Great Lakes Aquatic Habitat News
The Newsletter of the Great Lakes
Aquatic Habitat Network and Fund
Volume 11, Number 1 • Early Spring 2003
Great Lakes Aquatic Habitat NewsThe Newsletter of the Great Lakes
|
|
By: Joel Brammeier
The city of Highland Park recently hosted a public meeting to discuss the erosion problems plaguing Illinois’ north shore. The shoreline from Waukegan to Wilmette consists of a series of dramatic bluffs that naturally erode into the water. The material from these bluffs would traditionally feed material to the shoreline further south, but a history of armoring and hardening has resulted in significant erosion with no natural sand replenishment in sight. As hardening occurs in northern sections of the shoreline, it prevents sand from being re-deposited along the southern sections of the shoreline. Find a stretch of shoreline in Lake County that has been hardened, look south and you’ll see reduced sand deposition and reduced ability of the shoreline to withstand wave action.
With the beaches in the area now largely dependent on artificial means to keep sand levels up, area residents are searching for a long-term solution. The U.S. Army Corps of Engineers is proposing sinking tons of clean gravel into the lakebed near the shoreline to guard against erosion. This would be accompanied by berms to keep the gravel in place.
Unfortunately, the project’s projected cost is $50 million. The Corps has run out of funding to complete the project study, and has announced that the project is a low priority because of an apparently low cost to benefit ratio.
However, a community process is beginning that will supplement the Corps’ work. U.S. Representative Mark Kirk’s office proposed forming a task force of those impacted by the erosion problem to gauge the true costs of erosion and look at alternative solutions to the problem.
Lake Michigan Federation volunteers have been enormously helpful in staying on top of this issue. A thank you goes out to our Lakefront Task Force for bringing a Great Lakes voice to the discussion.
Illinois scientists are estimating that the bighead and silver carp threatening to invade Lake Michigan from the Mississippi River will reach an electrical barrier near Chicago by spring 2003. The real test of the barrier will come when hundreds of these fish line up to challenge the uncomfortable shock felt when attempting to slip through an electrified canal.
Laboratory tests demonstrate that the carp are sometimes able to penetrate electrical fields that simulate the real barrier in the Chicago Ship and Sanitary Canal. Researchers are hoping that the actual barrier proves more effective due to its significantly higher strength. Field tests utilizing a small number of grass carp have not yet shown any penetration of the fully powered barrier.
A committee in Chicago is already moving ahead with plans to build a second barrier in the canal. The new structure will likely combine sound and bubbling water to create a disturbance that repels the carp. This project should be completed sometime in 2004, and will provide extra insurance against species transfer between the Mississippi and Great Lakes basins.
Continuing support of these programs is strongly tied to passage of the new National Aquatic Invasive Species Act. The bill would provide several million dollars in funding and authorize the Corps to continue supporting barrier operations and new construction.
Joel Brammeier |