Following a White House summit meeting, the US Government has decided to hit the threat of an alien carp species “with all of the tools in the toolbox”.
The plan however failed to impress both environmentalists and some Governors from concerned states.
The Asian imports, the bighead and silver carps, were brought to America for aquaculture purposes, but escaped fish farm into the Mississippi river following floods in the 1990s. Consuming up to 40 percent of their body weight daily in plankton, they can considerably exceed one metre in length and 50 kilos in weight, starving out other less aggressive species, and are now threatening to spread in to the Great Lakes, the world’s largest freshwater lake system.
After the US Supreme Court rejected a proposal from six Governors, and from the Canadian Ontario province, to cut off the Illinois River, a tributary to the Mississippi, from Lake Michigan, the White House recently decided to call a summit meeting to discuss this threat to the whole Great Lakes ecosystem. The meeting gathered representatives from the concerned states – including Illinois, whose Governor was the only state head that had been opposing the closure, together with representatives of the tugboat, towboat and barge industry – environmentalists and federal bureaucrats.
The biggest stumbling block had been a Michigan call for a permanent closing of the locks between the Illinois River, close to Chicago, and Lake Michigan. It was now decided that they would be kept open only according to a strict schedule.
Environmentalists however protested this was far from enough, and Michigan Governor Jennifer Granholm said after the meeting that “you have to permanently shut these locks down”.
The plan also includes an additional electrical barrier in the Chicago Sanitary and Ship Canal to repel the fish: if fish are detected near the locks the water could be electrified or treated with fish poison.
Such a barrier had already been established some 30 kilometres from Lake Michigan, supposedly the last, best way to stop the carp from invading the Great Lakes, but last month genetic material from the fish was found in Lake Michigan for the first time.