If you depend on fishing for a living, you’ve noticed a rapidly changing ocean ecosystem in the Gulf of Maine in recent years the effects of climate change and the consequences of decades, if not centuries, of overfishing.

The effects are devastating for fishermen who rely on traditional, cold-water Gulf of Maine species such as cod and shrimp. Shrimp are off limits for the second year in a row as stocks fail to recover to healthy levels. And regulators on Tuesday slashed cod catch limits 75 percent from last year’s levels, a week after they closed off large swaths of the Gulf of Maine to cod fishing.

Maine’s prize crustacean is plentiful, but where lobstermen are landing their catch is changing as lobsters seek cooler waters up the coast and baby lobsters’ natural predators disappear. Lobstermen in Washington County hauled in 18.8 percent of the state’s lobster landings in 2013, according to the Maine Department of Marine Resources. That’s double the figure from 1998, when Washington County accounted for 9.3 percent of the catch.

Knox and Waldo counties, by contrast, accounted for more than 35 percent in 1998, but their share was down to 27.2 percent in 2013. Farther south, the lobster fisheries in Connecticut and Rhode Island have collapsed over the past 15 years.

Meanwhile, Gulf of Maine fishermen are increasingly noticing species that traditionally sought out warmer waters, including Maryland blue crab, red hake, turbot, squid, black sea bass, dogfish and others. Some prey on shrimp, partially explaining that crustacean’s decline.

The shock of shutting down a fishery is real, but the Gulf of Maine’s fishing history has been building up to this moment of uncertainty over the future of Maine’s fishing economy.

As regulators institute emergency cod fishery closures, fishermen and some politicians including Massachusetts’ governor-elect, Charlie Baker are questioning the science behind regulators’ decisions.

“I’ve been struck by the dynamic in which the federal government says there are no fish and then fishermen go out and fish for a few hours and catch 10,000 pounds or 5,000 pounds, Baker said Saturday in Gloucester, Massachusetts, according to The Boston Globe.

But there’s little reason to doubt the science behind the cod catch limitations and it’s self-defeating. When cod start to decline, they tend to congregate in small areas that skilled fishermen can exploit, The Globe reported. Plus, there’s an undeniable history of overfishing in the Gulf of Maine that has led to this moment, when fisheries scientists say Gulf of Maine cod stocks are at 3 percent of the target level for a sustainable population.

Over the past century, the history of groundfishing in the Gulf of Maine is one marked by overfishing by vessels both foreign and domestic, the government-subsidized buildup of an oversized groundfish fleet, and slow action to institute mostly insufficient regulations aimed at preserving dwindling stocks.

Gulf of Maine groundfishing peaked in the 1980s following strong cod and haddock spawning years in 1975 and 1978 and has been in decline since then. Today, regulators use a sector system to manage the Gulf of Maine groundfisheries allocating an aggregate catch limit to groups of fishermen who operate in defined areas. The intent is to allow Atlantic cod and other species to rebound, but the outlook isn’t promising.

Just up the coast, Canada’s Grand Banks offer a cautionary tale. Cod fishing off the coast of Newfoundland and Labrador followed much the same pattern as the Gulf of Maine. In the 15 years between 1960 and 1975, fishermen there landed 8 million metric tons of cod, the same amount fishermen landed in the two-and-a-half centuries between 1500 and 1750, according to report prepared for the Canadian Parliament’s Fisheries and Oceans Committee. When regulators turned their attention to conservation, they often overestimated the size of cod stocks. In 1992, the Canadian government declared the northern cod commercially extinct, making the fishery off limits and putting 30,000 people out of work.

It’s tempting to doubt generally accepted science one finds unsatisfactory. But doubting the science, then failing to take any action in response to warning signs, sets up the Gulf of Maine for a bleak fisheries future.

Bangor Daily News