James Bodkin - Academia.edu (original) (raw)
Papers by James Bodkin
Molecular Ecology Resources, Aug 17, 2011
CRC Press eBooks, Jun 9, 2021
Scientific Reports, Feb 28, 2020
Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enh... more Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We examined the spatial distribution of S. neurona exposure risk based on serum antibody testing and assessed risk factors for exposure in animals from California, Washington, British Columbia and Alaska. Significant spatial clustering of seropositive animals was observed in California and Washington, compared with British Columbia and Alaska. Adult males were at greatest risk for exposure to S. neurona, and there were strong associations with terrestrial features (wetlands, cropland, high human housing-unit density). In California, habitats containing soft sediment exhibited greater risk than hard substrate or kelp beds. Consuming a diet rich in clams was also associated with increased exposure risk. These findings suggest a transmission pathway analogous to that described for Toxoplasma gondii, with infectious stages traveling in freshwater runoff and being concentrated in particular locations by marine habitat features, ocean physical processes, and invertebrate bioconcentration. Sarcocystis neurona, most widely known as the main etiologic agent of equine protozoal myeloencephalitis, is one of two pathogens that causes fatal protozoal encephalitis (PE) in sea otters (Enhydra lutris). Following recognition of this disease in sea otters 1 , S. neurona and Toxoplasma gondii were identified as important causes of mortality of southern sea otters (E. lutris nereis) 1. Although exposure to S. neurona may be slightly less common overall 2 , S. neurona-related disease is generally more severe, at least in acute and subacute cases 1,2. A mass-stranding event in 2004 was attributed largely to S. neurona infection: forty sick or dead sea otters stranded on beaches near Morro
The sea otter, Enhydra lutris, is the largest member of the Mustelidae family and is the only one... more The sea otter, Enhydra lutris, is the largest member of the Mustelidae family and is the only one which lives entirely in marine waters. Sea otters are unique among marine mammals because, unlike whales, dolphins and seals, they do not have a layer of fat or blubber to keep them warm in the cool oceans of the North Pacific. Instead, sea otters depend on dense fur that traps tiny air bubbles to insulate them from the cold water. To stay warm, they also must maintain a very high metabolic rate, requiring the sea otter to eat about 25% of its body weight per day. Sea otters eat mostly invertebrates-clams, crabs, ur chins, and mussels-found in shallow coastal waters.
Diversity and Distributions, Apr 11, 2019
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Alaska Sea Grant, University of Alaska Fairbanks eBooks, Jun 1, 2005
All existing sea otter (Enhydra lutris) populations have suffered at least 1, and in some cases 2... more All existing sea otter (Enhydra lutris) populations have suffered at least 1, and in some cases 2, population bottlenecks. The 1st occurred during the 18th and 19th centuries as a result of commercial hunting that eliminated sea otters from much their native range and reduced surviving populations to small remnants. The 2nd bottleneck occurred when small numbers of otters were reintroduced, via translocation, to areas where the species had been eliminated. We examined genetic variation at 7 microsatellite loci and the mitochondrial DNA (mtDNA) control region in 3 remnant populations, Amchitka Island (Aleutian Islands, Alaska), central coastal California, and Prince William Sound (Alaska), and in 2 reintroduced populations, southeast Alaska and Washington, that were founded with transplants from Amchitka, and in the case of southeast Alaska, individuals from Prince William Sound as well. We found no evidence of reduced genetic diversity in translocated populations. Average expected microsatellite heterozygosities (H E) were similar in all populations (range, 0.40-0.47), and mtDNA haplotype diversities were higher in reintroduced populations (0.51 for both Washington and southeast Alaska) than in remnant populations (X ϭ 0.35; range, 0.18-0.45). The levels of genetic diversity we observed within sea otter populations were relatively low when compared with other mammals and are thought to be the result of fur trade exploitation.
to elucidate the process of, and constraints to, population recovery. These studies demonstrated ... more to elucidate the process of, and constraints to, population recovery. These studies demonstrated that harlequin ducks were exposed to lingering oil over a much longer time frame (i.e., through at least 2011, 22 years following the spill) than expected at the time of the spill, based on elevated levels of cytochrome P4501A induction in birds from oiled areas. In addition, several lines of evidence suggested that direct population injury persisted through at least 1998. Specifically, female winter survival probabilities were found to differ between oiled and unoiled areas, and densities were shown to be lower in oiled than unoiled areas after accounting for habitat-related effects. More recent data have indicated that female winter survival did not differ between oiled and unoiled sites during 2000-03, suggesting that direct effects of oil exposure on demographic properties had abated. Using demographic data, a population model was constructed to estimate timeline until recovery of numbers to pre-spill levels, which was projected to be 24 years post-spill or 2013. However, persistence of oil in the environment and evidence of exposure of harlequin ducks to that oil through 2011 has led to continued monitoring to evaluate the timeline of exposure. The current work was designed as another data point in that time series for 2013.
California Fish and Game, 1985
Encyclopedia of Marine Mammals, 2018
Summary The following account provides a broad overview of the comparative biology and ecology of... more Summary The following account provides a broad overview of the comparative biology and ecology of otters, with particular emphasis on those species or populations that live in the sea. Sea otters are featured prominently, in part because they are comparatively well known and in part because they live exclusively in the sea whereas other otters have obligate associations with freshwater and terrestrial environments.
Molecular Ecology Resources, Aug 17, 2011
CRC Press eBooks, Jun 9, 2021
Scientific Reports, Feb 28, 2020
Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enh... more Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We examined the spatial distribution of S. neurona exposure risk based on serum antibody testing and assessed risk factors for exposure in animals from California, Washington, British Columbia and Alaska. Significant spatial clustering of seropositive animals was observed in California and Washington, compared with British Columbia and Alaska. Adult males were at greatest risk for exposure to S. neurona, and there were strong associations with terrestrial features (wetlands, cropland, high human housing-unit density). In California, habitats containing soft sediment exhibited greater risk than hard substrate or kelp beds. Consuming a diet rich in clams was also associated with increased exposure risk. These findings suggest a transmission pathway analogous to that described for Toxoplasma gondii, with infectious stages traveling in freshwater runoff and being concentrated in particular locations by marine habitat features, ocean physical processes, and invertebrate bioconcentration. Sarcocystis neurona, most widely known as the main etiologic agent of equine protozoal myeloencephalitis, is one of two pathogens that causes fatal protozoal encephalitis (PE) in sea otters (Enhydra lutris). Following recognition of this disease in sea otters 1 , S. neurona and Toxoplasma gondii were identified as important causes of mortality of southern sea otters (E. lutris nereis) 1. Although exposure to S. neurona may be slightly less common overall 2 , S. neurona-related disease is generally more severe, at least in acute and subacute cases 1,2. A mass-stranding event in 2004 was attributed largely to S. neurona infection: forty sick or dead sea otters stranded on beaches near Morro
The sea otter, Enhydra lutris, is the largest member of the Mustelidae family and is the only one... more The sea otter, Enhydra lutris, is the largest member of the Mustelidae family and is the only one which lives entirely in marine waters. Sea otters are unique among marine mammals because, unlike whales, dolphins and seals, they do not have a layer of fat or blubber to keep them warm in the cool oceans of the North Pacific. Instead, sea otters depend on dense fur that traps tiny air bubbles to insulate them from the cold water. To stay warm, they also must maintain a very high metabolic rate, requiring the sea otter to eat about 25% of its body weight per day. Sea otters eat mostly invertebrates-clams, crabs, ur chins, and mussels-found in shallow coastal waters.
Diversity and Distributions, Apr 11, 2019
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Alaska Sea Grant, University of Alaska Fairbanks eBooks, Jun 1, 2005
All existing sea otter (Enhydra lutris) populations have suffered at least 1, and in some cases 2... more All existing sea otter (Enhydra lutris) populations have suffered at least 1, and in some cases 2, population bottlenecks. The 1st occurred during the 18th and 19th centuries as a result of commercial hunting that eliminated sea otters from much their native range and reduced surviving populations to small remnants. The 2nd bottleneck occurred when small numbers of otters were reintroduced, via translocation, to areas where the species had been eliminated. We examined genetic variation at 7 microsatellite loci and the mitochondrial DNA (mtDNA) control region in 3 remnant populations, Amchitka Island (Aleutian Islands, Alaska), central coastal California, and Prince William Sound (Alaska), and in 2 reintroduced populations, southeast Alaska and Washington, that were founded with transplants from Amchitka, and in the case of southeast Alaska, individuals from Prince William Sound as well. We found no evidence of reduced genetic diversity in translocated populations. Average expected microsatellite heterozygosities (H E) were similar in all populations (range, 0.40-0.47), and mtDNA haplotype diversities were higher in reintroduced populations (0.51 for both Washington and southeast Alaska) than in remnant populations (X ϭ 0.35; range, 0.18-0.45). The levels of genetic diversity we observed within sea otter populations were relatively low when compared with other mammals and are thought to be the result of fur trade exploitation.
to elucidate the process of, and constraints to, population recovery. These studies demonstrated ... more to elucidate the process of, and constraints to, population recovery. These studies demonstrated that harlequin ducks were exposed to lingering oil over a much longer time frame (i.e., through at least 2011, 22 years following the spill) than expected at the time of the spill, based on elevated levels of cytochrome P4501A induction in birds from oiled areas. In addition, several lines of evidence suggested that direct population injury persisted through at least 1998. Specifically, female winter survival probabilities were found to differ between oiled and unoiled areas, and densities were shown to be lower in oiled than unoiled areas after accounting for habitat-related effects. More recent data have indicated that female winter survival did not differ between oiled and unoiled sites during 2000-03, suggesting that direct effects of oil exposure on demographic properties had abated. Using demographic data, a population model was constructed to estimate timeline until recovery of numbers to pre-spill levels, which was projected to be 24 years post-spill or 2013. However, persistence of oil in the environment and evidence of exposure of harlequin ducks to that oil through 2011 has led to continued monitoring to evaluate the timeline of exposure. The current work was designed as another data point in that time series for 2013.
California Fish and Game, 1985
Encyclopedia of Marine Mammals, 2018
Summary The following account provides a broad overview of the comparative biology and ecology of... more Summary The following account provides a broad overview of the comparative biology and ecology of otters, with particular emphasis on those species or populations that live in the sea. Sea otters are featured prominently, in part because they are comparatively well known and in part because they live exclusively in the sea whereas other otters have obligate associations with freshwater and terrestrial environments.