Anthropogenic activities have led to the decline and sometimes extinction of several species native to the Great Lakes. Species that were extirpated in some or all of the Great Lakes include lake trout, Atlantic salmon, blue pike, and several species of ciscoes. Species whose populations have dramatically declined include American eel, lake sturgeon, lake trout, lake whitefish, lake herring, coaster brook trout, deepwater sculpin, and several species of native unionid clams. Several of these species were historically used by Native American tribes for subsistence and ceremonial purposes.

No single factor led to the decline of native fish species in the Great Lakes. For migratory species such as Atlantic salmon and American eel, dams are thought to have severed historic migration routes. For other species, such as lake trout and blue pike, combinations of factors including over-harvest and predation by sea lamprey are considered the major causes of their declines. Alewife, an invasive marine species that is now a major prey species in several Great Lakes, is thought to have led to the decline of ciscoes and perhaps deepwater sculpin in some of the Great Lakes by a combination of predation and competition.

Because of the variety of anthropogenic activities that have led to the extinction and decline of native fish species in the Great Lakes and the complex life history strategies of these species, restoration efforts must be comprehensive and multi-faceted. Recent changes in the Great Lakes ecosystem brought about by a host of new invasive species including dreissenid mussels, Asian clams, ruffe, round goby, and Phragmites (common reed) make restoration attempts even more difficult. Restoration of native species must take into consideration many issues including genetics, strains, and disease. For example, genetic concerns will be less important in the case of extirpated species (i.e., Atlantic salmon) and strain evaluation will be a high priority. In the case of declining species (e.g., lake sturgeon), genetics will be a high priority to ensure that restoration activities do not adversely impact native gene pools (i.e., cause founder effects).

Native species recovery in the Great Lakes also includes the restoration of degraded habitats that have been chemically and/or physically altered by anthropogenic activities. For example, the nearshore area is an important spawning and nursery ground for over 100 fish species in the Great Lakes; however, this area is also most prone to human interference. Habitat restoration activities can be targeted to achieve ecological benefits at either the community or individual species level and are critical for preserving aquatic biodiversity throughout the Great Lakes. Developing a better understanding of how existing anthropogenic activities; such as water level control to support shipping and hydropower industries, hardening and development of shorelines, and modification of harbors and tributaries to facilitate vessel navigation; impact habitat and biological communities in the Great Lakes is a critical need of resource managers.

The ecological health of the Great Lakes is a priority concern for all the partners of the Great Lakes Science Center (GLSC). Consequently, developing indices to quickly and effectively identify the ecological health of deepwater, nearshore, and tributary ecosystems in the Great Lakes is important. Furthermore, establishing linkages among these ecosystems and with riparian and terrestrial landscapes will be necessary to provide resource managers with the information they need to effectively manage the world’s largest freshwater ecosystem.

The Great Lakes Science Center’s Fisheries: Aquatic and Endangered Resources (FAER) research program places a heavy emphasis on field studies by scientists located at both Ann Arbor and our numerous field stations. Based largely on our partner needs, these studies vary in scope, complexity, and scale. Under the broad categorization of restoration ecology, GLSC scientists are involved with a wide range of studies that focus on habitat, fish, and mussels. The GLSC’s habitat restoration research includes helping the Fish and Wildlife Service identify the most effective ways to restore wetlands at several national wildlife refuges throughout the basin. Center scientists are also carrying out risk assessment research associated with habitat restoration and remediation. Fisheries restoration research is directed at American eel, Atlantic salmon, lake sturgeon, and lake trout. Restoration research on native unionid mussels is being carried out in cooperation with several of our partners. Common to all restoration ecology research activities carried out by GLSC scientists is the elucidation of causal mechanisms contributing to the decline of associated species, which may aid in recovery efforts.

Center scientists are also working on a variety of research projects associated with aquatic ecosystem health. One of the Center’s major efforts in this area involves thiamine deficiency of top fish predators in the Great Lakes. Thiamine deficiency is attributed to the consumption of the invasive alewife, a species high in thiaminase, and has been shown to affect fry survival (“Early Mortality Syndrome”) and, more recently, the migratory ability of adult salmonids. GLSC research in this area is directed at both helping managers better understand the cause and linkages of thiamine deficiency and developing management techniques to circumvent the problem. Research linking nearshore ecosystems to deepwater, tributary, and terrestrial ecosystems is ongoing in the Great Lakes and involves teams of Ann Arbor and field station scientists. In Lake Erie, a research team is looking at how abiotic and biotic factors such as substrate type, water quality, invasive species, and watershed use may affect larval fish communities in nearshore nursery areas. The scope of this research can be expanded to include other life history variables, and the protocols developed may be used to implement similar comparison studies in the other Great Lakes and connecting channels. Center scientists are also conducting research to improve sampling protocols for and risk assessment of E. coli in nearshore waters of the Great Lakes and are examining the decline of Diporeia and associated causes. Several scientists at Ann Arbor and at field stations are working on the Great Lakes Regional Aquatic Gap Analysis project, which is attempting to determine the biodiversity within the basin and identify gaps in species distribution information and conservation coverage at the landscape scale.

Some research activities of GLSC scientists within the FAER research program lie beyond the central scope of restoration ecology or aquatic ecosystem health, but are undertaken in response to emerging needs of partners and incorporate the specialized skills and expertise of GLSC scientists. Center researchers are conducting studies to help resource managers determine the impacts of double-crested cormorants on fish populations as well as the effects of water level changes on key biotic resources. The center is also providing scientific leadership in using new technologies to better understand the life history patterns of several important deepwater salmonid species in the Great Lakes.

The future direction of the FAER research program at the GLSC will be shaped to some extent by the rapid rate of change now occurring throughout the Great Lakes basin. Possibly never before in the history of this ecosystem has this rate been so rapid, nor the changes so dynamic. The changes have been greatly accelerated by invasive species, most notably dreissenid mussels. Consequently, charting a fixed course of action for the future at this time is probably imprudent. At best, an adaptive course can be plotted that responds to changes now underway in the ecosystem, with full recognition that new changes and challenges will arrive in the future and need to be addressed at that time.

In plotting this new and adaptive direction for the Center’s FAER research program, it should be recognized that restoration ecology and aquatic ecosystem health will remain major thematic research areas. Our partners’ interests in restoring native species and determining and improving aquatic ecosystem health will not diminish. The changes underway in the Great Lakes ecosystem will, however, very much determine what specific research the Center undertakes in these reas in the future. The rate of change in the Great Lakes ecosystem is probably most pronounced in the lower trophic levels. Consequently, food-web disruption should be anticipated and our research focus should attempt to examine if and how this disruption will infiltrate higher trophic levels. Will food web disruption vary among lakes, within lakes, among habitats between nearshore and offshore areas? The magnitude of these questions suggests that an integrated multi-disciplinary approach will be necessary to address them. Within the GLSC’s own research staff, integration between deepwater science and nearshore science programs will certainly be required.

Perturbations at the lower trophic levels in the Great Lakes may also afford managers the opportunity to re-couple native food webs in some of the lakes by restoring native coregonid species. There is management interest in considering this in Lake Erie (lake herring) and Lake Ontario (bloater). The GLSC’s FAER and deepwater science programs are highly capable at assisting managers with these unique and large-scale efforts, if undertaken.

The FAER research program of the GLSC is, and will continue to be, diverse. Similar to the deepwater science program, the strength of the Centers’ FAER research program is that it is being carried out throughout the basin, by researchers located at both Ann Arbor and at field stations. The size, complexity, and rate of change in the Great Lakes ecosystem will require FAER research efforts in the future to have more robust sampling designs and modeling approaches leading to increased predictive capability, better integration with other scientific disciplines, increased innovation and use of new technologies, landscape or basin-wide scale studies, and new perspectives, new approaches and new partnerships.

Canada Species at Risk
Canadian Biodiversity Web Site
Ontario's Biodiversity: Species at Risk

Michigan Natural Features Inventory
Michigan DNR Endangered & Nongame Wildlife
Minnesota DNR Endangered, Threatened & Special Concern Species
Indiana DNR Endangered Wildlife
Indiana Endangered, Threatened, and Rare Vertebrate Species
New York DEC Endangered Species List
Ohio DNR Endangered Species List
Pennsylvania Department of Conservation and Natural Resources