European Union scientists have given Sweden until July 31 to address U.S. and Canadian objections to Sweden’s claims that North American lobster is an invasive species that should be subject to an import ban.

The scientific forum on invasive species met Wednesday to discuss Sweden’s claim that North American lobsters, which have been found in small numbers off the coasts of Sweden, Norway and Great Britain, pose a threat to the smaller European lobster.

The forum asked Sweden to update its scientific justification for labeling the North American lobster as an invader to address objections raised by U.S. and Canadian scientists this month, including the argument that Sweden can’t show proof of an invasion despite decades of imports, or that offspring of the two species can spawn a second-generation hybrid.

The information came from a joint statement issued Wednesday by Maine’s congressional delegation, which called for the U.S. scientific assessment and has been following action in Brussels through an EU trade official.

“We are pleased that both U.S. and Canadian experts have found there is no firm evidence that American lobsters are an invasive threat to Europe and that their analysis will be considered in the risk assessment,” Sens. Susan Collins and Angus King and Reps. Chellie Pingree and Bruce Poliquin said in the statement. “We will continue to fight for Maine’s lobster industry and do everything we can to ensure that all of the facts are considered in this assessment.”

Sweden has until July 31 to update its scientific justification for declaring the North American lobster an invasive species. The forum would then consider the data and issue its opinion on the merit of the scientific evidence by Aug. 31.

If Sweden’s proposal meets the scientific criteria for an invasive species label, the proposed ban would then move to a full review by the committee on invasive species, which would include a consideration of the economic impacts of a ban as well as the environmental threat, EU officials have told Maine’s delegation. If North American lobster is labeled as an invasive species, that would automatically trigger an import ban on live lobster throughout the 28 countries that make up the European Union.

Fisheries officials from the National Oceanic and Atmospheric Administration had said in early June, when they released the rebuttals by U.S. and Canadian scientists of the Swedish invader claims, that both countries hoped to stop the proposed import ban at the science stage, before it reaches the European Union’s political arena.

In March, Sweden petitioned the European Union to declare the North American lobster an invasive species, which would ban live imports. America exports about $150 million worth of lobster to the EU annually, and Canada sells another $75 million a year, according to export data.

Sweden backed up its claims with an 85-page risk assessment that says the discovery of North American lobsters in the waters off Great Britain, Norway and Sweden over the past 30 years, including one female lobster carrying hybrid eggs, proved crossbreeding has taken place. The Swedish scientists say a ban would protect the European lobster from crossbreeding and diseases carried by the North American lobster, and preserve the resources it depends on for survival from the more rapacious American cousin.

But Canadian and American scientists argue that Sweden’s claims are “not supported by the best available science.” The number of lobsters found in European waters over the past decade number less than 100, which is not large enough to constitute an invasion, they argue. And Sweden has not provided proof that crossbreeding lobsters produce fertile hybrid offspring, which would be necessary for the North American lobster to take over the chilly waters of the Northeast Atlantic, U.S. and Canadian scientists say.

Scientists here think most Northeast Atlantic waters are too warm, fished too hard and too full of predators, such as crabs, snapping shrimp and squat lobsters, for Homarus americanus to gain a toehold, much less overwhelm the European lobster population.

If Sweden is able to get an environmental hearing, Canada and the U.S. will continue to oppose the invader classification with help from a few members and interest groups that support continued import of American lobsters, such as European restaurants, lobster dealers and lobster distributors, American fisheries officials said.