Attack of the Silver Carp

January 13, 2010

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It is seemingly commonplace that the actions of humanity negatively affect our environmental world around us, and no continent is exempt from this reality. In the midwestern United States, a legal battle has recently begun that could forever change interstate commerce and leave a legacy of saving the largest freshwater fishery on the planet, the Great Lakes..

In December of 2009, the state of Michigan sued the state of Illinois, the Army Corps of Engineers, and the states of Indiana and Wisconsin to force the closure of the Illinois Sanitary and Shipping Canal (ISSC), a man-made channel that is the only direct water link between the Mississippi River Watershed and the Great Lakes. The channel is some 28 miles long and is jointly controlled by the Army Corps of Engineers (ACoE) and the State of Illinois. Why was this lawsuit brought forth? To stop the rapid encroachment of a prolific invasive fish, the Asian Carp.

Asian Carp, a general term referencing four different types of carp species originating from Asia, have exploded in population in the Mississippi River Basin since 1990. The main culprit is one species whose common name is the “Silver Carp”. These Silver Carp grow to nearly 2 feet long and can weigh up to 40 lbs, and are known for their spectacular ‘leaping’ ability. They are able to launch themselves upwards of 10 feet into the air; a behavior that is not fully understood. The Carp are filter feeders and devour plankton and detritus almost constantly, as they lack a true stomach. As compared to other fish, they reproduce at a fantastic rate and have no natural predators in American waters. They were originally introduced into the U.S. as a biological means to reduce algae growth in wastewater treatment facilities and within one year of introduction, had found their way into public waterways.

Many people ask why a planktivorous filter feeding fish would be a concern for a fishery, and it is a legitimate question with a specific and far-reaching answer. Nearly all native sportfish and commercially important fish in North America (bass, sunfish, pikes, etc) are planktivorous in their youth stages of development. If a vast, reproducing population of Silver Carp were to be established in Lake Michigan (and the other Great Lakes), the rippling population effects on native, commercially important fish would be devastating. The Carp would essentially “clean out” the Great Lakes and youth populations of those native fish would be starved, causing a catastrophic drop as quickly as a decade from introduction. And once established, a Silver Carp population will be virtually impossible to eradicate from waterways as large as the Great Lakes.

To stop this encroachment, the ACoE built two massive electrified barriers that supposedly disallow fish from passing in either direction at a point on the ISSC some 9 miles from Lake Michigan. Unfortunately, in November of 2009, Silver Carp DNA was found on the Lake Michigan side of the barriers, causing a massive response from the U.S. Environmental Protection Agency and the Illinois Department of Natural Resources. Three weeks after the DNA finding, those two agencies intervened with a massive chemical fish kill which resulted in 90 tons of dead fish, but almost no Carp were amongst the kill. The Michigan lawsuit requests that the ISSC be closed semi-permanently, until a more effective barrier can be constructed to protect the Great Lakes fishery.

If the lawsuit is successful, and the canal is closed, thousands of jobs may be lost as the canal provides a vital link from the Great Lakes throughout the midwestern and western United States. However, other thousands of fisheries-related jobs may be saved, and a massive irreversible environmental disaster would be averted. Considered yourself urged to further look into this matter, and contact your congressman or senator to voice your opinion, especially if you live in a Great Lakes state.

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