The 1987 Canada-U.S. Great Lakes Water Quality Agreement required Remedial Action Plans (RAPs) be collaboratively generated between local stakeholders and government agencies to implement an ecosystem approach in cleaning up 43 historically polluted Areas of Concern (AOCs) throughout the Laurentian Great Lakes. The institutional arrangements that have emerged over the past 35 years to foster an ecosystem approach in RAPs are expected to have changed over time and be varied in some aspects-reflecting unique socio-ecological contexts of each AOC-while also sharing some characteristics that were either derived from the minimally prescribed framework or developed convergently. Here we surveyed institutional arrangements to describe changes over time relevant to advancing an ecosystem approach in restoring beneficial uses in the 43 AOCs. While eight AOCs evidenced little institutional change, the remaining 35 AOCs demonstrated a growing involvement of local organizations in RAPs, which has enhanced local capacity and ownership and helped strengthen connections to broader watershed initiatives. We also noted an expansion of strategic partnerships that has strengthened science-policy-management linkages and an increasing emphasis on sustainability among RAP institutions. Our study details how institutional arrangements in a decentralized restoration program have evolved to implement an ecosystem approach and address new challenges.

Keywords: Ecosystem-based management; Institutional Frameworks; Remedial Action Plans; Water Governance.