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article imageAsian carp poised to destroy the ecology of the Great Lakes

By Ken Wightman     Nov 9, 2009 in Environment
Riding a wave of flood water, Asian carp are poised to make their final thrust past all barriers to reach Lake Michigan. Will government react in time to prevent this environmental disaster?
Get out the list; It's a long one with more than 160 entries — zebra mussel, sea lamprey, round goby, spiny and fishhook waterflea . . . . If measures aren't taken soon, the next addition to the Great Lakes invasive species list will not be just the latest but will be truly the greatest, read most disastrous — Asian carp.
Flooding enabled these foreign fish to escape into the Mississippi River from Southern carp containment ponds in the '70s. Now, these aggressive, invaders have travelled up the Mighty Mississippi and are poised to move into The Great Lakes with flooding again offering to provide the gateway — flooding teamed with human ineptitude.
Presently, the carp migration is stopped by an electric barrier system on the Chicago Sanitary and Ship Canal (CSSC). The CSSC is a man-made waterway connecting two formerly separated watersheds. Designed in the early 20th century to carry sewage away from the large Midwestern city, the CSSC is the only direct link from the Mississippi to Lake Michigan.
An engineering achievement or an engineering faux pas? This has often been debated. To create the CSSC the direction of the flow of the Chicago River was reversed. This created a well documented pathway facilitating the movement of aquatic invaders.
The electric barrier system on the CSSC, begun in April 2002 and now in use, is actually unfinished. According to the U.S. Army Corps of Engineers, "Construction of Barrier IIB is expected to begin in fall 2009 and will be completed in 2010." A $16 million U.S. barrier system that may fail for want of some sandbags.
The Sierra Club and other environmental groups worry that the Des Plaines River, only metres away from the CSSC in many places, and the Illinois and Michigan (I&M) canal, connected to the CSSC by small culverts, provide bypass routes. One heavy downpour could broach the separation of the CSSC from both the Des Plaines River and the I&M canal.
According to the Globe and Mail, a Toronto newspaper, ". . . DNA tests designed to detect the presence of silver carp found that they (silver carp) had infiltrated the Des Plaines River . . ." A witty Globe writer wrote that the carp were just one flop away from the Great Lakes.
In North America the term Asian carp denotes four distinct species of fish: bighead, grass, silver and black — all of which have self-sustaining populations in the Mississippi watershed, except the mollusk-eating black carp. Voracious feeders, these bad actors can grow to more than a meter in length (40 in.) and weight from 40-50 kg (90-110 lbs.) depending upon the species.
Silver Carp
The silver carp has been found in the Des Plaines River just meters from the Chicago Sanitary and Ship Canal.
U.S. Fish & Wildlife Service
The silver carp may be the worst of a bad lot. With gill rakers extending from the sides of their heads, they trap plankton as they swim. Each day they devour as much as 40 per cent of their body weight in plankton. Free in the Great Lakes, they could out-compete native fish, degrading the ecosystem forever.
And it gets worse: The silver carp, also called the flying carp, has the frightening habit of leaping violently up to ten feet out of the water when startled by passing boats. Maclean's magazine in Canada reported that in 2003, a woman operating a personal water craft struck a jumping carp, breaking her nose and a vertebra. She nearly drowned. The U.S. Fish and Wildlife Service is concerned that someone may be killed.
The Canadian Department of Fisheries and Oceans has warned that Asian carp species would not only survive, but, due to similar temperatures found in its native range in China, would likely thrive in the Great Lakes. This is an environmental disaster in the offing.
Conservation organizations are urging a quick response from the U.S. federal government. “This is an emergency and we are down to sandbags and mortar,” says Jennifer Nalbone, Campaign Director of Invasive Species and Navigation for Great Lakes United “Barriers must be built between these nearby waterways and the Chicago Sanitary and Ship Canal to ensure that during a fall flood live carp cannot be carried into the CSSC past the electrical barrier.”
The race is on. Will the barriers be built in time? Will the electrical barriers be completed on schedule? It's said, to the victor goes the spoils; In this case, if the carp win, the spoils will be the spoiled Great Lakes.
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