Designing a Climate Change Decision-Support Tool for Great Lakes Whitefish
Currently, the Great Lakes whitefish fishery is the most economically valuable commercial fishery in the upper Great Lakes. But, this fishery could face new rules of the game as the climate continues to change. This research project is focused on developing a decision-support tool to ensure that the fish and fishery — and the livelihoods that depend upon them — remain sustainable.
About Lake Whitefish
Lake whitefish, a member of the salmon family, are found in coldwater lakes throughout much of northern North America. Like many salmon species, they are highly valued as food fish. They are versatile and can be used in a variety of ways, including fresh fillets, smoked fillets, frozen fillets, fish cakes, spread and sausage. Lake whitefish have been a staple of native communities in the Great Lakes for thousands of years and were a particular favorite of early French explorers — one even wrote that “a better fish cannot be eaten!” They are a favorite still today; more than 15 million pounds of lake whitefish are consumed each year in the Great Lakes region alone.
To learn more about lake whitefish, see: Species Profile
The Journey to Adulthood
To reach someone’s dinner plate, a lake whitefish must survive a treacherous journey from egg to larvae, to juvenile, and finally to an adult life phase. When a whitefish reaches adult stage or is large enough to catch and keep, it is referred to as “a recruit to the fishery.”
Ultimately, managers want to know how many lake whitefish enter the fishery so that they can determine how many can be harvested without negatively impacting future populations and harvest. But, it is impossible to know how many lake whitefish are actually out there. So, the population is estimated using mathematical modeling. Including biologically relevant variables in the model can often improve our ability to predict fish populations.
This research, performed by Michigan State University Ph.D. student Abigail Lynch and adviser Bill Taylor, professor of fisheries and wildlife at Michigan State University and associate director of Michigan Sea Grant, examines which climate factors influence recruitment of lake whitefish to the commercial fishery. Because lake whitefish spawn in the fall and hatch as larvae in the spring, these time periods are critical to the survival of lake whitefish. Preliminary results indicate that fall and spring water temperatures are particularly important influences on lake whitefish populations.
The relationship between water temperatures and lake whitefish recruitment has significant implications for the fishery in the context of climate change. Climate change is expected to increase surface water temperatures of the Great Lakes by as much as 7o F. The positive relationship between spring temperatures and recruitment (survival) suggests a potential for increased lake whitefish production in the Great Lakes, if food resources are available for larval lake whitefish. However, the negative relationship between fall temperatures and recruitment (survival), possibly reflective of increased storm events, may inhibit egg survival and lake whitefish production.
These potential changes in lake whitefish populations have significant repercussions for fishermen and the communities dependent upon this fishery. This research is aimed at helping the lake whitefish fishery adapt to anticipated climate change.
Decision-support tools help guide decisions by incorporating information, accounting for uncertainties, or evaluating trade-offs between alternative choices. A Global Positioning System (GPS) unit is one everyday example of such a tool. A GPS unit helps a driver decide the best navigation path to reach his or her destination based on criteria determined by the driver (e.g., shortest time, avoidance of traffic jams, shortest distance).
The same rationale can apply to fisheries management. The goal of fisheries management is sustainable use of a given fishery resource (i.e., continued use with minimal ecological impact). Scientific research, historically external to this decision-making process, can provide information to assist with these decisions if reliable information is available and clearly articulated to the policy makers. Decision-support tools can help present the science in a context of management needs.
Learn more: Decision-support Tool