Giant Crab 'Red Army' Invades Norway

James Owen
for National Geographic News

March 9, 2004

The Cold War might be over, but a red army of monster crustaceans—marshaled by Soviet-era leaders—is threatening to
invade Western Europe, according to environmentalists.

First introduced to the Barents Sea off northern Russia in the 1960s, red king crabs (Paralithodes camtschaticus) are now spilling down western Norway by the millions. Some fear these massive crabs, native to Alaskan seas and the North Pacific, could reach as far south as Spain and Portugal, devouring almost everything in their path.

Some fishing communities in northern Norway say the crab, among the largest in the world, has already had a devastating impact. "The bloody things Hoover [vacuum] everything off the bottom of the sea, and all the fish are disappearing," one resident from the town of Kirkenes told the U.K.'s Daily Telegraph.

Yet others welcome the red king crab, saying its delicious taste and size—the crabs can grow to 22 pounds (10 kilograms) and measure 4.9 feet (1.5 meters) across—make it an extremely lucrative catch. In the United States the crab's meaty legs fetch around $25 per pound.

WWF Norway says the crab's population has increased sixfold since 1995. The environmental group puts the current population at at least 12 million in the Barents Sea alone. The group says that any economic benefits derived from this population explosion may be vastly outweighed by the long-term cost to the marine environment.

For instance, WWF Norway says it is concerned about the impact of the crab—which has no natural enemies in Arctic waters—on the capelin, a fish considered central to the Barents Sea food chain.

"Absolutely nothing has been done by Norwegian authorities to mitigate the impacts of the red king crab," WWF Norway said in a prepared statement.

The crabs were first transported to the Barents Sea in a plan hatched under Soviet dictator Josef Stalin. The aim was to provide a new food source for people working in the frozen far north.

Handpicked

Initial crab introduction attempts in the Barents Sea were unsuccessful, however. Scientists involved in the project say it wasn't until the 1960s, when only the biggest and strongest crabs were handpicked to make the journey to the U.S.S.R., that the crustacean became established.

Norwegian scientists say the crab, which can live up to 30 years, has broad tastes, eating everything from worms and mollusks to sea urchins and sea stars. They caution that the impact of these aliens on other marine life has yet to be established.

"So far we have no indication of what impacts the crab will have on the native ecosystem and how serious any affects may be," said Jan Sundet, senior scientist at the Institute of Marine Research in Tromso, Norway. He added: "We know very well what the crab eats, and that is almost anything that is available on the bottom."

The crab is now reported to have reached the Lofoten Islands, about a third of the way down the Norwegian coast, having traveled some 400 miles (680 kilometers) since the early 1990s.

"It is spreading much faster that we anticipated," Sundet said. He notes that the crab's recent population explosion parallels that of some other alien species, where rapid growth occurs only after a relatively long period, during which an animal becomes established.

In its native North Pacific, where seabed competition is tougher, red king crabs have ventured as far south as northern Japan, which is on the same latitude as southern European countries.

Estimates by scientists of the potential southern limit for the species in Europe vary widely. Some say the Lofoten Islands, some the North Sea, and some Portugal.

Crab Management

WWF Norway says the Norwegian government's management policy towards the species has been to maximize population size to increase potential catches, while ignoring the possible consequences for the marine environment.

"Considering the importance of the Barents Sea as one of the world's most productive marine ecosystems, this policy can be described as high-level gambling with international conservation values and food supplies," wrote WWF Norway secretary general, Rasmus Hansson, in a letter to the Secretariat of the Convention on Biological Diversity, in Montreal, Canada.

The environmental group says the policy constitutes a clear violation of the convention, which requires signatories like Norway to control or eradicate alien species that threaten ecosystems or native species.

Although commercial fishing for the crabs off Russia and Norway began in 2002, only mature males are allowed to be landed. All females must be returned to the sea.

However, both countries now accept that crab numbers have risen massively in recent years. In 2003 the two nations agreed to double the total annual fishing quota to 800,000 crabs. Unrestricted fishing for the species is also planned in certain areas.

"Norwegian and Russian authorities recently agreed to set a western border for the joint management of the crab stock, and it is expected that the management west of this border will be an 'extinction' strategy to keep the crab stock as low as possible," Sundet said.

Whether such a measure will be enough to stop the red king crab's relentless march is questionable. The crustacean can't be decimated by fishing alone, Sundet says, adding that further action will be needed, "independent of [the crab] being of great commercial value or not."

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