By Patrick Whittle, Associated Press

PORTLAND, Maine (AP) — Exactly how 32 American lobsters wound up in Swedish waters isn't clear. But because some of them were wearing the rubber bands that are put on lobsters' claws in captivity, many suspect the shellfish had been exported to Europe and then either escaped into the wild or were set free by animal rights activists.

Whatever the case, their discovery has set off a high-stakes trade dispute between Sweden on one side and the U.S. and Canada on the other.

Sweden has asked the European Union to bar imports of live American lobsters into the 28-nation bloc, saying the crustaceans could spread disease and overwhelm the smaller European variety by outcompeting them for food.

The American and Canadian lobster industries are skeptical of Sweden's call for a ban, saying they suspect it has more to do with business than with sound science. They suggest Sweden is trying to protect the market for European lobsters.

"Is it an invasion of species or an invasion of economics?" said Beth Casoni, executive director of the Massachusetts Lobstermen's Association. "This ban is unnecessary."

The North Americans are recruiting members of Maine's congressional delegation and U.S. ambassadors and asking Secretary of State John Kerry and the White House for help.

The stakes are high: The U.S. and Canada export a combined $200 million in lobster to Europe annually, and Europe took nearly one-fifth of all U.S. lobster exports last year. Lobsters are also Maine's signature product, depicted on license plates and tourist T-shirts.

The North American side points to a Swedish report that says a ban on American crustaceans "would potentially be beneficial in terms of profits and jobs" for Europe. The report also says the discovery of the 32 American lobsters over the past eight years raises the prospect of shell disease and red-tail disease.

Gunvor Ericson, state secretary for the Swedish Ministry of Environment and Energy, said Sweden considers American lobsters an invasive species. She said the country's concerns are based entirely on the scientific risk assessment done by Swedish authorities.

"Once the American lobster is established, it will be impossible to eradicate. This poses a severe threat to the native European lobster, as well as to other native crustacean species," she said.

A ban on imports would probably benefit countries such as Iceland, which exported more than 2 million pounds of lobster to the EU in 2014, and Cuba.

American lobster, a species that is caught in the cold waters of the Northeast and Maritime Canada, tends to be bigger and meatier than the European species. The European species also has a bluish hue, though both varieties turn scarlet when cooked.

American scientists share the doubts of the country's lobster industry.

Robert Bayer, director of the University of Maine Lobster Institute, said research on shell disease does not suggest it is contagious, and red-tail disease hasn't been seen in years.

Rick Wahle, a research professor at the university's marine science school, dismissed the danger of interbreeding, another risk raised by the Swedes. He said there is no evidence hybrids of the two lobster species are viable in the wild.

"Attempts to introduce American lobsters elsewhere have failed," Wahle said. "A newly introduced lobster would face a gantlet of different species that it has no experience with."

Swedish fishing industry officials insist the push for a ban is driven by environmental, not commercial, concerns. Yngve Bjorkman, a leader of the Swedish fishing industry association, noted that lobstering in Sweden is allowed only during the fall and winter and is almost entirely for domestic consumption.

"It is not Swedish fishermen who are against it," he said. "It's the environmental movement."

Gerry Cushman, a lobsterman who works out of Port Clyde, Maine, said a ban on exports to Europe based on a few escaped lobsters would be unfair.

"If they ban Maine lobsters, are we going to ban selling Volvos in Maine?" he said.

Associated Press writer Karl Ritter in Stockholm, Sweden, contributed to this report.

To Learn More:

Swedish Companies Take Advantage of Cheap Labor in U.S. (by Noel Brinkerhoff, AllGov)

Sweden First Country to Label Foods with Pollution Ratings (by Noel Brinkerhoff, AllGov)