Editorial

The story of Great Lakes protection and management can be traced as far back as the signing of Boundary Waters Treaty in 1909 between the United States and Great Britain (signed on behalf of Canada), which dealt with the principles and mechanisms of preventing and resolving disputes about water quality and quantity across the border (United States and Great Britain, 1909). The Boundary Waters Treaty resulted in the formation of an independent advisor, namely the International Joint Commission, for preventing any disputes between the two countries. More recently a binational Great Lakes Water Quality Agreement was signed in 1972 (GLWQA, 2012) between the United States and Canada (with revisions in 1978, 1987 and 2012) committing to the restoration, protection and use of an ecosystem approach (Vallentyne and Beeton, 1988; Vallentyne and Munawar, 1993). The GLWQA set water quality objectives to prevent the further pollution of boundary waters of the Great Lakes. The primary focus of the 1972 GLWQA was controlling cultural eutrophication by reducing phosphorus inputs from point and nonpoint sources. A major contribution behind the GLWQA was the excellent empirical evidence by Vollenweider et al. (1974), which indicated that cultural eutrophication was caused by excessive phosphorus loadings. The wide applicability of Vollenweider’s empirical relationships resulted in regulations for sewage treatment plants, regulations on phosphate levels in detergents, reductions in nonpoint phosphorus loadings, and establishment of total phosphorus loading reduction targets. Similar abatement actions were also implemented in European lakes (Will en, 2001). Another major scientific initiative adopted in 1985 through Canada-United States cooperation under the GLWQA, was the development of remedial action plans to restore beneficial use impairments in Areas of Concern-AOCs (IJC, 1985; 1987; Hartig and Thomas, 1988; Hartig and Vallentyne, 1989; Hartig and Zarull, 1992; Minns et al., 2011). Forty-three AOCs were identified: 12 in Canada, 26 in the United States and 5 shared bi-nationally. These restoration efforts have been underway for over 30 years, resulting in substantial progress and many ongoing challenges. In 2017, in conjunction with the 32 anniversary of the onset of remedial action plans to restore AOCs, the Aquatic Ecosystem Health & Management Society (AEHMS), International Association for Great Lakes Research (IAGLR), Great Lakes Commission, International Joint Commission, and the Detroit River International Wildlife Refuge co-sponsored a two-day symposium titled “Restoring Great Lakes Areas of Concern” at the 2017 annual IAGLR conference in Detroit, Michigan. A binational Symposium Steering Committee was established to coordinate the event. The symposium attracted a large number of delegates. Twenty-six papers, originating from both countries, were presented with a panel discussion at the end of the symposium which generated discussion about achievements, lessons learned, and the future of AOCs. The AEHMS is pleased to publish this special issue on Great Lakes AOCs. The AEHMS has a long history of publishing such special issues, including those on AOCs like the Bay of Quinte (AEHMS, 2011, 2012), Hamilton Harbour (AEHMS, 2016, 2017), and Toronto and Region (AEHMS, 2018). Keeping with this tradition, the AEHMS has organized this special issue comprised of 11