Monday, March 11, 2013

Invasive species may be key to understanding death of hundreds of loons

by Dan Kraker, Minnesota Public Radio

DULUTH, Minn. — Spring is in the air, with daylight savings taking effect on Sunday, and loons will begin their migration back to the north woods in less than a month.
Loons, of course, are a cultural and natural icon, not only in Minnesota but across the Great Lakes states. But last fall, nearly 900 loons died while migrating south across Lake Michigan, probably more. And it's likely at least some were from Minnesota.
Scientists are not sure what killed the loons, but they suspect that invasive species may be to blame.

In October, Lynette Grimes was hiking toward Lake Michigan at Sleeping Bear Dunes National Lakeshore, outside Traverse City, Mich. The 52-year-old from the nearby town of Benzonia has walked the beaches there for years. But she wasn't prepared for what she saw. ...

The scientists offered an idea about what might have happened: Invasive zebra and quagga mussels filter the water so it's incredibly clear, allowing an algae called cladophora to grow in huge amounts. Big storms churn up the algae, which settles to the lake bottom and rots. That creates an environment without any oxygen, an ideal home for bacteria that produces a deadly toxin called Type E botulism. That botulism is ingested by invertebrates, tiny worms and freshwater shrimp. And then it works its way up the food chain. They are eaten by fish, including the invasive round goby, which are then eaten by diving birds like loons. ...

Read the full story at link.

Image: J.M. Kosciw

Monday, March 4, 2013

Myths lie at root of native, exotic plants

Written by
Yew Dell Botanical Gardens

Amur honeysuckle, burning bush, ‘Bradford’ pear ... a few poster children for the invasive exotic plant debate. The debate has raged for decades.  But it is often myth that fuels the dissension.

But before we dispel some myths, how about a few definitions?

Continue reading at link.


Conn. trying to contain tree-eating borer

By QUANNAH LEONARD, Republican-American of Waterbury

Piles of ash bark cushioned the feet of state workers inside a state garage on Middlebury Road on a recent day. The men and women used draw knives to slowly peel back bark on bolts of ash trees, looking for signs of a tiny green beetle.

Their work began at the beginning of February, and will continue for at least one more session this month. They want to determine just how long and far the emerald ash borer has infested the woodlands of Connecticut.

The answers will help federal and state agencies, plus municipalities, work together to reduce the spread of this bug.

With each strip of bark, the workers uncovered a pale canvas that can potentially show a history of the highly mobile critter. They are peering for a tell-tale sign — serpentine tunnels left by the larvae as they eat.

Last summer, the bug was first found in the Nutmeg state in Prospect. Since then, it has been confirmed in Beacon Falls, Bethany, Naugatuck and Waterbury. The critter is an invasive species native to Asia that measures a half-inch long.

The infestation threatens Connecticut's valuable stands of ash trees, and experts say could present a threat to public safety.

Read the full article at link.