Algae: Clouding our waters

INDIANAPOLIS — From border to border, coast to coast, algae blooms are on the increase. Possibly they are related to climate change, specifically to warmer worldwide temperatures.

 Anglers are concerned because of the harm that algae can inflict on fisheries.

In New England, didymo is spreading across stream bottoms, killing vital links in the food chain. Mostly in the Southeast, lyngbya is causing similar damage in lakes and reservoirs. Golden algae, meanwhile, continues to kill fish and other species in the Southwest, specifically in Texas and Arizona. Varieties of blue-green algae are on the increase in the Great Lakes, depleting oxygen in the water.

 But we should not overlook other threats posed by algae, particularly the blue-green species.

For example, resource managers advised against swimming in Indianapolis' Geist Lake this past summer because of a blue-green bloom.

"I've been here since 1982. This is the worst I've seen the algae," said Kent Duckwall, director of operations at Geist Lake Marina.

"We recommend avoiding swimming in Geist Reservoir, and being careful not to swallow water when skiing or boating," added Robert Teclaw, an epidemiologist with the Indiana State Department of Health. "Anyone who comes in contact with untreated water from Geist Reservoir should wash thoroughly with fresh water and soap as soon as possible."

The Indianapolis Star newspaper called the nutrient-rich lake "a vast Petri dish for a thriving culture of the algae."

Why avoid some blue-green algae blooms? Unlike golden alga, which harms only fish, these types can be harmful to people and animals who drink it or come in contact with contaminated water. No fatalities have been reported in the United States thus far, but plenty of people have been made ill, experiencing allergic reactions and respiratory problems, among other symptoms.

And animals have died. This past summer, blue-green algae killed livestock southwest of Saskatoon, Saskatchewan.

"It's primarily the breeding bulls and the heavier milking females that are dying," said rancher Ivan Thomson.

"They're more active, so their systems require more moisture. They drink more water, then [they die]."

Some of his bison died within 30 minutes of ingesting the water, sometimes while they still were standing in a body of water. Others lived a couple of days.

"If the blue-green alga doesn't get at them instantly, then the toxins accumulate in their liver," Thomson added.

"Blue-green algae have been choking lakes in many parts of Canada this year," the Edmonton Journal newspaper reported.

Back in Indiana, the algae also were reported in Morse and Eagle Creek reservoirs. Resource managers theorized that hot days with little rain contributed to the blooms, as did fertilizer runoff from lawns and golf courses, as well as other organic pollution.

"We know that these algae are doing better in these man-made reservoirs because they like stagnant conditions, they like the warm water, and they like nutrients," said Lenore Tedesco, director of the Center for Earth and Environmental Science. "We've created a habitat that is conducive to their growth."

But nutrient-rich reservoirs and livestock ponds aren't the only places that alga blooms are on the rise. Even once pristine Lake Tahoe is being degraded by algae.

According to the Tahoe Environmental Research Center, the lake is becoming cloudier and warmer, with weather a major reason.

"Some of the largest changes are related to climate change," said Center Director Geoffrey Schaldow. "For example, over the last nine or so years, there's been a significant decrease in the amount of snowfall each year. And nighttime temperatures have increased."

Those two factors combine to increase erosion, while runoff from urbanized areas has added nutrient pollution.

"The changes may make Lake Tahoe eventually less of a tourist destination if the water is no longer this beautiful cobalt blue and instead has more algae in it," Schaldow said.

Possibly most telling is the fact that Tahoe's water clarity was an average of 102 feet during the 1960s. Last year it was 67.7 feet.

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