Reducing Phosphorus Loadings and Harmful Algal Blooms

The problem of excess nutrients in Lake Erie and resulting algal blooms has challenged scientists and troubled the public for more than 50 years. Stirred by public concern, governments responded with vigor to the problem in the 1960s and 1970s, resulting in measurable reductions in phosphorus inputs and a steep reduction in algal blooms. By the mid-1980s, the rapid recovery of Lake Erie was a globally-known success story.

However, Lake Erie is once again severely threatened. It is the shallowest of the Great Lakes, the warmest and the most susceptible to eutrophication and the effects of climate change. The recent accelerating decline of this lake, manifested as impaired water quality, massive, summer-long algal blooms, hypoxia and fish kills, has focused binational attention on the need for urgent actions to reduce external inputs of phosphorus. While Lake Erie's health suffers from multiple stressors, the rising proportion of dissolved reactive phosphorus is seen as the primary cause of this decline.

The return of severe Lake Erie algal blooms in the 2000s has again galvanized public concern and a governmental response. The worst algal bloom ever experienced on the lake occurred in 2011, prompting the International Joint Commission (IJC) to make binational investigation into the science and opportunities for action by governments to reduce algal bloom-causing pollution a priority.

The IJC recognizes and applauds the commitment of the United States and Canadian governments to restoring the lake's health. The United States Great Lakes Restoration Initiative is providing substantial funding to Lake Erie Basin restoration. The Canadian Great Lakes Nutrient Initiative is also contributing substantially to understanding the sources of excess nutrients and measures to reduce them. However, in carrying out the Lake Erie Ecosystem Priority, the IJC finds that more needs to be done.

This report is the product of a binational cooperative effort that involved more than 60 scientists, engineers, planners and technical experts in Canada and the United States. The IJC expresses its sincere appreciation to these individuals for their contributions to the planning, applied research and analysis that went into the preparation of this report. Their collaborative efforts have produced findings and recommendations that will enable the governments of Canada and the United States to more effectively address the challenges facing Lake Erie and the millions of citizens who depend on and enjoy its waters.

Related Clusters: 
Western Lake Erie Cluster