Black Bay & Black Sturgeon River native fisheries rehabilitation: Options evaluation

Black Bay was once home to the largest population of walleye in Lake Superior, supporting sizable commercial and recreational fisheries. The walleye population collapsed in 1968, due to a combination of factors, including overfishing, habitat loss, and predation of juvenile walleye by rainbow smelt. Several initiatives to rehabilitate the walleye population have been largely unsuccessful. These initiatives have included stocking of various life stages, and both recreational and commercial fishing closures. Recent studies (e.g. Furlong et al. 2006, Biberhofer & Prokopec 2007) have shown that spawning habitat is limiting in Black Bay, and that the remnant walleye stock spawns in the Black Sturgeon River. The Camp 43 dam (also known as the Twin Rapids dam or the Black Sturgeon dam) was constructed on the Black Sturgeon River, 17 km from the mouth, in 1959/60, cutting off access to spawning habitat formerly available to migratory walleye and other native fish species, including lake sturgeon. The creation of artificial spawning shoals is untenable due to the amount of new habitat required, the extreme cost involved, and the lack of road access for the transportation of materials. Providing fish access to naturally occurring habitat is therefore the best remaining approach available for the large scale rehabilitation of the native fish community in Black Bay and the Black Sturgeon River. The Camp 43 dam is an essential component for the binational sea lamprey control program mandated by the Great Lakes Fishery Commission and carried out by the Canadian Department of Fisheries and Oceans on the Black Sturgeon River. Currently, sea lamprey chemical treatments are carried out once every five years at a cost of $118,000. Removing the Camp 43 dam would necessitate increasing the frequency and magnitude of sea lamprey chemical treatments. This would reduce treatment efficacy, resulting in higher numbers of sea lampreys in Lake Superior. Increased program costs required to treat the Black Sturgeon watershed would impair the Department of Fisheries and Oceans' ability to deliver their sea lamprey control program throughout the Great Lakes Basin. The Fisheries Management Zone 9 Advisory Council has been charged with evaluating several options for rehabilitation and with providing a recommendation for a preferred option. A number of options considered in earlier restoration plans have been rejected as being either too costly or as of limited potential including: stocking; artificial spawning habitat construction; and further harvest restrictions. Five options involving the Camp 43 dam are presented: 1) Status quo; 2) Decommissioning Camp 43 and installation of a new barrier below Shillabeer Creek; 3) Decommissioning Camp 43 and installation of a new barrier at Camp 1; 4) Modifying Camp 43 to include a trap and sort fishway, and; 5) Decommissioning Camp 43 without replacement. A hydro development proponent has recently made informal inquiries concerning developing the Camp 43 dam for hydro generation. This has necessitated two further options for consideration: 1a) Status quo with hydro generation; 4a) Trap and sort fishway with hydro generation. Evaluation of the seven options includes consideration of numerous variables: walleye rehabilitation potential and value; lake sturgeon rehabilitation potential; coaster brook trout rehabilitation potential; sea lamprey treatment efficacy and cost; sea lamprey predation on native species; impact to northern brook lampreys; invasion of aquatic invasive species, other than sea lampreys; construction and operational costs, and structural longevity, and; uncertainty. Legal and policy considerations are also presented.

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