Department or Program

Environmental Studies

Abstract

Carcinus maenas, AKA the European Green Crab, is a highly invasive species that has established populations in many non-native sites, altering trophic systems and ecological well-being. In recent years, C. maenas populations have drastically increased throughout the Gulf of Maine, and have been particularly harmful to Maine’s estuarine and intertidal ecosystems (Miller et. al., 2014). In this study, we used carbon and nitrogen stable isotope analysis of green crab tissue to examine their dietary patterns, with the hope of parameterizing how they are feeding in and depleting the resources of Maine’s coastal ecosystems. Specimens for this study were collected from three different coastal salt marshes: Webhannet, Broad Cove, and Day Cove, with the expectation that there would be some degree of variety in C. maenas consumption between the sites. The results of this study indicated that C. maenas are highly omnivorous feeders in all of these sites, and are predominately consuming bivalve mollusks, in addition to some marine gastropods, algae, detritus, salt marsh plants, and small fish. Larger crabs are able to feed at higher trophic levels, but a large range of C. maenas size class at all 3 sites indicates that the populations are well established. This study displays that the presence of C. maenas is highly impactful to the trophic systems of Maine’s salt marshes, and that their increased presence could pose significant threats to marsh ecosystems.

Level of Access

Open Access

First Advisor

Justin Baumann

Date of Graduation

5-2025

Degree Name

Bachelor of Arts

Number of Pages

64

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