A new map shows that slimy, smelly, toxic blooms of blue-green algae are widespread across the nation’s lakes, rivers. and ponds. Between May 5 and mid-September, 21 states issued warnings or advisories in 147 locations, according to information compiled by the National Wildlife Federation and Resource Media, a nonprofit communications firm.
But the map’s blank spots also tell a story. They highlight the absence of any coordinated, nationwide tracking system for blooms of cyanobacteria, also known as blue-green algae, which can kill exposed pets, contaminate drinking water, close lakes to boating, and more, with an annual economic toll in the billions. Not all states monitor blooms.
“No one has been able to document the total national extent of the problem and what it’s costing us,” says Andy Buchsbaum, Regional Executive Director of the National Wildlife Federation’s Great Lakes Regional Center.
He believes the map shows “just the tip of the iceberg.” The 50 incidents reported in New York state this summer, for example, probably reflect concerted monitoring efforts rather than a bigger problem, according to a report published with the map.
Last summer FERN reported that toxic blue-green algae can cause devastation when agricultural runoff combines with warm summer temperatures. When excess nitrogen and phosphorus wash off fields or feed lots, especially in springtime, they load up lakes with nutrients that can promote the formation of the blooms once temperatures rise. As the summer gets hotter, conditions are perfect for cyanobacteria to take over—and to produce toxins that can cause respiratory problems, burning eyes, and neurological symptoms in people.
Reducing blooms requires better control of agricultural runoff, Buchsbaum says. The Senate version of the new Farm Bill currently under consideration includes provisions that tie crop insurance subsidies to conservation practices. These provisions would be“a really significant step in the right direction,”he told FERN. He added that while researching the new report he encountered “a number of farmers that are really doing phenomenal stewardship work,” such as planting cover crops and applying fertilizer wisely.
Richard Stumpf of the National Oceanic and Atmospheric Administration, who tracks blooms on Lake Erie and elsewhere, says that monitoring is “a hard problem.”Even states that want to monitor their lakes for blooms face a daunting task, he says: 100 lakes is more than a state can realistically track, let alone the thousands in states like Florida and Minnesota. “The map actually indicates that one of the challenges is that we don’t know enough about when and where there are blooms,” he says. This makes it difficult to know if the problem really is getting worse, how much of a health problem blooms present, and whether any measures to curb them are working.
Stumpf hopes satellite data may help. He is working to determine whether the right type of satellite images can identify algal blooms on lakes of sufficient size from space. If this method proves effective, it could help solve the problem of monitoring at the national scale. One satellite that can collect this type of information is Sentinel-3, scheduled to launch in 2014 to replace its predecessor, which stopped working in 2012.