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Mercury (Hg) poses a health risk to wildlife populations and has been documented at relatively high concentrations in many marine mammals, including wild-caught pinnipeds along the central California, US coast. We measured total Hg concentrations ([THg]) in hair and blood of live-stranded harbor seals (HS; Phoca vitulina ), California sea lions (CSL; Zalophus californianus ), and northern elephant seals (NES; Mirounga angustirostris ) in California to quantify species, temporal, and spatial variability in [THg] and assess the relationships between [THg] measured by different methods (blood vs. filter paper) and in different matrices (blood vs. hair). We compared [THg] with toxicologic thresholds of concern to aid in identification of at-risk individuals or groups and better understand how the use of different methods and matrices affects assumed toxicologic risk. There was a wide range of [THg] in blood (<0.01-1.13 μg/g) and hair (0.45-81.98 μg/g), and NES had higher [THg] compared with HS and CSL. All three species had individuals with [THg] that exceeded the lower threshold for one or both matrices, but only HS pups had [THg] exceeding upper thresholds. Spatial differences in [THg] were detected, with higher concentrations in HS pups from areas surrounding San Francisco Bay, but differences were dependent on sampling year and matrix. The relationship between [THg] in blood and filter paper ( r 2 =0.98) was strong, and differences had little influence on comparisons with toxicologic thresholds. Blood and hair [THg] were generally in agreement ( r 2 =0.72), but large mismatches for a few seals underscore the importance of combined sampling in adverse effects studies where accurate assessment of Hg exposure is crucial. The wide range of [THg] in stranded HS pups that exceeded published thresholds of concern makes them a promising candidate for adverse effects studies, particularly because different matrices represent Hg exposure across key developmental stages.

Varying concentrations of the highly conserved acute phase response protein, haptoglobin, can indicate changes to the health and disease status of mammals, including the Steller sea lion (SSL; Eumetopias jubatus). To better understand factors relating to acute phase response in SSLs, circulating haptoglobin concentrations (Hp) were quantified in plasma collected from 1,272 individuals sampled near rookeries and haulouts off the coast of Alaska, US. We compared Hp in SSLs between sexes and among different age classes (young pups, young-of-the-year, yearlings, subadults, and adults) sampled within distinct regions in Alaska (Aleutian Islands, Gulf of Alaska, Southeast Alaska). Regional and age-related differences were observed, particularly in younger SSLs. No sex-related differences were detected. We identified weakly significant relationships between Hp and hematology measurements including white blood cell counts and hematocrit in young pups from the Aleutian Islands and Southeast Alaska. No relationship between Hp and body condition was found. Lastly, a nonlinear relationship of plasma Hp and whole blood total mercury concentrations (THg) was observed in SSLs from the endangered western distinct population segment in Alaska. These results demonstrated that regional variation in Hp, especially in younger SSLs, may reflect regional differences in health and circulating THg.

We explored the use of filter paper soaked in whole blood for measuring carbon (C) and nitrogen (N) stable isotopes, often used in feeding ecology or diet studies, to better understand drivers of exposure to contaminants. Our results showed no statistically or biologically relevant differences in C and N stable isotope measures between our gold standard (whole blood with anticoagulant) and eluates from processed, blood-soaked filter paper. Our data supported the effectiveness of using filter paper for assessing C and N stable isotopes in blood to address feeding ecology and other uses. The ease of sampling and processing should allow blood-soaked filter paper to be used in sampling of live (e.g., captured, stranded) and lethally taken (e.g., hunter-killed) wild vertebrates.

We recently documented an epizootic of beak deformities in more than 2,000 Blackcapped Chickadees (Poecile atricapillus) and other wild bird species in North America. This emerging avian disease, which has been termed avian keratin disorder, results in gross overgrowth of the rhamphotheca, the outer, keratinized layer of the beak. To test the hypothesis that the beak deformities characteristic of this disorder are associated with accelerated keratin production, we measured rates of beak growth and wear in affected Black-capped Chickadees (n=16) and a control sample of unaffected chickadees (n=14) collected from south-central (61°09'-61°38'N, 149°11' -149°48'W) and interior Alaska (64°51' -64°53'N, 147°49' -147°59'W). Rates of absolute growth were 50-100% higher in affected birds than they were in control birds and exceeded records from other passerine species. These results suggest that abnormally rapid epidermal growth is the primary physical mechanism by which beak deformities develop and are maintained in affected chickadees. Although beak overgrowth typically worsened over time, differential patterns of wear influenced the severity and morphology of deformities. In some cases, the effects of accelerated keratin growth were partially mitigated by frequent breakage of rhamphothecal tips. However, mortalities occurred in 9 of 16 birds (56%) with beak deformities during the study, suggesting that avian keratin disorder results in severe health consequences for affected birds. Additional study of factors that control beak keratin production is needed to understand the pathogenesis of this debilitating disease in wild birds.

The harbor seal population in Glacier Bay National Park, Alaska, has declined by over 70% since 1992. The reasons for this decline are not known. We examined serum antibodies and feces for evidence of exposure to multiple pathogens in this population. We also studied harbor seals from a reference site on Kodiak Island. In 2007, we found antibodies against Leptospira spp. in 31% of specimens from harbor seals in Glacier Bay, but no detectable serum antibodies in samples from Kodiak. In 2008, no samples had detectable antibodies against Leptospira spp. No serum antibodies against Toxoplasma gondii, morbilliviruses, or presence of Cryptosporidium in fecal samples were detected. However, Giardia was found in 6% of the fecal samples from Glacier Bay. Our results indicate that the harbor seal population in Glacier Bay National Park could be immunologically naïve to distemper viruses and therefore vulnerable to these pathogens. Given the relatively low prevalence of antibodies and low titers, pathogens likely are not the reason for the harbor seal decline in Glacier Bay.

Full-thickness epidermal biopsy samples were collected from free-ranging common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida, USA. Season (summer or winter) of collection, mercury (Hg) concentration, and selenium (Se) concentration were compared to histologic parameters. Epidermal Hg concentration was positively related to age (P<0.001) and negatively related to height of the stratum spinosum (P<0.05). The mitotic index and heights of the stratum externum and intermedium were lower in summer than in winter (P<0.01). Transmission electron microscopic examination revealed variation in the diameters (60-138 nm) and arrangements of collagen fibers, regardless of age or concentrations of Hg and Se. The significance of the variation in height of the stratum spinosum and the perivascular collagen degeneration to dolphin health need further investigation.

We report on the presence of specific antibodies to Brucella spp. and Yersinia enterocolitica in polar bears (Ursus maritimus) from northern Alaska (southern Beaufort Sea) during 2003-2006. Based on numerous known stressors (e.g., climate change and loss of sea ice habitat, contaminants), there is increased concern regarding the status of polar bears. Considering these changes, it is important to assess exposure to potentially pathogenic organisms and to improve understanding of transmission pathways. Brucella or specific antibodies to Brucella spp. has been reported in marine mammals. Various assays were used to elucidate the pathway or source of exposure (e.g., "marine" vs. "terrestrial" Brucella spp.) of northern Alaska polar bears to Brucella spp. The standard plate test (SPT) and the buffered Brucella antigen card test (BBA) were used for initial screening for antibodies specific to Brucella. We then evaluated positive reactors (presence of serum antibody specific for Brucella spp.) using immunoblots and competitive enzyme-linked immunosorbent assay (cELISA; based on pinniped-derived Brucella spp. antigen). Annual prevalence of antibody (BBA and SPT) for Brucella spp. ranged from 6.8% to 18.5% over 2003-2006, with an overall prevalence of 10.2%. Prevalence of Brucella spp. antibody did vary by age class. Western blot analyses indicated 17 samples were positive for Brucella spp. antibody; of these, 13 were negative by marine (pinniped) derived Brucella antigen cELISA and four were positive by marine cELISA. Of the four samples positive for Brucella antibody by marine cELISA, three cross-reacted with Y. enterocolitica and Brucella spp. (one sample was Brucella negative and Y. enterocolitica positive). It appears the polar bear antibody does not react with the antigens used on the marine cELISA assay, potentially indicating a terrestrial (nonpinniped) source of Brucella spp.

In this study, we evaluated concentrations of twelve essential and non-essential elements (As, Cd, Co, Cu, Pb, Mg, Mn, Hg, Mo, Se, Ag, and Zn) in tissues of ringed seals (Phoca hispida) and polar bears (Ursus maritimus) of arctic Alaska (USA). All samples were collected between 1995-97 in conjunction with subsistence harvests. The essential elements are reported to help develop reference ranges for health status determination and to help assess known or suspected interactions affecting toxicoses of cadmium (Cd) and mercury (Hg). In some tissues, Cd, Hg, and selenium (Se) were present at concentrations that have been associated with toxicoses in some domestic animals. Nevertheless, tissue levels of all elements were within ranges that have been reported previously in other pinnipeds and polar bears. Significant associations included: Cd with Zn or Cu; Cu with Zn or Ag; and Hg with Se, Zn, or Cu. This study found hepatic Hg:Se molar ratios to be lower than unity and different between the two species. Based upon significant differences in mean tissue elemental concentrations for polar bear versus ringed seal, we concluded that biomagnification factors (bear/seal) were significant for: Cu in liver and muscle; Pb in kidney; Se in kidney and muscle; Zn in liver and muscle; and Hg in liver. Possible explanations for observed elemental correlations (i.e., interactions) and ancillary mechanisms of Cd and Hg detoxification are discussed.

In this study, we evaluated concentrations of twelve essential and non-essential elements (As, Cd, Co, Cu, Pb, Mg, Mn, Hg, Mo, Se, Ag, and Zn) in tissues of bowhead (Balaena mysticetus) and beluga (Delphinapterus leucas) whales from arctic Alaska (USA) and northwestern Canada. Tissue samples were collected between 1983 and 1997, mostly in 1995-97. The essential elements are reported to develop reference ranges for health status determination, and to help assess known or suspected interactions affecting toxicoses of cadmium (Cd) and mercury (Hg). In some tissues, Cd, Hg, and selenium (Se) were present at concentrations that have been associated with toxicoses in some domestic animals. Nevertheless, tissue levels of all elements were within ranges that have been reported previously in marine mammals. While mean Ag concentrations in beluga whale liver were relatively high (15.91 micrograms/g ww), Ag was not associated with hepatic Se levels or age, contrary to previous findings. Significant associations included: Cd with age, Zn, or Cu; Cu with age, Zn or Ag; and Hg with age, Se, Zn, or Cu. This study found hepatic Hg:Se molar ratios to be consistently lower than unity and different between species. Possible explanations for observed elemental correlations (i.e., interactions) and ancillary mechanisms of Cd and Hg detoxification are discussed.

Moose (Alces alces) found dead (FD) and hunter-killed (HK) in 1995 on the north slope of Alaska (USA) in the Colville River Drainage were evaluated for heavy metal and mineral status. Compared to previous reports for moose and domestic cattle, and data presented here from Alaska moose outside the Colville River area, levels of Cu were determined to be low in hoof, hair, liver, kidney, rumen contents, and muscle for these north slope moose. Iron (Fe) was low in muscle as well. These findings, in conjunction with evidence of poor calf survival and adult mortality prompted investigation of a mineral deficiency in moose (serum, blood, and hair) captured in the spring of 1996 and 1997. Captured males had higher Ca, Zn and Cu levels in hair than captured females. Female moose hair samples were determined to be low (deficient) in Cu, Ca, Fe, and Se with mean levels (ppm) of 2.77, 599.7, 37.4, and 0.30, respectively. Serum Cu level was low, and to a lesser degree Zn was deficient as well. Whole blood (1997 only) was marginally deficient in Se and all animals were deficient in Cu. Based on whole blood, sera and hair, Cu levels were considered low for moose captured in spring 1996 and 1997 in the Colville River area as compared to published data and other populations evaluated in this study. Low levels of ceruloplasmin activity support this Cu deficiency theory. Evidence indicates that these moose are deficient in Cu and other minerals; however, the remote location precluded sufficient examination of animals to associate this apparent deficiency with direct effects or lesions. Renal levels of Cd increased with age at expected levels.

Organochlorine (OC) levels in liver and blubber of 20 bowhead whales (Balaena mysticetus) collected during the Eskimo subsistence harvest at Barrow (Alaska, USA) in 1992 and 1993 are presented. Liver sum DDT (lipid weight) was significantly greater in male whales than in females. Most of the organochlorines measured were at higher levels in longer (older) than in shorter (younger) males. For female bowhead whales, hexachlorobenzene and lipid levels decreased and other OC levels did not change significantly with increasing length. Most organochlorine contaminants have low concentrations in tissues of the bowhead whale compared to concentrations in tissues of other cetaceans, especially Odontocetes. Based on allowable daily intakes (ADI) levels established by the Canadian Northern Contaminants Program (Ottawa, Ontario, Canada) "safe" levels of blubber to consume were calculated. Chlordane levels in bowhead whale blubber results in the most restrictive consumption amount (50 g blubber/day). We expect no adverse effects related to these organochlorine contaminants to occur in bowhead whales or in consumers of their tissues. However, investigation of low level chronic exposure effects and a more rigorous assessment of histopathology, biomarkers, and immune status in the bowhead whale would be required to conclude "no effect" with more certainty.

To determine if 12 moose (Alces alces) from northern Alaska with agglutinating antibodies specific for Brucella spp. had been exposed to either B. suis biovar 4 or B. abortus biovar 1, western immnnoblot serologic analysis was performed. Differential serologic responses to strain specific A and M antigenic variances of the lipopolysaccharide O-polysaccharide sugar allowed strain identification. Prior to examination, test sera were absorbed with killed whole cells from either B. abortus biovar 1, containing predominately A antigen (A+ M-); B. melitensis biovar 1, containing essentially M antigen (A- M+); or B. suis biovar 4, containing both antigenic tyes (A+ M+). The resulting sera were then examined by western immunoblot for recognition of either B. abortus biovar 1, B. melitensis biovar 1, or B. suis biovar 4 cell lysates. The results of this study indicate that these moose were exposed to B. suis biovar 4, a known pathogen of caribou (Rangifer tarandus) from arctic 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 detected was VESV F55 with 6 of 36 (17%) by the Monto and Bryan (MB) titer calculation method, and 17 of 36 (47%) by the S-K titer calculation method. Vesicular exanthema of swine virus 1934B antibody was detected in 3 of 36 (8%) and 5 of 36 (14%) whales using the MB and S-K methods, respectively. Vesicular exanthema of swine virus J56 antibody was detected in 3 of 36 (8%) by the S-K method only. All whales < 8.5 m (estimated yearlings, n = 6) were seronegative for VESV J56 and 1934B while 10% and 17% of the whales > 8.5 m were positive, respectively. Whales assumed to be sexually mature (> 13 m) had a higher prevalence of antibody to VESV 1934B and SMSV 8 than those < 13 m. Gender had an effect on seroprevalence of antibody to VESV 1934B as titers > or = 1:28 (S-K method) occurred in 18% of the females and 7% of the males. Antibody to other serotypes (SMSV 8 and 12) occurred less frequently (< 6%) at an antibody titer > or = 1:28 by the S-K method. All 36 whale sera were negative for antibody to VESV-A48, B51, C52, D53, E54, G55, H54, I55, and K54; Tillamook calicivirus, and dolphin morbillivirus; and SMSV-1, 2, 4, 5, 6, 7, 9, 10, 11, and 13 by the S-K method.