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    Some unwelcome visitors from North America have been turning up in the waters off the coast of Great Britain.

    North American lobsters (龙虾) have been found in the North Sea (between Great Britain and Northwest Europe), far from their own habitat. The lobsters usually live along the eastern coast of Canada and the United States.

    It is impossible that the lobsters could have made the 5,600-kilometre journey on their own. They were probably brought to Britain and then got away from containers. Some of the lobsters that were caught had elastic bands (松紧带) holding their legs shut, like lobsters that are kept in containers in stores or restaurants.

    Many may have been “set free” from some ships passing through the area. Sometimes passengers order a live lobster from a tank in the dining room and then ask the waiter to throw it overboard instead of cooking it.

    According to official records, 26 North American lobsters have been caught in waters off Great Britain since 1988. However, it is believed many more have been found but not reported.

    It is against the law to let North American lobsters come into British waters. If they settle down in European waters, it would be bad for the local lobsters. The two live in the same place and eat the same food. But North American lobsters are larger, stronger and more aggressive (好斗的) than European lobsters, and they produce young more quickly.

    As a result, they could take food and space away from the local lobsters, and from other types of shellfish that live in the same area. These lobsters may also carry diseases that could harm the local lobsters.