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Postmortem data for harbor seals (Phoca vitulina richardsii) in the Salish Sea were analyzed for epidemiologic trends in congenital diseases. Cleft palate, cleft lips, or both (n=8) and cardiac defects (n=5) were the most common congenital abnormalities, followed by cases with multiple defects (n=4). No temporal trends or spatial clusters of cases were seen from 2003 to 2019, during which time monitoring effort was consistent. Cases could not be linked to specific causes such as environmental contamination or maternal malnutrition. Our study suggests that a yearly prevalence of 2.9%±2.2 is the endemic level of congenital disease in this stable harbor seal population. Continued monitoring of birth defects and overall harbor seal population status could help to identify emerging teratogens. [ABSTRACT FROM AUTHOR]

Documenting human impacts on marine mammals is critical for understanding and mitigating harm. Although propeller strike injuries in small marine mammals are often debilitating and fatal, little is known about the occurrence or demographics of these types of injuries in pinniped populations. Using data of stranded harbor seals (Phoca vitulina) in the Salish Sea from 2002–19, we identified 27 cases of fatal propeller strikes. Weaned pups were the most frequently affected (64% of cases) with a much higher rate of propeller strikes than expected for the age class. Although they do represent animal welfare concerns, harbor seals in the Salish Sea probably are not threatened by these types of injuries at the population level; nevertheless, propeller strike cases increased significantly over the time of this study period, indicating increased interactions between boats and seals in the region. Continued monitoring and increased efforts to consistently quantify vessel traffic in the area are recommended to create and monitor long-term effectiveness of mitigation measures. [ABSTRACT FROM AUTHOR]

The article discusses a study that described the epizootiology of Brucella pinnipedialis in harbor seals from Washington. No sex predilection was found in harbor seal exposure or infection with the zoonotic pathogen. However, a significant difference was identified among age classes, with weaned pups, yearlings and sub-adults having the highest exposure and infection. Verminous pneumonia due to Parafilaroides or Otosrongulus circumlitus was the most common postmortem finding.

The article discusses the death of seven harbor seals, Phoca vitulina, in Washington State between 2006 and 2011 due to tissue perforation and penetration by dorsal fine spines of spotted ratfish, Hydrolagus colliei. Necropsy shows spines or spine parts that had perforated the esophagus or stomach of six animals and migrated into vital tissues. In the seventh animal, a ratfish spine was found from the mouth. Gross examination shows an abscess within the left cerebrum.

The article investigates two cases of Coxiella burnetii infection of marine mammals in the Pacific Northwest from 1997-2010. The researchers used polymerase chain reaction to detect C. burnetti from the placentas of mammals including Pacific harbor seals, harbor porpoises, and Steller sea lions. Serosurvey results showed the presence of antibodies in the placentas of harbor seals against either Phase 1 and Phase 2 of C. burnetti.