Chinese mitten crabs invade German waters
Destroying fishing nets, hurting other fishes, and damaging the dams… the mitten crabs originating from China have grown into a disaster in German with their huge population, leading to a loss of up to €80 million. However, German fishermen came up with a brilliant idea recently, and that is to sell the Chinese mitten crabs to Chinese restaurants.
According to Berliner Kurier’s report on Sep 2nd, several Chinese mitten crabs marched towards the Deutscher Bundestag in the summer sunset glow a few days ago. This incidence “alerted” some German tourist who called the police. And these “invaders” were “captured” by an animal protection organization.
It was reported by Voice of Germany on Sep 1st that at 7am, fisherman Schroeder began driving his fishing boat to fish on the Elbe. When he halted the boat and pulled the fishing basket onto the boat with his assistant, they found that they did not get eels as expected, but several dozens of Chinese mitten crabs waving their claws.
It is said that these Chinese mitten crabs “migrated”from China to Europe as early as 1900. And in 1922, for the first time, German official reports claimed to find these crabs which were unique to China. In 9133, after investigation, German scientists believed that the Chinese mitten crabs migrated to Europe through ballast water in commercial vessels.
Since then these eight-legged fighters, who “eat almost anything”, started to rampage in European rivers, posed serious threat to the survival of local species, and hence became the only fresh-water crab species in Germany. Every midsummer, the mature crabs living in rivers like Elbe commence their “carpet” migration up to the North Sea, which is thousands of miles away, in order to prepare for reproduction in the next spring.
These “armored animals”, which can crawl 12 km per day, are good at digging holes and damaging dams. They will destroy fishing tools and eat the small fishes and shrimps in the net. What is more, some industrial infrastructures are also their targets to destroy. WWF’s report said that the loss caused by Chinese mitten crabs has amounted to €80 million in Germany only.
German Focus weekly believes that Chinese mitten crabs “invading” German rivers is “the result of globalization”. However, Biological Professor Geist at University of Munich does not agree with it. He points out that it is just a normal process in the development of nature, while such phenomenon has become very common. At present, there are air conditioners in many cabinets, providing survival chance for some species. There are more than 2000 alien species in Germany.
Geist also defends Chinese mitten crabs, saying that some small animals become aggressive because human beings change their living conditions continuously. River courses in China are straightened, dams and flood gates block their way to reproduction areas, and the water is seriously polluted by factories. As a result, the population of Chinese mitten crabs has been declining. While the clean water of Elbe and Havel River provides better living condition for these crabs.
In the past, when dealing with the huge population of Chinese mitten crabs, German fishermen usually used the crabs to product soaps or animal feed, or simply killed them in large quantity. However, no significant result was achieved. At the same time, they opposed the idea of killing crabs with chemical drugs, because they would also kill other fishes including eel. Later, fishermen near Ludwig-Maximilians area became the first batch to “eat the crabs”. They regularly sold the crabs to Chinese and Vietnam families who loved tasty food, and even Asia supermarkets and restaurants, at a price of €5-8 per kg. Nowadays, many German fishery companies and fishermen join this business, which too some extent could alleviate the depressing fishing market in summer.
It is said that since there is no other fresh-water crabs in European waters, and local people do not eat these animals of weird shape, Chinese mitten crab has managed to maintain authenticity in their reproduction in Europe in the past 100 years. Since 2003, some Chinese merchants have been shipping crabs from Germany back to China for reproduction.