Abstract

Fecal pathogen pollution comes from diverse sources in coastal watersheds and may be transported overland during storm events and downstream via rivers to the ocean. Both point and non-point fecal sources contribute to pathogen pollution, with some sources related to humans and others coming from domestic animals or wildlife.^4,7 The sea otter acts as a sentinel species in coastal ecosystems, serving as a "canary in a coal mine," for disturbances that may be subtle initially but which may ultimately impact individual animals, wildlife populations, and/or ecosystem health. Sea otters and a suite of marine and terrestrial animals were studied along the central California coast to highlight linkages and pathogen pollution issues related to microbes of public health importance. Over a two-year period, three linked studies were performed: 1) fecal samples and coastal surface waters were tested for fecal pathogens^5-7; 2) surface waters were screened for microbial source tracking markers⁷; and 3) wetlands were studied as a locally relevant and sustainable Beneficial Management Practice (BMP) where water quality is improved by the filtration and cleaning of contaminated surface waters before their release to the ocean^1,2. These studies help to characterize linkages at the land-sea interface and provide critical insights into long-term solutions for improving wildlife, public, and ecosystem health. Results from these studies provide insights into pathogen pollution relevant to a broad audience, illustrating how goals for interdisciplinary research and conservation can be interwoven among controlled laboratory studies, complementary fieldwork, and epidemiologic modeling efforts.^3,8 Forming collaborative relationships with resource managers, stakeholders, and policy makers is critical to facilitate and optimize long-term change once useful interventions are identified. This interdisciplinary research is an example of the One Health concept in action in California, and shows how addressing key environmental problems across multiple disciplines can maximize contributions toward reducing pathogen pollution and associated health risks for people and animals, including those that live or recreate in coastal ecosystems.

Acknowledgements

This work was performed under the auspices of the Central Coast Long-term Environmental Assessment Network (CCLEAN), with funding provided by Grant #06-076-553 from the California State Water Board to the City of Watsonville, with additional support from the California Sea Grant Program.

* Presenting author 

Literature Cited

1.  Hogan J.N., M.E. Daniels, F.G. Watson, P.A. Conrad, S.C. Oates, M.A. Miller, D. Hardin, B. Byrne, C. Dominik, A. Melli, D.A. Jessup, W.A. Miller. Longitudinal Poisson regression to evaluate Cryptosporidium, Giardia, and fecal indicator bacteria epidemiology in coastal California wetlands. Appl Environ Microbiol. 2012;78(10): 3603–3613.

2.  Hogan J.N., M.E. Daniels, F.G. Watson, S.C. Oates, M.A. Miller, P.A. Conrad, K. Shapiro, D. Hardin, C. Dominik, A. Melli, D.A. Jessup, W.A. Miller. Hydrologic and vegetative removal of Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii surrogate microspheres in coastal wetlands. Appl Environ Microbiol. 2013;79(6):1859–1865.

3.  Miller M.A., B.A. Byrne, S.S. Jang, E.M. Dodd, E. Dorfmeier, M.D. Harris, J. Ames, D. Paradies, K. Worcester , D.A. Jessup, and W.A. Miller. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff. Vet Res. 2009;41:1.

4.  Miller M.A., W.A. Miller, P. A. Conrad, E. R. James, A. C. Melli, C. M. Leutenegger, H. A. Dabritz, A. E. Packham, M. Harris, Jack Ames, D. A. Jessup, Karen Worcester, M. E. Grigg. Type X Toxoplasma gondii in a wild mussel and terrestrial carnivores from coastal California: New linkages between terrestrial mammals, runoff and toxoplasmosis of sea otters. Int J Parasitol. 2008;38:1319–1328.

5.  Oates S.C., M.A. Miller, B.A. Byrne, N. Chouicha, D. Hardin, D. Jessup, C. Dominik, A. Roug, A. Schreiwer, S. S. Jang, W.A. Miller. Epidemiology and potential land-sea transfer of enteric bacterial pathogens from terrestrial to marine species in the Monterey Bay region of California. J Wildl Dis. 2012;48(3):654–658.

6.  Oates S.C., M.A. Miller, A. Melli, D. Hardin, D. Jessup, C. Dominik, A. Roug, P.A. Conrad, W.A. Miller. Prevalence, molecular characterization, and environmental loading of Cryptosporidium and Giardia isolates from domestic and wild animals along the central California coast. Appl Environ Microbiol. 2012;78(24):8762–72.

7.  Schriewer A., W.A. Miller, B.A. Byrne, M.A. Miller, P.A. Conrad, D. Hardin, H. Yang, S.C. Oates, N. Chouicha, A. Melli, D. Jessup, S. Wuertz. Bacteroidales as a predictor of pathogens in surface waters of the central California coast. Appl Environ Microbiol. 2010;76:5802–5814.

8.  Shapiro K., P.A. Conrad, J.A.K. Mazet, W.W. Wallender, W.A. Miller, J.L. Largier. Effect of estuarine wetland degradation on transport of Toxoplasma gondii surrogates from land to sea. Appl Environ Microbiol. 2010;76:6821–6828.