacteria in canned-tuna processing environments.

  19. Mitigating by-catch of diamondback terrapins in crab pots

    USGS Publications Warehouse

    Hart, Kristen M.; Crowder, Larry B.

    2011-01-01

    Chronic by-catch of diamondback terrapins (Malaclemys terrapin) in blue crab (Callinectes sapidus) pots is a concern for terrapin conservation along the United States Atlantic and Gulf of Mexico coasts. Despite the availability of by-catch reduction devices (BRDs) for crab pots, adoption of BRDs has not been mandated and by-catch of terrapins continues. We conducted experimental fishing studies in North Carolina's year-round blue crab fishery from 2000 to 2004 to evaluate the ability of various BRDs to reduce terrapin by-catch without a concomitant reduction in the catch of blue crabs. In 4,822 crab pot days fished, we recorded only 21 terrapin captures. Estimated capture rates were 0.003 terrapins/pot per day in hard crab experimental fishing and 0.008 terrapins/pot per day in peeler experimental fishing. All terrapin captures occurred from April to mid-May within 321.4 m of the shoreline. Longer soak times produced more dead terrapins, with 4 live and 4 dead during hard crab experimental fishing and 11 live and 2 dead during peeler experimental fishing. The 4.0-cm BRDs in fall and 4.5-cm and 5.0-cm BRDs in spring reduced the catch of legal-sized male hard crabs by 26.6%, 21.2%, and 5.7%, respectively. Only the 5.0-cm BRDs did not significantly affect the catch of legal-sized hard male crabs. However, BRDs had no measurable effect on catch of target crabs in the peeler crab fishery. Our results identify 3 complementary and economically feasible tools for blue crab fishery managers to exclude terrapins from commercially fished crab pots in North Carolina: 1) gear modifications (e.g., BRDs); 2) distance-to-shore restrictions; and 3) time-of-year regulations. These measures combined could provide a reduction in terrapin by-catch of up to 95% without a significant reduction in target crab catch.

  20. Ecological indicators display reduced variation in North American catch share fisheries.

    PubMed

    Essington, Timothy E

    2010-01-12

    A growing push to implement catch share fishery programs is based partly on the recognition that they may provide stronger incentives for ecological stewardship than conventional fisheries management. Using data on population status, quota compliance, discard rates, use of habitat-damaging gear, and landings for 15 catch share programs in North America, I tested the hypothesis that catch share systems lead to improved ecological stewardship and status of exploited populations. Impacts of catch share programs were measured through comparisons of fisheries with catch shares to fisheries without catch shares or by comparing fisheries before and after catch shares were implemented. The average levels of most indicators were unaffected by catch share implementation: only discard rate, which declined significantly in catch share fisheries, showed a significant response. However, catch share fisheries were distinguished by markedly reduced interannual variability in all indicators, being statistically significant for exploitation rate, landings, discard rate, and the ratio of catch to catch quotas. These impacts of catch shares were common between nations and ocean basins and were independent of the number of years that catch share programs had been in place. These findings suggest that for the indicators examined, the primary effect of catch shares was greater consistency over time. This enhanced consistency could be beneficial to fishery systems and might also be an indication of more effective management.

  1. Ecological indicators display reduced variation in North American catch share fisheries

    PubMed Central

    Essington, Timothy E.

    2009-01-01

    A growing push to implement catch share fishery programs is based partly on the recognition that they may provide stronger incentives for ecological stewardship than conventional fisheries management. Using data on population status, quota compliance, discard rates, use of habitat-damaging gear, and landings for 15 catch share programs in North America, I tested the hypothesis that catch share systems lead to improved ecological stewardship and status of exploited populations. Impacts of catch share programs were measured through comparisons of fisheries with catch shares to fisheries without catch shares or by comparing fisheries before and after catch shares were implemented. The average levels of most indicators were unaffected by catch share implementation: only discard rate, which declined significantly in catch share fisheries, showed a significant response. However, catch share fisheries were distinguished by markedly reduced interannual variability in all indicators, being statistically significant for exploitation rate, landings, discard rate, and the ratio of catch to catch quotas. These impacts of catch shares were common between nations and ocean basins and were independent of the number of years that catch share programs had been in place. These findings suggest that for the indicators examined, the primary effect of catch shares was greater consistency over time. This enhanced consistency could be beneficial to fishery systems and might also be an indication of more effective management. PMID:20080747

  2. Effects of on-board and dockside handling on the formation of biogenic amines in mahimahi (Coryphaena hippurus), skipjack tuna (Katsuwonus pelamis), and yellowfin tuna (Thunnus albacares).

    PubMed

    Staruszkiewicz, Walter F; Barnett, James D; Rogers, Patricia L; Benner, Ronald A; Wong, Lynn L; Cook, John

    2004-01-01

    Consumer illnesses by scombroid poisonings have been a continuing problem for many years. The intoxications follow the ingestion of fish such as tuna and mahimahi that have undergone bacterial decomposition, leading to the formation of biogenic amines. Research studies have concluded that histamine is one of the indicators of scombrotoxic fish and that other amines, such as cadaverine, could be involved in the illnesses. Guidance for the handling of fish on board fishing vessels to prevent the production of scombrotoxic fish has been limited by a lack of data addressing changes that occur in fish from the water to delivery at dockside. In this study, the changes in selected biogenic amines were determined in mahimahi and tuna, which were captured and held in seawater at 25 to 35 degrees C for incubation times up to 18 h. The fillets from the treated fish were sectioned by transverse cuts and analyzed for histamine, cadaverine, and putrescine. Results showed that at 26 degrees C, more than 12 h of incubation were required before a histamine concentration of 50 ppm was reached in mahimahi. At 35 degrees C, 50 ppm histamine formed within 9 h. Similar results were found for skipjack and yellowfin tuna. Histamine concentrations exceeded 500 ppm within an additional 3 h of incubation in mahimahi. At both temperatures, an increase in the concentration of cadaverine preceded an increase in histamine levels. Changes in putrescine concentrations in the fish were less pronounced. The study also demonstrated that histidine decarboxylase activity was retained in some frozen samples of fish and could result in further increases in histamine on thawing.

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

    PubMed

    Zhu, Guoping; Xu, Liuxiong; Zhou, Yingqi; Chen, Xinjun

    2009-01-01

    Age and growth parameters were estimated for bigeye tuna Thunnus obesus Lowe, 1839 sampled from China longline fisheries in the central Atlantic Ocean from October 2002 to July 2003 and from August 2004 to March 2005. The von Bertalanffy growth parameters were estimated at L(infinity)=217.9 cm fork length, k=0.23 year(-1), and t(0)=-0.44 year. The total mortality rate (Z) was estimated to be from 0.82 to 1.02, the fishing mortality (F) and the natural mortality were 0.54 year(-1) and 0.39 year(-1), respectively. The exploitation ratio (E) was 0.35. This study provides the detailed estimates of growth and mortality rate for bigeye tuna in the central Atlantic Ocean, which can be used as biological input parameters in further stock evaluations in this region. However, age analysis, additional validation of the size composition and stock structure are needed for future studies.

  4. Transectional heat transfer in thermoregulating bigeye tuna (Thunnus obesus) - a 2D heat flux model.

    PubMed

    Boye, Jess; Musyl, Michael; Brill, Richard; Malte, Hans

    2009-11-01

    We developed a 2D heat flux model to elucidate routes and rates of heat transfer within bigeye tuna Thunnus obesus Lowe 1839 in both steady-state and time-dependent settings. In modeling the former situation, we adjusted the efficiencies of heat conservation in the red and the white muscle so as to make the output of the model agree as closely as possible with observed cross-sectional isotherms. In modeling the latter situation, we applied the heat exchanger efficiencies from the steady-state model to predict the distribution of temperature and heat fluxes in bigeye tuna during their extensive daily vertical excursions. The simulations yielded a close match to the data recorded in free-swimming fish and strongly point to the importance of the heat-producing and heat-conserving properties of the white muscle. The best correspondence between model output and observed data was obtained when the countercurrent heat exchangers in the blood flow pathways to the red and white muscle retained 99% and 96% (respectively) of the heat produced in these tissues. Our model confirms that the ability of bigeye tuna to maintain elevated muscle temperatures during their extensive daily vertical movements depends on their ability to rapidly modulate heating and cooling rates. This study shows that the differential cooling and heating rates could be fully accounted for by a mechanism where blood flow to the swimming muscles is either exclusively through the heat exchangers or completely shunted around them, depending on the ambient temperature relative to the body temperature. Our results therefore strongly suggest that such a mechanism is involved in the extensive physiological thermoregulatory abilities of endothermic bigeye tuna.

  5. Nisin Migration in Shelf Stable, Tuna-Filled Tortillas During Storage

    DTIC Science & Technology

    2014-09-22

    IL); sweet pickle relish, Pinnacle Foods (Peoria, IL); glycerol, KIC Chemicals, (Amonk, NY); Dijon mustard, Kraft Foods Group Inc. (Northfield, IL...a boiling water bath for 5 min. Extract B was obtained Ingredient Percent Solid White Tuna 60.00 Mayonnaise 24.31 Sweet  Pickle Relish 5.50 Glycerol...Debevere J. 2005. Antimicrobial effect of nisin and carvacrol and competition between Bacillus cereus and Bacillus circulans in vacuum-packed potato

  6. Improving the safety and quality of raw tuna fillets by x-ray irradiation

    USDA-ARS?s Scientific Manuscript database

    In this study, raw tuna fillet (25 g) samples were inoculated by immersing in 0.1% peptone water that contained 108-9 CFU ml-1 of a three-strain mixture of Salmonella enterica for 1 min. The samples were then air dried at 22 oC for 30 min and were packaged separately in sterilized bags prior to X-ra...

  7. What's the catch? Validity of whaling data for Japanese catches of sperm whales in the North Pacific.

    PubMed

    Ivashchenko, Yulia V; Clapham, Phillip J

    2015-07-01

    The failure of international efforts to manage commercial whaling was exemplified by revelations of large-scale illegal whale catches by the USSR over a 30 year period following World War II. Falsifications of catch data have also been reported for Japanese coastal whaling, but to date there has been no investigation of the reliability of catch statistics for Japanese pelagic (factory fleet) whaling operations. Here, we use data of known reliability from Soviet whaling industry reports to show that body lengths reported to the International Whaling Commission (IWC) by Japanese factory fleets for female sperm whales caught in the North Pacific are not credible. In 1968/1969, Japanese whaling fleets in the North Pacific killed 1568 females, of which 1525 (97.3%) were reported as being at or above the IWC's minimum length of 11.6 m (legal-sized females, LSFs). By contrast, Soviet fleets operating during this period killed 12 578 females; only 824 (6.6%) were LSFs. Adjusting for effort, catches of LSFs were up to 9.1 times higher for Japan compared with the USSR, and even higher for very large females. Dramatic differences in body length statistics were evident when both nations operated in the same area. Significantly, the frequency of LSFs and very large females in the Japanese catch markedly declined after the IWC's International Observer Scheme in 1972 made illegal whaling more difficult. We conclude that the Japanese length data reflect systematic falsification of catch statistics submitted to the IWC, with serious implications for the reliability of data used in current population assessments. The apparent ease with which catch data were falsified in the past underscores the necessity of transparent and independent inspection procedures in any future commercial whaling.

  8. What's the catch? Validity of whaling data for Japanese catches of sperm whales in the North Pacific

    PubMed Central

    Ivashchenko, Yulia V.; Clapham, Phillip J.

    2015-01-01

    The failure of international efforts to manage commercial whaling was exemplified by revelations of large-scale illegal whale catches by the USSR over a 30 year period following World War II. Falsifications of catch data have also been reported for Japanese coastal whaling, but to date there has been no investigation of the reliability of catch statistics for Japanese pelagic (factory fleet) whaling operations. Here, we use data of known reliability from Soviet whaling industry reports to show that body lengths reported to the International Whaling Commission (IWC) by Japanese factory fleets for female sperm whales caught in the North Pacific are not credible. In 1968/1969, Japanese whaling fleets in the North Pacific killed 1568 females, of which 1525 (97.3%) were reported as being at or above the IWC's minimum length of 11.6 m (legal-sized females, LSFs). By contrast, Soviet fleets operating during this period killed 12 578 females; only 824 (6.6%) were LSFs. Adjusting for effort, catches of LSFs were up to 9.1 times higher for Japan compared with the USSR, and even higher for very large females. Dramatic differences in body length statistics were evident when both nations operated in the same area. Significantly, the frequency of LSFs and very large females in the Japanese catch markedly declined after the IWC's International Observer Scheme in 1972 made illegal whaling more difficult. We conclude that the Japanese length data reflect systematic falsification of catch statistics submitted to the IWC, with serious implications for the reliability of data used in current population assessments. The apparent ease with which catch data were falsified in the past underscores the necessity of transparent and independent inspection procedures in any future commercial whaling. PMID:26587276

  9. Signature of ocean warming in global fisheries catch.

    PubMed

    Cheung, William W L; Watson, Reg; Pauly, Daniel

    2013-05-16

    Marine fishes and invertebrates respond to ocean warming through distribution shifts, generally to higher latitudes and deeper waters. Consequently, fisheries should be affected by 'tropicalization' of catch (increasing dominance of warm-water species). However, a signature of such climate-change effects on global fisheries catch has so far not been detected. Here we report such an index, the mean temperature of the catch (MTC), that is calculated from the average inferred temperature preference of exploited species weighted by their annual catch. Our results show that, after accounting for the effects of fishing and large-scale oceanographic variability, global MTC increased at a rate of 0.19 degrees Celsius per decade between 1970 and 2006, and non-tropical MTC increased at a rate of 0.23 degrees Celsius per decade. In tropical areas, MTC increased initially because of the reduction in the proportion of subtropical species catches, but subsequently stabilized as scope for further tropicalization of communities became limited. Changes in MTC in 52 large marine ecosystems, covering the majority of the world's coastal and shelf areas, are significantly and positively related to regional changes in sea surface temperature. This study shows that ocean warming has already affected global fisheries in the past four decades, highlighting the immediate need to develop adaptation plans to minimize the effect of such warming on the economy and food security of coastal communities, particularly in tropical regions.

  10. Shifting from marine reserves to maritime zoning for conservation of Pacific bigeye tuna (Thunnus obesus)

    PubMed Central

    Sibert, John; Senina, Inna; Lehodey, Patrick; Hampton, John

    2012-01-01

    Over 50% of the total bigeye tuna (BET) landed in the Western Central Pacific Ocean is caught incidentally in the purse seine fishery and sold for canning at prices less than US$2/kg. The remainder is landed in longline fisheries directed at BET and sold as fresh or frozen tuna at prices greater than US$10/kg. The combined fishing mortality by all gears will soon reduce the BET biomass in the Pacific Ocean to less than that capable of producing maximum sustainable yield. Closure of the high-seas enclaves in 2009 was hailed as a conservation measure, but was not scientifically evaluated before implementation and appears to have had no beneficial effect on the BET stock. A spatially explicit age-structured ecosystem model, SEAPODYM, is used to simulate alternative area-based fishery management policies to conserve bigeye tuna in the Western Central Pacific Ocean. Closing the high-seas enclaves to purse seine fishing has negligible effect on the BET biomass. Fishery management policies that control mortality on both juveniles and adults, through prohibition of fish aggregation devices in the purse seine fishery and restrictions on longline fishing in spawning areas, are the most efficient conservation policies. Large-scale benefits from bigeye conservation measures will become apparent only in the 2030s, assuming timely implementation and minimal effects of climate change. PMID:23064639

  11. Shifting from marine reserves to maritime zoning for conservation of Pacific bigeye tuna (Thunnus obesus).

    PubMed

    Sibert, John; Senina, Inna; Lehodey, Patrick; Hampton, John

    2012-10-30

    Over 50% of the total bigeye tuna (BET) landed in the Western Central Pacific Ocean is caught incidentally in the purse seine fishery and sold for canning at prices less than US$2/kg. The remainder is landed in longline fisheries directed at BET and sold as fresh or frozen tuna at prices greater than US$10/kg. The combined fishing mortality by all gears will soon reduce the BET biomass in the Pacific Ocean to less than that capable of producing maximum sustainable yield. Closure of the high-seas enclaves in 2009 was hailed as a conservation measure, but was not scientifically evaluated before implementation and appears to have had no beneficial effect on the BET stock. A spatially explicit age-structured ecosystem model, SEAPODYM, is used to simulate alternative area-based fishery management policies to conserve bigeye tuna in the Western Central Pacific Ocean. Closing the high-seas enclaves to purse seine fishing has negligible effect on the BET biomass. Fishery management policies that control mortality on both juveniles and adults, through prohibition of fish aggregation devices in the purse seine fishery and restrictions on longline fishing in spawning areas, are the most efficient conservation policies. Large-scale benefits from bigeye conservation measures will become apparent only in the 2030s, assuming timely implementation and minimal effects of climate change.

  12. Prediction of Quality Change During Thawing of Frozen Tuna Meat by Numerical Calculation I

    NASA Astrophysics Data System (ADS)

    Murakami, Natsumi; Watanabe, Manabu; Suzuki, Toru

    A numerical calculation method has been developed to determine the optimum thawing method for minimizing the increase of metmyoglobin content (metMb%) as an indicator of color changes in frozen tuna meat during thawing. The calculation method is configured the following two steps: a) calculation of temperature history in each part of frozen tuna meat during thawing by control volume method under the assumption of one-dimensional heat transfer, and b) calculation of metMb% based on the combination of calculated temperature history, Arrenius equation and the first-order reaction equation for the increase rate of metMb%. Thawing experiments for measuring temperature history of frozen tuna meat were carried out under the conditions of rapid thawing and slow thawing to compare the experimental data with calculated temperature history as well as the increase of metMb%. The results were coincident with the experimental data. The proposed simulation method would be useful for predicting the optimum thawing conditions in terms of metMb%.

  13. The aggregation of tuna around floating objects: what could be the underlying social mechanisms?

    PubMed

    Robert, Marianne; Dagorn, Laurent; Deneubourg, Jean Louis

    2014-10-21

    Several empirical and theoretical studies have shown how the exploitation of food sources, the choice of resting sites or other types of collective decision-making in heterogeneous environments are facilitated and modulated by social interactions between conspecifics. It is well known that many pelagic fishes live in schools and that this form of gregarious behavior provides advantages in terms of food intake and predator avoidance efficiency. However, the influence of social behavior in the formation of aggregations by tuna under floating objects (FOBs) is poorly understood. In this work, we investigated the collective patterns generated by different theoretical models, which either include or exclude social interactions between conspecifics, in the presence of two aggregation sites. The resulting temporal dynamics and distributions of populations were compared to in situ observations of tuna behavior. Our work suggests that social interactions should be incorporated in aggregative behavior to reproduce the temporal patterns observed in the field at both the individual and the group level, challenging the common vision of tuna aggregations around FOBs. Our study argues for additional data to further demonstrate the role of social behavior in the dynamics of these fish aggregations. Understanding the interplay between environmental and social factors in the associative behavior of fish with FOBs is necessary to assess the consequences of the widespread deployment of artificial FOBs by fishermen.

  14. Simulating tsunami run-up onto a planar beach by TUNA-RP

    NASA Astrophysics Data System (ADS)

    Tan, Wai Kiat; Teh, Su Yean; Koh, Hock Lye; Abas, Mohd Rosaidi Che

    2014-10-01

    The devastating 2004 Andaman tsunami and the crippling 2011 Fukushima tsunami highlight the vulnerability to future tsunamis for coastal communities living in affected regions. An important application of tsunami modeling is to simulate the maximum inundation distance and maximum run-up heights along beaches for improved tsunami hazard assessments. Numerical tsunami models are able to assess which coastal communities are vulnerable once a tsunami source is identified, helping emergency management to develop risk maps and evacuation routes. This paper begins with a brief introductory review on contemporary run-up and draw-down simulation models to provide insights for choosing an appropriate model to be developed. Based upon the nonlinear shallow water equations (NSWE) coupled with a moving boundary algorithm, a one-dimensional tsunami run-up model, codenamed TUNA-RP, is developed. The moving boundary algorithm implemented allows the NSWE to be computed over the entire computational domain, including dry nodes. TUNA-RP is validated by comparing simulation results to a known semi-analytical solution. TUNA-RP has a wider range of applicability compared to the semi-analytical solution. Some scenarios of potential tsunami inundation along Malaysian coasts will be presented to highlight vulnerability in the event of another large tsunami in the Andaman Sea.

  15. Total mercury in fresh and processed tuna marketed in Galicia (NW Spain) in relation to dietary exposure.

    PubMed

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

    2016-12-01

    Mercury is a toxic trace metal, which can accumulate to levels threatening human and environmental health. In this study, contents of total mercury have been determined by ICP-MS spectrometry in fresh and processed tuna (110 samples) purchased from supermarkets in NW Spain. Mercury was present in all samples analyzed; however, only one sample of fresh tuna (1.070 mg kg(-1) wet weight (w.w.)) slightly exceeded the limit of the EU (1.0 mg kg(-1) w.w.). The average mercury concentration in processed tuna was lower than fresh, 0.306 mg kg(-1) w.w., and ranged from 0.080 to 0.715 mg kg(-1) w.w. Results were compared with literature data. In regard to the three types of preparation-packaging media for canned tuna, total Hg content was found in the following order: olive oil > natural > pickled sauce; the last showed significant statistical differences (p < 0.01) with the other two preparations. Between the two evaluated canned tuna species, significant statistical differences (p = 0.008) were observed and Thunnus alalunga presented a greater mean content (0.332 ± 0.114 mg kg(-1) w.w.) compared to Thunnus albacares (0.266 ± 0.171 mg kg(-1) w.w.).Taking into account the AESAN recommendation for adults and children, as well as the EU regulations and the tuna consumption by the Spanish population, the Hg levels obtained in this study pose no risk to consumer health. However, additional studies, a monitoring process, and efforts to reduce Hg concentration in tuna would be necessary, as well as considering other sources of exposure to Hg.

  16. Retractable tool bit having latch type catch mechanism

    NASA Astrophysics Data System (ADS)

    Voellmer, George

    1993-01-01

    A retractable tool bit assembly for a tool such as an allen key is presented. The assembly includes one or more spring loaded nestable or telescoping tubular sections together with a catch mechanism for capturing and holding the tool in its retracted position. The catch mechanism consists of a latch mechanism located in a base section and which engages a conically shaped tool head located at the inner end of the tool. The tool head adjoins an eccentric oval type neck portion which extends to a rear lip of the tool head. The latch mechanism releases when the ovular neck portion rotates about the catch members upon actuation of a rotary tool drive motor. When released, all the telescoping sections and the tool extends fully outward to a use position.

  17. Resolving the molecular mechanism of cadherin catch bond formation

    SciTech Connect

    Manibog, Kristine; Li, Hui; Rakshit, Sabyasachi; Sivasankar, Sanjeevi

    2014-06-02

    Classical cadherin Ca(2+)-dependent cell-cell adhesion proteins play key roles in embryogenesis and in maintaining tissue integrity. Cadherins mediate robust adhesion by binding in multiple conformations. One of these adhesive states, called an X-dimer, forms catch bonds that strengthen and become longer lived in the presence of mechanical force. Here we use single-molecule force-clamp spectroscopy with an atomic force microscope along with molecular dynamics and steered molecular dynamics simulations to resolve the molecular mechanisms underlying catch bond formation and the role of Ca(2+) ions in this process. Our data suggest that tensile force bends the cadherin extracellular region such that they form long-lived, force-induced hydrogen bonds that lock X-dimers into tighter contact. When Ca(2+) concentration is decreased, fewer de novo hydrogen bonds are formed and catch bond formation is eliminated

  18. Retractable tool bit having latch type catch mechanism

    NASA Technical Reports Server (NTRS)

    Voellmer, George (Inventor)

    1993-01-01

    A retractable tool bit assembly for a tool such as an allen key is presented. The assembly includes one or more spring loaded nestable or telescoping tubular sections together with a catch mechanism for capturing and holding the tool in its retracted position. The catch mechanism consists of a latch mechanism located in a base section and which engages a conically shaped tool head located at the inner end of the tool. The tool head adjoins an eccentric oval type neck portion which extends to a rear lip of the tool head. The latch mechanism releases when the ovular neck portion rotates about the catch members upon actuation of a rotary tool drive motor. When released, all the telescoping sections and the tool extends fully outward to a use position.

  19. Vertical behavior and diet of albacore tuna (Thunnus alalunga) vary with latitude in the South Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Williams, Ashley J.; Allain, Valerie; Nicol, Simon J.; Evans, Karen J.; Hoyle, Simon D.; Dupoux, Cyndie; Vourey, Elodie; Dubosc, Jeff

    2015-03-01

    Albacore tuna (Thunnus alalunga) are an important upper tropic-level oceanic predator with a circum-global distribution. Little is known of the movements and diet of albacore tuna in the South Pacific Ocean and how variability in both might influence the vulnerability of albacore tuna to fisheries across their range. We coupled data derived from satellite-tagged albacore tuna with stomach samples collected from individuals at the same locations to characterize the vertical behavior, thermal and dietary habits of albacore tuna at tropical (New Caledonia and Tonga) and temperate (New Zealand) latitudes. A total of 18 pop-up satellite archival tags deployed on albacore tuna remained attached for 0-50 days. Position estimates, calculated from 11 tags, described short-term movements of predominantly less than 500 km, although one fish moved more than 1000 km over a period of 50 days. Vertical behavior and diet differed substantially between tropical and temperate latitudes. At tropical latitudes, albacore tuna showed a distinct diel pattern in vertical habitat use, occupying shallower, warmer waters above the mixed layer depth (MLD) at night, and deeper, cooler waters below the MLD during the day. In contrast, there was little evidence of a diel pattern of vertical behavior in albacore tuna at temperate latitudes, with fish limited to shallow waters above the MLD almost all of the time. Spatial patterns of species composition in stomach contents were consistent with vertical movement patterns, with significantly more deepwater prey species consumed in tropical waters than in temperate waters. Albacore in tropical waters also consumed significantly greater diversities of prey than in temperate waters, predominately preying on fish species, whereas those in temperate waters predominately preyed on crustacea. Our results indicate that the vertical distribution of albacore is constrained either by thermal preferences with diet reflecting these preferences, by the vertical

  20. Food-web inferences of stable isotope spatial patterns in copepods and yellowfin tuna in the pelagic eastern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Olson, Robert J.; Popp, Brian N.; Graham, Brittany S.; López-Ibarra, Gladis A.; Galván-Magaña, Felipe; Lennert-Cody, Cleridy E.; Bocanegra-Castillo, Noemi; Wallsgrove, Natalie J.; Gier, Elizabeth; Alatorre-Ramírez, Vanessa; Ballance, Lisa T.; Fry, Brian

    2010-07-01

    Evaluating the impacts of climate and fishing on oceanic ecosystems requires an improved understanding of the trophodynamics of pelagic food webs. Our approach was to examine broad-scale spatial relationships among the stable N isotope values of copepods and yellowfin tuna ( Thunnus albacares), and to quantify yellowfin tuna trophic status in the food web based on stable-isotope and stomach-contents analyses. Using a generalized additive model fitted to abundance-weighted-average δ 15N values of several omnivorous copepod species, we examined isotopic spatial relationships among yellowfin tuna and copepods. We found a broad-scale, uniform gradient in δ 15N values of copepods increasing from south to north in a region encompassing the eastern Pacific warm pool and parts of several current systems. Over the same region, a similar trend was observed for the δ 15N values in the white muscle of yellowfin tuna caught by the purse-seine fishery, implying limited movement behavior. Assuming the omnivorous copepods represent a proxy for the δ 15N values at the base of the food web, the isotopic difference between these two taxa, “ ΔYFT-COP,” was interpreted as a trophic-position offset. Yellowfin tuna trophic-position estimates based on their bulk δ 15N values were not significantly different than independent estimates based on stomach contents, but are sensitive to errors in the trophic enrichment factor and the trophic position of copepods. An apparent inshore-offshore, east to west gradient in yellowfin tuna trophic position was corroborated using compound-specific isotope analysis of amino acids conducted on a subset of samples. The gradient was not explained by the distribution of yellowfin tuna of different sizes, by seasonal variability at the base of the food web, or by known ambit distances (i.e. movements). Yellowfin tuna stomach contents did not show a regular inshore-offshore gradient in trophic position during 2003-2005, but the trophic

  1. Why do tuna maintain elevated slow muscle temperatures? Power output of muscle isolated from endothermic and ectothermic fish.

    PubMed

    Altringham, J D; Block, B A

    1997-10-01

    It has been hypothesised that regional endothermy has evolved in the muscle of some tunas to enhance the locomotory performance of the fish by increasing muscle power output. Using the work loop technique, we have determined the relationship between cycle frequency and power output, over a range of temperatures, in isolated bundles of slow muscle fibres from the endothermic yellowfin tuna (Thunnus albacares) and its ectothermic relative the bonito (Sarda chiliensis). Power output in all preparations was highly temperature-dependent. A counter-current heat exchanger which could maintain a 10 degrees C temperature differential would typically double maximum muscle power output and the frequency at which maximum power is generated (fopt). The deep slow muscle of the tuna was able to operate at higher temperatures than slow muscle from the bonito, but was more sensitive to temperature change than more superficially located slow fibres from both tuna and bonito. This suggests that it has undergone some evolutionary specialisation for operation at higher, but relatively stable, temperatures. fopt of slow muscle was higher than the tailbeat frequency of undisturbed cruising tuna and, together with the high intrinsic power output of the slow muscle mass, suggests that cruising fish have a substantial slow muscle power reserve. This reserve should be sufficient to power significantly higher sustainable swimming speeds, presumably at lower energetic cost than if intrinsically less efficient fast fibres were recruited.

  2. Benefits and risks associated with consumption of raw, cooked, and canned tuna (Thunnus spp.) based on the bioaccessibility of selenium and methylmercury.

    PubMed

    Afonso, C; Costa, S; Cardoso, C; Oliveira, R; Lourenço, H M; Viula, A; Batista, I; Coelho, I; Nunes, M L

    2015-11-01

    The Se, Hg, and methylmercury (MeHg) levels in raw, cooked (boiled and grilled), and canned tuna (Thunnus spp.) were determined before and after an in vitro digestion, thereby enabling the calculation of the respective bioaccessibility percentages. A risk-benefit evaluation of raw and canned tuna on the basis of the Se and MeHg data was performed. Selenium bioaccessibility was high in tuna, though slightly lower in canned than in raw products. Mercury levels were high in raw and cooked tuna. Hg bioaccessibility percentages were low (39-48%) in the cooked tuna and even lower (<20%) in canned tuna. For the bioaccessible fraction, all molar Se:MeHg ratios were higher than one (between 10 and 74). A probabilistic assessment of MeHg risk vs Se benefit showed that while a weekly meal of canned tuna presents very low risk, raw, boiled, and grilled tuna consumption should not exceed a monthly meal, at least, for pregnant and nursing women.

  3. The efficacy of X-ray does on murine norovirus-1 (MNV-1) in pure culture, half-shell oyster, salmon sushi, and tuna salad

    USDA-ARS?s Scientific Manuscript database

    In this investigation, we determined the efficacy of X-ray doses on reducing a human norovirus (HuNoV) surrogate [murine norovirus-1 (MNV-1)] in pure culture, half-shell oyster, salmon sushi and tuna salad. The pure culture (phosphate-buffer saline, pH 7.4), half-shell oyster, salmon sushi and tuna ...

  4. The efficacy of x-ray doses on murine norovirus-1 (MNV-1) in pure culture, half-shell oyster, salmon sushi, and tuna salad

    USDA-ARS?s Scientific Manuscript database

    n this investigation, we determined the efficacy of X-ray doses on reducing a human norovirus (HuNoV) surrogate [murine norovirus-1 (MNV-1)] in pure culture, half-shell oyster, salmon sushi and tuna salad. The pure culture (phosphate-buffer saline, pH 7.4), half-shell oyster, salmon sushi and tuna s...

  5. 76 FR 21705 - Fisheries of the Exclusive Economic Zone Off Alaska; Catch Accounting in the Longline Catcher...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-18

    ... Alaska; Catch Accounting in the Longline Catcher/Processor Pacific Cod Fishery AGENCY: National Marine... Islands to support different catch accounting methods for Pacific cod catch. NMFS is considering proposed...

  6. Persistent Organic Pollutants in albacore tuna (Thunnus alalunga) from Reunion Island (Southwest Indian Ocean) and South Africa in relation to biological and trophic characteristics.

    PubMed

    Munschy, C; Bodin, N; Potier, M; Héas-Moisan, K; Pollono, C; Degroote, M; West, W; Hollanda, S J; Puech, A; Bourjea, J; Nikolic, N

    2016-07-01

    The contamination of albacore tuna (Thunnus alalunga) by Persistent Organic Pollutants (POPs), namely polychlorinated biphenyls (PCBs) and dichlorodiphenyl-trichloroethane (DDT), was investigated in individuals collected from Reunion Island (RI) and South Africa's (SA) southern coastlines in 2013, in relation to biological parameters and feeding ecology. The results showed lower PCB and DDT concentrations than those previously reported in various tuna species worldwide. A predominance of DDTs over PCBs was revealed, reflecting continuing inputs of DDT. Tuna collected from SA exhibited higher contamination levels than those from RI, related to higher dietary inputs and higher total lipid content. Greater variability in contamination levels and profiles was identified in tuna from RI, explained by a higher diversity of prey and more individualistic foraging behaviour. PCB and DDT contamination levels and profiles varied significantly in tuna from the two investigated areas, probably reflecting exposure to different sources of contamination. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Comparing catch orientation among Minnesota walleye, northern pike, and bass anglers

    USGS Publications Warehouse

    Schroeder, Susan A.; Fulton, David C.

    2013-01-01

    We compared the catch orientations of Minnesota walleye (Sander vitreus), northern pike (Esox lucius), largemouth bass (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu) anglers. Results were derived from 2009, 2010, and 2012 surveys of anglers targeting these different species. Consistent with previous research, we identified four dimensions of anglers’ catch orientation: (a) catching something, (b) catching big fish, (c) catching many fish, and (d) keeping fish. Walleye anglers were the most motivated to keep fish, while northern pike anglers were more oriented toward catching big fish. Largemouth bass anglers, and to a lesser extent smallmouth bass anglers, were also oriented toward catching big fish. Bass anglers reported the lowest interest in keeping fish. An orientation to keep fish was negatively related to more restrictive management actions, regardless of species. A stronger orientation to catch big fish was associated with support for increased harvest restrictions only for northern pike and smallmouth bass.

  8. 76 FR 23962 - Fisheries Off West Coast States; Highly Migratory Species Fisheries; Annual Catch Limits and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-29

    ... States; Highly Migratory Species Fisheries; Annual Catch Limits and Accountability Measures AGENCY... annual catch limits (ACLs) and accountability measures (AMs). This proposed rule to implement Amendment 2... have any direct or indirect socioeconomic impacts, because harvest limits and management measures...

  9. 78 FR 48075 - Western Pacific Fisheries; 2013 Annual Catch Limits and Accountability Measures; Correcting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ... Catch Limits and Accountability Measures; Correcting Amendment AGENCY: National Marine Fisheries Service... limit specifications for western Pacific fisheries that were published in the Federal Register on March... Pacific Fishery Management Council (Council) recommended annual catch limits for western Pacific fisheries...

  10. 77 FR 5473 - Pacific Halibut Fisheries; Catch Sharing Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... National Oceanic and Atmospheric Administration 50 CFR Part 300 RIN 0648-BB68 Pacific Halibut Fisheries; Catch Sharing Plan AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... IPHC. These measures include the sport fishery allocations and management measures for Area 2A. These...

  11. A minimum attention control law for ball catching.

    PubMed

    Jang, Cheongjae; Lee, Jee-eun; Lee, Sohee; Park, F C

    2015-10-06

    Digital implementations of control laws typically involve discretization with respect to both time and space, and a control law that can achieve a task at coarser levels of discretization can be said to require less control attention, and also reduced implementation costs. One means of quantitatively capturing the attention of a control law is to measure the rate of change of the control with respect to changes in state and time. In this paper we present an attention-minimizing control law for ball catching and other target tracking tasks based on Brockett's attention criterion. We first highlight the connections between this attention criterion and some well-known principles from human motor control. Under the assumption that the optimal control law is the sum of a linear time-varying feedback term and a time-varying feedforward term, we derive an LQR-based minimum attention tracking control law that is stable, and obtained efficiently via a finite-dimensional optimization over the symmetric positive-definite matrices. Taking ball catching as our primary task, we perform numerical experiments comparing the performance of the various control strategies examined in the paper. Consistent with prevailing theories about human ball catching, our results exhibit several familiar features, e.g., the transition from open-loop to closed-loop control during the catching movement, and improved robustness to spatiotemporal discretization. The presented control laws are applicable to more general tracking problems that are subject to limited communication resources.

  12. 50 CFR 648.140 - Catch quotas and other restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... otter trawls, pots and traps on the mortality of black sea bass; and any other relevant information. (b... Measures for the Black Sea Bass Fishery § 648.140 Catch quotas and other restrictions. Link to an amendment published at 76 FR 60636, Sept. 29, 2011. (a) Review. The Black Sea Bass Monitoring Committee shall review...

  13. 50 CFR 648.230 - Catch quotas and other restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Measures for the Spiny Dogfish Fishery § 648.230 Catch quotas and other restrictions. Link to an amendment published at 76 FR 60642, Sept. 29, 2011. (a) Process for setting specifications. The Spiny Dogfish... target fishing mortality rate specified in the Spiny Dogfish Fishery Management Plan will not be exceeded...

  14. CATCH: Child and Adolescent Trial for Cardiovascular Health. [Multimedia.

    ERIC Educational Resources Information Center

    National Heart, Lung, and Blood Inst. (DHHS/NIH), Bethesda, MD.

    The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health has launched an initiative called the Cardiovascular Health Promotion Project to teach heart-healthy habits to children. One of the programs developed by this initiative, CATCH, the Child and Adolescent Trial for Cardiovascular Health, is the largest…

  15. Catch Up® Literacy: Evaluation Report and Executive Summary

    ERIC Educational Resources Information Center

    Rutt, Simon; Kettlewell, Kelly; Bernardinelli, Daniele

    2015-01-01

    Catch Up® Literacy is a structured one-to-one literacy intervention for pupils between the ages of 6 and 14 who are struggling to learn to read. It teaches pupils to blend phonemes (combine letter sounds into words), segment phonemes (separate words into letter sounds), and memorise particular words so they can be understood without needing to use…

  16. 50 CFR 648.140 - Catch quotas and other restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....140 Section 648.140 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE NORTHEASTERN UNITED STATES Management... research catch data; current estimates of fishing mortality; stock status; recent estimates of recruitment...

  17. 13. CANVAS NET USED TO CATCH TOOLS OR SUPPORT PERSONNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. CANVAS NET USED TO CATCH TOOLS OR SUPPORT PERSONNEL FALLING FROM UPPER LEVELS OF MOBILE SERVICE STRUCTURE. BELOW NET IS A NINETY FOOT DROP TO THE PAVEMENT; VIEW TO NORTHEAST. - Cape Canaveral Air Station, Launch Complex 17, Facility 28416, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

  18. 50 CFR 665.211 - Total Allowable Catch (TAC) limit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Total Allowable Catch (TAC) limit. 665.211 Section 665.211 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... of, Hawaii Restricted Bottomfish Species by vessels legally registered to Mau Zone, Ho`omalu Zone,...

  19. 76 FR 14300 - Pacific Halibut Fisheries; Catch Sharing Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-16

    ... coasts of the Alaska Peninsula and Unimak Island to the point of origin at Cape Sarichef Light are closed... specified in section 8 shall be limited to the net weights expressed in pounds or metric tons shown in the... Metric tons 2A: directed commercial, and incidental 159,380 72.3 commercial catch during salmon...

  20. West Indian Ocean variability and East African fish catch.

    PubMed

    Jury, M; McClanahan, T; Maina, J

    2010-08-01

    We describe marine climate variability off the east coast of Africa in the context of fish catch statistics for Tanzania and Kenya. The time series exhibits quasi-decadal cycles over the period 1964-2007. Fish catch is up when sea surface temperature (SST) and atmospheric humidity are below normal in the tropical West Indian Ocean. This pattern relates to an ocean Rossby wave in one phase of its east-west oscillation. Coastal-scale analyses indicate that northward currents and uplift on the shelf edge enhance productivity of East African shelf waters. Some of the changes are regulated by the south equatorial current that swings northward from Madagascar. The weather is drier and a salty layer develops in high catch years. While the large-scale West Indian Ocean has some impact on East African fish catch, coastal dynamics play a more significant role. Climatic changes are reviewed using 200 years of past and projected data. The observed warming trend continues to increase such that predicted SST may reach 30 degrees C by 2100 while SW monsoon winds gradually increase, according to a coupled general circulation model simulation with a gradual doubling of CO(2).

  1. Content Analysis Schedule for Bilingual Education Programs: Catch-Up.

    ERIC Educational Resources Information Center

    Ehrlich, Roselin S.; Shore, Marietta Saravia

    This content analysis schedule for Project Catch-Up in Zapata, Texas, presents information on the history, funding, and scope of the project. Included are sociolinguistic process variables such as the native and dominant languages of students and their interaction. Information is provided on staff selection and the linguistic background of project…

  2. CATCH: Child and Adolescent Trial for Cardiovascular Health. [Multimedia.

    ERIC Educational Resources Information Center

    National Heart, Lung, and Blood Inst. (DHHS/NIH), Bethesda, MD.

    The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health has launched an initiative called the Cardiovascular Health Promotion Project to teach heart-healthy habits to children. One of the programs developed by this initiative, CATCH, the Child and Adolescent Trial for Cardiovascular Health, is the largest…

  3. Scholarships and School Improvement: Annual Report of Catching the Dream.

    ERIC Educational Resources Information Center

    Chavers, Dean, Ed.

    2001-01-01

    This issue of "The Native Scholar" is comprised entirely of the annual report of Catching the Dream (CTD), an organization that awards scholarships to Native American students and grants for improving Native American schools. CTD scholarship programs are described, as are scholarships in general and how to find them. Fourteen scholarship websites…

  4. Metal Concentrations in Two Commercial Tuna Species from an Active Volcanic Region in the Mid-Atlantic Ocean.

    PubMed

    Torres, Paulo; Rodrigues, Armindo; Soares, Lília; Garcia, Patrícia

    2016-02-01

    Concentrations of cadmium (Cd), mercury (Hg), and lead [Pb (µg g(-1) wet weight)] were determined in liver and muscle samples of 15 bigeye (Thunnus obesus) and 15 skipjack tunas (Katsuwonus pelamis) caught over an active volcanic region in the Mid-Atlantic Ocean (Azores, Portugal) and evaluated regarding consumption safety. None of the muscle samples (edible part) exceeded the European Union (EU) maximum limits (MLs) for Hg and Pb. Cd concentrations in muscle were much greater than EU MLs with 53 and 26 % of the bigeye tuna and skipjack tuna, respectively, in exceedance of the limits. Results obtained in this work, together with other studies in the same region, support the existence of an important volcanic source of Cd in waters of the Mid-Atlantic region, which should be carefully monitored given the importance of many commercial marine species for human consumption, mainly in Europe.

  5. Effect of electron irradiation and bayberry polyphenols on the quality change of yellowfin tuna fillets during refrigerated storage

    NASA Astrophysics Data System (ADS)

    Bu, Tingting; Jin, Yang; Li, Xiaohui; Zhang, Jinjie; Xu, Dalun; Yang, Wenge; Lou, Qiaoming

    2017-09-01

    This study evaluated the synergistic effect of bayberry polyphenols and electron irradiation in controlling the chemical, microbiological and sensory changes of raw yellowfin tuna fillets at 4 °C for 7 days. The results indicated that the initial values of each index were dose-dependent. The dose of 5 kGy notably accelerated adenosine triphosphate degradation and lipid oxidation, while the doses of 1 and 3 kGy had acceptable sensory quality and yielded a shelf-life of 5 days. The addition of bayberry polyphenols had evident effect in inhibiting freshness breakdown, bacteria growth, histamine formation, and discoloration of tuna fillets. Bayberry polyphenols, as an antioxidant, could inhibit lipid oxidation and sensory side-effects made by irradiation up to 3 kGy. The dose of 1-3 kGy coupled with bayberry polyphenols was optimum to preserve tuna fillets which prolonged the shelf-life to 7 days.

  6. Deepening Thermocline Displaces Salmon Catch On The Oregon Coast

    NASA Astrophysics Data System (ADS)

    Harrison, C. S.; Lawson, P.

    2015-12-01

    Establishing a linkage between fish stock distributions and physical oceanography at a fine scale provides insights into the dynamic nature of near-shore ocean habitats. Characterization of habitat preferences adds to our understanding of the ecosystem, and may improve forecasts of distribution for harvest management. The Project CROOS (Collaborative Research on Oregon Ocean Salmon) Chinook salmon catch data set represents an unprecedented high-resolution record of catch location and depth, with associated in-situ temperature measurements and stock identification derived from genetic data. Here we connect this data set with physical ocean observations to gain understanding of how circulation affects salmon catch distributions. The CROOS observations were combined with remote and in situ observations of temperature, as well as a data assimilative regional ocean model that incorporates satellite and HF radar data. Across the CROOS data set, catch is primarily located within the upwelling front over the seamounts and reef structures associated with Heceta and Stonewall Banks along the shelf break. In late September of 2014 the anomalously warm "blob" began to arrive on the Oregon coast coincident with a strong downwelling event. At this time the thermocline deepened from 20 to 40 m, associated with a deepening of salmon catch depth. A cold "bulb" of water over Heceta Bank may have provided a thermal refuge for salmon during the initial onshore movement of the anomalously warm water. These observations suggest that a warming ocean, and regional warming events in particular, will have large effects on fish distributions at local and regional scales, in turn impacting fisheries.

  7. Different Strategies for Using Motion-in-Depth Information in Catching

    ERIC Educational Resources Information Center

    Gray, Rob; Sieffert, Randy

    2005-01-01

    Previous studies on ball catching have had the limitation that the catcher was restricted to lateral hand movements. The authors investigated catching behavior in the more natural situation in which hand movements were unconstrained. Movements of the hand were tracked as participants tried to "catch" an approaching ball simulated with changing…

  8. Different Strategies for Using Motion-in-Depth Information in Catching

    ERIC Educational Resources Information Center

    Gray, Rob; Sieffert, Randy

    2005-01-01

    Previous studies on ball catching have had the limitation that the catcher was restricted to lateral hand movements. The authors investigated catching behavior in the more natural situation in which hand movements were unconstrained. Movements of the hand were tracked as participants tried to "catch" an approaching ball simulated with changing…

  9. Catch rates relative to angler party size with implications for monitoring angler success

    USGS Publications Warehouse

    Miranda, L.E.

    2005-01-01

    Angler catch rates often are used to monitor angler success, assess the need for additional management actions, and evaluate the effectiveness of management practices. Potential linkages between catch rate and angler party size were examined to assess how party size might affect the use of catch rate as an index of angler success in recreational fisheries. Data representing 22,355 completed interviews conducted at access points in lakes and reservoirs throughout Mississippi during 1987-2003 were analyzed. Total party catch was not proportional to total party effort; thus, catch rate decreased as party size increased. Depending on the taxa targeted, the average catch rate per angler decreased 40-50% between parties of one and parties of two, although subsequent decreases were less substantial. Because party size accounted for a considerable portion of the variability in catch rate over time and space, failure to remove this variability weakens the manager's ability to detect differences or changes in catch rates. Therefore, the use of catch rates to monitor fisheries may be inappropriate unless party size is taken into account. Party size may influence the angler's ability to catch fish through a variety of processes, including partitioning a limited number of catchable fish among members of a party and party composition. When catch rates are used to estimate total catch rather than to index angler success, party size is not a concern.

  10. 76 FR 7155 - Atlantic Highly Migratory Species; Announcement of Billfish and Swordfish Catch Card Pilot...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ...; Announcement of Billfish and Swordfish Catch Card Pilot Program for Puerto Rico AGENCY: National Marine...; Announcement of Billfish and Swordfish Catch Card Pilot Program for Puerto Rico. SUMMARY: Accurate information... accuracy of recreational billfish and swordfish landings data, NMFS will pilot test a new catch card...

  11. 76 FR 17808 - Fisheries in the Western Pacific; Mechanism for Specifying Annual Catch Limits and Accountability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... Pacific; Mechanism for Specifying Annual Catch Limits and Accountability Measures AGENCY: National Marine... specifying annual catch limits (ACLs) and accountability measures (AMs) for western Pacific fisheries. The... specific areas, changing bag limits, or otherwise restricting effort or catch. Any inseason restriction...

  12. The development and validation of the clinicians' awareness towards cognitive errors (CATChES) in clinical decision making questionnaire tool.

    PubMed

    Chew, Keng Sheng; Kueh, Yee Cheng; Abdul Aziz, Adlihafizi

    2017-03-21

    Despite their importance on diagnostic accuracy, there is a paucity of literature on questionnaire tools to assess clinicians' awareness toward cognitive errors. A validation study was conducted to develop a questionnaire tool to evaluate the Clinician's Awareness Towards Cognitive Errors (CATChES) in clinical decision making. This questionnaire is divided into two parts. Part A is to evaluate the clinicians' awareness towards cognitive errors in clinical decision making while Part B is to evaluate their perception towards specific cognitive errors. Content validation for both parts was first determined followed by construct validation for Part A. Construct validation for Part B was not determined as the responses were set in a dichotomous format. For content validation, all items in both Part A and Part B were rated as "excellent" in terms of their relevance in clinical settings. For construct validation using exploratory factor analysis (EFA) for Part A, a two-factor model with total variance extraction of 60% was determined. Two items were deleted. Then, the EFA was repeated showing that all factor loadings are above the cut-off value of >0.5. The Cronbach's alpha for both factors are above 0.6. The CATChES questionnaire tool is a valid questionnaire tool aimed to evaluate the awareness among clinicians toward cognitive errors in clinical decision making.

  13. Anti-wrinkle effects of a tuna heart H2O fraction on Hs27 human fibroblasts

    PubMed Central

    KIM, YOUNG-MIN; JUNG, HEE-JIN; CHOI, JAE-SUE; NAM, TAEK-JEONG

    2016-01-01

    With the increase in life expectancy, there is also growing interest in anti-aging treatments and technologies. The development of anti-aging functional drugs for the skin, and foods from natural sources, may offer solutions to this global matter. Aging involves structural, functional and biochemical changes that occur throughout cells and bodily tissues; the amount of hormones secreted from of all human organs, including the skin, decreases over time. Matrix metalloproteinase (MMP) genes (MMP-1 and -8) play an important role in the aging of skin fibroblasts. For example, an increased MMP expression causes accelerated aging and the degradation of skin elasticity-related genes. In the present study, we examined the anti-wrinkle effects of tuna heart extract which are mediated through the inhibition of MMPs in skin cells. Generally, tuna contains high concentrations of selenium and antioxidants, which serve to remove free radicals, and is known to delay skin and body aging. In addition, unsaturated fatty acids in tuna help to maintain the natural glossy look of skin, and increase skin elasticity, providing moisture for dry skin. A recent study confirmed the various bio-effects of boiled tuna extract and muscle. However, bioactivity studies using tuna heart are limited. Thus, in the present study, we obtained extracts and fractions of tuna heart, and examined their effects on Hs27 human fibroblast proliferation using an MTS assay. In addition, we measured procollagen type 1 levels and elastase activity, and performed β-galactosidase staining. We then measured the expression levels of phosphatidylinositol 3-kinase/Akt and MMP-related genes by western blot analysis and RT-PCR. Our results revealed that tuna heart extract decreased MMP expression by upregulating tissue inhibitors of metallopro-teinase-1 (TIMP-1) and decreasing elastase activity, thus exerting anti-aging and anti-wrinkle effects by increasing collagen synthesis and promoting skin fibroblast proliferation

  14. Swimming performance studies on the eastern Pacific bonito Sarda chiliensis, a close relative of the tunas (family Scombridae) II. Kinematics.

    PubMed

    Dowis, Hawkins J; Sepulveda, Chugey A; Graham, Jeffrey B; Dickson, Kathryn A

    2003-08-01

    The swimming kinematics of the eastern Pacific bonito Sarda chiliensis at a range of sustained speeds were analyzed to test the hypothesis that the bonito's swimming mode differs from the thunniform locomotor mode of tunas. Eight bonito (fork length FL 47.5+/-2.1 cm, mass 1.25+/-0.15 kg) (mean +/- S.D.) swam at speeds of 50-130 cm s(-1) at 18+/-2 degrees C in the same temperature-controlled water tunnel that was used in previous studies of tunas. Kinematics variables, quantified from 60 Hz video recordings and analyzed using a computerized, two-dimensional motion analysis system, were compared with published data for similar sized tunas at comparable speeds. Bonito tailbeat frequency, tailbeat amplitude and stride length all increased significantly with speed. Neither yaw (6.0+/-0.6%FL) nor propulsive wavelength (120+/-65% fish total length) varied with speed, and there were no mass or body-length effects on the kinematics variables for the size range of bonitos used. Relative to similar sized yellowfin (Thunnus albacares) and skipjack (Katsuwonus pelamis) tunas at similar speeds, the bonito has a lower tailbeat frequency, a higher yaw and a greater stride length. The lateral displacement and bending angle of each intervertebral joint during a complete tailbeat cycle were determined for the bonito at a swimming speed of 90 cm s(-1). The pattern of mean maximum lateral displacement (z(max)) and mean maximum bending angle (beta(max)) along the body in the bonito differed from that of both chub mackerel Scomber japonicus and kawakawa tuna Euthynnus affinis; z(max) was highest in the bonito. This study verifies that S. chiliensis is a carangiform swimmer and supports the hypothesis that the thunniform locomotor mode is a derived tuna characteristic associated with changes in this group's myotomal architecture. The finding that yaw and z(max) were greater in the bonito than in both mackerels and tunas suggests that swimming kinematics in the bonito is not intermediate

  15. Anti-wrinkle effects of a tuna heart H2O fraction on Hs27 human fibroblasts.

    PubMed

    Kim, Young-Min; Jung, Hee-Jin; Choi, Jae-Sue; Nam, Taek-Jeong

    2016-01-01

    With the increase in life expectancy, there is also growing interest in anti-aging treatments and technologies. The development of anti-aging functional drugs for the skin, and foods from natural sources, may offer solutions to this global matter. Aging involves structural, functional and biochemical changes that occur throughout cells and bodily tissues; the amount of hormones secreted from of all human organs, including the skin, decreases over time. Matrix metalloproteinase (MMP) genes (MMP-1 and -8) play an important role in the aging of skin fibroblasts. For example, an increased MMP expression causes accelerated aging and the degradation of skin elasticity-related genes. In the present study, we examined the anti-wrinkle effects of tuna heart extract which are mediated through the inhibition of MMPs in skin cells. Generally, tuna contains high concentrations of selenium and antioxidants, which serve to remove free radicals, and is known to delay skin and body aging. In addition, unsaturated fatty acids in tuna help to maintain the natural glossy look of skin, and increase skin elasticity, providing moisture for dry skin. A recent study confirmed the various bio-effects of boiled tuna extract and muscle. However, bioactivity studies using tuna heart are limited. Thus, in the present study, we obtained extracts and fractions of tuna heart, and examined their effects on Hs27 human fibroblast proliferation using an MTS assay. In addition, we measured procollagen type 1 levels and elastase activity, and performed β-galactosidase staining. We then measured the expression levels of phosphatidylinositol 3-kinase/Akt and MMP-related genes by western blot analysis and RT-PCR. Our results revealed that tuna heart extract decreased MMP expression by upregulating tissue inhibitors of metalloproteinase-1 (TIMP-1) and decreasing elastase activity, thus exerting anti-aging and anti-wrinkle effects by increasing collagen synthesis and promoting skin fibroblast

  16. Photobacterium angustum and Photobacterium kishitanii, Psychrotrophic High-Level Histamine-Producing Bacteria Indigenous to Tuna.

    PubMed

    Bjornsdottir-Butler, K; McCarthy, S A; Dunlap, P V; Benner, R A

    2016-01-29

    Scombrotoxin fish poisoning (SFP) remains the main contributor of fish poisoning incidents in the United States, despite efforts to control its spread. Psychrotrophic histamine-producing bacteria (HPB) indigenous to scombrotoxin-forming fish may contribute to the incidence of SFP. We examined the gills, skin, and anal vents of yellowfin (n = 3), skipjack (n = 1), and albacore (n = 6) tuna for the presence of indigenous HPB. Thirteen HPB strains were isolated from the anal vent samples from albacore (n = 3) and yellowfin (n = 2) tuna. Four of these isolates were identified as Photobacterium kishitanii and nine isolates as Photobacterium angustum; these isolates produced 560 to 603 and 1,582 to 2,338 ppm histamine in marine broth containing 1% histidine (25°C for 48 h), respectively. The optimum growth temperatures and salt concentrations were 26 to 27°C and 1% salt for P. kishitanii and 30 to 32°C and 2% salt for P. angustum in Luria 70% seawater (LSW-70). The optimum activity of the HDC enzyme was at 15 to 30°C for both species. At 5°C, P. kishitanii and P. angustum had growth rates of 0.1 and 0.2 h(-1), respectively, and the activities of histidine decarboxylase (HDC) enzymes were 71% and 63%, respectively. These results show that indigenous HPB in tuna are capable of growing at elevated and refrigeration temperatures. These findings demonstrate the need to examine the relationships between the rate of histamine production at refrigeration temperatures, seafood shelf life, and regulatory limits. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. The Conservation and Management of Tunas and Their Relatives: Setting Life History Research Priorities

    PubMed Central

    Juan-Jordá, Maria José; Mosqueira, Iago; Freire, Juan; Dulvy, Nicholas K.

    2013-01-01

    Scombrids (tunas, bonitos, Spanish mackerels and mackerels) support important fisheries in tropical, subtropical and temperate waters around the world, being one of the most economically- and socially-important marine species globally. Their sustainable exploitation, management and conservation depend on accurate life history information for the development of quantitative fisheries stock assessments, and in the fishery data-poor situations for the identification of vulnerable species. Here, we assemble life history traits (maximum size, growth, longevity, maturity, fecundity, spawning duration and spawning interval) for the 51 species of scombrids globally. We identify major biological gaps in knowledge and prioritize life history research needs in scombrids based on their biological gaps in knowledge, the importance of their fisheries and their current conservation status according to the International Union for Conservation of Nature Red List. We find that the growth and reproductive biology of tunas and mackerel species have been more extensively studied than for Spanish mackerels and bonitos, although there are notable exceptions in all groups. We also reveal that reproductive biology of species, particular fecundity, is the least studied biological aspect in scombrids. We identify two priority groups, including 32 species of scombrids, and several populations of principal market tunas, for which life history research should be prioritized following the species-specific life history gaps identified in this study in the coming decades. By highlighting the important gaps in biological knowledge and providing a priority setting for life history research in scombrid species this study provides guidance for management and conservation and serves as a guide for biologists and resource managers interested in the biology, ecology, and management of scombrid species. PMID:23950930

  18. The conservation and management of tunas and their relatives: setting life history research priorities.

    PubMed

    Juan-Jordá, Maria José; Mosqueira, Iago; Freire, Juan; Dulvy, Nicholas K

    2013-01-01

    Scombrids (tunas, bonitos, Spanish mackerels and mackerels) support important fisheries in tropical, subtropical and temperate waters around the world, being one of the most economically- and socially-important marine species globally. Their sustainable exploitation, management and conservation depend on accurate life history information for the development of quantitative fisheries stock assessments, and in the fishery data-poor situations for the identification of vulnerable species. Here, we assemble life history traits (maximum size, growth, longevity, maturity, fecundity, spawning duration and spawning interval) for the 51 species of scombrids globally. We identify major biological gaps in knowledge and prioritize life history research needs in scombrids based on their biological gaps in knowledge, the importance of their fisheries and their current conservation status according to the International Union for Conservation of Nature Red List. We find that the growth and reproductive biology of tunas and mackerel species have been more extensively studied than for Spanish mackerels and bonitos, although there are notable exceptions in all groups. We also reveal that reproductive biology of species, particular fecundity, is the least studied biological aspect in scombrids. We identify two priority groups, including 32 species of scombrids, and several populations of principal market tunas, for which life history research should be prioritized following the species-specific life history gaps identified in this study in the coming decades. By highlighting the important gaps in biological knowledge and providing a priority setting for life history research in scombrid species this study provides guidance for management and conservation and serves as a guide for biologists and resource managers interested in the biology, ecology, and management of scombrid species.

  19. Encapsulation of mixtures of tuna oil, tributyrin and resveratrol in a spray dried powder formulation.

    PubMed

    Sanguansri, Luz; Day, Li; Shen, Zhiping; Fagan, Peter; Weerakkody, Rangika; Cheng, Li Jiang; Rusli, Jenny; Augustin, Mary Ann

    2013-12-01

    Spray dried emulsions are effective for carrying and stabilising combinations of fish oil and tributyrin, fish oil and resveratrol, or fish oil, tributyrin and resveratrol in one formulation. The encapsulation efficiencies were >99% for all three bioactives when a heated mixture of sodium caseinate: glucose: dried glucose syrup matrix (Encapsulant matrix 1) was used. When a heated sodium caseinate: glucose: processed starch matrix (Encapsulant matrix 2) was used, the encapsulation efficiencies were 90-92% for tributyrin and approximately 98% for resveratrol for all formulations but 79-91% for tuna oil where the efficiency was more formulation dependent. There was 84-86% remaining EPA, 85-87% remaining DHA, 85% remaining tributyrin and 94-96% remaining resveratrol after 18 months at 25 °C storage of the spray dried emulsions using Encapsulant matrix 1 across all formulations. In comparison, there was 83-87% remaining EPA and 84-89% remaining DHA, 80-82% remaining tributyrin, and 81-100% remaining resveratrol across all formulations with Encapsulant matrix 2. In vitro studies showed that on sequential exposure to simulated gastric and intestinal fluids, <5% tuna oil was found as triglycerides, but all the tributyrin had been lipolysed. The presence of diglycerides, monoglycerides and free fatty acids in the in vitro digests suggested that lipolysis of tuna oil had occurred. The type of matrix used for encapsulating the bioactives had little effect on the lipolysis of the oils but affected the amount of solvent extractable resveratrol. The ability of delivering mixtures of bioactives within one formulation was demonstrated.

  20. Photobacterium angustum and Photobacterium kishitanii, Psychrotrophic High-Level Histamine-Producing Bacteria Indigenous to Tuna

    PubMed Central

    McCarthy, S. A.; Dunlap, P. V.; Benner, R. A.

    2016-01-01

    Scombrotoxin fish poisoning (SFP) remains the main contributor of fish poisoning incidents in the United States, despite efforts to control its spread. Psychrotrophic histamine-producing bacteria (HPB) indigenous to scombrotoxin-forming fish may contribute to the incidence of SFP. We examined the gills, skin, and anal vents of yellowfin (n = 3), skipjack (n = 1), and albacore (n = 6) tuna for the presence of indigenous HPB. Thirteen HPB strains were isolated from the anal vent samples from albacore (n = 3) and yellowfin (n = 2) tuna. Four of these isolates were identified as Photobacterium kishitanii and nine isolates as Photobacterium angustum; these isolates produced 560 to 603 and 1,582 to 2,338 ppm histamine in marine broth containing 1% histidine (25°C for 48 h), respectively. The optimum growth temperatures and salt concentrations were 26 to 27°C and 1% salt for P. kishitanii and 30 to 32°C and 2% salt for P. angustum in Luria 70% seawater (LSW-70). The optimum activity of the HDC enzyme was at 15 to 30°C for both species. At 5°C, P. kishitanii and P. angustum had growth rates of 0.1 and 0.2 h−1, respectively, and the activities of histidine decarboxylase (HDC) enzymes were 71% and 63%, respectively. These results show that indigenous HPB in tuna are capable of growing at elevated and refrigeration temperatures. These findings demonstrate the need to examine the relationships between the rate of histamine production at refrigeration temperatures, seafood shelf life, and regulatory limits. PMID:26826233