The early August toxic algae bloom in Lake Erie that forced Toledo, Ohio authorities to cut drinking water to 400,000 people is no longer an immediate health threat, but the algae problem in the Western Lake Erie Basin continues to grow. Algae bloom occurrences arise from many factors, but a major cause in Lake Erie is a significant uptick in dissolved reactive phosphorus (DRP), a form more readily available for algae to use. There are many sources of DRP that pollute the Western Lake Erie Basin, but agriculture is the largest contributor at 78 percent of the total. (See infographic on right for details.) Agriculturally derived DRP gets into waterways through runoff loaded with synthetic fertilizers from farm fields and livestock manure lagoons, both of which wash into the Sandusky and Maumee Rivers and eventually empty into Lake Erie. The USDA and State of Ohio have taken note of agriculture’s nonpoint source DRP problem and have created a mitigation plan. As FERN’s Chuck Abbot writes in a recent Ag Insider:
Farmers in Ohio can get up to $2 million in cost-share money to reduce run-off into Lake Erie, said USDA, acting only weeks after algae blooms in the lake disrupted the water supply for Toledo. The funding is allocated for the Western Lake Erie Basin to accelerate water-quality efforts. USDA's Natural Resources Conservation Service is holding a one-week signup for interested growers and landowners. "This signup will be focused on planting cover crops on vulnerable soils this fall in order to reduce soil and nutrient loss from farm fields," said USDA. The money will come from the Environmental Quality Incentives Program. USDA also will provide $1 million for expert advice to landowners.
Experts say cover crops offer the best protection against soil and nutrient erosion, says USDA. Algae blooms are blamed on warm water and runoff from farms, lawns and other sources.
The goal is to encourage farmers to increase cover crop plantings that absorb runoff, thereby reducing the amount of DRP, other nutrients and pesticides that flow into Lake Erie tributaries and curtailing algae blooms. This work is increasingly important as heavy rains and worsened runoff are expected as climate change intensifies.
Go to the USDA’s Environmental Quality Incentives Program to learn more, and check out Circle of Blue to get exceptional reporting, graphics and charts regarding Lake Erie nutrient pollution.
Infographic (c) Erin Aigner for Circle of Blue.
Main image: “Harmful algae bloom. Lake Erie. July 22, 2011." By the NOAA Great Lakes Environmental Research Laboratory on Flickr under a Creative Commons Attribution-NonCommercial-Share Alike 2.0 Generic license.