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Ocean Acidification Could Wipe Out Shellfish Industry: Report



A new statewide report is urging fast action to address ocean acidification to avoid catastrophic effects on the region’s shellfish industry. 


Over the last year, the Massachusetts Special Legislative Commission on Ocean Acidification, which is made up of 18 legislators, conservationists, scientists, and fishermen, has been studying how a more acidic ocean—one of the many effects of climate change— could devastate the state’s $460 million shellfish industry by the end of the century. In the new report, they’ve released findings, warnings, and a roadmap to prevent the worst effects. 


The report maintains that the world’s oceans are becoming more acidic as they absorb about a third of the world’s carbon emissions each year. Across Massachusetts, acidification is worsened by nutrients like nitrogen and phosphorus that are released into waterways, mostly through lawn fertilizers and septic systems. As much 85 percent of homes and businesses on Cape Cod rely on septic systems to handle wastewater, yet these systems do little too prevent nutrients from entering the environment.


As the ocean absorbs more carbon emissions and nutrient pollution, it becomes more acidic, which in turn limits certain ions that help mollusks like scallops, oysters, and clams form and maintain their protective shells. 


“Not only will there be smaller populations of these species,” said Falmouth Rep. Dylan Fernandes, who co-chaired the commission, “but the ones that do survive will have weaker shells, which puts them at higher risk of predation.” 


Acidification can reduce mollusk survival rates by 34%, and surviving mollusks can be 17% smaller, according to the report. 


“For the aquaculturists, we all depend on the hatcheries and the hatcheries depend on well-balanced water in the nursery,” said Seth Garfield, president of the Massachusetts Aquaculture Association and owner of Cuttyhunk Shellfish Farms. “If they have poor water quality due to ocean acidification, and their production is wiped out and has a much higher mortality, then all of a sudden the shellfish hatcheries will not have the ability to supply the juvenile shellfish to the variety of shellfishermen.” 


The Massachusetts marine economy, which includes fisheries as well as seafood processors and vendors, employs more than 5,700 individuals across more than 500 establishments and generates over $300 million in annual wages. Overall, it generates more than $600 million of Gross State Product (GSP), compared to $200 million in Maine and less than $100 million in Connecticut, New Hampshire, or Rhode Island, according to the report.


“The total value of all mollusks harvested in Massachusetts now exceeds $459 million annually, with the majority derived from sea scallop landings,” the report said. “The total value of American lobsters caught in Massachusetts has increased by nearly 67% over the past nine years.” In 2019, it grossed just under $100 million. 

The report notes that while it appears that crustaceans like lobsters may be more resistant to ocean acidification than mollusks, the combined effect of rising ocean temperatures and ocean acidification “have not been thoroughly studied in most economically-relevant crustacean species.” In fact, the report found that zero studies have examined the effects on Atlantic surf clams, horseshoe crabs, Jonah crabs, or Atlantic deep-sea red crabs. 


Looming over all of this is a deadline: by 2100, the average temperature of the world’s oceans could increase by 1 to 4 degrees Celsius. As water temperatures rise, the ocean’s capacity to absorb carbon dioxide will decrease, which will disproportionately affect marine economies and ecosystems in Massachusetts. 


“Because Massachusetts contains some of the most acidification-vulnerable communities in the country, it will be disproportionately affected as the shellfish industry is predicted to lose more than $400 million annually by 2100 as a result of ocean acidification,” said Emiley Lockhart, a commission member from the Woods Hole Oceanographic Institution. 


The report’s authors are now recommending improved acidification monitoring along the coastline, a permanent ocean acidification council, and funding to research the economic and ecological effects of acidification. They also called for legislative changes to update and improve nutrient pollution regulations. 


“Ocean acidification is an existential threat to these marine ecosystems and to the livelihood to the people who work in them,” Fernandes said. “We’re running out of time before the consequences become truly catastrophic.”


Eve Zuckoff covers the environment and human impacts of climate change for CAI.