Research ProjectChesapeake Bay Otter Alliance

Chesapeake Bay Otter Alliance

  • Parasitic worms from river otter

    Parasitic worms found in fecal matter left by river otters. Photo credit: K. McDonald

  • Evidence of a river otter latrine

    River otters congregate around latrine areas, leaving behind evidence of their presence, diet, and parasites. Photo credit: K. McDonald

  • River otter scat

    DNA and undigested bits from fecal matter, or scat, left behind by river otters can tell us about their population size, diet, and health. Photo Credit: K. McDonald

Project Goal

We are developing the Chesapeake Bay Otter Alliance, a coalition of researchers from across the Smithsonian and local universities, to study and educate the public about North American River Otters in the Chesapeake Bay.


North American river otters (Lontra canadensis) are aquatic-habitat generalists, living in freshwater systems, estuaries, and some coastal marine areas. They occupy the highest tropic level, with a diet comprised mostly of fish,  crustaceans, amphibians, reptiles,  and birds.


River otters prefer undisturbed riparian habitat with adequate cover for denning and resting,  are primarily nocturnal, and generally maintain low population densities.  River otters are an incredibly charismatic species and possess several other characteristics of “indicator” and “flagship” species. First, the river otter is broadly distributed and well known in the contiguous US. Second, as an apex predator, otter dietary research can inform predator-prey dynamics and trophic interactions, including trophically-transmitted parasites (i.e., digenetic trematodes). Third, they are  hosts for multiple zoonotic pathogens (e.g., Giardia spp., Toxoplasma gondii). Together, these characteristics make it a compelling species for education, research, and conservation activities. 

We are developing the Chesapeake Bay Otter Alliance (CBOA), including experts in river otter ecology (Thomas Serfass, Kelly Pearce) and genomics (Klaus Koepfli), parasite and disease ecology (Katrina Lohan, Anna Phillips), fisheries and estuarine ecology (Matthew Ogburn), veterinary medicine (Victoria Hall), education (Karen McDonald, SERC Education), and citizen science (Alison Cawood) from SERC, the Smithsonian’s National Zoological Park, the Smithsonian’s National Museum of Natural History, the Arundel Rivers Federation, Frostburg State University, Allegheny College, and private citizens.

Our specific objectives include: 1) mapping river otter presence and abundance in the Rhode, South, and West Rivers; 2) conducting diet and parasite analyses; 3) developing protocols for citizen science engagement; and 4) generating K-12 curriculum on river otter biology and ecology.