For decades, climate change has wreaked havoc on New England’s historic fishing communities. Now we know precisely how much.

A new study from the University of Delaware shows that erratic changes in atmospheric pressure, a phenomenon known as the North Atlantic oscillation, were singularly responsible for a 13-percent loss in fishing revenue between 1996 and 2017, and a 16-percent loss of jobs in New England’s hardest-hit communities.

Large pressure increases occur naturally, but are exacerbated by man-made emissions. They raise sea temperatures, scramble ocean currents, and drive a rapidly changing climate in the northern hemisphere. The warmer weather causes fish to leave the region and seek colder waters.

Because fishermen are paid based on what they catch, fewer fish naturally means fewer earnings and jobs. Each unusual increase in pressure was associated with a 35-percent drop in wages, an effect that persisted for years. Over time, climate change took away 16 percent of jobs in New England’s most afflicted fishing communities. 

“The individuals who can’t weather these climate shocks are the small mom-and-pop businesses and smaller fishing establishments,” says economist Kimberly Oremus, the study’s author. “There are communities that are just not going to be fishing communities anymore.”

New England waters were once home to an abundance of bottom-dwelling fish, such as haddock, redfish, and especially cod. That fish was once so abundant that one could purportedly walk “across the Atlantic on their backs,” as the saying went. 

No longer. Due to overfishing, cod stocks are nearly depleted. To avert complete collapse, the National Oceanic and Atmospheric Administration now sets limits on fish catches, or quotas. In the past decade, catches have plummeted, from 100 million pounds of cod in the early 1980s to a fraction today. 

At the same time, the Gulf of Maine, a frigid inlet between Cape Cod and Nova Scotia, has been warming faster than 99.9 percent of the global ocean. As cold-water species like lobster migrate north, fisherman are left empty-handed, and wait for warm-water blue crabs to eventually take their place. 

Sudden “shocks” of atmospheric pressure contribute to that change, but that isn’t evident until one to six years later, when squid, sea scallops, and other species are mature enough to be fished.

Oremus didn’t observe any correlation between these “signal lags” and lowered quotas, which means NOAA fishing managers may not be including climate shocks in their calculations. That could lead to unintentional overfishing, and perhaps eventual collapse of the stock, she says.

According to Oremus’ analysis, between 1996 and 2017, each unusual shock reduced the total catch in New England fishing counties by 2 percent. Those 2-percent reductions accumulated to a 13-percent overall decline in fish revenue. That 13-percent decline in fish revenue resulted in a 13-percent drop in employment, and a 35-percent drop in wages, over a six-year period.

All told, those positive climate shocks were responsible for an on-average 16-percent decline in county-level fishing employment over that same 20-year period. Other factors included industry consolidation, market swings, regulation of overfishing, and an aging workforce.

Ironically, as climate shocks were negatively impacting fishing jobs, wages and businesses, Oremus observed that the mining industry was enjoying a boom. Although labor data suggests that fishers could have been leaving their boats for mining and fracking jobs, Oremus cautions that more research is needed to prove the connection.

The study is available in full here.

Jessica Fu contributed reporting.