The Associated Press reports that, “For thousands of years, the Great Lakes were protected by Niagara Falls on the east and a subcontinental divide on the west, but those barriers to the country’s grandest freshwater system were obliterated over the past century so that oceanic freighters could float in and Chicago sewage could float out. Unwanted species have been invading with tick-tock regularity ever since.”
“It is a problem that lacks the graphic horror of the gulf oil spill, but is more environmentally catastrophic in that it unleashes a pollution that does not decay or disperse – it breeds. Native fish populations have crashed, freshwater beaches have suffocated under mounds of rotting algae, bird-killing botulism outbreaks have soared…”
ASIAN CARP AND THE CHICAGO CANAL
“While the lakes have become a biological stew thick with an estimated 185 foreign species, elected officials from both parties in all eight Great Lakes states are demanding that federal agencies muster the will to stop No. 186.” The CBC reported last week that, “An 18-month, binational program will assess the risks the carp pose and look at vulnerable pathways that the fish – currently being held at bay near Chicago – could use to enter the Great Lakes, Fisheries Minister Gail Shea said Tuesday.”
Another AP article adds, “Asian carp were imported in the early 1970s to cleanse algae from Southern fish farms and sewage treatment plants. They escaped into the Mississippi River and have migrated northward ever since. The carp have advanced to within about 25 miles of Lake Michigan, where their path is blocked by two electronic barriers on the Chicago Sanitary and Ship Canal. Their DNA has been detected in numerous spots above the barriers, although just one actual Asian carp has been found there.”
“(Elected officials) have turned to the courts and to Congress to compel the U.S. Army Corps of Engineers to keep Asian carp from colonizing Lake Michigan by slamming shut the back door to the Great Lakes blasted open by Chicago canal builders more than a century ago.”
THE ST. LAWRENCE SEAWAY
“Biologists say the artificial shipping link between the Great Lakes and Atlantic Ocean has already wrought more damage than the carp might ever do.” The 306-kilometre seaway which connects Montreal to Lake Ontario was opened in 1959. The Globe and Mail reported last year that, “Since the seaway opened, scientists estimate that as many as 57 foreign species (about one-third of the 185 now on record and almost all of those that have been found in the past 50 years) have arrived in the ballast water shed by saltwater ships. They have displaced native plants and animals, decimated fish stocks, even disrupted power plants. The seaway is hardly the only cause of the Great Lakes’ decline – aquaculture and recreational boating have done much damage, along with pollution from industry and agriculture – but many scientists believe that it is responsible for the most harm, and certainly let in the most destructive intruders.”
THE QUAGGA MUSSEL, THE ROUND GOBY
AP notes that, “Gary Fahnenstiel, an ecologist with the National Oceanic and Atmospheric Administration, says one tiny Seaway invader – the quagga mussel – has in just the past five years literally sucked much of the life out of Lake Michigan, turning it into a ghost of its former self in terms of fish-sustaining plankton. …Next door on Lake Huron, chinook salmon… is now all but gone. Fishery managers blame the salmon crash on quaggas and the oceangoing vessels that brought them in. University of Michigan biologist David Jude says… the quaggas are also implicated in bird-killing botulism outbreaks, chronic blooms of blue-green algae – toxic to humans – and ‘dead zone’ areas of Lake Erie where the water is so oxygen-depleted it cannot sustain any fish. The mussels also provide sustenance for another Seaway invader, the round goby, which also feasts on the eggs of native species such as smallmouth bass and is now so great in number that the U.S. Geological Survey describes areas of the lakes where they flourish as infested.”
BALLAST
“Ballast discharges are blamed for the majority of invasions since the Seaway opened, including zebra mussels, quagga mussels, round gobies, spiny water fleas and, most recently, the bloody red shrimp. Ships take in ballast to steady less-than-full vessels on the high seas, and then that water – and whatever life is lurking in it – can get discharged as cargo is loaded at port. By 2006, a new species was being discovered in the lakes, on average, every 28 weeks, according to McGill University professor Anthony Ricciardi. Since then, the U.S. and Canada have begun requiring all overseas ships bound for the Great Lakes to flush their ballast tanks with mid-ocean saltwater in an attempt to kill or expel unwanted species. …(But) total sterilization is considered a technological impossibility at this point…”
The Toronto Star reported in 2007 that, “a group of more than 90 U.S. environmental organizations want ocean-going tankers banned from entering the Great Lakes.” The Globe and Mail article on the 50th anniversary of the seaway notes, “the seaway has wreaked so much havoc on the world’s greatest supply of fresh water that some critics now propose that it be abandoned as a route for saltwater ships…”
The AP articles are at http://www.stltoday.com/news/national/article_b9ddf7a0-4603-531b-ad6f-d52737d7dad4.html and http://www.google.com/hostednews/ap/article/ALeqM5gPBBiKJKfp1MbkPXxJCnNjnZCCrQD9ILQ9HO2?docId=D9ILQ9HO2. The Globe and Mail article is at http://www.theglobeandmail.com/news/national/fallen-hero-the-st-lawrence-seaway-at-50/article1198801/singlepage/.
