The United States and Canada Adopt Phosphorus Load Reduction Targets to Combat Lake Erie Algal Blooms

Satellite image of an algal bloom on Lake Erie, taken on September 6, 2015. Credit: NASA Worldview.
Satellite image of an algal bloom on Lake Erie, taken on September 6, 2015. Credit: NASA Worldview.

To combat the growing threat of toxic and nuisance algal development in Lake Erie, the United States and Canada committed, through the 2012 Great Lakes Water Quality Agreement, to establish binational phosphorus load reduction targets for Lake Erie by February, 2016.

In response to this commitment, following a robust binational science-based process and extensive public consultation, Canada and the U.S. have adopted the following phosphorus reduction targets (compared to a 2008 baseline) for Lake Erie:

  • To minimize the extent of hypoxic zones in the waters of the central basin of Lake Erie: a 40 percent reduction in total phosphorus entering the western and central basins of Lake Erie—from the United States and from Canada—to achieve an annual load of 6,000 metric tons to the central basin. This amounts to a reduction from the United States and Canada of 3,316 metric tons and 212 metric tons respectively.
  • To maintain algal species consistent with healthy aquatic ecosystems in the nearshore waters of the western and central basins of Lake Erie: a 40 percent reduction in spring total and soluble reactive phosphorus loads from the following watersheds where algae is a localized problem: in Canada, Thames River and Leamington tributaries; and in the United States, Maumee River, River Raisin, Portage River, Toussaint Creek, Sandusky River and Huron River (Ohio).
  • To maintain cyanobacteria biomass at levels that do not produce concentrations of toxins that pose a threat to human or ecosystem health in the waters of the western basin of Lake Erie: a 40 percent reduction in spring total and soluble reactive phosphorus loads from the Maumee River in the United States.

Further work to establish targets that will minimize impacts from nuisance algae in the eastern basin of Lake Erie continues.

Efforts to develop these targets for Lake Erie were led by the Nutrients Annex Subcommittee and the following factsheet, technical report, and consultation summary document their recommendations.

Canada and the United States are moving forward, working in close collaboration with other jurisdictions and stakeholders, to develop domestic action plans that will outline strategies for meeting the new targets.