Streaming Media
Presentation Abstract
Establishment of the European green crab (Carcinus maenas) on the west coast United States has led to concerns regarding loss of eelgrass beds and influence on marine communities. To begin examining whether predators can potentially buffer green crab expansion, I studied river otter (Lontra canadensis) diet from scat remains and green crab abundance was estimated from removal trapping efforts. River otter scats on the Wa’atch and Tsoo-Yess rivers, Washington, USA, were collected during August-September 2018 and April-September 2019. Hard remains of prey were reported as percent frequency of occurrence, and green crab prey were compared to monthly catch-per-unit-effort (CPUE). Scats collected from the Tsoo-Yess River contained no green crab, perhaps due to the relatively low abundance of green crab compared to other crustacean and fish prey. River otters consumed green crab in the Wa’atch River, but its low occurrence in their diet (0.7-5.2%) suggests that they were not an important prey source. However, I hypothesize that if green crab numbers increase there will be a subsequent increase in consumption by river otters and, as such, suggest documenting the population status of green crabs in both rivers, and conducting additional predator-prey studies to gauge the potential for long-term biotic resistance of green crab populations.
Session Title
Poster Session 2: The Salish Sea Food Web and Cycles of Life
Conference Track
SSE14: Posters
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-posters-80
Start Date
26-4-2022 4:30 PM
End Date
26-4-2022 5:00 PM
Type of Presentation
Poster
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Carcinus maenas--Washington (State); North American river otter--Washington (State); Eelgrass--Washington (State); Wildlife conservation--Washington (State)
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Holistic approaches for invasive species management: Exploring biotic resistance of European green crab (Carcinus maenas) via river otter (Lontra canadensis) diet
Establishment of the European green crab (Carcinus maenas) on the west coast United States has led to concerns regarding loss of eelgrass beds and influence on marine communities. To begin examining whether predators can potentially buffer green crab expansion, I studied river otter (Lontra canadensis) diet from scat remains and green crab abundance was estimated from removal trapping efforts. River otter scats on the Wa’atch and Tsoo-Yess rivers, Washington, USA, were collected during August-September 2018 and April-September 2019. Hard remains of prey were reported as percent frequency of occurrence, and green crab prey were compared to monthly catch-per-unit-effort (CPUE). Scats collected from the Tsoo-Yess River contained no green crab, perhaps due to the relatively low abundance of green crab compared to other crustacean and fish prey. River otters consumed green crab in the Wa’atch River, but its low occurrence in their diet (0.7-5.2%) suggests that they were not an important prey source. However, I hypothesize that if green crab numbers increase there will be a subsequent increase in consumption by river otters and, as such, suggest documenting the population status of green crabs in both rivers, and conducting additional predator-prey studies to gauge the potential for long-term biotic resistance of green crab populations.
