Lake Michigan mud snails
Kathi
western states and all the Great Lakes except Lake Huron."
**I wonder how it skipped Huron, when that's the lake in the middle of
it all!**
Mud snails in Lake Michigan worry scientists
By DAVID MERCER • Associated Press • August 15, 2008
CHAMPAIGN, Ill. — Scientists worry that a rapidly reproducing, tiny
invasive snail recently found in Lake Michigan could hurt the lake's
ecosystem.
The New Zealand mud snail joins a long and growing list of nonnative
species moving into the Great Lakes, threatening to disrupt the food
chain and change the local environment.
Scientists checking Lake Michigan water samples earlier this summer
found a population of the New Zealand mud snail, the Illinois Natural
History Survey said. They grow to only a few millimeters — several
dozen could sit on the surface of a dime — making them hard to spot.
The snails reproduce asexually and in large numbers, and have no
natural predators in North America, said Kevin Cummings, a scientist
who works for the Natural History Survey, on Thursday.
That means they could quickly spread, at high enough densities to
out-compete native invertebrates for food and living space, he and
other scientists say.
"It's hard enough to contain a species once it makes its way into
nonnative waters," Cummings said in a statement. "When each mud snail
has the ability to produce large quantities of embryos without a
partner, you've really got a problem."
Scientists won't know for some time how well the mud snail will do in
Lake Michigan, but it has been in Lake Ontario since the early 1990s
and lives in high numbers there and in Lakes Superior and Erie, said
Rochelle Sturtevant, an ecologist with the National Oceanographic and
Atmospheric Administration's Great Lakes Environmental Research
Laboratory in Ann Arbor.
The snail is native to New Zealand but is now found in several western
states and all the Great Lakes except Lake Huron. It is carried in
ships' ballast water and, once in lakes and streams, hitches a ride on
boats and even the clothes worn by human waders.
"Where they've gotten into streams in the western part of the country,
they've caused a lot of problems," said Sturtevant. "They're taking
over space that should have other native species living in it."
Plenty of invasive species have made homes for themselves in the Great
Lakes. Zebra and quagga mussels are a threat to the region's $4
billion-a-year fishery, eating up algae that is the lowest link in the
lakes' food chain.
And some invasive species make it possible for others to follow,
Sturtevant said. The round goby, an aggressive fish native to Eurasia,
now thrives in the Great Lakes because it eats zebra mussels.
Those are just a handful of what Sturtevant says are now at least 186
invasive species in the lakes.
Environmental groups are particularly critical of the role oceangoing
ships play in introducing species like mussels to the lakes.
Ships that aren't loaded down with cargo fill their ballast tanks with
water for better stability when they're on the ocean, then empty the
tanks when they arrive in port. That ballast water often contains any
number of species, from microscopic organisms to mussels and fish.
The U.S. Environmental Protection Agency introduced a plan earlier
this summer that would require ships to dump ballast water at least
200 miles from shore. But the plan, called a permit, includes an
exemption for loaded ships.
Environmental groups are particularly critical of the EPA's plan.
"I could sum it up in one word: nothing. The permit doesn't change a
thing," said Joel Brammeier, vice president for policy at the Alliance
for the Great Lakes.
The shipping industry, including the U.S. Great Lakes Shipping
Association, has said it supports the idea of treating ballast tanks
to kill potentially invasive species. But industry officials say that
while possible solutions are being researched, so far there isn't a
feasible way to do it.
Find this article at:
http://www.freep.com/apps/pbcs.dll/article?AID=/20080815/NEWS06/80815022
.
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Dave Moorman
Kathi <seidl-nos...@ic.net> wrote:
> CHAMPAIGN, Ill. — Scientists worry that a rapidly reproducing, tiny
> invasive snail recently found in Lake Michigan could hurt the lake's
> ecosystem.
>
> The New Zealand mud snail joins a long and growing list of nonnative
> species moving into the Great Lakes, threatening to disrupt the food
> chain and change the local environment.
I feel like trying to fight non-native species like this is a losing
battle. Given the nature of world commerce, this is going to be
happening over and over.
I'm wondering if mud snails and fish coexist in New Zealand. If so, can
these fish be imported to the GLs? Maybe they'd flourish, too