Toxic Algae Blooms Across the U.S.

Image: Aleem Yousaf via Wikimedia Commons

By Natasha Lasky, ODP Staff Writer

Toxic algal blooms have been spreading throughout the United States. This year, states like Utah and Washington, Florida, and the Great Lakes are seeing explosive algal growth. 

In fact, a report from the nonprofit Environmental Working Group (EWG) found cases of toxic algae in every state except Alaska. Last year the EWG saw 400 cases, an extreme increase from 2010 when the organization started keeping track. This year, as of July, the number of cases has skyrocketed by 46 percent compared to the same period last year.

Why This Matters:

Algal blooms produce toxins that can be dangerous to people and wildlife. Saxitoxin, for instance, causes paralysis, and the most widespread algal toxin, microcystin, can cause rashes, diarrhea, sore throat, and vomiting. Long-term, microcystin can cause liver failure and is linked to cancer and Alzheimer’s disease. Algal toxins are also suspected in the recent death of a family of three along the Sierra National Forest trail.

Algal blooms are especially harmful to waterside communities. This summer in Florida, both coastal and lakeside towns have had to shut down beaches after blooms poisoned fish and beachgoers. The outbreak threatened Floridians’ quality of life and the state’s tourism and fishing economies.

“The scariest part is that it’s really hard to predict toxins—you can’t tell if they’re toxic by looking at them, so you can’t just avoid them, and we don’t understand what triggers a bloom to be toxic,” Anne Schechinger, senior economic analyst at the EWG, told Outside“We’re really at the beginning of the science.”

Why Is It Happening?

Not all algal blooms are toxic, but an increasing number of them are. They have been exacerbated by industrial farming and climate change. Fertilizer, animal-manure runoff, stormwater runoff, and septic water release phosphorous and nitrogen into the waterways. Phosphorus used in commercial agriculture has put so many nutrients into ecosystems that the Environmental Protection Agency called it “one of America’s most widespread, costly, and challenging environmental problems.”

Climate change also contributes to algal blooms. Rising air and water temperatures create a more optimal algae habitat, which allows them to bloom in more significant numbers. More rain worsens the problem, which is bad news given that climate change has made extreme weather events commonplace. 

Stopping the Spread: NOAA has begun forecasting harmful algal blooms in Florida and Maine and plans to expand to the Pacific Northwest. Satellite mapping has also made it easier to locate the sources of pollution causing the blooms. Some states, like Minnesota, have passed laws that require barriers between farms and waterways. 

If the federal government doesn’t take action, this crisis will continue to worsen. Algal blooms cost the U.S. an estimated$2.2 billion each year, and that number will balloon as blooms get more pervasive.

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