Toxic algae

Misha (mgs23@pacbell.net)
Tue, 27 Jul 1999 16:38:19 -0700

Howdy, all--

Thought this might interest some of you.

peace
misha

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TOXIC ALGAE, ALLIGATOR & BIRD DEATHS - USA (FLORIDA)
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[1]
Date: Fri, 23 Jul 1999 11:54:42 -0400
From: "Marjorie P. Pollack"
Source: States News Service [edited]

In Florida, University researchers' preliminary laboratory tests
show mysterious bacteria in Florida Lakes. Researchers are
unsure whether they are harmful to humans. But the bacteria are a
strong suspect in several alligator deaths in Lake Griffin over the
past 2 years. The one-celled bacteria are also reported in Lakes
Yale, Harris and Eustis.

***
[2]
Date: Fri, 23 Jul 1999
From: *Marjorie P. Pollack*
Source: Miami Herald <http://www.herald.com/> and Associated
Press [edited]

The deaths of about 150 alligators in Lake Griffin over the past 2
years may have been caused by toxic algae.

_Cylindrospermopsis_ spp, a green, slimy alga looks like harmless
pond scum, but can release deadly toxins.

The algae now cover almost all of Lake Griffin and have been
found in 3 other Lake County lakes, a Seminole County lake and
the St. Johns River.

In the United States, the algae have previously been found in
Kansas, Minnesota and Texas, but none of those cases involved
dangerous toxins. [The algae only produce toxins under certain
nutrient, and weather conditions, which may account for no reports
of toxicities.]

"As with many environmental issues involving microbes causing
emerging problems, we don't pay much attention to them until they
affect something we become concerned about,'' said Wayne
Carmichael, a professor at Wright State University in Ohio who is
studying the algae.

A growing number of birds around Lake Griffin have shown
symptoms similar to those of the dying alligators: lethargic
behavior, convulsions and then death. If the algae aren't killing the
alligators, scientists say, then the culprit is either a pesticide or an
unknown virus. [Have any virus or bacteria isolations been done, or
pesticide residues looked for in the alligator carcasses?]

Lake Griffin has no public swimming beaches and fewer people are
using it for water recreation because of deteriorating water quality.

"Personally, I would not want to be drinking the water or eating the
fish from there,'' said Donna Morris, a wildlife recovery specialist.

- ---
ProMED-mail

[_Cylindrospermopsis_ spp. is one of many species of toxic algae
or blue-green algae (commonly known as cyanobacteria, literally,
blue-green bacteria) that can produce toxic water blooms.
_Cylindrospermopsis_ spp. can produce a potent hepatotoxic (liver
toxic) alkaloid called cylindrospermopsin. Poisoning usually does
not occur unless there is a heavy waterbloom that forms a dense
surface scum. Factors contributing to heavy waterblooms include
nutrient-rich eutrophic or hypereutrophic water and warm, sunny
weather.

Some agricultural practices are thought to contribute to the nutrient
enrichment and the waterbloom formation. Animal size and species
sensitivity influences the degree of intoxication. Single stomach
animals (monogastrics, ie, dogs, cats, etc) are less sensitive than
ruminants (cows, deer etc) and birds. Apparently, alligators are
sensitive to this species of toxic alga.

Depending on bloom densities and toxin content, animals may need to
ingest only a few ounces or up to several gallons to experience acute or
lethal toxicity - Mod.TG]

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