DV-20-05 Quantifying Soft-Shell Clam Fecundity Across Two Regions of the Maine Coast

Brian Beal

Soft-shell clams are a culturally important fishery. Yet, over the past 40 years, commercial clam landings have declined by 75%, due in part to declines in standing stock and clam population size based on recent changes in their ecosystems. Predators, such as the invasive green crab (Carcinus maenas) and native milky ribbon worms (Cerebratulus lacteus) that thrive in Maine’s warming waters, are consuming 99% of clams within a year of settling out of the water column. For standing stock to increase, more clams need to survive to adulthood.

Larger female clams produce more eggs, making them disproportionately important to maintaining population levels. The goal of this project is to more closely examine fecundity, the number of eggs produced by a female in a breeding or spawning season, of soft-shell clams. Program development funds will support two clammers to collect female adult clams in two geographically distinct regions (southern Maine and eastern Maine) at three tidal heights (upper, mid, and lower intertidal zones), and an intern to collect shell size, age, and egg size measurements. This study aims to inform the management decisions of local municipalities, including a current proposal for a clam harvest size limit.

Sea Grant Funds $4000