observations on the infectivity of parasitic third-stage larvae of uncinaria lucasi stiles 1901 (nematoda: ancylostomatidae) of northern fur seals, callorhinus ursinus linn., on st. paul island, alaska.twelve fur seal pups, which had not nursed their mothers, were used in an infectivity experiment. pups were exposed to parasitic 3rd-stage larvae of uncinaria lucasi from belly tissues of fur seal bulls, bachelors, and pregnant cows, to determine maturation capability of the larvae. hookworms were not recovered from the intestines of 3 pups receiving larvae from belly blubber of bulls, 6 pups receiving larvae from belly blubber of bachelors, and 1 nonexposed pup. maturation of hookworms did occu ...1978149188
viral serologic survey of bowhead whales in alaska.serum samples from 21 of 36 eskimo harvested bowhead whales (balaena mysticetus) were positive by virus neutralization (50% endpoint titer > or = 1:28 and/or 100% endpoint titer > or = 1:20) for antibodies to at least one virus serotype from the calicivirus family, vesicular exanthema of swine virus (vesv) and san miguel sea lion virus (smsv). many animals were positive to more than one serotype when using the spearman-karber (s-k) method for calculating antibody titers. the most common serotype ...19989476224
viral and bacterial serology of free-ranging pacific walrus.serum or heparinized plasma samples were obtained between 1994 and 1996 from 20 male and 20 female adult free-ranging pacific walrus (odobenus rosmarus divergens) from st. lawrence island and round island, alaska. samples were screened for antibodies to some potentially pathogenic bacteria and viruses. no sample had detectable antibody to brucella spp. three of 40 (8%) had low antibody titers to leptospira interrogans serovars. phocine distemper virus antibodies were not detected. serologic resp ...200211838234
historic importance of some aspects of research by o. wilford olsen on hookworms (uncinaria lucasi) in northern fur seals (callorhinus ursinus) and steller sea lions (eumatopias jubatus) in 1951 on st. paul island, alaska.the purpose of this paper is to disseminate, more widely, certain historically important aspects of research by o. wilford olsen on hookworms (uncinaria lucasi) in northern fur seals (callorhinus ursinus) and steller sea lions (eumatopias jubatus) in 1951 on st. paul island, alaska. highly meaningful facets of the research were recorded only in a report with limited availability by olsen in 1952. portions of his research presented here include measurements of hookworm free-living infective third ...200515719260
infectious disease and the decline of steller sea lions (eumetopias jubatus) in alaska, usa: insights from serologic data.serologic data were examined to determine whether infectious disease may have played a role in the decline of steller sea lions (eumetopias jubatus) in the gulf of alaska and aleutian islands, usa. available published data, unpublished data, and recent collections (1997-2000) were compared and reviewed. data were stratified by geography to compare the declining western alaskan population in the aleutian islands through eastern prince william sound to the increasing population in southeastern ala ...200516244061
poxvirus infection of steller sea lions (eumetopias jubatus) in alaska.lesions suggestive of poxvirus infection were observed in two steller sea lions (eumetopias jubatus) in alaska during live capture-and-release studies during 2000 and 2001. both of these animals, female pups in poor body condition, were from prince william sound; this population is part of the declining western stock. umbilicated, typically ulcerated dermal nodules were present, primarily on the fore flippers in one case, and over most of the body in the second case. histologically, there were d ...200516456163
associations between the alaska steller sea lion decline and commercial fisheries.the steller sea lion (ssl) population in alaska was listed as threatened under the endangered species act in 1990. at that time, several procedural restrictions were placed on the commercial fisheries of the region in an effort to reduce the potential for human-induced mortality on sea lions. several years have elapsed since these restrictions were put into place, and questions about their efficacy remain. in an effort to determine whether or not fisheries management measures have helped the ssl ...200616711057
the effects of age, season and geographic region on thyroid hormones in steller sea lions (eumetopias jubatus).the purpose of this study was to investigate thyroid hormone concentrations, thyroxine (t4) and triiodothyronine (t3), in order to determine basal levels in steller sea lions of different ages and over seasons. serum concentrations of total t4 were highest in steller sea lions followed by total t3 concentrations. concentrations of free t4 and free t3 were three to four orders of magnitude lower. concentrations for all four thyroid hormone measurements tended to a lower level as animals matured b ...200616815718
age-structured modeling reveals long-term declines in the natality of western steller sea lions.since the mid-1970s, the western steller sea lion (eumetopias jubatus), inhabiting alaskan waters from prince william sound west through the aleutian islands, has declined by over 80%. changing oceanographic conditions, competition from fishing operations, direct human-related mortality, and predators have been suggested as factors driving the decline, but the indirect and interactive nature of their effects on sea lions have made it difficult to attribute changes in abundance to specific factor ...200718213964
genomic characterization of novel marine vesiviruses from steller sea lions (eumetopias jubatus) from alaska.marine vesiviruses were isolated in cell culture from oral and rectal swabs and vesicular fluid from alaskan steller sea lions (ssl; eumetopias jubatus). further characterization by rt-pcr, complete genomic sequencing, and phylogenetic analyses indicated that these viruses are most closely related to the marine vesiviruses, but are distinct viruses and represent two novel genotypes. the complete genome of these two ssl isolates was sequenced after cloning their viral cdna. the genomes were found ...200818765261
expression and self-assembly of virus-like particles from two genotypes of marine vesiviruses and development of an elisa for the detection of antibodies.sequences encoding the major and minor capsid proteins (vp1 and vp2) from two marine vesivirus isolates (steller sea lion viruses v810 and v1415) were engineered for expression of virus-like particles (vlps) in the baculovirus system. the resulting vlps were morphologically similar to native vesivirus virions. purified vlps were probed in immunoblots with pooled antisera specific for nine san miguel sea lion virus (smsv) types, and a predominant protein of approximately 60kda was detected. an en ...201019913368
aerobic oral and rectal bacteria of free-ranging steller sea lion pups and juveniles (eumetopias jubatus) in alaska.bacteriologic cultures from oral, rectal, and lesion samples from free-ranging steller sea lion (ssl, eumetopias jubatus) pups and juveniles in alaska (2001-2005) were examined to determine frequency of infection by a specific subset of common and pathogenic aerobic bacteria. associations between isolated bacteria and age, sex, body condition, location, and sampling season were investigated. salmonella spp. isolates were further evaluated to determine spatial clustering (n=48) and to identify se ...201122102651
coxiella burnetii in northern fur seals and steller sea lions of alaska.coxiella burnetii, a zoonotic bacterium, has recently been identified in several marine mammal species on the pacific coast of north america, but little is known about the epidemiology, transmission, and pathogenesis in these species. we tested sera archived from northern fur seals (nfs, callorhinus ursinus; n=236) and steller sea lions (ssl, eumetopias jubatus; n=72) sampled in alaska for c. burnetii antibodies, and vaginal swabs from nfs (n=40) for c. burnetii by qpcr. the antibody prevalence ...201323568925
ecological, morphological, and molecular studies of acanthocheilonema odendhali (nematoda: filarioidea) in northern fur seals (callorhinus ursinus) on st. paul island, alaska.studies of northern fur seal (callorhinus ursinus linnaeus, 1758) infection by the filariid nematode acanthocheilonema odendhali were carried out in 2011-2012 on st. paul island, pribilof archipelago, alaska. skins of 502 humanely harvested northern fur seals from haul-out areas of five rookeries, polovina (n = 122), morjovi (n = 54), zapadni (n = 72), lukanin (n = 109), and gorbatch (n = 145), were examined. a. odendhali was found in 18% of northern fur seals. the prevalence of infection ranged ...201323760875
mercury concentrations in the fur of steller sea lions and northern fur seals from alaska.we compared total mercury (thg) concentrations in the fur of northern fur seals (callorhinus ursinus) from the depleted pribilof islands population with those of both declining and thriving populations of steller sea lions (eumetopias jubatus) from prince william sound (pws) and southeast alaska (sea), respectively. relatively low wet weight concentrations (ranges) of thg were detected in the fur of steller sea lion (ssl) pups (0.90-3.14 microg/g) and juveniles (0.56-6.75 microg/g) from both are ...200212474974
the effect of novel research activities on long-term survival of temporarily captive steller sea lions (eumetopias jubatus).two novel research approaches were developed to facilitate controlled access to, and long-term monitoring of, juvenile steller sea lions for periods longer than typically afforded by traditional fieldwork. the transient juvenile steller sea lion project at the alaska sealife center facilitated nutritional, physiological, and behavioral studies on the platform of temporary captivity. temporarily captive sea lions (tjs, n = 35) were studied, and were intraperitoneally implanted with life history t ...201526580549
organochlorine contaminant concentrations in multiple tissues of free-ranging steller sea lions (eumetopias jubatus) in alaska.the relationships of selected organochlorine (oc) contaminants between blubber, blood, feces, and milk of young, free-ranging steller sea lions (eumetopias jubatus) were examined. both between and within each tissue there was considerable individual variation. in spite of the variation, similar patterns were observed across the tissues for most of the selected pcb congeners. in all four tissues, the major pcb congeners were pcb101, pcb118, pcb138, and pcb153. the most prominent congener, both as ...201626524270
population trend and elasticities of vital rates for steller sea lions (eumetopias jubatus) in the eastern gulf of alaska: a new life-history table analysis.steller sea lion (eumetopias jubatus) numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. this study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern gulf of alaska (a sub-region of the western population) in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. ...201526488901
assessment of competition between fisheries and steller sea lions in alaska based on estimated prey biomass, fisheries removals and predator foraging behaviour.a leading hypothesis to explain the dramatic decline of steller sea lions (eumetopias jubatus) in western alaska during the latter part of the 20th century is a change in prey availability due to commercial fisheries. we tested this hypothesis by exploring the relationships between sea lion population trends, fishery catches, and the prey biomass accessible to sea lions around 33 rookeries between 2000 and 2008. we focused on three commercially important species that have dominated the sea lion ...201525950178
a longitudinal study of steller sea lion natality rates in the gulf of alaska with comparisons to census data.steller sea lion (eumetopias jubatus) numbers in the western distinct population segment are beginning to recover following the dramatic decline that began in the 1970s and ended around the turn of the century. low female reproductive rates (natality) may have contributed to the decline and remain an issue of concern for this population. during the 2000s we found high natality among steller sea lions in the gulf of alaska indicating a healthy population. this study extends these previous estimat ...201425383865
serum chemistry reference ranges for steller sea lion (eumetopias jubatus) pups from alaska: stock differentiation and comparisons within a north pacific sentinel species.blood chemistry and hematologic reference ranges are useful for population health assessment and establishing a baseline for future comparisons in the event of ecosystem changes due to natural or anthropogenic factors. the objectives of this study were to determine if there was any population spatial structure for blood variables of steller sea lion (eumetopias jubatus), an established sentinel species, and to report reference ranges for appropriate populations using standardized analyses. in ad ...201324419664
no evidence of metabolic depression in western alaskan juvenile steller sea lions (eumetopias jubatus).steller sea lion (eumetopias jubatus) populations have undergone precipitous declines through their western alaskan range over the last four decades with the leading hypothesis to explain this decline centering around changing prey quality, quantity, or availability for this species (i.e., nutritional stress hypothesis). under chronic conditions of reduced food intake sea lions would conserve energy by limiting energy expenditures through lowering of metabolic rate known as metabolic depression. ...201424416394
inter-population movements of steller sea lions in alaska with implications for population separation.genetic studies and differing population trends support the separation of steller sea lions (eumetopias jubatus) into a western distinct population segment (wdps) and an eastern dps (edps) with the dividing line between populations at 144° w. despite little exchange for thousands of years, the gap between the breeding ranges narrowed during the past 15-30 years with the formation of new rookeries near the dps boundary. we analyzed >22,000 sightings of 4,172 sea lions branded as pups in each dps ...201323940543
maternal steller sea lion diets elevate fetal mercury concentrations in an area of population mercury concentrations ([thg]) measured in western aleutian island steller sea lion pup hair were the highest maximum [thg] documented in this endangered species to date. some pups exceeded concentrations at which other fish-eating mammals can exhibit adverse neurological and reproductive effects (21% and 15% pups above 20 and 30 μg/g in hair, respectively). of particular concern is fetal exposure to mercury during a particularly vulnerable stage of neurological development in late gestati ...201323545490
predation on an upper trophic marine predator, the steller sea lion: evaluating high juvenile mortality in a density dependent conceptual framework.the endangered western stock of the steller sea lion (eumetopias jubatus)--the largest of the eared seals--has declined by 80% from population levels encountered four decades ago. current overall trends from the gulf of alaska to the aleutian islands appear neutral with strong regional heterogeneities. a published inferential model has been used to hypothesize a continuous decline in natality and depressed juvenile survival during the height of the decline in the mid-late 1980's, followed by the ...201222272296
spatial patterns and scaling behaviors of steller sea lion (eumetopias jubatus) distributions and their environment.fractal geometry and other multi-scale analyses have become popular tools for investigating spatial patterns of animal distributions in heterogeneous environments. in theory, changes in patterns of animal distributions with changes in scale reflect transitions between the controlling influences of one environmental factor or process over another. in an effort to find linkages between steller sea lions (eumetopias jubatus) and their environment, the objective of this study was to determine if the ...201121241711
accumulation and maternal transfer of polychlorinated biphenyls in steller sea lions (eumetopias jubatus) from prince william sound and the bering sea, alaska.the western stock of the steller sea lion (eumetopias jubatus) in the northern pacific ocean has declined by approximately 80% over the past 30 years. this led to the listing of this sea lion population as an endangered species in 1997. chemical pollution is [corrected] one of several contributing causes. in the present study, 145 individual pcbs were determined in tissues of male sea lions from tatitlek (prince william sound) and st. paul island (bering sea), and placentae from the aleutian isl ...201120965632
regional differences in the spatial and temporal heterogeneity of oceanographic habitat used by steller sea lions.over the past three decades, the decline and altered spatial distribution of the western stock of steller sea lions (eumetopias jubatus) in alaska have been attributed to changes in the distribution or abundance of their prey due to the cumulative effects of fisheries and environmental perturbations. during this period, dietary prey occurrence and diet diversity were related to population decline within metapopulation regions of the western stock of steller sea lions, suggesting that environment ...200919769109
entanglement of steller sea lions (eumetopias jubatus) in marine debris: identifying causes and finding solutions.entanglement in marine debris is a contributing factor in steller sea lion (ssl; eumetopias jubatus) injury and mortality. we quantified ssl entanglement by debris type, sex and age class, entanglement incidence, and estimated population level effects. surveys of ssl haul-outs were conducted from 2000-2007 in southeast alaska and northern british columbia. we recorded 386 individuals of all age classes as being either entangled in marine debris or having ingested fishing gear. packing bands were ...200919631950
predicting synergistic effects of resources and predators on foraging decisions by juvenile steller sea lions.many theoretical and experimental studies suggest that synergistic interactions between resources and predators influence foraging decisions and their fitness consequences. this framework, however, has been ignored almost completely by hypotheses on causes of the population decline of steller sea lions (ssls) (eumetopias jubatus) in western alaska. by comparing predictions from a dynamic state variable model to empirical data on the behaviour of individuals instrumented with satellite-linked tim ...200918953573
organochlorine contaminants in endangered steller sea lion pups (eumetopias jubatus) from western alaska and the russian far east.investigations into the cause of the steller sea lion population decline have focused on numerous factors, including exposure to toxic contaminants such as organochlorines (ocs). ocs, such as polychlorinated biphenyls (pcbs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, or dichlorodiphenyltrichloroethane (ddt), have been associated with various biological effects in marine mammals. we measured these compounds in whole blood of free-ranging steller sea lion pups in order to determine the extent ...200818384839
parasites of forage fishes in the vicinity of steller sea lion (eumetopias jubatus) habitat in serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as steller sea lions (eumetopias jubatus). we examined the prevalence of parasites from 229 fish collected between march and july 2002 near two islands used by steller sea lions in southeast alaska and island habitats in the aleutian islands. sea lion populations have remained steady in southeast alaska but have been declining over the last 30 yr in the aleutian islands. e ...200717699075
contaminant exposure and effects in pinnipeds: implications for steller sea lion declines in alaska.after nearly 3 decades of decline, the western stock of steller sea lions (ssl; eumetopias jubatus) was listed as an endangered species in 1997. while the cause of the decline in the 1970s and 1980s has been attributed to nutritional stress, recent declines are unexplained and may result from other factors including the presence of environmental contaminants. ssl tissues show accumulation of butyltins, mercury, pcbs, ddts, chlordanes and hexachlorobenzene. ssl habitats and prey are contaminated ...200312826388
health status of young alaska steller sea lion pups (eumetopias jubatus) as indicated by blood chemistry and hematology.blood chemistry and hematology were examined in 238 steller sea lion pups (eumetopias jubatus) to assess the health status of pups <1 month of age. failure of juvenile recruitment (possibly due to nutritionally or physiologically compromised pups) into breeding populations has been proposed as a cause of recent declines of this endangered species in alaska. to identify potential correlations with areas of high population decline, blood chemistry data were considered for three areas: eastern aleu ...199810400492
plasma haptoglobin levels in threatened alaskan pinniped populations.we evaluated the plasma concentration of the acute phase protein haptoglobin (hp) from steller sea lions (eumetopias jubatus) and harbor seals (phoca vitulina) in regions of alaska (usa) where the populations of these pinnipeds were declining and compared the values with concentrations of hp from the same species in areas where the populations were stable. samples were collected from 1992 through 1994 at sites in southeast alaska, prince william sound, the gulf of alaska, and the aleutian island ...19979027692
use of telazol to immobilize female northern sea lions (eumetopias jubatus) in alaska.twenty-nine female northern sea lions (eumetopias jubatus) were immobilized using telazol in dosages ranging from 1.8 to 8.1 mg/kg. best results were achieved with telazol dosages ranging between 1.8 and 2.5 mg/kg which resulted in smooth induction and recovery. optimal injection location was in the muscle mass of the lower back and hip. dosages greater than 3.5 mg/kg resulted in a tendency toward hypothermia. six mortalities occurred which were partially caused by the location of drug injection ...19892761007
causes and consequences of marine mammal population declines in southwest alaska: a food-web perspective.populations of sea otters, seals and sea lions have collapsed across much of southwest alaska over the past several decades. the sea otter decline set off a trophic cascade in which the coastal marine ecosystem underwent a phase shift from kelp forests to deforested sea urchin barrens. this interaction in turn affected the distribution, abundance and productivity of numerous other species. ecological consequences of the pinniped declines are largely unknown. increased predation by transient (mar ...200919451116
natal and breeding philopatry of female steller sea lions in southeastern alaska.information on drivers of dispersal is critical for wildlife conservation but is rare for long-lived marine mammal species with large geographic ranges. we fit multi-state mark-recapture models to resighting data of 369 known-aged steller sea lion (eumetopias jubatus) females marked as pups on their natal rookeries in southeastern alaska from 1994-2005 and monitored from 2001-15. we estimated probabilities of females being first observed parous at their natal site (natal philopatry), and of not ...201728591130
the yield and challenges of charitable state-wide photoscreening.state-wide cooperative programs for pediatric vision screening utilizing the mti photoscreener and centralized interpretation were established in alaska (the alaska blind child discovery, abcd) and in tennessee (tennessee lions outreach).200616792524
highly specific photoscreening at the alaska state fair. valid alaska blind child discovery photography and interpretation.during the alaska state fair, from 1999 through 2001, experienced mti photoscreeners from the district 49-a lions club screened 1844 children as a part of the alaska blind child discovery. physician interpretation produced the following recommendations: normal 93.8%, "normal +" 3.4%, "positive" 2.7% and inconclusive 0.2%. extrapolating from 53 confirmatory follow-up exams estimates the specificity of this screening (true negatives/all normal follow-up exams) from 97% to 100%, with a positive pre ...200412971063
rural medicine in alaska: the view from point lions. 20007446867
Displaying items 1 - 41 of 41