I saw this news article on bbc.com (http://news.bbc.co.uk/chinese/trad/hi/newsid_4690000/newsid_4693300/4693318.stm). Apparently great britain has been invaded by these crabs (Eriocheir sinensis) that came from china. They think they got there because the water inside the tankers may contain the eggs of the crabs. Experts think these crabs are a big problem because they disrupts the balance of the ecosystem.
Obvious these "experts" have not been to china. Chinese people love these fucking things, we almost ate them to the brink of extinction. Now people in china raise them in farms to keep up with the demand. And their prices have being going up steadily over the years. I have had them, they are fucking delicious.
Easily solution for them, really. Get people to start eating the fuckers, they will disappear in no time.