An American lobster, also known as a Maine lobster. (Photo: U.S. National Oceanic and Atmospheric Administration/Public Domain)

For some reason, American lobsters have begun washing up on Sweden’s shores—and Sweden is not pleased.

Swedish officials claim that American lobsters could spread disease to their European counterparts, threatening their survival as a species. The European lobster, Homarus gammarus, is known for its blue appearance, and are found in the eastern Atlantic Ocean, often off the shores of many European countries, in contrast to the American lobster, Homarus americanus, which lives off a vast swath of the North American coast.

The two populations don’t ordinarily mix, but Sweden says they’ve found dozens of American lobsters off their shores lately. The lobsters, Swedish officials think, were probably imported from North America, while somehow finding their way into Swedish waters.

The country fears new diseases as well as the “negative genetic effects” of interbreeding, according to the Associated Press.

What’s next? Maybe an import ban, since Sweden wants the European Union to designate lobsters as an invasive species, though American officials declared themselves pretty unimpressed.

“We need to understand how 32 lobsters found in EU waters over an 8-year period constitutes an ‘invasion,’” John Connolly, president of the National Fisheries Institute, said in a statement.