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Environment: Overfishing Lead to Current Sea Crisis, Data Shows

Posted on: Monday, 7 November 2005, 21:00 CST

By Stephen Leahy for Tierramrica

TORONTO, Nov. 5, 2005 (IPS/GIN) -- New historical data reveal that the world's oceans are in crisis, largely due to overfishing, and they may not recover.

Commercial fishing will exhaust fisheries in a decade or two if it continues unchanged, the records indicate.

"The oceans are dramatically different than they were 150 years ago," said Poul Holm, a scientist with the Center for Maritime and Regional Studies at the University of Southern Denmark.

Back then, "there were many more top predatory fish like tuna, and nearly all fish were much larger ... and found over wider areas than today," Holm told Tierramerica.

Several hundred historians and marine scientists from around the world have been conducting research for more than five years into what the oceans were like up to 300 years ago. They presented their findings last week at the History of Marine Animal Populations "Oceans Past" Conference in Kolding, Norway.

Historical records revealed, for example, that the ling cod (Molva molva) of the North Sea had been fished out before 1920, when the decline was previously believed to have started in the 1970s.

Fisheries data only goes back a few decades so it is difficult to know the true extent of the crisis or to be able to manage remaining stocks without information from the era before large-scale industrial fishing, Holm said.

"Just as important as changes in fish stocks, we need to know how the marine ecosystem has changed," he said.

Even without direct fishing pressure, the ling cod, the northern cod and other species have not recovered, suggesting fundamental ecological changes.

What this new data on the history of the oceans makes clear is a pattern of commercial fishing that depletes one stock in a decade or two and then moves on to the next, and then the next.

That pattern is evident among a collection of 200,000 U.S. restaurant menus, dating back to the 1860s.

In the 1870s, 20-pound lobsters were so common that they were canned and rarely found on menus. "It was considered a trash fish no one wanted -- it was not something you'd want to be seen eating," said Glenn Jones from Texas A&M University at Galveston.

As more favored species declined, lobster found its way onto menus, and by the 1920s was priced at an average of $24 a pound -- about the same price as today, Jones said in a Tierramerica interview.

Lobster sizes dropped to a half-pound, the minimum for harvest, but their stocks are not endangered.

"Lobsters are one of the best-managed marine resources we have," he said. Larger 4- and 5-pound lobsters have been showing up on menus in the last decade, a sign that new deep-sea areas on the outer continental shelf, 200 miles offshore, are now being harvested, Jones said.

"Within 10 years those large ones will be gone too," he predicted.

Abalone (Haliotis rufescens), a tasty, slow-growing mollusk from the seas off California's coast, followed a similar pattern. Popular in the 1920s and priced at about $7 for a meal in today's currency, prices rose seven to 10 times faster than inflation by the 1950s as the species was increasingly overfished.

California banned commercial abalone fishing in 1997. Most abalone in California restaurants today is imported from Australia and New Zealand and priced at $50 to $70 a portion.

The importance of having a long-term data set is illustrated by a study of Mexican fishers from the Gulf of California on the western coast east of the Baja California peninsula.

Compared to the average 30-year-old in the business, those who were over 55 could name five times as many depleted sites and five times as many fish species that had disappeared, according to Andrea Saenz-Arroyo at the University of York in England.

Those 30-year-old fisherfolk were unaware that the seas they had fished all their lives were once abundant with sharks, huge groupers, snappers, green turtles, rock oysters and conch.

"There was a dramatic shift in perception of what constitutes the natural state of the environment," Saenz-Arroyo told Oceans Update, a newsletter from SeaWeb, a Washington-based educational non- governmental organization.

Three hundred years before the older fisherman were born, the Gulf of California was remarkably different, with heaps of pearl oysters lying about, according to Spanish explorers. Goliath groupers were a common and favored meal back then, but no fisherman of any age today knew they once swam there.

People fail to appreciate the scale of environmental degradation in their own lifetimes she said, and that reduces expectations of what constitutes a "healthy" ecosystem.

"An understanding of past environmental conditions is essential for effective conservation today," said Saenz-Arroyo.

Short memories and the twin myths of abundance and endless seas keep enlarging the global fishing fleet, despite much evidence that a crisis is at hand.

Even wide-ranging species like the Atlantic bluefin tuna (Thunnus thynnus), which were found in abundance from northern Norway to the Black Sea, and from Newfoundland to southern Brazil, have vanished from half of this vast area.

Although fished for several centuries, the Atlantic bluefin tuna decline is the result of the development of new fishing equipment and technologies during the mid-1900s. Moreover, modern fishing practices and regulations (such as intentional and unintentional capture of immature fish, mis- and non-reporting of catches) are reducing the likelihood that bluefin tuna will recover, experts reported at the conference.

The global output of fish and seafood has been in decline for some years, despite an ever-increasing effort to catch fish, said Holm.

"The demand for fish is well beyond what the oceans can now provide."

The continuing pattern of pursuing new species after other stocks fail is now endangering the slow-growing Patagonian toothfish and Chilean sea bass.

Pirate fishing boats illegally net millions of dollars worth of these fish and sell them on the black market.

"Global governance over the deep-sea regions is badly needed," concludes Holm.

(*Originally published Oct. 29 by Latin American newspapers that are part of the Tierramerica network. Tierramerica is a specialized news service produced by IPS with the backing of the United Nations Development Program and the United Nations Environment Program.

Source: Global Information Network

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