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International Society for Infectious Diseases <http://www.isid.org>

Date: Mon 24 Oct 2011
Source: The Barrie Examiner, QMI (Quebec Media, Inc) Agency report [edited] <http://www.thebarrieexaminer.com/ArticleDisplay.aspx?e=3344545>

Type E botulism to blame for bird deaths, MNR says
About 1000 dead birds washed up on along a 3 km [2 mi] stretch of Nottawasaga Bay shoreline on the weekend [22-23 Oct 2011].

Ministry of Natural Resources (MNR) clean-up crews were in the Wasaga Beach area on Monday [24 Oct 2011] to dispose of carcasses on provincial park property.

The largest number was found near Allenwood Beach, northeast of the main beach area. At least 1000 dead birds had washed up on shore.

The ministry hasn't done a survey to confirm how many birds washed up as of Monday, but MNR spokesman John Cooper says the number is unusually high for this area.

Cooper says this sort of die-off -- in terms of time of year and species -- is typical of type E botulism, a potentially fatal form of bacteria. "We had a much smaller die-off at this time of year last year [2010] in this area," said Cooper, adding there were hundreds last year as opposed to thousands this year.

The ministry received sporadic reports of dead fish and birds beginning in late August 2011, but cases increased in frequency and distribution in the past month, with the steepest increase in dead birds occurring at the end of last week and over the weekend [21-23 Oct 2011].

"We've had some recent stormy conditions that have washed many of these birds up on shore," said Cooper, adding it appears the birds were already dead when they washed up.

"It's a factor of wind currents, with the strong winds we've had recently, because these are birds that normally would be out in the deeper water," Cooper said.

Reports from the public suggest the birds are mainly long-tailed ducks, but also include loons and grebes, he added.

"These aren't birds that are in the marshes or shallow areas along the lakeshore," Cooper said "They could be dying out there and their bodies may never make it to shore."

In an earlier interview, Cooper said botulism is a "naturally occurring event" and little is known about the ecology of the bacterium which produces the botulism toxin.

The bacterium naturally occurs as harmless spores in lake-bottom sediment. Under certain conditions -- rich nutrient source, lack of oxygen, and optimum temperature -- the bacterium begins producing the toxin. It then enters the food chain, primarily affecting birds and fish.

Some birds likely ingested the toxin by eating bottom-feeding fish which have died and floated to the water's surface. In the case of the long-tailed duck, they dive and pick up food from the bottom of the lake, making it more likely for them to ingest the toxin. Cooper says this is the largest bird die-off the Georgian Bay area has seen, but there have been much larger die-offs in the Great Lakes, pointing to a case in eastern Lake Erie about a decade ago when about 18 000 birds died. The fish die-offs include channel fish, freshwater drum, carp, and lake whitefish.

Wasaga Beach Provincial Park staff have disposed of about 120 dead sturgeon. Cooper says sturgeon, and other fish that swim and feed along the bottom, are most prone to contamination.

Samples were sent to the University of Guelph on 6 Oct 2011 to test for fish and bird diseases, including the type E botulism toxin, which Cooper says is quite likely the cause. The ministry is still waiting for results. Cooper says the botulism toxin takes effect within a day and people should be wary of abnormally behaving fish and birds. [How interesting! The title leads one to believe that type E botulism has been confirmed, and this paragraph says, "quite likely‚" clearly indicating that it has not been officially confirmed. - Mod.TG]

He says the toxin is very susceptible to heat and fish should be cooked thoroughly.

Cooper says the bacteria become active in dead organisms, so the ministry is advising people to keep their children and pets away from dead animals on the shoreline.

The ministry is cleaning up provincial park land and private landowners are responsible for disposing of fish or birds on their property. Cooper says there are 3 options: leave the carcass and let it decay, bury it, or double-bag it for municipal waste pickup. [If the birds and fish are left to decay, then the problem only perpetuates itself. As maggots move into the carcasses those maggots are perfect food for other birds. As those birds come to feed they are ingesting the botulism and there will be more dead birds. Leaving the dead carcasses is not only smelly, but causes the die off to be much larger. - Mod.TG]

He says if landowners choose to dispose of the birds, they should wear gloves and wash up after.

Cooper says these birds and fish don't pose a health risk to humans and the toxin is not in the water.

Several members of the Hamilton Conservation Authority parks management were at a local conference and stopped by the Allenwood Beach to see if the dead birds were still on-site Monday [24 Oct 2011].

Evidence of zebra mussels convinced Bruce MacKenzie, Hamilton Parks superintendent that Lake Huron was suffering the same fate they had in Lake Erie in 2004.

"It has to be the right water conditions, and a whole bunch of things have to line up," said MacKenzie. "But when I saw the zebra mussels -- they look like little crabs -- that's what we were seeing, too."

MacKenzie said they filled a 40-yard [37 m] dumpster with dead ducks and loons from a 16 km [10 mi] stretch along the Burlington Skyway Bridge that allows Fort Erie to empty into Lake Ontario.

"It seems to be a fall thing," he said.

Together with park manager Brian Hall, they walked along the stretch of Allenwood Beach where the birds had washed ashore last Friday [21 Oct 2011]. Hall explained that in 1988, indiscriminate ships from Europe that were supposed to empty their ballast (holds) out at sea, left it too late and dumped their dirty water -- including zebra mussels and another invasive species called the goby fish -- into the Great Lakes.

[Byline: Kristen Smith]

Communicated by:
ProMED-mail from HealthMap alerts

[This appears to be a more detailed article than the piece that was posted on 23 Oct 2011 (archive no 20111023.3153).

For a more detailed look at the botulism situation, readers are referred to the moderator's comment in ProMED-mail post 20111009.3031.
- Mod.TG]

[Georgian Bay can be located on the HealthMap/ProMED-mail interactive map at <http://healthmap.org/r/1mZ->. - Sr.Tech.Ed.MJ]

[see also:
Botulism, fish, avian - Canada 20111023.3153 Botulism, avian - USA (04): (NV) 20111009.3031 Botulism, avian - Canada: (AB) 20110818.2502
Botulism, avian - Canada: Great Lakes 20080103.0031
Botulism, birds, fish - Canada (Lake Ontario): susp. 20040825.2376
Botulism, fish, birds - Canada, USA (Lake Erie) (03) 20021209.6023 Botulism, fish, birds - Canada, USA (Lake Erie) (02) 20021011.5519 Botulism, fish, birds - Canada, USA (Lake Erie) 20021010.5508
Botulism, fish, birds - Canada & USA 20010901.209
Botulism, birds, fish - Canada (Lake Ontario): susp. 20040825.2376
Botulism, fish, birds - Canada, USA (Lake Erie) (03) 20021209.6023 Botulism, fish, birds - Canada, USA (Lake Erie) (02) 20021011.5519 Botulism, fish, birds - Canada, USA (Lake Erie) 20021010.5508
Botulism, fish, birds - Canada & USA 20010901.2095] .................................................sb/tg/mj/dk/ll
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