Lakes study raises worry
Invasive species are advancing, group cautions
CHICAGO - Connections engineered more than a century ago between the Great Lakes and the Mississippi River watershed should be changed to block the advance of invasive species that can cause irreversible damage, an environmental advocacy group says.
Separating the two basins is the only way to stop the transfer of some species, including the voracious Asian carp that is within 50 miles of Lake Michigan, says a study issued yesterday by the Alliance for the Great Lakes.
"If you want to protect the Great Lakes, this is what you have to do," said Joel Brammeier, Alliance vice president and lead author of the study. "Invaders like Asian carp are unpredictable, but their effects are catastrophic and irreversible."
Researchers fear the carp, which can grow up to 100 pounds and more than 4 feet long, could eat all the food that's available for other species in the Great Lakes ecosystem, possibly leading to the collapse of the lakes' multibillion-dollar fishing industry, Brammeier said.
Scientists say more than 150 invasive species have entered the Great Lakes, multiplying rapidly and feeding on native species or outcompeting with them for food. Millions of dollars have been spent trying to control the zebra mussel and round goby, which already have moved between the Great Lakes and Mississippi River basins.
There are no natural connections between the Great Lakes and Mississippi River watersheds. More than a century ago, engineers linked them with a complex network of manmade canals and existing rivers to reverse the flow of the Chicago River and keep waste from flowing down it to Lake Michigan, which Chicago uses for drinking water.
Possible changes include erecting concrete walls and constructing more shipping locks, according to the study. It does not make explicit recommendations but calls on the US Army Corps of Engineers and Environmental Protection Agency to conduct further study.
"The EPA is very concerned about the impact of invasive species on the health of the Great Lakes," EPA spokeswoman Phillippa Cannon said. "Limiting their spread is important for protecting the Lakes and we need to look at all options for controlling their movement." 