BERLIN (AP) — Berlin animal control officials say they've caught 3,000 American crayfish that have been proliferating in a downtown park.

Over the summer, Berliners have seen the invasive crustaceans scuttling around the Tiergarten park and sometimes across roads during rain.

City animal expert Derk Ehlert said Wednesday the freshwater red swamp crayfish, indigenous to northern Mexico and the southern U.S., were probably introduced some time ago by someone dumping pets in the park.

With three consecutive mild winters, he says "there's been an explosion" that even crayfish-eating fish introduced last year couldn't slow.

The crayfish caught over the past two weeks have been between six months and five years old. They will be destroyed once they have been studied.

The city is hoping it has removed enough crayfish to solve the problem.