Green Slime: Algae Blooms in Nation’s Freshwater Causes Health Risks | Civil Eats

Green Slime: Algae Blooms in Nation’s Freshwater Causes Health Risks

In a new report out today, the Food & Environment Reporting Network (FERNnews) highlights how toxic blue-green algae–or cyanobacteria–is thriving in freshwater across the U.S., creating health risks. The story appears online at the Center for Investigative Reporting and The Atlantic.

“Every summer as temperatures rise, ‘blooms’ of cyanobacteria develop in lakes and rivers across the country, turning waters intense green, and coating swaths of their surfaces with putrid-smelling blue-green algae that looks like pea soup,” writes FERNnews reporter Jessica Marshall. “The blooms occur in nearly every state, peaking in August and September, and—though no national agency tracks the blooms—experts say they are getting worse, driven by fertilizer and manure run-off into lakes and streams combined with a warming climate.”

Marshall explains that cyanobacteria occur naturally in lakes, typically at low concentrations that are not harmful and not visible. But when levels of key nutrients—particularly phosphorus—in a water body soar and combine with hot temperatures and stagnant water, the organisms thrive. Under these conditions, they outpace growth of other types of algae and streak or coat the water with bright, sometimes iridescent, blooms of green or blue-green cells.

Many people near the blooms complain of the smell produced by ammonia and hydrogen sulfide as the cyanobacteria rot. “But worse,” Marshall reports, “Under conditions that scientists don’t completely understand, cyanobacteria can produce toxins that cause asthma-like symptoms, severe vomiting or diarrhea, or irritated skin or eyes.”

Marshall interviews Dan Jenkins, who was partially paralyzed after washing bright, stinking algae blooms—or green slime—off his dog, Casey, after he had swam in a tainted lake in Ohio. The dog later died from its exposure–one of at least 10 algae-related dogs deaths reported nationwide in the last two years. In Wisconsin alone, 98 people have reported illness from blue-green algae exposure over the last three years–though experts agree that many cases go unreported or misidentified.

In looking for the source of the problem, Marshall reports, experts point to agriculture: Phosphorus-laden fertilizer and manure can wash directly into waterways, and eroding sediment from farmlands carries the substance too. In addition, flows from sewage treatment plants and urban storm drains, runoff from lakeside lawns, and discharges from industries such as pulp and paper mills can also contribute phosphorus to streams and lakes.

newsmatch banner 2022

The story reveals how climate change is also part of the picture, especially when hot, dry conditions follow intense spring storms. Those extreme storms may become more frequent with global warming.

You can find the full report at the Center for Investigative Reporting and The Atlantic. You can also read the report here on the Food & Environment Reporting Network Web site.

Photo: October 09, 2011 satellite image when the cyanobacteria bloom covered the largest area of Lake Erie. Bright green is the bloom as scum or right near the surface. Courtesy NASA MODIS data processed by R. Stumpf, NOAA.

We’ll bring the news to you.

Get the weekly Civil Eats newsletter, delivered to your inbox.

Today’s food system is complex.

Invest in nonprofit journalism that tells the whole story.

Paula Crossfield is a founder and the Editor-at-large of Civil Eats. She is also a co-founder of the Food & Environment Reporting Network. Her reporting has been featured in The Nation, Gastronomica, Index Magazine, The New York Times and more, and she has been a contributing producer at The Leonard Lopate Show on New York Public Radio. An avid cook and gardener, she currently lives in Oakland. Read more >

Like the story?
Join the conversation.

More from

General

Featured

Ann Tenakhongva, 62, and her husband, Clark Tenakhongva, 65, sort traditional Hopi Corn at their home on First Mesa on the Hopi Reservation in Arizona on September 28, 2022. The corn comes from the families’ field in the valley between First Mesa and Second Mesa, which Clark had just harvested. The corn is organized on racks to dry out and then stored in cans and bins for years to come. Much of the corn is ground up for food and ceremonial purposes. Corn is an integral part of Hopi culture and spirituality. (Photo by David Wallace)

Climate-Driven Drought Is Stressing the Hopi Tribe’s Foods and Traditions

Most Hopi grow corn with only the precipitation that falls on their fields, but two decades of drought have some of them testing the waters of irrigation and hoping they can preserve other customs with their harvests.

Popular

A Young Oyster Farmer Carrying on the Family Business

Gaby Zlotkowsky on a boat holding a basket of oysters. (Photo credit: Capshore Photography)

Young People Working for Food Justice in North Carolina

Michael

Young Fishermen Are Struggling to Stay Afloat

Lucas Raymond holding a halibut. (Photo courtesy of the New England Young Fishermen's Alliance)

This Mother-Daughter Team Is Sharing Food Traditions from the Ho-Chunk Nation

Elena Terry, (left) and Zoe Fess smile after showcasing Seedy SassSquash, a signature family dish, during the Smithsonian’s