Tuesday, March 31, 2009

Invasive species grow to 188 in Great Lakes

From the Windsor Star

There are now 188 invasive species identified in the Great Lakes and while chances of ridding the water of established populations is considered slim, steps are being taken to control them and the public is called upon to help.

That was the message Sarah Bailey, research scientist for the Great Lakes laboratory for Fisheries and Aquatic Science Fisheries - Oceans Canada brought to an audience at Windsor’s main library branch Sunday.

Bailey, a University of Windsor professor with the Great Lakes Institute for Environmental Research, said the most recent arrival is the Bloody Red Shrimp, which was first discovered in 2006.

This non-native species joins the zebra mussel, the fanwort, the rusty crayfish and the spiny water flea in an invasion that, Bailey said, could cost the Canadian economy $3 billion over the 10 next years through depleted fish stocks, environmental changes and the sheer cost of cleanup. She added that already mid-sized municipalities pay an extra $360,000 annually to clear and clean water intakes.

The good news, Bailey said, is that the federal government’s introduction of ballast regulations on foreign shipping entering the waterway in the 1990s — requiring captains to flush home-port ballast at sea and replace it with salty water from the open ocean — is improving the situation. Ships carrying the species in ballast or on their hulls have long been the prime suspect in the introduction of invasive species.

But, she added, the fact species are always being discovered may be because there is often a time lag of several years, even decades, before they are detected. At the same time, she said, when a ship’s ballast tank is pumped there usually remains a certain amount of residual ballast water that is too shallow for pumping. “In a 700-foot ship that can really add up,” she said.

The ships may exchange sea ballast for Great Lakes ballast water during their voyage up through Lake Superior. But, typically, they will load up on grain at Duluth or Thunder Bay for the return trip and so, dump much of the mixed water out again.

“This residual water, we find, poses the highest risk,” she said, adding that Transport Canada introduced more stringent regulations and stricter monitoring on ship ballast to deal with this threat in 2006.

Asked whether it makes sense to simply ban foreign vessels from the Great Lakes, Bailey said removing shipping from the transportation equation would only add to other environmental problems. A ship, she said, can carry as much cargo as 400 transport trucks with much less impact on air quality.

She also added that shutting our doors to shipping is shutting our doors to trade. “Global commerce,” she said, “we’re not going to stop it.”

People living along the Great Lakes have a role to play in limiting invasive species. Noting that a study showed up to 10,000 domestic aquariums are typically emptied into the St. Lawrence around Montreal every year, Bailey said people here have a greater impact on the problem than one might think.

Among the suggestions Bailey had for citizens was to avoid emptying aquariums in a way that could see the contents end up in the river. Also, boat owners should keep pleasure boats clean and all water pumped out before moving from one body of water to another.

Owners should also inspect boats and trailers for plants and animals that may be in mud, drain all water from bilge, motors and transom wells. Also, live bait should not be released into the waterways.


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