YARMOUTH — The town’s commercial clam harvesting licenses could swell – to the dismay of local fishermen – if a new study finds the area’s shellfish population is sufficient.
The study comes after the Department of Marine Resources, which oversees the state’s shellfish resources, said the area’s clam flats could absorb more commercial harvesting.
Clammers disagreed, citing increased competition, water quality issues and decreasing clam populations, prompting the Town Council to commission the study.
“Being that Yarmouth has such an important history with shellfish and clams, before making a decision on changing the number of permits, we thought it was important to get a compete survey,” Council Chairman Steve Woods said. “The Yarmouth Town Council wanted to be responsible to both point of views, and we thought the only way to do that was by doing an independent, technical survey.”
The Town Council last week appropriated up to $21,000, funded by fees from licenses and permits, to research the productivity of the town’s shell-fishing areas.
If the shellfish populations, mainly clams, are healthy enough to support more fishermen, the town could begin issuing more licenses, Town Manager Nat Tupper said. The town currently issues six licenses annually.
The Cousins River was closed for extended periods because of concerns about bacterial contamination. Those flats have now reopened and expanded the areas of harvesting, prompting DMR to suggest the town could issue more licenses, which could lead to greater economic impact.
Clammers argue that more licenses could further devastate their industry through over-harvesting and create shortages in the future.
Although there are many variables that can explain the diminishing populations – water quality, over-harvesting, disease, soil disturbance from worm harvesters – two of the most common culprits pointed to by industry and scientists alike are green crabs and ocean acidification.
Green crabs are an invasive species that eat young clams, known as spat. The crab populations have boomed in recent years, due to increasing water temperatures that are no longer cold enough to keep them in check.
Warming water temperatures have allowed the invasive species to devour soft-shell clams at an alarming rate. The town of Freeport has commissioned a comprehensive study to determine, among other things, if green crab trapping is effective.
The study, part of a $100,000 effort by the town, will also conduct research on the effect of ocean acidification, caused by increases in carbon dioxide.
Lower pH levels are thought to have a damaging effect on clams, making it harder for them to build their shells, and if it’s low enough, actually dissolving them. It is also thought to be a common stress on clams, leading to the disease known as neoplasia, which often plagues clam flats with low pH.
While Yarmouth’s study, to be conducted by MER Assessment Corp. of Brunswick, will not address some of these larger concerns, it will provide clarity on shellfish populations in Yarmouth, said Landis Hudson, a member of the Shellfish Commission and executive director of Maine Rivers.
“There are a lot of variables when it comes to shellfish these days, with some areas opening up recently, but also problems with predators like the green crabs,” Hudson said. “Hopefully this will be a path toward mutual understanding.”