One of the bright spots in the state’s struggling fishing industry is shellfish, a lucrative crop of oysters, clams and sea scallops that generate hundreds of millions of dollars a year for the Massachusetts economy.

But climate change is affecting the water chemistry these shellfish need to grow and thrive. The process is called ocean acidification, and Massachusetts is playing catch-up on addressing the threat.

Six other coastal states with big shellfishing economies have already formed task forces to grapple with the problem, but Massachusetts legislators are still debating such a step.

Scientists say ocean water has grown 30 percent more acidic since the Industrial Revolution and is on track to get worse in coming decades as it soaks up excess carbon dioxide from air fouled with fossil fuel emissions.

“If shellfish can’t form shells and can’t grow, that’s going to decimate a multi, multi-million dollar industry here,” said State Rep. Dylan Fernandes, who is proposing legislation to form a 19-member task force on ocean acidification.

The problem is worse for coastal waters, which is where shellfish aquaculture farms are located. That’s because climate change alone isn’t causing acidification. Pollution runoff is another source, and so are rivers whose water is naturally more acidic.

Even sea scallops -- farther off-shore -- could also come under threat from acidifying water, according to researchers at the Woods Hole Oceanographic Institution. In 2015, Massachusetts fishermen landed nearly 179 million pounds of sea scallops, worth over $264 million, the state’s biggest commercial haul.

Of all the New England states, Maine has seen the most significant impact of coastal acidification.

Anna Priester, a scientist working at Island Creek Oysters in Duxbury, readies a tank for the next batch of algae, a crucial food source for growing oysters.
Chris Burrell/NECIR

Bill Mook, who runs a shellfish hatchery on the Damariscotta River in Maine, is among the first oyster growers in New England to see how acidic water was harming tiny oysters that rely on healthy water for ingredients to grow their shells.

“We started really noticing a lot of problems with larval production, the most sensitive stage in lifecycle of the oyster,” he said.

Mook had heard about acidic ocean water devastating oyster crops in the Pacific Northwest.

His own oysters were stunted, and it was costing him tens of thousands of dollars in lost production.

His solution was simple chemistry, measuring and treating the water in his hatchery when it got too acidic.

“Think of it like taking TUMS; you need to correct the water chemistry by adding antacid,” he said. “It was literally like turning the light switch on.”

Robert Chen, a marine chemist at the University of Massachusetts Boston, likened acidified ocean water to the acid in your stomach that dissolves food.

“Or like Coca Cola,” he said. ”If you put your tooth in there, it will dissolve.”

His analogy shows just how corrosive acidic water can be to animals that need to build shells. Scientists like Chen and others at Boston area universities are researching acidification in their labs, but they are also eager to understand what’s happening in the sea.

Maine and New Hampshire track acidification with at least eight sensors on their combined coastlines.

Massachusetts has just one, located off the south coast of Martha’s Vineyard. But Chen and his colleague, Francesco Peri, are building a second sensor with a $64,000 grant from the Environmental Protection Agency.

The sensor will pump in hourly water samples and share the data with people whose livelihoods could depend on it. Like oyster farmers in Duxbury.

“We could have a bad year where there’s low pH for a year in a place like Duxbury Harbor, which has 18 oyster farmers growing there. And their crop could be wiped out for the year,” said Chen.

The biggest player in Duxbury’s shellfish industry is Island Creek Oysters. Harvesting a million oysters a month, it employs 37 people full-time and another 600 at its restaurants.

The marine science lab at University of Massachusetts-Boston is tasked with building the state’s second sensor for tracking ocean acidification. Professors Francesco Peri (left) and Robert Chen (right) are leading the project with help from graduate student Shannon Davis (center).
Chris Burrell/NECIR

Company President Chris Sherman, who also heads up the state’s aquaculture association, said oysters are in the “cross hairs” of coastal acidification. He said it’s all part of the challenge of climate change.

“We’ve been dealing with these changes every day, from 49 degrees and a nor-easter in June today, to when an easterly breeze heats the bay up to a temperature we haven’t seen in decades and wreak[s] havoc on animals,” he said.

Sherman questions if Massachusetts is doing enough about ocean acidification but admits that he and other growers also need to speak out more about the threat.

The shellfish industry rakes in nearly $400 million a year, more than triple the combined commercial value of all finfish species caught in the state, like haddock, flounder and cod.

State officials say they are working with coastal communities to lessen pollution that contributes to acidification.

Meanwhile, big cuts to programs aimed at ocean acidification are looming in Washington. President Trump’s budget proposal would completely scrap the EPA estuary program that funded the Duxbury sensor project and would cut 40 percent from the National Sea Grant program for university research.

Oyster growers like Mook think that’s crazy.

“What’s being proposed is absolute lunacy. If we’re going to adapt and have economic development, we need information,” he said.

Massachusetts will be under more pressure to pick up the slack if Congress approves Trump’s proposed cuts to environmental programs.

The Eye is the online news site of the New England Center for Investigative Reporting, based at WGBH Public Radio and Boston University. Chris Burrell can be reached at For more on this article, go to