How lobsters became victims of the tragedy of the commons

Lobster traps in the sunset
Shutterstock EddieCloud
The lobster is at serious risk of overfishing.

 From "The Last Lobster: Boom or Bust for Maine's Greatest Fishery?" by Christopher White. Copyright 2018 by the author and reprinted with permission of St. Martin's Press, LLC. 

By net, trap, trawl and hook and line, fishermen are taking far more produce out of the seas than can be replenished by the breeding stock that remains. As a consequence, 53 percent of global fisheries are "fully exploited,"  says the World Wildlife Fund, and nearly a third are "overexploited, depleted, or recovering from depletion." Unless the trend reverses, all species harvested for food may collapse by 2048.

If asked to single out one factor that prompts such a gloomy forecast, scientists point to "overcapacity" of the world’s fishing fleets. The roster of boats is two times larger than the level that oceans can accommodate sustainably. Experts argue that the industry could return to the profile of fewer, smaller boats of the 1970s and still produce the same yield. The same argument is made for lobster boats and traps.

The Last LobsterHow did this overcapacity develop around the world? Declining stocks prompt more competition for a limited resource — a "gilded trap," in Bob Steneck’s words, if you will. This led to overcapitalization of larger and larger boats, of more nets, of a bigger fleet. When a fishery goes bust, the whole armada steams toward a new patch of blue, as if suffering from some unquenchable addiction.

The solution offered for this dilemma is usually aquaculture, which may take some pressure off overfished seas. But lobsters, it turns out, are not well suited to sea farming. Larvae can be raised in hatcheries, but they take five to seven years to mature. Meanwhile, they require a huge food input. If not, they become cannibalistic. So if aquaculture is to help Maine lobstermen, it will be to augment stocks of other species — clams, mussels, scallops — that lobstermen might harvest in their spare time. Right now, lobstermen have only one prize in mind: lobster.

Such single-mindedness is the Maine lobsterman’s potential downfall. In Newfoundland, where single-minded fisherman watched their exclusive cod fishery collapse in 1992, some 40,000 people lost their jobs overnight; 10,000 were fishermen. More than 25 years later, the cod have shown only a slight rebound on the Grand Banks. Thanks to ocean warming, they may never recover completely. Canadians have few places and species left.

Just to the southwest, the Gulf of Maine has its own challenges. Maine has a long tradition of overfishing. Its track record is poor: Herring, hake, halibut, croaker and cod have been overexploited. Same goes for flounder — winter flounder, witch flounder and windowpane. Trawlers also have depressed pollock and redfish populations. In fact, all groundfish have been overharvested. Invertebrates such as clams and sea urchins have succumbed. Pelagic species such as mackerel are not exempt. Unless managed well, black sea bass likely will be next. Does anyone learn from their neighbor or from the past?

Overfishing may be generally defined as harvesting from a population at a rate greater than the population’s reproduction capacity to replace the harvested animals. However, for each species, managers have developed a more specific measure of overfishing. The Atlantic States Marine Fisheries Commission (ASMFC), along with the National Marine Fisheries Service and the state of Maine, manages lobster stocks in the Gulf of Maine. The ASMFC’s official definition of overfishing lobster reads: "The American lobster resource is overfished when it is harvested at a rate that results in egg production, on an egg-per-recruit basis, that is less than 10 percent of the level produced by an unfished population."

In other words, the average female lobster should be allowed to live long enough to produce at least 10 percent of the eggs that she would produce if she were allowed to live her natural life. If she is harvested ahead of that schedule, overfishing is in play.

Out of the many casualties in the long parade of Maine fisheries, let’s look at the most recent: northern shrimp. In December 2013, the ASMFC banned all shrimp fishing in the Gulf of Maine, citing overfishing and ocean warming. The shrimp population had collapsed so swiftly in just two years that the ASMFC considered there was "very little hope for recovery in the near future."

"It’s the lowest biomass in history," said Terry Stockwell of the Maine Department of Marine Resources at the time. The shrimp have suffered a one-two punch. First, overfishing depressed stocks. In 2010, for example, shrimpers caught 2.2 million pounds over their federal limit of 10.8 million pounds, a 20 percent overage. Subsequent years showed a similar excess. Second, the warmer waters have affected the shrimp by killing off the phytoplankton that shrimp consume. As overfishing is a relative concept, it was hoped that the moratorium on fishing would allow the small crustaceans to replenish themselves.

But the initial ban had little effect. The numbers of shrimp from 2012 to 2016 were the "lowest on record." Like cod, once northern shrimp are knocked down, they don’t seem able to get back up. Ocean warming has compounded the effects of overfishing.

Ironically, climate change may keep fishermen from having to face up to the responsibility of overfishing. In the long run, warming seas may overshadow the impact of exploitation. In the short term, their impacts may reinforce each other’s impacts. This synergy has happened with both cod and northern shrimp, bringing on an intense search for the last remaining stocks.

Old-time lobstermen know the trap well; they can remember years of low catches, followed by frantic hauling and a further decline in stocks. The 1920–1940 lobster seasons fit the pattern. Young lobstermen have shorter memories, and the senior men warn them, to no avail. Today, even in the face of a historic boom, old-timers are cautious. They warn of the threat of overfishing from a new generation of lobstermen who captain bigger boats — some over 50 feet long — bearing traps they turn over more frequently. These mavericks go farther out in the ocean and lobster all year, instead of taking the traditional midwinter break. By adding three months to their season, the cowboys augment their catch by one-third or more. Today’s winters tend to be milder, so it’s no sacrifice. More and more lobstermen are trying their hand at winter. Meanwhile, a 120-million-pound season could turn into 150 million pounds, a record. But would it be sustainable?

We do not know yet, since climate forces coupled with overfishing have not reached their zenith. In the shadow of ocean warming, prevention of illegal harvesting and other forms of overfishing will be even more important. Climate change intensifies overexploitation. Both are immediate threats to the livelihood of lobstermen.

Ecologists, the scientists who study organisms in relation to their environment, claim there is a common thread to shared resources like ocean fisheries, and a common tendency to overexploit them. In many ways, the bluefin tuna fishery, the cod fishery and the herring fishery have the same history. Fishermen act in their own self-interest, catching the maximum amount of fish, sometimes contrary to the best communal interests of the fleet. They deplete the common resource even when they would be served better by conserving it.

This common paradox, or psychology, if you will, was characterized by ecologist Garrett Hardin in 1968. He pointed to short-term selfish behavior as the critical personality trait of the ranchers, farmers and fishermen who landed in trouble, especially when they ignored what was best for the group. He identified Aristotle as the first observer to write about the phenomenon, so the dilemma had gone unchecked for centuries. Thanks to Hardin, the issue took center stage again. Hardin’s revolutionary thesis has been at the center of debate in ecology and economics circles ever since.

Hardin presented a parable, "The Tragedy of the Commons," which teaches a simple lesson — initially set in farming country — with powerful implications for managing fisheries and other common resources. The parable imagines a pasture "open to all," a sea of grass. Several herders graze their sheep there, motivated to expand their flocks — infinitely, if possible — even though it is not in the best interest of the community. Quickly, each animal added to the turf degrades the commons by a small amount, eating the grass, leaving the soil bare. The herder receives all the benefits of an additional ram or ewe, while the damage to the commons is suffered by all. If all the owners continue the pattern of overuse, the turf becomes overgrazed. The commons is destroyed.

Therein lies the tragedy: Each owner is locked into short-term selfish behavior that causes long-term environmental harm to everyone.

Tags: