Abstract

A variety of systemic mycoses have been reported in captive and wild marine mammals from North America.^4,3 Prominent examples include regionally prevalent, endemic pathogens such as Coccidioides and Blastomyces spp., and novel pathogens like Cryptococcus gattii which appears to have been introduced to North America through anthropogenic activity.^1,3 Because systemic mycoses may pose a zoonotic risk and can become locally established through environmental contamination, monitoring for these pathogens is an important part of surveillance efforts at marine mammal care and research facilities.² In addition, temporospatial patterns may exist between detection of these fungi in coastal marine species and adjacent human populations.⁵ We collected stranding and necropsy data from three marine mammal stranding facilities (The Marine Mammal Center, The UC Santa Cruz Marine Mammal Stranding Program, and the Marine Wildlife Veterinary Care and Research Center) located along the central California coast to assess the host demographics and regional distribution of systemic mycoses affecting endemic marine mammals. Retrospective stranding and necropsy records from 1998–2012 were reviewed to identify cases and to provide insight on the lesion severity and tissue distribution in affected animals. Our objectives were to review regional stranding data pertaining to locally invasive and systemic mycoses, and to compare our findings from central California with reports from other areas. Of over 3,500 wild marine mammals that were necropsied by the three facilities between January 1, 1998 and June 30, 2012, 40 were found to be infected with locally invasive or systemic mycoses, including 36 cases of coccidiomycosis and 2 cases each of zygomycosis and cryptococcosis. Affected animals included 20 southern sea otters (Enhydra lutris nereis), 18 California sea lions (Zalophus californianus), one harbor seal (Phoca vitulina) and a Dall's porpoise (Phocoenoides dalli). Systemic coccidioidomycosis was identified in 20 sea otters, 16 sea lions, and one harbor seal, re-confirming Coccidioides spp. as the most common fungus infecting marine mammals from central California. Cryptococcus gattii was isolated from a stranded wild Dall's porpoise.

Acknowledgements

The authors wish to thank Shelbi Stoudt for calculating the total number of animals necropsied at the Marine Mammal Center (TMMC). We thank TMMC, UCSC and MWVCRC staff and volunteers for sample collection and archiving. Financial support was provided by the California Department of Fish and Wildlife. We acknowledge the staff and volunteers of UCSC, CDFG, the Marine Mammal Center, USGS-BRD, the United States Fish and Wildlife Service and the Monterey Bay Aquarium for their efforts to recover and care for sick, stranded marine animals in California.

* Presenting author
⁺ Student presenter

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