Final Contract Report to the North Pacific Coast Marine Resource Committee: Food Habits of River Otters (Lutra canadensis) in the Lake Ozette Watershed
Scordino J, Riemer S, Gearin P. 2010. Final Contract Report to the North Pacific Coast Marine Resource Committee: Food Habits of River Otters (Lutra canadensis) in the Lake Ozette Watershed. Neah Bay, WA
River otter food habits have not previously been studied in the state of Washington. Food habits of river otters in the Lake Ozette watershed were of interest because anecdotal evidence suggested that river otters were predating threatened Lake Ozette sockeye salmon. Two hundred and seventy-two river otter scat samples were collected from the Lake Ozette watershed in 1998, 1999, 2002, and 2003. Food habits of river otters in the Lake Ozette watershed were similar to most published studies on river otter food habits. Of interest for the Lake Ozette watershed in relation to other studies was the high frequency of occurrence of salmonid remains in river otter scat samples. Samples collected in the lake and in the river had high frequency of juvenile salmonid remains in July. Adult salmonid remains were frequently observed from samples collected at the river and weir sampling areas in July and October. The high frequency of occurrence of adult salmon in river otter scat in July coincides with the upstream migration of Lake Ozette sockeye. Genetic analysis of salmonid bones collected from fecal samples is needed to determine what portion of salmonid remains found are in fact Lake Ozette sockeye salmon. Future studies should also focus on collecting river otter scat from the lake sampling area in the late fall and early winter to determine if river otters are predating on sockeye salmon that are holding or spawning in the lake.
- Type
- Unpublished Report
- Authors
- Scordino, Jonathan; Riemer, Susan; Gearin, Patrick
- Date of Issue
- 2010
- Units
- OLYM
- Keywords
- Diet, fecal samples, Lake Ozette, Lake Ozette sockeye, Ollympic National Park, Ozette River Watershed, River Otter (Lutra canadensis), Salmonid