Is it time to give up on doomed fisheries?

This story was originally published by Hakai Magazine and appears here as part of the Climate Desk collaboration.

In the 1980s, Rich Hittinger’s favourite rite of early spring was chasing winter flounder. On many March days, he anchored his six-metre boat, Ermala — named for his three children, Eric, Mark, and Lauren — in a sheltered cove in Narragansett Bay, the estuary off Rhode Island’s southeastern coast. He and the kids chummed the water with rabbit feed and lowered hooks baited with clam worms, then ducked into the boat’s cabin to warm their bellies with hot chocolate.

“They’d put the rod in the holder, and by the time they’d come back, they’d have a fish on the other end,” says Hittinger, vice-president of the Rhode Island Saltwater Anglers Association. “They’d catch flounder one after the other.”

Fishermen around Rhode Island shared Hittinger’s passion. Winter flounder, so named because they spawn between December and April, were a valuable commercial species and a dinnertime staple; anglers said that Narragansett Bay was practically paved with the mottled flatfish.

In the late 1980s, though, the species began to buckle beneath the weight of overfishing. Managers took the logical step of restricting harvest, but winter flounder never recovered. Now the southern New England population hovers at just 30 per cent of government targets, and catches in Narragansett Bay are a measly one one-hundredth of their historical apex. “There’s so few of them that recreational fishing is basically closed,” Hittinger says.

For years, winter flounder’s stagnancy was something of a mystery. Today, however, a growing body of evidence implicates a familiar culprit: climate change. Coastal ecosystems along the New England seaboard have been upended by rising ocean temperatures, none more so than Narragansett Bay, where waters have warmed by 1.7 C over the past century.

This is a troubling realization, since global warming, unlike overfishing, isn’t a problem that fisheries managers can rectify. It also forces us to confront a series of disturbing questions: What if winter flounder and other climate-stressed fisheries never bounce back? Do we keep trying to rebuild them, even if conditions make their recovery unlikely? Or do we lower our expectations — perhaps even give up altogether?

“It’s not that we can’t get more winter flounder, it’s that we can’t get 1980 levels of winter flounder,” says Joe Langan, a fisheries oceanographer who conducted his doctoral research on winter flounder at the University of Rhode Island. “The climate of the 1970s is not our current climate. The rules of the game have changed.”

In 2017, Langan received a grant to investigate a seemingly straightforward question: what would it take to bring winter flounder back? He and his colleagues trawled Narragansett Bay in late winter, scooping up flounder larvae in a windsock-shaped plankton net. “Catching microscopic larval fish while it’s snowing is super fun,” he recalls unironically.

When Langan examined historical trawl survey data, he found that reducing fishing pressure hadn’t brought back winter flounder for a simple reason: their young were dying before they got big enough to catch.

Juvenile flounder confront two crises, both temperature-related. As Rhode Island’s waters have warmed, the populations of predators such as comb jellies and shrimp have spiked, exposing flounder eggs and larvae to more hungry mouths. Young flounder are especially vulnerable to striped sea robins, bottom-dwellers that swoop around on winglike pectoral fins and vacuum prey from the sand. Langan’s research found that sea robins spend nearly three more months in Narragansett Bay annually than they did 60 years ago. And life doesn’t get much easier for the few young flounder that survive this hungry gauntlet. Hotter water temperatures and lower oxygen levels stress flounder during the summer and can even kill them outright.

So what can fisheries managers do about it?

Not much, Langan and his colleagues found in a recent study. Fishermen could start targeting sea robins, although there’s not much of a market for them. Government agencies could also cull or drive off cormorants, which eat plenty of flounder themselves, or try to improve Narragansett Bay’s water quality. Yet Langan’s modelling suggests that even those measures are highly unlikely to bring winter flounder back. The dispiriting takeaway is that the halcyon fishing that Rich Hittinger remembers is probably gone for good. The bay’s winter flounder population, wrote Langan and his colleagues in their study, was a “climate loser in an evolving ecosystem.”

Winter flounder’s unrelenting collapse is testing some of the bedrock tenets of fisheries management. American fisheries law requires managers to rebuild overfished stocks to healthy levels. But if climate change means that winter flounder can’t be rebuilt, fisheries managers may have to shoot for more modest goals that reflect the diminished capacity of warmer oceans.

“This isn’t a Rhode Island-specific question — it’s a question for many stocks that face stresses as a result of changes in climate,” says Conor McManus, the chief of Rhode Island’s Division of Marine Fisheries. “Winter flounder is a case study for the challenges that we face as fisheries managers.”

The likelihood that some fisheries can’t be entirely rebuilt, however, comes with worrisome implications. If managers revise their recovery goals too dramatically, they risk succumbing to shifting baselines syndrome — the phenomenon whereby every generation forgets how abundant fish used to be and regards their own degraded present as normal.

“You don’t want to just say, Oh well, we lowered our target and now they’re fine and we can ignore them,” Langan says. Accepting the inevitability of a stock’s collapse also suggests moral hazards: if winter flounder is doomed anyway, why not let fishermen catch as many as they want while they still can?

These quandaries will only grow more pressing. Winter flounder is just one climate loser among many. How much effort should we spend propping up chinook salmon in California’s Central Valley, where heat and drought have conspired to spread disease throughout once-prime spawning streams? How will we react when lobster — which have already fled Rhode Island and Long Island Sound — abandon Maine for cooler pastures in Newfoundland? These decisions are a form of conservation triage, the controversial notion that scientists should focus on saving species that stand a decent chance of surviving the Anthropocene, rather than the ones whose climate sensitivity puts them beyond hope.

“It seems horrible to ask whether it’s worth trying to recover a population,” Langan says. “But in a world of limited resources, at what point do you say that you don’t want to spend all your money on a population that’s toast with another half degree of warming?”

Triage is especially fraught in the fisheries world, where human livelihoods rest on every decision and no species exists in a vacuum. In New England, fishermen catch winter flounder alongside other groundfish like cod, haddock, and hake. If managers institute draconian catch restrictions in a desperate bid to protect Rhode Island’s flagging flounder, they could inadvertently shut down the entire groundfishery. “You run the risk of impacting fisheries for sustainable stocks while trying to help rebuild a single species,” McManus points out — one that isn’t especially likely to recover anyway.

No one, to be clear, is suggesting that Rhode Island give up on winter flounder. At least, not yet. Fish are eternally capable of surprising us. Cod, another presumed climate loser, has lately been thriving in Rhode Island, much to scientists’ bemusement. And as the winter flounder wanes, Hittinger says that other more heat-tolerant species, like black sea bass, have moved up the Eastern Seaboard to fill the void. Still, it’s hard not to mourn what Narragansett Bay has already lost.

“Families can’t do what we once did,” Hittinger says. “It’s sad that winter flounder isn’t here anymore.”