Climate change is altering glacial lake fisheries in the Upper Midwest region of the United States, presenting a complex challenge for fisheries managers.
This menu provides a regional perspective to guide the management of heterogeneous and yet interdependent fishery resources in glacial lakes of the upper Midwest. The main objective is to promote the adaptation of inland glacial lake fisheries management to climate change by outlining processes that support regional plans.
Using examples from the glacial lakes region, approaches are outlined for regional prioritization, strategies are specified for moving from regional prioritization to on-the-ground action, and guidance is provided on the implementation of management plans given resource limitations and potential stakeholder conflict.
Integrating ecological, social, and economic data with climate change vulnerability assessments can be useful in generating “lake-priority levels” to help identify where to focus actions to support system resilience. Managers can use lake-priority levels and ecosystem-specific strategies to make decisions about where and when to apply fisheries management action ranging from traditional (i.e., stocking, harvest regulations) to nontraditional approaches (i.e., catchment land management).
Although the implementation of several approaches may be beyond an agency’s financial and logistical capacity, funds can be secured through other sources ranging from grant programs to nontraditional partnerships identified by “thinking outside the lake.” Regional plans may be an important step toward successful climate adaptation for inland glacial lakes fisheries management, and the proactive efforts of managers may help facilitate their development and implementation.
Effects from Climate Change
In the upper Midwestern United States, climate change is anticipated to lead to warmer air temperatures, higher intensity precipitation, and prolonged drought. These changes are likely to strongly influence inland glacial lake fishes and the ecosystem services they support. For example, increases in temperature have already contributed to abundance declines and extirpations of native, coldwater cisco Coregonus artedi, and further projected habitat loss will disrupt food webs and ecosystem function in many lakes. Increased temperature is also a plausible driver of declines in recruitment and production of walleye Sander vitreus in Wisconsin lakes. Current projections indicate additional loss of self-sustaining walleye populations, threatening the persistence of the most popular fishery among multiple user groups. Widespread shifts toward species assemblages dominated by tolerant, warmwater fishes have also been observed and are likely to continue, further disrupting a recreational fishing industry that generates billions of US dollars annually.
Adaptation in Action
To promote the adaptation of inland glacial lakes fisheries management to climate change processes are outlined that support the development and operationalization of regional plans. First a regional prioritization approach is described that accounts for the relative interdependency and heterogeneity of inland glacial lake fisheries and concepts are integrated from existing climate adaptation tools. This approach consists of (1) defining a regional goal, (2) assessing climate vulnerability, and (3) prioritizing lakes. Second, ecosystem-specific strategies and approaches are presented, that when paired with regional prioritizations, can be used to help plan on-the-ground action.
This Inland Glacial Lakes Fisheries Adaptation Menu is designed to be used as a stand-alone resource, and it can also be used to supplement structured adaptation planning with the Adaptation Workbook process (published in Forest Adaptation Resources: Climate Change Tools and Approaches for Land Managers).
Strategies and approaches
The 5 strategies, 13 approaches, and 50+ tactics were developed through an assessment of existing adaptation tools, focus group discussions, and workshops with natural resource professionals.
Adaptation strategies are very general and can be applied in many ways across different ecosystems and cultural contexts. Adaptation approaches are more specific, describing in greater detail how strategies could be put into practice.
These strategies and approaches are designed to serve as stepping stones to allow natural resource managers and planners to translate broad concepts into targeted and specific actions (tactics) for putting climate change adaptation into practice to achieve a specific management objective in a specific location.
Example tactics are provided in the menu as illustrations of a few of the possible actions that could implemented for climate adaptation.
Below is an example of how climate change adaptation strategies, approaches, and potential tactics work together.
-
Example strategy: Protect or restore access to physical habitat
Physical structure (coarse woody habitat, macrophytes, and substrate) is a second critical component of fisheries habitat. Restoring or preventing the degradation of littoral and spawning habitat in prioritized lakes may be an important approach to retaining resilient systems. In addition, increased drought may lower lake water levels and limit available spawning, foraging, and refuge habitat. Ensuring that physical habitat remains available to fishes during and following drought conditions can increase ecological resiliency within vulnerable lakes. Finally, restoring hydrologic connectivity among lakes and fluvial habitat can allow fishes to move to more suitable connected habitat under extreme conditions. In addition, populations of some potadromous fishes (e.g., walleye) may be more resilient to warming temperatures in lakes with hydrologic connectivity to naturally recruiting river populations.
-
Example approach: Ensure access to physical habitat remains under more variable and extreme precipitation regimes
Increased drought may lower lake water levels and limit available spawning, foraging, and refuge habitat. Ensuring that physical habitat remains available to fishes during and following drought conditions can increase ecological resiliency within vulnerable lakes.
-
Example tactics
- Addition of coarse woody habitat at greater depths in drought-vulnerable lakes.
- Engage agricultural landowners to promote water conservation to limit drawdowns.
- Protect coarse woody habitat stranded above water so it is available when lake levels rise.
Menu of Strategies and Approaches for Wildlife Management
-
Approach 1.1 Prevent new sources of sediment, pollutants, and nutrient runoff
Approach 1.2 Reduce sources of sediment, pollutant and nutrient runoff
Approach 1.3 Implement engineering solutions to retain habitat during periods of stress
-
Approach 2.1 Restore or prevent the degradation of littoral habitat
Approach 2.2 Ensure access to physical habitat remains under more variable and extreme precipitation regimes
Approach 2.3 Restore hydrologic connectivity among habitats
-
Approach 3.1 Reduce the chance of spread to un-impacted lakes
Approach 3.2 Control invasive species effects once introduced
-
Approach 4.1 Adjust regulations to anticipated population-level changes
Approach 4.2 Retain or promote genetic diversity
-
Approach 5.1 Facilitate transitions in response to changing conditions
Approach 5.2 Eliminate ineffective or unsustainable management actions
Approach 5.3 Facilitate shifts in stakeholder or user preference to emerging or dominant fisheries
Read more about all 5 strategies, 13 approaches, and 50+ example tactics
Citation
Tingley III, R.W., Paukert, C., Sass, G.G., Jacobson, P.C., Hansen, G.J., Lynch, A.J. and Shannon, P.D., 2019. Adapting to climate change: guidance for the management of inland glacial lake fisheries. Lake and Reservoir Management, 35(4), pp.435-452. https://doi.org/10.1080/10402381.2019.1678535
