DEI’s research which pinpoints predation by predators such as the invasive green crab and milky ribbon worms as the cause of southern Maine’s clam decline has been published in the April edition of the Journal of Shellfish Research. The paper details the results of six large-scale field experiments, which excluded predators such as green crabs, that were deployed in three different tidal estuaries (at different tidal heights) in southern Maine over the course of two years. Two of the experiments, conducted in Freeport, were part of the largest intertidal research project in the history of the state of Maine. Results found that clams suffered from predation rates as high as 99% in southern Maine, putting the state’s iconic soft-shell clam fishery in jeopardy unless major changes in soft-shell clam management occur.
The research was conducted cooperatively with members of the fishing community. Leadership from the Maine Clammers Association were co-authors of the study. Clam landings have plummeted over the past 30 years with 2017’s landings the lowest since 1930. During the same time period seawater temperatures in the Gulf of Maine have risen substantially and winters in the region have become milder. During this period of warming ocean temperatures populations of invasive green crabs, Carcinus maenas, have increased rapidly in Maine, especially along the southern Maine coast.
To read more about the study, go here: https://downeastinstitute.org/research/soft-shell-clams/