Abstract

The Punta San Juan (PSJ) marine protected area in Peru includes critical rookery sites for the Peruvian fur seal (Arctocephalus australis unnamed subspecies, PFS) and South American sea lion (Otaria byronia, SASL). Both populations are protected as endangered species in Peru and at risk due to competition with commercial fisheries for prey, bycatch, illegal poaching, and El Niño climatic events that depress prey availability. Over the past decade research efforts have aimed to assess overall health of these populations and the role of infectious disease in morbidity and mortality through health assessments and surveillance of deceased individuals.

Samples collected from 186 (120 PFS and 66 SALS) free-ranging, adult pinnipeds since 2009 have expanded knowledge on disease in the PSJ ecosystem beyond results previously reported from female PFS tested in 2009–2010.¹ We have demonstrated serologic exposure and/or molecular detection of calicivirus, Leptospira interrogans, otarine herpesvirus, Toxoplasma gondii, Sarcocystis neurona, and Neospora caninum. Testing for canine and phocine distemper viruses has been negative. Molecular testing of tissues from aborted PFS fetuses (n=25) has identified the presence of Coxiella burnetii and Sarcocystis neurona, but the role of these pathogens in fetal loss remains unclear. Molecular testing for Toxoplasma, herpesviruses, leptospirosis, and morbilliviruses in aborted tissues has been negative. Brucella spp. have been identified in umbilical and placental tissues. Histopathologic evaluation of 19 dead animals has revealed no evidence of major infectious diseases of concern. The impact of marine biotoxins on population health remains under active investigation, with domoic acid and okadaic acid exposure having been identified in samples from adult animals.² Competition with scavenger species for carcass access at PSJ, coupled with the absence of a Peruvian stranding network, has greatly limited availability of diagnostic quality post-mortem samples. Through continued capacity building programs and active collaboration with government agencies, future access to naturally deceased animals will hopefully increase allowing for improved diagnostics.

Acknowledgments

The authors thank Marco Cardeña, Fernando Vilchez Delgado, Leticia Escobar Mendoza, and all the biologists who have supported our projects with sample and data collection. We further thank Dr. Gwen Jankowski, Dr. Jenny Meegan, and the veterinary teams who have assisted with anesthesia and sample collection. Funding for components of this research has been provided by generous support from the Chicago Board of Trade Endangered Species Fund, Paul M. Angell Family Foundation, Feay Family, Waitt Foundation, and Saint Louis Zoo WildCare Institute.

We acknowledge the Peruvian government agencies SERNANP for access inside the RNSIIPG-Punta San Juan reserve and AGRORURAL for use of field facilities. Research and samples were collected under permits RJ No. 09-2010-, 23-2011-, 022-2012-, 09-2013-, 024-2014, 008-2015-, 019-2016-SERNANP-RNSIIPG.

* Presenting author

Literature Cited

1.  Jankowski G, Adkesson MJ, Saliki JT, Cardenas-Alayza S, Majluf P. 2015. Survey for infectious disease in the South American fur seal (Arctocephalus australis) population at Punta San Juan, Peru. Journal of Zoo and Wildlife Medicine. 46(2):246–254.

2.  Fire S, Adkesson MJ, Wang Z, Jankowski G, Cárdenas-Alayza S, Broadwater M. 2017. Peruvian fur seals (Arctocephalus australis ssp.) and South American sea lions (Otaria byronia) in Peru are exposed to the harmful algal toxins domoic acid and okadaic acid. Marine Mammal Science. 33:630–644.