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E. coli was isolated from the Salish Sea (Puget Sound) ecosystem, including samples of marine and fresh water, and wildlife dependent on this environment. E. coli isolates were assessed for phenotypic and genotypic resistance to antibiotics. A total of 305 E. coli isolates was characterized from samples collected from: marine water obtained in four quadrants of the Salish Sea; select locations near beaches; fresh water from streams near marine beaches; and fecal samples from harbor porpoises ( Phocoena phocoena ), harbor seals ( Phoca vitulina ), river otters ( Lontra canadensis ), and English sole ( Parophrys vetulus ). Isolates were evaluated using antimicrobial susceptibility typing, whole-genome sequencing, fumC , and multilocus sequence typing. Resistance and virulence genes were identified from sequence data. Of the 305 isolates from Salish Sea samples, 20 (6.6%) of the E. coli were intermediate, and 31 (10.2%) were resistant to ≥1 class of antibiotics, with 26.9% of nonsusceptible (resistant and intermediate resistant) E. coli isolates from marine mammals and 70% from river otters. The proportion of nonsusceptible isolates from animals was significantly higher than samples taken from marine water ( p < 0.0001). A total of 196 unique STs was identified including 37 extraintestinal pathogenic E. coli (ExPEC)-associated STs [ST10, ST38, ST58, ST69, ST73, ST117, ST131, and ST405]. The study suggests that animals may be potential sentinels for antibiotic-resistant and ExPEC E. coli in the Salish Sea ecosystem.

As long-lived marine mammals found throughout the temperate coastal waters of the North Pacific and Atlantic Oceans, harbour seals (Phoca vitulina) have become an invaluable sentinel of food-web contamination. Their relatively high trophic position predisposes harbour seals to the accumulation of harmful levels of persistent organic pollutants (POPs). We obtained skin/blubber biopsy samples from live-captured young harbour seals from various sites in the northeastern Pacific (British Columbia, Canada, and Washington State, USA) as well as the northwestern Atlantic (Newfoundland and Quebec, Canada). We developed harbour seal-specific primers to investigate the potential impact of POP exposure on the expression of eight important genes. We found correlations between the blubber mRNA levels of three of our eight target genes and the dominant persistent organic pollutant in seals [polychlorinated biphenyls (PCBs)] including estrogen receptor alpha (Esr1: r 2  = 0.12, p = 0.038), thyroid hormone receptor alpha (Thra: r 2  = 0.16; p = 0.028), and glucocorticoid receptor (Nr3c1: r 2  = 0.12; p = 0.049). Age, sex, weight, and length were not confounding factors on the expression of genes. Although the population-level consequences are unclear, our results suggest that PCBs are associated with alterations of the expression of genes responsible for aspects of metabolism, growth and development, and immune function. Collectively, these results provide additional support for the use of harbour seals as indicators of coastal food-web contamination.

B-cell lymphoma, a common morphologic variant of non-Hodgkin lymphoma, has been associated with persistent pollutants in humans, but this association is not well-characterized in top-level predators sharing marine resources with humans. We characterized and compared blubber contaminants and hormones of a pregnant harbor porpoise (Phocoena phocoena) with B-cell lymphoma, with those in two presumed healthy fishery by-caught porpoises with no lymphoma: a pregnant adult and female juvenile. Common historic use compounds, including polychlorinated biphenyls, polybrominated diphenyl ethers, and pesticides, were evaluated in blubber samples from three porpoises. In addition, blubber cortisol and progesterone levels (ng/g) were determined in all three animals. Total pollutant concentrations were highest in the juvenile porpoise, followed by the lymphoma porpoise and the nonlymphoma adult. Blubber cortisol concentrations were 191% greater in the pregnant with lymphoma porpoise compared with the pregnant no lymphoma porpoise, and 89% greater in the juvenile female compared with the pregnant no lymphoma porpoise. Although both adults were pregnant, progesterone levels were substantially greater (90%) in the healthy compared with the lymphoma adult. Health monitoring of top-level marine predators, such as porpoise, provides a sentinel measure of contaminants that serve as indicators of potential environmental exposure to humans.

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in blubber biopsy samples from 22 live-captured Steller sea lions (Eumetopias jubatus) that had just entered the Strait of Georgia, British Columbia, Canada, for their overwintering feeding season. ∑PBDE ranged from 50μgkg(-1) (lipid weight) in adult females to 3780μgkg(-1) in subadult individuals. ∑PCBs ranged from 272μgkg(-1) in adult females to 14280μgkg(-1) in subadult individuals. While most PBDE and PCB congeners were transferred through milk to pups, PCBs with logK(OW)>7.0 (PCBs 206, 207, 208 and 209) appeared constrained, resulting in a lighter mixture in pups compared to adult females. The ratio of individual PCB congeners by metabolic group (Groups I, II, III, IV and V) to PCB-153 regressed against length of males suggested poor biotransformation of these compounds (slopes did not differ from zero, p>0.05). PBDE congeners 49, 99, 153 and 183 appeared bioaccumulative (slopes of ratio BDE/PCB 153 versus length were higher than zero, p<0.05), but the dominance of the single congener, BDE-47 (64% of total PBDEs), likely due in part to debromination pathways, reduced our ability to explore congener-specific dynamics of PBDEs in these pinnipeds. With 80% of our Steller sea lions exceeding a recent toxicity reference value for PCBs, the fasting-associated mobilization of these contaminants raises concerns about a heightened vulnerability to adverse effects during annual migrations., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

An aborted mid-gestational male Steller sea lion fetus with an attached placenta was recovered on the floor of an open floating capture trap located off Norris Rock near Denman Island, British Columbia. Viral culture of the placenta demonstrated cytopathic effect. Although no specific signal was obtained in microarray experiments using RNA obtained from viral culture, elution and sequence analysis revealed the presence of a reovirus. Complete genome pyrosequencing led to the identification of an orthoreovirus that we have tentatively named Steller sea lion reovirus (SSRV). Phylogenetic analysis revealed similarities between SSRV and orthoreoviruses of birds, bats and other mammals that suggests potential for interspecies transmission.

Leptospirosis is one of the most widespread bacterial zoonoses in the world and affects most mammalian species. Although leptospirosis is well documented and characterized in terrestrial species, less information is available regarding the distribution and impact of leptospirosis in marine mammals. Additionally, the role of animal migrations on the geographical spread of leptospirosis has not been reported. Periodic epizootic outbreaks of acute leptospirosis among California sea lions (Zalophus californianus) have been reported since 1971. In this study, we collected samples from California sea lions stranded along the Pacific coast of North America during the most recent epidemic in 2004, and maintained leptospirosis surveillance of the California sea lion population along the California coast through 2007. Several isolates of Leptospira interrogans serovar Pomona were obtained from kidney and urine samples collected during this study, a finding consistent with serological evidence that California sea lions are persistently exposed to this leptospiral serovar. Combined, these data support a model whereby California sea lions are maintenance hosts for L. interrogans serovar Pomona, yet periodically undergo outbreaks of acute infection. During the 2004 outbreak, the incidence of new leptospirosis cases among California sea lions coincided with the seasonal movement of male sea lions from rookeries along the coast of central and southern California north as far as British Columbia. These data show that seasonal animal movement contributes to the distribution of leptospirosis across a large geographical region.