California: Beware the Green Goblin—aka Harmful Algal Blooms

The Green Goblin is back. Not the Stan Lee supervillain, but something much more insidious and harmful: outbreaks of toxic green algae in waterways throughout the United States. 

Peg McAloon via Wisconsin DNR

Harmful algal blooms, or HABs, are not just smelly and gross-looking. HABs pose serious human health risks, kill pets and other animals that ingest them, harm aquatic ecosystems, contaminate drinking water, and prevent the use of rivers and lakes for swimming, boating, and other uses. HABs are also a growing problem globally and one which the United States is woefully behind in tackling. In fact, the U.S. Environmental Protection Agency (EPA) does not even have a national HABs tracking and reporting system so that people can see if their favorite waterway poses a danger, despite HAB outbreaks occurring in all 50 states.

In response, NRDC put together a national database based on state-reported HAB outbreaks over the last 12 years. With this map, you can see whether your favorite lake or river has suffered from HABs and learn what your state is doing to address this problem. Our review indicates that no state agency is doing all they should to tackle these outbreaks, so we’ve also provided this link to ask your governor to do more.

Like many pollution problems, harmful algae blooms often hit the hardest in under-resourced communities and communities with large populations of people of color. One of the most notorious HAB outbreaks occurred in Lake Erie in 2014, shutting down the water system for the city of Toledo, Ohio, for several days. More than a quarter of Toledo’s population are Black and more than a quarter live in poverty. HAB outbreaks in Lake Erie continue to this day. While EPA has recently provided funds to install trash-collection devices around the lake, Toledo’s mayor notes that those devices do not address the toughest issue facing Lake Erie and Maumee River. “Look, it’ll be a good thing if there’s less plastic and bottles and such in Lake Erie,” Mayor Kapszukiewicz says. “But the water turns green because of agricultural runoff.”

Like Lake Erie, the Klamath Basin, straddling California and Oregon, has had an ongoing HAB problem for many years that threatens the health of people who use the Klamath River. The Klamath is home to several Indigenous tribes—including the Hoopa Valley, Yurok, and Karuk—that rely on a healthy watershed for fishing and cultural needs. Toxic water quality in the Klamath stems from multiple causes, but is particularly bad due to the presence of PacifiCorp’s dams, which create warm, stagnant pools for algae to develop and thrive. Federal and state environmental agencies were slow to do anything about the Klamath Basin HABs, leading the Klamath Basin tribes to develop the first water quality standards for microcystins—the toxins in cyanobacteria that cause the harmful health effects of HABs. Now, the tribes are key supporters of the cooperative effort to remove the lower four Klamath River dams and restore the health of the River.

Male ruddy duck in algae in the Lower Klamath National Wildlife Refuge.

Brett Cole

The city of Stockton, California, is another case in point. Stockton was recently described by U.S. News & World Report as America’s most diverse city: “An already-poor port city that was ravaged by the 2008 housing crisis…whose roughly 310,000 residents were 42 percent Hispanic, 24 percent Asian, 19 percent non-Hispanic white and 13 percent black—the most racially diverse large city in America, according to a U.S. News analysis based on recent census data.” Stockton has suffered such bad HAB outbreaks since microcystins was first detected in the San Francisco Bay–Delta in 1999 that state officials warned in 2016 that the city might soon experience year-round HAB outbreaks. This is what Stockton’s waterfront looked like in early July of 2020, in the midst of a growing bloom:

Barbara Barrigan-Parilla

The photo was taken by Restore the Delta’s Barbara Barrigan-Parrilla, who reported that kids were playing around in a rubber raft near this outbreak. State officials recently confirmed that samples from this HAB outbreak not only exceeded recreational criteria for microcystins, but measured up to 49 times higher than the “Danger” level (the highest advisory threshold).

While San Joaquin County does its best to warn residents of HAB outbreaks, it is unconscionable that the state and federal government are not doing more to prevent these growing outbreaks, especially in underserved communities like Stockton. Of course children are playing in this water, especially when summer temperatures are routinely in the 90s and COVID-19 has confined all of us to our neighborhoods. Shared natural spaces like rivers and parks are all the more critical during these challenging times to provide needed relief from the heat and sheltering in place. It is the government’s job to keep these shared natural spaces safe and available for public use—a job that the state is currently failing in Stockton. It’s time for California to step up and tackle this growing HABs threat through updated water quality standards for the Delta.

This problem is not going away. A recent study of HAB outbreaks in the San Francisco Bay–Delta estuary concluded that “since Microcystis blooms have become established in the estuary, they will persist, despite flushing from extreme wet conditions, and will develop once water quality conditions, particularly water temperature, become favorable.”

The next wet year is not going to save us but other steps will:

  1. reducing nutrient pollution that feed HAB outbreaks;
  2. increasing instream flows to diminish the size and extent of outbreaks;
  3. restoring pollutant-filtering wetlands; and
  4. effectively monitoring and warning people to stay away from outbreaks that occur.

Join us in urging Governor Newsom to take immediate action to tackle HABs in California.

About the Authors

Kate Poole

Senior Director, Water Division, Nature program

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