Zebra Mussels Promote Blue-Green Algae Blooms

[hatrack]

PONTIAC, Mich. - "A new study has found that the presence of zebra mussels in inland lakes promotes the growth of a blue-green algae that produces a toxin harmful to people and animals.

The study, conducted by researchers from Michigan State University's Department of Fisheries and Wildlife, found that lakes infested with zebra mussels have, on average, levels of a blue-green algae called Microcystis three times higher than lakes without the mussels. The infested lakes also have about twice the level of microcystins — poisons produced by the algae.


While the findings may alarm some who live around such lakes, one of the study's authors cautions against panic. "I'm not familiar with any instance of people being poisoned just by swimming," Orlando "Ace" Sarnelle, an associate professor at MSU, told The Daily Oakland Press for a Thursday story. "You have to ingest the water, and you have to consume large quantities." The toxin can cause liver damage if it is consumed in large enough amounts.

The study included water samples from about 100 inland lakes in Michigan. Sarnelle said the number of blue-green algae blooms has increased in Michigan's inland lakes and appears to be linked to the spread of the mussels. While the zebra mussels eat algae, they tend to steer clear of the toxic blue-green algae."

EDIT

[Cooley Hurd]

1. Another reason to hate the little buggers...

They're invaded the NY Barge canal and every waterway attached. They're little clam-looking-like things that get into everything, especially boat outdrives...

[Viking12]

2. I live on a lake infested w/zebra mussels

and I'm a diehard angler. The talk around here is that the toxic algae could affect zooplankton feeding and change the whole ecosystem. I can't confirm or deny the veracity of those claims, but that is the lastest buzz from this report.

[hatrack]

3. I thought the focus of the article was narrow

Although it mentioned a minimal chance for potential liver toxicity in humans, it didn't really say much at all about possible ecological impact.

Of course, it's probably too early to project long-term biotic consequences, but I've yet to hear much in favor of zebras and their effects. Add this one to the "negative" heap, or so it seems.

[mike_c]

4. as filter-feeding planktivores go, bivalves in general don't benefit...

...trophic webs nearly as much as small crustaceans, rotifers, and insects. Bivalves tend to sequester plankton and FPOM biomass rather than serving as important trophic intermediaries in most freshwater systems. This is especially problematic in the case of invasive species like zebra mussles because they are capable of filtering HUGE volumes of water and therefore of disrupting FPOM based food webs.

[hatrack]

5. I've seem some interesting reports on zebra dieoffs in the Great Lakes

Apparently, once they really get going, huge mats of them stretch on for miles and miles, in the process stripping huge amounts of biomass out of their area. They then promptly die in large numbers.

I remember reading that in some areas of Lake Erie, zebra dieoffs have led to substantial hypoxia from the breakdown of the mussels.