May 22, 2017 — Clammers face a shrinking harvest again this year after predator green crabs survived the mild winter, but one scientist may have an answer – aquaculture.
The second mild winter in a row means Maine’s tidal flats will likely be overrun by large, ravenous invasive green crabs this summer.
That’s bad news for the state’s already weakened soft-shell clam industry. One green crab can consume 40 half-inch clams a day and will dig 6 inches to find clams to eat. In 2016, clam landings fell 21 percent, from 9.3 million to 7.3 million pounds, the lowest total reported since 1991, according to the state Department of Marine Resources.
Some of the landings decline was undoubtedly a result of an unusual bloom of toxic algae that forced a monthlong shellfishing ban along about a third of Maine’s coastline last fall. But researcher Sara Randall of the Downeast Institute in Beals notes that a review of clam landings in towns with traditionally high numbers south of the Deer Isle-Stonington closure line found that 19 out of 24 towns, or 79 percent, had harvested fewer clams.
For example, from 2015 to 2016, landings fell 35 percent in Harpswell, 87 percent in Yarmouth and 21 percent in Scarborough. In Freeport, a town on the front line of the effort to combat the green crab invasion, landings decreased 17 percent despite efforts by municipal officials, clammers and researchers like Randall, among others, to use protective measures such as nets and other tools to ward off the green crabs.
The mild winter may only make matters worse. Clammers had hoped for a cold winter so the deep freeze and ice would kill off a lot of the crabs, allowing the clam seed still found in high numbers in Maine waters a chance to settle in the tidal flats and grow, forming those telltale tiny holes that tell clammers a harvest awaits them under the mud.