Relationship of Intra-Specific Diversity to Ecosystem Services in Great Lakes Restoration Programs

The ecological role and ecosystem services provided by the intra-specific diversity of native fishes in the Laurentian Great Lakes historically have been given little attention within programs focused on species restoration.  Originally, the levels of diversity within lake trout and coregonines (whitefishes, ciscoes) were comparable to the Mackenzie Great Lakes of Northern Canada, such as Great Slave Lake.  The complexity of native fish assemblages were linked via energy and nutrient pathways.  Tremendous losses of this diversity, and sometimes species extirpations, occurred during the 20^th century due to overfishing, predation by non-native sea lamprey, and by invasive species such as zebra mussels.  Restoration programs for several decades beginning in the 1950s focused solely on a single shallow water lake trout form.  This approach ignored more than 50% of the deepwater habitat (> 55m) available for restoration and sacrificed the opportunity to engage more of the lakes’ productive capacity to provide ecosystem services.  Recently in the past 10 years, restoration programs have begun to be modified to introduce different forms of lake trout, Coregonus hoyi, and C. artedi.  These changes are a welcome step towards ecosystem management.