Lake Erie phosphorus targets: An imperative for active adaptive management

Management actions taken to meet the phosphorus load targets in the 1978 Great Lakes Water Quality Agreement proved highly successful, initially. Eutrophication symptoms abated, and attention was redirected toward other important water quality problems. However, in the early 2000s Lake Erie, in particular, began to re-experience severe algal blooms and other problems associated with excessive nutrient inputs. The 2012 GLWQA prompted the development of updated phosphorus targets, and endorsed the concept of adaptive management. We propose that an active adaptive management program that maximizes learning opportunities will be imperative to sustain any future improvements realized in response to the new targets. Every year offers natural, albeit uncontrolled experiments to exploit the adaptive management concept of "learning by doing." A carefully thought out plan of complementary monitoring and modeling, supported by stakeholder engagement, will promote an improved understanding the processes that influence lake behavior and guide essential refinements to management goals and appropriate actions to attain them. In 2019 the International Joint Commission released a set of recommendations regarding the use of modeling approaches to support adaptive management in Lake Erie. We have incorporated those recommendations herein to further inspire the Great Lakes community to invest in an active adaptive management strategy that will serve us into the future. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.