[BCNnet] Article: Botulism Killing Birds in Lake MI

[Randi Doeker - Chicago]

FYI - Randi Doeker

 

Add to this news the recent local finding that Zebra mussels spit out
pellets with concentrations of PCB (which the mussels didn't want to absorb,
apparently) and the pellets are then eaten by small fish.

 

________________________________________

From: ILbirds at yahoogroups.com [mailto:ILbirds at yahoogroups.com] On Behalf Of
PPrich39 at aol.com

Sent: Thursday, October 26, 2006 11:40 AM

To: ILbirds at yahoogroups.com

Subject: IBET Article: Botulism Killing Birds in Lake MI (No Sightings)

 

Though this article is from a Minnesota newspaper, it regards Lake Michigan 

and thought it might be of interest to IBETers here.

____________________________________

 

Botulism is killing migratory birds in Lake Michigan

The die-off of loons, grebes, cormorants and other migrating birds is linked


to invasive species of mussels and fish in the Great Lakes.

 

 

(http://www.startribune.com/531/story/764349.html) 

Hundreds of loons, 

grebes, mergansers, cormorants and other migrating birds have been killed in
Lake 

Michigan recently, most likely from bacteria linked to non-native fish and 

mussels. 

 

Biologists at Sleeping Bear Dunes National Lakeshore estimated this week
that 

2,600 dead birds have washed up on beaches during the past two months. It is


the first large-scale bird die-off in Lake Michigan in decades. 

"I've worked here for almost 30 years and I've never seen anything like it,"


said Steve Yancho, chief of natural resources at the park's office in
Empire, 

Mich. He said the cause of the deaths seems to be Type E botulism, which 

occurs naturally in the sediment of the lake, but rarely enters the food
chain. 

Many wildlife biologists around the Great Lakes have noted similar mass bird


deaths since 1999 in Lakes Erie, Ontario and Huron. Lake Superior seems to
be 

the only Great Lake that has not been affected so far, said Doug Jensen, 

aquatic invasive species coordinator for the Minnesota Sea Grant at the 

University of Minnesota Duluth. 

He said he doesn't know whether similar problems will occur in Lake
Superior, 

because scientists are still trying to understand how water temperature and 

other factors may play a role in transforming the botulism bacterium into a 

potent neurotoxin. 

What's clear from the evidence, said Jensen, is that the die-offs involve
the 

interaction of two invasive species -- quagga mussels and a type of fish 

called round gobies -- which came originally from the Black and Caspian
seas. 

They were carried into the Great Lakes in the ballast water of oceangoing
ships 

and have been spreading since their arrival in the late 1980s. 

Biologists believe that the birds die as the neurotoxin makes its way
through 

the aquatic food chain. 

First, invasive quagga mussels move into a lake-bottom area, filter the 

sediment and accumulate the botulism's bacteria, which produce the toxin.
Then, 

the round gobies eat the mussels and become contaminated. Finally, migrating


birds spot the dead or dying gobies, eat them and in turn get poisoned. 

The toxin attacks the birds' nervous system and paralyzes their muscles, 

causing large numbers to drown when they can no longer flap their wings or
hold 

up their necks. 

Large bird die-offs have occurred in late summer when gulls eat poisoned 

fish, but especially in the late fall when migrating birds are searching for


food. 

New York biologists picked up more than 17,000 dead birds along the southern


shore of Lake Erie in 2002. The toxin has also killed tens of thousands of 

other fish that consume gobies, and the gulls that feed on them. 

Yancho said the botulism outbreak at Sleeping Bear Dunes occurred just after


the piping plover, an endangered bird species, left the area. 

"Had they been here when this was going full speed, it could have been 

disastrous," he said, adding that there are only 50 pairs of piping plovers
left 

in the Great Lakes. 

Helen Domske, senior extension specialist at the New York Sea Grant, is 

especially concerned about loons. 

"They're wonderful birds that are such a critical part of the ecosystem,"
she 

said. "You start to wonder what kind of impact so many deaths is having on 

the entire [loon] population." 

Tom Meersman . 612 673-7388 . _meersman at startribune.com_ 

(mailto:meersman at startribune.com) 

_____________________ 

 

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