-- Lake Michigan could be just one big rainstorm away from an invasion of Asian carp
Chicago — In “man versus invasive species” stories, why does it so often seem that the invasives are winning? The story of the Electric Fish Dispersal Barrier on the Chicago Sanitary and Ship Canal was always complicated. Now it’s become even more so. Whether it will actually do its job of repelling Asian carp and preventing them from entering the Great Lakes only time will tell.
The canal was originally built in 1900 to carry Chicago’s sewage away from Lake Michigan, where it drew its water supply. It is the only shipping link between the Great Lakes and the Mississippi River — via the Illinois and Des Plaines rivers.
Asian carp escaped from southern fish farms and invaded the Mississippi River in the early 1990s. They soon began moving up the Illinois River, closer to Chicago, the canal and the Great Lakes.
The Army Corps of Engineers studied the problem and decided to build a $9 million electric “fence” to stop the four-foot, 100-pound fish. The barrier was built about 20 miles south of Lake Michigan. Prodded by the shipping industry, the Corps studied the effects the electric fence would have on barges and towboats and concluded that no harm would be done. They gave more than $1 million to the U.S. Coast Guard (USCG) to study the possibility of injury to a person falling into electrified water. The Coast Guard’s conclusion was inconclusive: a person might or might not die from it.
Last June, DNA tests showed that Asian carp were just five miles from the barrier — much closer than anyone had imagined. On August 12, the Corps turned up the juice to twice the original levels (from one to two volts per inch) in the hope of repelling juvenile Asian carp as well as adults. Recreational boats can proceed with caution, while small vessels, kayaks, canoes and personal watercraft are prohibited from entering the safety zone in the canal.
Now some fear that the invading fish might slip around the barrier entirely, if the adjacent Des Plaines River floods its banks. In some places the canal and the river are only a few yards apart.
Lake Michigan could be just one big rainstorm away from an invasion of the big carp, according to Phil Moy, with University of Wisconsin Sea Grant. Moy and others are pushing to build an earthen berm along a six-mile-long flood zone and get ready to supplement it with sandbags if needed.
A rapidly-increasing population of the big carp in the Great Lakes would likely displace native fish and ravage what’s left of the big lakes’ food chain.
For information and advisories about the canal and boating through it, visit the Coast Guard web site. (Journal Sentinel 9-29-9, Great Lakes Boating Federation press release 9-15-9)
--- The shovelnose sturgeon harvest in the Mississippi has increased from about 6,600 pounds in 1995 to 23,000 pounds in 2007.
Alton, Ill. — The pallid sturgeon has been protected as an endangered species in the United States since 1990, making it illegal to harvest its roe for caviar. Because young shovelnose sturgeons resemble the pallids, the U.S. Fish and Wildlife Service (FWS) has proposed regulating the take of shovelnose sturgeons by commercial fishing operations where the two ranges commonly overlap.
In the ”Similarity of Appearance” provision, the Endangered Species Act authorizes protection of a threatened species when it may be hard to differentiate from an endangered species, thus helping in the recovery of the endangered species. A proposed special rule would prohibit harvest of flesh or roe of the shovelnose and shovelnose-pallid hybrids during commercial fishing.
The areas of the Mississippi that would be affected are south of the Melvin Price Locks and Dam. Also affected are portions of the Missouri, Platte, Kansas, Yellowstone and Atchafalaya rivers.
There were 18 licenses in Missouri for roe harvest last year, according to the St. Louis Post-Dispatch, 7-28-9.
According to the FWS, the shovelnose sturgeon harvest in the Mississippi has increased from about 6,600 pounds in 1995 to 23,000 pounds in 2007. This increase is believed to be a result of the crash of traditional sources of caviar, especially in the former Soviet Union. Over the last few decades, wild sturgeon populations world-wide have declined because of the roe harvested for caviar. The roe of both the pallid and shovelnose cannot be told apart by genetic analysis, according to the FWS.
Comments on the proposed rule will be accepted until November 23, 2009.
How to submit comments:
• U.S. mail or hand-delivery: Public Comments Processing, Attn: FWS–R6– ES–2009–0027; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA 22203.
The FWS will not accept e-mail or faxes. They will post all comments on http://www.regulations.gov. This generally means that they will post any personal information you provide them.