Re: Toxic algae blooming in area lakes; scientists blame zebramussels

The article is included below and can be found at
http://www.mlive.com/news/muchronicle/index.ssf?/base/news-
5/109800815086820.xml

Toxic algae blooming in area lakes; scientists blame zebra mussels
Sunday, October 17, 2004
By Jeff Alexander
CHRONICLE STAFF WRITER

For years, scientists have pondered the worst-case scenario that could result from zebra mussels infesting the Great Lakes and scores of inland waters.

That picture is becoming increasingly, and alarmingly, clear.

A potent group of toxic compounds has been discovered in a common algae found in Muskegon Lake and the poisons may be present in other Michigan lakes. What makes this environmental horror story so unusual and troubling is that the toxins, called microcystins, were not dumped into Muskegon Lake by a renegade industry.

The culprits in this case: Zebra mussels.

What's worse, the only obvious solution would be killing all the zebra mussels in lakes, which isn't possible at this point.

Imported to the Great Lakes in the 1980s by trans-oceanic freighters, the mollusks have increased water clarity in lakes by eating algae as they filter huge volumes of water through their tiny bodies. The down side is that zebra mussels eat only nutritious algae -- they spit out algae containing toxic compounds.

The result: Blue-green algal blooms, which can contain microcystins, are proliferating in relatively clean lakes across Michigan and other states, including Muskegon and White lakes, Lake Leelanau in northern Michigan and Lake Champlain in Vermont. The blooms create a blue-green layer of scum on the water's surface that looks like floating paint.

Scientists who recently tested algae scum on Muskegon Lake found elevated concentrations of microcystins. When ingested via drinking tainted water, the naturally occurring poisons can cause vomiting, diarrhea, fever, rashes, throat irritation and, in extreme cases, liver damage and cancer.

"I don't want to scare people, but the levels of microcystins we found are significant. These are very high concentrations and are on the same order of magnitude as the highest concentrations of microcystins ever reported," said Gary Fahnenstiel, director of the National Oceanic and Atmospheric Administration's Lake Michigan Field Station NOAA's in Muskegon.

Fahnenstiel, one of the world's leading experts on algae, said people should avoid swimming, wading, windsurfing, canoeing or water-skiing in areas of lakes with blue-green algal blooms. Dogs also should avoid those waters.

Although full-blown algal blooms are easy to spot on the water's surface, those blooms are hard to spot while forming or after being dispersed by waves. Here's a hint for next summer: In its diffuse stage, blue-green algae resembles a cloud of pollen in the water.

Blue-green algal blooms have long been common in lakes with high levels of phosphorous, such as Spring Lake. Zebra mussels are now causing the blooms in lakes with low phosphorous levels, according to scientific studies.

Although blue-green algae has poisoned drinking water supplies in other countries, Fahnenstiel said it is unlikely microcystins will foul Lake Michigan, a source of drinking water for much of Muskegon, Ottawa and Kent counties. Wave action in the lake is usually too intense to allow blue-green algal blooms to form, and the local drinking water intakes are deep enough to avoid the harmful algae, which floats to the water's surface.

The Muskegon Lake samples represented the "worst-case scenario," Fahnenstiel said, because they were taken from algae scum floating on the lake. But the Bear Lake sample was taken in an area with no scum on the water -- the blue-green algae looked more like pollen in the water.

Although few people are out on area lakes now, Fahnenstiel said it would be wise in the future to avoid going in water where blue-green algae is present. Wind and waves will disperse the surface scum, but the algae usually slips below the surface and returns when the water is calm.

"As a scientist and boater who spends time on Muskegon Lake -- my kids swim and tube in the lake -- I would not go in the water when these blooms are present," Fahnenstiel said.

Rick Rediske, a professor of water resources at Grand Valley State University and chairman of the Muskegon Lake Public Advisory Council, said he would limit activities in any lake with a blue-green algal bloom: "I would boat in it but I wouldn't swim in it," he said.

A Michigan State University study published earlier this year concluded that blue-green algal blooms could occur in any lake where zebra mussels are present. More than 100 Michigan lakes are infested with zebra mussels, according to state data.

"These algae blooms are not likely to go away," Fahnenstiel said. "Our experience in the Great Lakes has been that once these blooms appear, they occur every year. If you have zebra mussels in your lake, you'd better be looking out for these algal blooms."

Sarah Holden, a Michigan Department of Environmental Quality aquatic biologist, said the state has not been monitoring for microcystins in lakes.

"I think it is a relatively uncommon thing that is starting to become more frequent," Holden said. "We're trying to get a handle on it, figure out the best way to find lakes with problems, figure out what the health concerns are for people and how to get the word out."

A 2000 study performed by NOAA scientists in Saginaw Bay and Lake Erie warned that microcystins, which don't break down quickly in the environment, could move up the food chain, from invertebrates to fish and, ultimately, to people who eat the tainted fish.

The levels of microcystins in Muskegon Lake exceeded those found in Lake Erie.

There is no evidence that microcystins have affected fish or humans here, but no studies have been conducted.

Microcystin contamination has never been documented in area lakes until now because no one ever tested for the toxins. Although blue-green algae has been a problem in other parts of the world for more than a century, it has only emerged as an issue in the United States in recent years, according to several scientists.

"There could be lakes out there, such as Spring Lake, that could be very high (for microcystins). We just haven't sampled them," Fahnenstiel said.

Spring Lake, one of West Michigan's most popular and intensely studied lakes, is notorious for massive blue-green algal blooms. Scientists from Grand Valley State University have thoroughly studied those blooms and phosphorous pollution in Spring Lake, but did not test for toxic microcystins in the algae, said Alan Steinman, director of GVSU's Annis Water Resources Institute. He said the test is difficult and costly to perform.

"I've always been told that blue-green algae is not a harmful thing," said John Nash, chairman of the Spring Lake Lake Board.

When informed that some blue-green algae contains toxins, Nash said, "That concerns me."

Rediske said he has seen people swim, water ski and ride tubes in blue-green algal blooms on Spring Lake. "People seem to go out in Spring Lake in all conditions. This is something that really needs to be looked at," he said.

Microcystin contamination has been a problem for more than 100 years in other countries. There have been numerous cases of people, dogs and livestock becoming ill after drinking or wading in water laced with microcystins.

In Brazil, more than 60 kidney patients died after drinking water laced with microcystins passed through their dialysis machines.

People have become ill and some dogs have died recently in Vermont after falling into blue-green algae on picturesque Lake Champlain. Soldiers in Great Britain were sickened after canoeing through a blue-green algal bloom, and a Wisconsin boy died last year after falling into an agricultural pond contaminated with microcystins, Fahnenstiel said.

The problem is a relatively new one in the Great Lakes region. That's because zebra mussels are increasing the number of lakes experiencing blue-green algal blooms.

The concentration of microcystins in algae scum floating in the middle of Muskegon Lake was four times higher than the highest levels found in Lake Erie in 2000.

The 238 parts per billion of microcystins found in the Muskegon Lake algae bloom "does represent a health risk -- mostly to accidental ingestion by pets or swimmers," said Wayne Carmichael, a professor of biological sciences at Wright State University. Carmichael is one of the world's leading experts on microcystins.

The World Health Organization's maximum exposure guideline for microcystins in recreational waters is 20 parts per billion, Carmichael said.

The other samples taken here found: 96 parts per billion of microcystins in a boat basin at the Lake Michigan Field Station, near the Muskegon Lake channel; 41 ppb near the Harbour Towne beach; and 20 ppb in the middle of Bear Lake.

© 2004 Muskegon Chronicle. Used with permission
Copyright 2004 Michigan Live. All Rights Reserved.

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