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Eelgrass (Zostera marina L.) is the dominant seagrass species of northern temperate coastal waters, where it contributes vital functions to the ecological integrity and economic value of coastal ecosystems. Various human-induced disturbances have contributed to declines in distribution and abundance of eelgrass in New England and elsewhere, with the direct effects of human activities emerging as a significant source of local habitat loss with the potential for large-scale cumulative impacts.
Interest in effects of commercial fishing on eelgrass has intensified recently, due in large part to new federal and state policies acknowledging the critical dependence of healthy fish stocks on sustainable fish habitat. Implementation of policies to protect eelgrass from adverse affects of fishing is hampered by the paucity of scientific information on the extent of disturbance from commercial harvest operations and the recovery potential within impacted areas.
The USGS in cooperation with the Maine Department of Marine Resources and the University of New Hampshire is conducting a study to characterize impacts of commercial fishing activities on eelgrass and determine revegetation potential following disturbance. The overall approach is to evaluate ongoing impacts within a representative estuary, Maquoit Bay, which is the northwestern boundary of Casco Bay, Maine. Hand digging of soft shell clams and bait worms occurs throughout the intertidal eelgrass beds, and mechanical dragging for blue mussels occurs in subtidal grass beds. Preliminary aerial and field observations reveal patches that have been denuded by fishing activities, ranging in size from a few square meters to up to 70 acres. The following objectives will be addressed in 2000 and 2001:
This study will provide information on the extent and intensity of impacts to New England eelgrass beds from commercial harvest operations and estimates of revegetation rates following disturbance. This information will form the basis for regulatory decisions by State and Federal agencies with responsibilities for coastal habitat protection and commercial fisheries management.
Denuded patch within eelgrass bed in Maquoit Bay, Maine