It's unusual for the the President of the United States to be directly involved in an invasive animal matter, but if the Governor of Michigan has her way, President Obama may need to become involved to ease growing tensions between his home State of Illinois and other Great Lakes States.
The State of Michigan is renewing a motion in the US Supreme Court to force the closure of the Chicago Sanitary and Ship Canal to prevent Asian carp moving from the Mississippi Basin to the Great Lakes Basin. The US Supreme Court previously denied the motion but since then environmental DNA ("eDNA") samples showing the presence of Asian carp have become available and a new economic study concludes that previous claims of the cost of closing the canal by Illinois were greatly exaggerated. The $70 million cost needs to be compared with the billions an Asian carp incursion of the Great Lakes will cost. If you want more on the legal wrangling see Professor Noah Hall's Great Lakes Law blog.
"Asian" carp is a generic term used in the United States to describe silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), whose numbers in the Mississippi River have risen dramatically in the past decade. They cause environmental problems as well as risk to recreational river users (see previous post). The USA has long had a problem with common carp (Cyprinus carpio), which is often called European carp in Australia; thankfully we don't have a silver or bighead carp problem.
It's a big problem and it comes at a time when the Great Lakes have had half a century of slow recovery from incursion of the sea lamprey early in the 20th century. The US and Canadian Governments formed the Great Lakes Fishery Commission in 1955 specifically to battle sea lamprey, which had devastated the fishery.
Many millions of dollars have been spent on trying to prevent Asian carp reaching the Great Lakes. The US Army Corp of Engineers operate an electric fish barrier system in the shipping canals, but now environmental DNA samples have indicated the presence of Asian carp beyond those barriers and in Lake Michigan itself. Environmental DNA is a relatively new tool, developed by Dr. David Lodge's lab at the University of Notre Dame - it enables minute quantities of Asian carp DNA to be detected and amplified. As yet, Asian carp themselves have not been found on the lake-side of the fish barrier, and eDNA can't tell us the number of fish that may have entered the lake. Certainly there is no evidence yet of an established population. I'm visiting Dr. Lodge's labs in a week or so because our Cooperative Research Centre has had an interest in this technology - we would love to have a better detection method for invasive tilapia in the north of Australia.
Hopefully the involvement of the White House will avoid this matter becoming bogged down in Court actions between the States. So far, the US Government has backed Illinois in keeping the Chicago Sanitary and Ship Canal open. President Obama is of course a former Senator for Illinois and his Chief of Staff a former Congressman for a district along Lake Michigan. There are some difficult decisions coming up in the next few days and weeks. The President is briefly visiting Australia next month to celebrate 70 years of formal US-Australia relations. Maybe we can get invasive species onto his agenda with Prime Minister Kevin Rudd - we find we are sharing too many invasive species problems in common these days.
Posted by Tony Peacock, founder of 'Feral Thoughts'