The recently released plan to reduce Chinook salmon stocking in Lake Michigan is another, all too familiar, case of bureaucrats kicking the can down the road. It was fisheries managers’ version of the fiscal cliff compromise. They’re putting off tough decisions today only to make tougher decisions tomorrow. In Washington Lake Michigan fisheries managers are focusing on stocking levels when they need to make a decision regarding overall ecological fate of the lake. An article in the November issue of Fisheries highlighted the decision needed to be made by Lake Michigan fisheries managers.
In their article, Dettmers et al. (2012) first summarize the history of fisheries in the Great Lakes and then focus on the problem facing fishery managers today. The authors begin their summary in the late 1800’s when overfishing became an issue with the decline of lake trout Salvelinus namaycush, Atlantic salmon Salmo salar, lake sturgeon Acipenser fulvescans and some coregonine populations. In the early 1900’s, alewife Alosa pseudoharengus and sea lamprey Petromyzon marinus began their invasions. By 1960, overfishing and sea lamprey predation had caused the disappearance of lake trout from all lakes but Lake Superior . It was also at this time that sea lamprey control efforts had had their effect and the population was reduced to 10% of its previous high. In 1965, alewife were the dominant portion of biomass in Lake Michigan, Huron and Ontario Lake Michigan led to political pressure to control the alewife population. This led to the development of the commercial trawl fishery and the stocking of Coho salmon Oncorhynchus kisutch in 1966 and Chinook salmon O. tschawytscha in 1967. By the late 1970’s, the popularity of the salmon fishery and the resulting economic return had led to the stocking of rainbow trout O. mykiss and brown trout S. trutta. In 1984, the biomass of alewife was less than 20% of what it had been in 1967. Over the next decade, the decline in alewife led to improvements in native fish populations and a more diverse fish community. But the decline in alewife also caused a decrease in the size of Chinook salmon and die-offs due to a bacterial kidney disease. Finally, during the 1980’s and 90s, more invasive species began to appear in the Great Lakes , causing another shift in the fish community.
Dettmers at al. (2012) assert that managers must make a decision to manage for economic returns and continue to support the Pacific salmon fishery or manage for ecosystem sustainability and support rehabilitation of native fishes. The authors offer a short list of factors contributing to this dilemma. One, alewife suppress lake trout and other native fishes (see my earlier blog post on the effects of alewife). Two, the invasion of zebra and quagga mussels Dreissena sp. has led to a decline in the zooplankton that support alewife populations. Three, the invasion of zebra and quagga mussels has left the resources that support benthic-oriented native fishes intact. So overall, the ecosystem is shifting from a state that is good for the salmon fishery to a state that is good for native fishes. But the fourth factor is the political power of recreational anglers. The popularity and economic value (estimated at $7 billion annually) of the salmon fishery has given recreational anglers, who demand maintenance of the alewife population to support the salmon fishery, strong political influence. Dettmers et al. (2012) argue that because it is hard to balance alewife production and predatory demand of salmon in a constantly shifting ecosystem, managers might increase emphasis on rehabilitation of native stocks. The authors admit this is speculation and it is unknown how fishery managers will act in the future. However, they do suggest that ongoing changes to the ecosystem may make the decision for managers.
Implications for anglers
Fishery managers are in a bind, and instead of making a tough choice over two options they are trying to do both: maintain the Pacific salmon fishery while attempting to restore native fish populations. However, there is already evidence that local experts are leaning towards making a change in the Lake Michigan fishery. A recent article in the Journal Sentinel highlighted a presentation by UW-Milwaukee professor of fisheries ecology John Janssen called “A new paradigm for the Lake Michigan fishery” at the Lake Michigan Fisheries Forum. In the presentation, Janssen suggested that anglers should start to give consideration to fishing for native species. Also, in a Fox11 news report in June, U.S. Fish and Wildlife fisheries biologists saw evidence of natural reproduction during a lake trout survey off of Sheboygan Lake Michigan fishery might change from Pacific salmon to native fishes such as lake trout, yellow perch perca flavescens, lake whitefish Coregonus clupeaformis and cisco Coregonus artedi. However, one of the first lessons for fisheries students is that fisheries management isn’t about managing fish, it’s about managing people. As long as people, and their dollars, continue to demand a Pacific salmon fishery, management is not likely to make any drastic changes to the fishery.
Should managers find an opening to make the switch to native fishes, I don’t think it will be all that bad. Lake trout, if given the chance, can get as big as Chinook salmon. The influx of invasive species and competitors has just prevented them from doing so. Once the alewife and the salmon are gone, anglers looking to catch big fish will find lake trout that meet their desire. Anglers looking for fish to eat will still have all the native fishes they’ve always enjoyed, no salmon though. And I’m not convinced that salmon will disappear once they are no longer stocked into Lake Michigan . There is evidence of salmon naturally reproducing in the lake (in its tributaries, actually), stocking is just needed to make these populations viable fisheries. And the alewife isn’t going away, so there will always be food for these fish. So small salmon populations will continue to exists, but catches will be rare. Anglers will have to think of the salmon fishery like the musky fishery. One benefit of a native fishes-based fishery is that the fishery will be more stable, as native fishes will be more resilient to ecological changes over time. So you will no longer have the boom and bust cycles currently seen in the salmon fishery. Another benefit is that it will be cheaper to maintain a native fish-based fishery. There will no longer be the need to stock fish, one of the biggest costs of managing the fishery, so the cost of a fishing license could go down and there would be no need for stamps. And finally, as the fishery transition from Pacific salmon to native fishes, changes in the economic model will occur. But a fishery will comeback and those savvy enough to adapt to the changes will be in good position to make money exploiting the fisheries of Lake Michigan . There will be a hiccup in the economic benefits the lake gives to the area, but those benefits will return and be more stable.
Dettmers, J.M., C.I. Goddard, K.D. Smith. 2012. Management of alewife using Pacific salmon in the Great Lakes : Whether to manage for economics or the ecosystem. Fisheries. 37:495-501.
Selected definitions
Coregonine- fish of the freshwater whitefish subfamily
Benthic- the ecological zone at the lowest level of a body of water
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