60 ducks and 1 goose in Chesapeake – 08/15/2005

60 ducks, goose found dead on Havre de Grace shore

http://www.baltimoresun.com/news/local/harford/bal-
md.ducks10aug10,1,2617084.story?coll=bal-local-harford

Experts suspect toxic mix resulting from heat, runoff

By Candus Thomson
Sun Staff
Originally published August 10, 2005

Water temperatures in the 90s and runoff from recent squalls might
have combined to create a petri-dish mix of toxins that killed 60 of
the 200 mallard ducks that live along Havre de Grace’s waterfront
promenade.
State wildlife officials say the ducks and a Canada goose were found
dead Monday and yesterday, and they suspect that naturally occurring
botulism is to blame.

“It may not be that. You’re never sure. But these incidents happen
every year around the state, mostly in the Western Shore counties
that border the [Chesapeake] Bay. I’ve seen them many times before,”
said Larry Hindman, waterfowl project manager for the Department of
Natural Resources.

Two dying ducks were taken yesterday afternoon to the Maryland
Department of Agriculture’s Centreville Animal Health Diagnostic Lab
for testing. Dr. William P. Higgins, director, said he would send
blood serum samples to an out-of-state lab as part of his
investigation.

“You have to detect the toxin in the serum. You don’t see anything.
There are no lesions or other markings,” Higgins said.

Hindman said reports of botulism typically involve flocks in areas
frequented by people. With its lighthouse, decoy museum and skipjack
Martha Lewis, the promenade is a tourist attraction and gateway to
the Susquehanna River.

The biologist suspects that of the six types of botulism, Type C is
responsible for the deaths. The risk to humans is negligible.

Botulism can remain dormant in the soil for years. Under the right
weather conditions, such as when water rises and quickly recedes, the
spores germinate. Waterfowl nibbling on insects, mollusks and small
shellfish containing the toxin often become ill within 48 hours.

“We call it ‘limberneck disease’ because the toxin affects their
legs, wings and neck. They can’t walk or fly and their wings droop
and eventually they can’t hold their heads up,” Hindman said. “If you
put them in the shade and give them water, sometimes they can fight
through it.”

Type C was first reported in California and Utah in 1910, when
millions of birds died. The most recent major outbreak, in 1997,
killed 1.5 million birds in Utah and Canada, according to the U.S.
Geological Survey.

The Chesapeake Bay wetlands and tributaries have had about 17
outbreaks of avian botulism in the past 30 years, according to the
agency.

Hindman said Havre de Grace officials have removed all the carcasses
to prevent the spread of the bacteria and will continue to inspect
the shoreline for sick birds.