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Fredrick I Archer - One of the best experts on this subject based on the ideXlab platform.
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mitogenomic differentiation in spinner stenella longirostris and pantropical spotted dolphins s attenuata from the eastern tropical pacific ocean
Marine Mammal Science, 2019Co-Authors: Fredrick I Archer, Matthew S Leslie, Phillip A MorinAbstract:Endemic subspecies and multiple stocks have been proposed for spinner (Stenella longirostris) and spotted dolphins (Stenella attenuata), two species with historically high mortality due to bycatch in the eastern tropical Pacific yellowfin Tuna Fishery. However, there has been low statistical power in tests for genetic differentiation among most of these stocks, due to large historical abundances, ongoing gene flow, and recent divergence. We tested for structure at multiple hierarchical levels by collecting whole mitochondrial genome sequences (mtDNA) and nuclear SNPs (nuDNA) from 104 spinner and 76 spotted dolphins using capture array library enrichment and highly paralleled DNA sequencing. MtDNA showed weak but significant differences between subspecies of spotted (FST: 0.0125; P = 0.0402) and spinner dolphins (FST: 0.0133; P = 0.034). NuDNA supported subspecies of spotted but not spinner dolphins. Relatively strong and significant differentiation was detected between whitebelly and eastern spinner stocks using nuDNA (FST: 0.0297; P = 0.0059). Neither mtDNA nor nuDNA supported the division of existing offshore stocks of spotted dolphins or Tres Marias spinner dolphins. This work identifies a genetic basis for biologically meaningful management units of these two species, a critical component in understanding their response in the face of historical and continued Fishery interactions.
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mitogenome and nuclear dna differentiation in spinner stenella longirostris and pantropical spotted dolphins s attenuata from the eastern tropical pacific ocean
bioRxiv, 2016Co-Authors: Matthew S Leslie, Fredrick I Archer, Phillip A MorinAbstract:Endemic subspecies and multiple stocks have been proposed for spinner (Stenella longirostris) and spotted dolphins (Stenella attenuata), two species with historically high mortality due to bycatch in the eastern tropical Pacific yellowfin Tuna Fishery. However, there has been low statistical power in tests for genetic differentiation among most of these stocks, due to large historical abundances, ongoing gene flow, and recent divergence. We tested for structure at multiple hierarchical levels by collecting whole mitochondrial genome sequences (mtDNA) and nuclear SNPs (nuDNA) from 104 spinner and 76 spotted dolphins using capture array library enrichment and highly paralleled DNA sequencing. MtDNA showed weak but significant differences between subspecies of spotted (FST: 0.0125; P = 0.0402) and spinner dolphins (FST: 0.0133; P = 0.034). NuDNA supported subspecies of spotted but not spinner dolphins. Relatively strong and significant differentiation was detected between whitebelly and eastern spinner stocks using nuDNA (FST: 0.0297; P = 0.0059). Neither mtDNA nor nuDNA supported the division of existing offshore stocks of spotted dolphins or Tres Marias spinner dolphins. This work identifies a genetic basis for biologically meaningful management units of these two species, a critical component in understanding their response in the face of historical and continued Fishery interactions.
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pregnancy patterns of pantropical spotted dolphins stenella attenuata in the eastern tropical pacific determined from hormonal analysis of blubber biopsies and correlations with the purse seine Tuna Fishery
Marine Biology, 2013Co-Authors: Nicholas M Kellar, Marisa L Trego, Susan J Chivers, Fredrick I ArcherAbstract:The northeastern offshore population of the pantropical spotted dolphin (Stenella attenuata) in the east- ern tropical Pacific remains listed as depleted under the Marine Mammal Protection act, and recent estimates of abundance show that recovery has been slow. One hypoth- esis for the slow recovery is that continued chase and encir - clement by the Tuna Fishery negatively affects reproduction. Insufficient life-history sampling in this region over the last two decades makes traditional estimates of reproductive rates impossible. Here, we examine the current reproduc- tive patterns of these dolphins by measuring blubber pro- gesterone (BP) concentrations in biopsy samples to assess pregnancy state. BP was quantified in 212 biopsies from female offshore spotted dolphins sampled between 1998 and 2003 in the northeastern tropical Pacific, and we found that 11.5 % of the biopsied females (mature and immature) were pregnant. The relationship between pregnancy and Fishery exposure was analyzed, and we found that pregnant females were exposed to significantly less Fishery activ- ity than non-pregnant ones (p = 0.022), suggesting that the Fishery may have an inhibitive effect on pregnancy. Spatial analysis indicated that pregnancy was more aggre- gated than random (p < 0.05) at a scale up to 180-nmi, with
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pregnancy patterns of pantropical spotted dolphins stenella attenuata in the eastern tropical pacific determined from hormonal analysis of blubber biopsies and correlations with the purse seine Tuna Fishery
Marine Biology, 2013Co-Authors: Nicholas M Kellar, Marisa L Trego, Susan J Chivers, Fredrick I ArcherAbstract:The northeastern offshore population of the pantropical spotted dolphin (Stenella attenuata) in the eastern tropical Pacific remains listed as depleted under the Marine Mammal Protection Act, and recent estimates of abundance show that recovery has been slow. One hypothesis for the slow recovery is that continued chase and encirclement by the Tuna Fishery negatively affects reproduction. Insufficient life-history sampling in this region over the last two decades makes traditional estimates of reproductive rates impossible. Here, we examine the current reproductive patterns of these dolphins by measuring blubber progesterone (BP) concentrations in biopsy samples to assess pregnancy state. BP was quantified in 212 biopsies from female offshore spotted dolphins sampled between 1998 and 2003 in the northeastern tropical Pacific, and we found that 11.5 % of the biopsied females (mature and immature) were pregnant. The relationship between pregnancy and Fishery exposure was analyzed, and we found that pregnant females were exposed to significantly less Fishery activity than non-pregnant ones (p = 0.022), suggesting that the Fishery may have an inhibitive effect on pregnancy. Spatial analysis indicated that pregnancy was more aggregated than random (p < 0.05) at a scale up to 180-nmi, with the highest proportion pregnant in the mouth of the Gulf of California, an area with relatively low reported Fishery activity.
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age and length at weaning and development of diet of pantropical spotted dolphins stenella attenuata from the eastern tropical pacific
Marine Mammal Science, 2004Co-Authors: Fredrick I Archer, Kelly M RobertsonAbstract:Using stomach contents from 203 spotted dolphins (Stenella attenuata) killed in the yellowfin Tuna Fishery, we modeled the weaning process of calves. Spotted dolphins began to take solid food at approximately 6 mo of age, or 115 cm, but continued to suckle until they were nearly 2 yr old. Calves tended to feed more frequently on squid as they got older, which suggested there was a shift in diet during weaning. The average age and total body length at weaning was estimated to be 0.8 yr (approximately 9 mo) and 122 cm. The oldest suckling calf was almost 2 yr old, which suggests that some calves continued to suckle for more than a year after they could have been weaned. A better understanding of the weaning process, especially quantifying the period of time when calves are nutritionally dependent on their mothers may lead to a better evaluation of their potential vulnerability to the disturbance caused by the yellowfin Tuna purse-seine Fishery.
Thomas D Williams - One of the best experts on this subject based on the ideXlab platform.
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electronic tagging and population structure of atlantic bluefin Tuna
Nature, 2005Co-Authors: Barbara A Block, Andreas Walli, Michael J. W. Stokesbury, Charles J. Farwell, Andre Boustany, Heidi Dewar, Kevin C Weng, Thomas D WilliamsAbstract:The Atlantic bluefin Tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin Tuna Fishery collapsed and some conservationists say it will not recover unless the International Commission for Conservation of Atlantic Tunas adopts a tougher regime. Results from an electronic tagging programme on bluefin Tuna are presented this week, and they make alarming reading. Western tagged bluefin Tuna are shown to migrate freely across the international stock boundary into the eastern Atlantic, where they are vulnerable to European fisheries; and both known spawning grounds, in the Gulf of Mexico and the Mediterranean Sea, are shown to be linked to the endangered western Atlantic Fishery. Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems1,2,3,4,5,6. Here we report on the electronic tagging of 772 Atlantic bluefin Tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data7,8,9 that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin Tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin Tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin Tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin Tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.
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electronic tagging and population structure of atlantic bluefin Tuna
Nature, 2005Co-Authors: Barbara A Block, Andreas Walli, Michael J. W. Stokesbury, Charles J. Farwell, Andre Boustany, Heidi Dewar, Kevin C Weng, Thomas D WilliamsAbstract:The Atlantic bluefin Tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin Tuna Fishery collapsed and some conservationists say it will not recover unless the International Commission for Conservation of Atlantic Tunas adopts a tougher regime. Results from an electronic tagging programme on bluefin Tuna are presented this week, and they make alarming reading. Western tagged bluefin Tuna are shown to migrate freely across the international stock boundary into the eastern Atlantic, where they are vulnerable to European fisheries; and both known spawning grounds, in the Gulf of Mexico and the Mediterranean Sea, are shown to be linked to the endangered western Atlantic Fishery. Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems1,2,3,4,5,6. Here we report on the electronic tagging of 772 Atlantic bluefin Tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data7,8,9 that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin Tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin Tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin Tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin Tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.
Michael J. W. Stokesbury - One of the best experts on this subject based on the ideXlab platform.
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electronic tagging and population structure of atlantic bluefin Tuna
Nature, 2005Co-Authors: Barbara A Block, Andreas Walli, Michael J. W. Stokesbury, Charles J. Farwell, Andre Boustany, Heidi Dewar, Kevin C Weng, Thomas D WilliamsAbstract:The Atlantic bluefin Tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin Tuna Fishery collapsed and some conservationists say it will not recover unless the International Commission for Conservation of Atlantic Tunas adopts a tougher regime. Results from an electronic tagging programme on bluefin Tuna are presented this week, and they make alarming reading. Western tagged bluefin Tuna are shown to migrate freely across the international stock boundary into the eastern Atlantic, where they are vulnerable to European fisheries; and both known spawning grounds, in the Gulf of Mexico and the Mediterranean Sea, are shown to be linked to the endangered western Atlantic Fishery. Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems1,2,3,4,5,6. Here we report on the electronic tagging of 772 Atlantic bluefin Tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data7,8,9 that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin Tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin Tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin Tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin Tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.
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electronic tagging and population structure of atlantic bluefin Tuna
Nature, 2005Co-Authors: Barbara A Block, Andreas Walli, Michael J. W. Stokesbury, Charles J. Farwell, Andre Boustany, Heidi Dewar, Kevin C Weng, Thomas D WilliamsAbstract:The Atlantic bluefin Tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin Tuna Fishery collapsed and some conservationists say it will not recover unless the International Commission for Conservation of Atlantic Tunas adopts a tougher regime. Results from an electronic tagging programme on bluefin Tuna are presented this week, and they make alarming reading. Western tagged bluefin Tuna are shown to migrate freely across the international stock boundary into the eastern Atlantic, where they are vulnerable to European fisheries; and both known spawning grounds, in the Gulf of Mexico and the Mediterranean Sea, are shown to be linked to the endangered western Atlantic Fishery. Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems1,2,3,4,5,6. Here we report on the electronic tagging of 772 Atlantic bluefin Tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data7,8,9 that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin Tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin Tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin Tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin Tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.
Rognvaldur Hannesson - One of the best experts on this subject based on the ideXlab platform.
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the exclusive economic zone and economic development in the pacific island countries
Marine Policy, 2008Co-Authors: Rognvaldur HannessonAbstract:The exclusive economic zone (EEZ) became accepted internationally in the 1970s. This transferred resource wealth to the coastal states establishing such zones. The history of the EEZ is reviewed, and its impact on the economic development of the Pacific island states considered. The growth performance and the Tuna Fishery development of these states are reviewed and possible causes of limited success discussed. The use of trust funds to increase the resource wealth of the Pacific island states is briefly considered.
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the exclusive economic zone and economic development in the pacific island countries
Marine Policy, 2008Co-Authors: Rognvaldur HannessonAbstract:The exclusive economic zone (EEZ) became accepted internationally in the 1970s. This transferred resource wealth to the coastal states establishing such zones. The history of the EEZ is reviewed, and its impact on the economic development of the Pacific island states considered. The growth performance and the Tuna Fishery development of these states are reviewed and possible causes of limited success discussed. The use of trust funds to increase the resource wealth of the Pacific island states is briefly considered.
Phillip A Morin - One of the best experts on this subject based on the ideXlab platform.
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mitogenomic differentiation in spinner stenella longirostris and pantropical spotted dolphins s attenuata from the eastern tropical pacific ocean
Marine Mammal Science, 2019Co-Authors: Fredrick I Archer, Matthew S Leslie, Phillip A MorinAbstract:Endemic subspecies and multiple stocks have been proposed for spinner (Stenella longirostris) and spotted dolphins (Stenella attenuata), two species with historically high mortality due to bycatch in the eastern tropical Pacific yellowfin Tuna Fishery. However, there has been low statistical power in tests for genetic differentiation among most of these stocks, due to large historical abundances, ongoing gene flow, and recent divergence. We tested for structure at multiple hierarchical levels by collecting whole mitochondrial genome sequences (mtDNA) and nuclear SNPs (nuDNA) from 104 spinner and 76 spotted dolphins using capture array library enrichment and highly paralleled DNA sequencing. MtDNA showed weak but significant differences between subspecies of spotted (FST: 0.0125; P = 0.0402) and spinner dolphins (FST: 0.0133; P = 0.034). NuDNA supported subspecies of spotted but not spinner dolphins. Relatively strong and significant differentiation was detected between whitebelly and eastern spinner stocks using nuDNA (FST: 0.0297; P = 0.0059). Neither mtDNA nor nuDNA supported the division of existing offshore stocks of spotted dolphins or Tres Marias spinner dolphins. This work identifies a genetic basis for biologically meaningful management units of these two species, a critical component in understanding their response in the face of historical and continued Fishery interactions.
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mitogenome and nuclear dna differentiation in spinner stenella longirostris and pantropical spotted dolphins s attenuata from the eastern tropical pacific ocean
bioRxiv, 2016Co-Authors: Matthew S Leslie, Fredrick I Archer, Phillip A MorinAbstract:Endemic subspecies and multiple stocks have been proposed for spinner (Stenella longirostris) and spotted dolphins (Stenella attenuata), two species with historically high mortality due to bycatch in the eastern tropical Pacific yellowfin Tuna Fishery. However, there has been low statistical power in tests for genetic differentiation among most of these stocks, due to large historical abundances, ongoing gene flow, and recent divergence. We tested for structure at multiple hierarchical levels by collecting whole mitochondrial genome sequences (mtDNA) and nuclear SNPs (nuDNA) from 104 spinner and 76 spotted dolphins using capture array library enrichment and highly paralleled DNA sequencing. MtDNA showed weak but significant differences between subspecies of spotted (FST: 0.0125; P = 0.0402) and spinner dolphins (FST: 0.0133; P = 0.034). NuDNA supported subspecies of spotted but not spinner dolphins. Relatively strong and significant differentiation was detected between whitebelly and eastern spinner stocks using nuDNA (FST: 0.0297; P = 0.0059). Neither mtDNA nor nuDNA supported the division of existing offshore stocks of spotted dolphins or Tres Marias spinner dolphins. This work identifies a genetic basis for biologically meaningful management units of these two species, a critical component in understanding their response in the face of historical and continued Fishery interactions.
