UMaine Researchers Study Steep Decline in Down East Maine’s Soft-shell Clam Harvest
In eastern Maine, landings of soft-shell clams have been in steady decline for nearly three decades. Despite the $12.25 million clam harvest in Maine in 2007, the fishery is but a shadow of its former self when compared to highs in the past century.
Particularly hard-hit is Washington County, once the state’s largest source of clams. In contrast, landings have been relatively constant in southern Maine during the same period.
Restoration efforts hinge on just where the problem lies — in Mya arenaria’s larval stage in the water or in the juvenile stage on the mudflats.
To begin to answer the question, University of Maine researchers have attempted to fathom Maine’s regional differences in clam landings. Their most recent findings, published in the Journal of Shellfish Research, point primarily to reduced densities of larvae in near-shore waters in eastern Maine.
Small clam populations in eastern Maine appear to be unable to sufficiently repopulate local clam flats, the researchers write. Reestablishing a robust clam fishery and enhancing local breeding stocks will require intensive seeding of the flats with hatchery-raised juvenile clams, according to Tracy Vassiliev and Stephen Fegley, who conducted their research at UMaine and Maine Maritime Academy, respectively, and William Congleton, UMaine associate professor of animal and veterinary sciences.
The researchers say seeded flats should be managed to limit predation by invasive species such as green crabs and moon snails, and closed until clams are market size.