Climate change has already dramatically altered many inland waters through a combination of warming water, changes in phenology, and alterations to aquatic food webs. All of these forces can alter the growth, reproduction, survival, and behavior of fishes. Because these changes can influence fishes’ complex interactions with their habitat, predators, prey, and competitors, climate change can cause shifts in fish community composition that are difficult to prevent or reverse. Yet fishes also have the capacity to adapt to a changing environment through, for example, use of thermal refugia or changes in diet and habitat use. These adaptations may buffer the direct effects of climate change on fish populations, but may also involve trade-offs - e.g., thermal refugia may have few prey resources. For fish species targeted by recreational, commercial, Tribal, or subsistence fisheries, changes in fishing behaviors may further challenge our ability to understand and predict climate change impacts. For example, as many coolwater fishes face climate-driven declines in productivity, will fishers switch to targeting warmwater species and thus provide coolwater species with a compensatory reduction in fishing mortality? And how might managers encourage and leverage such stabilizing social-ecological feedbacks in order to confer greater resilience on harvested fish populations under climate change?
This session will integrate research from a broad range of disciplinary perspectives seeking to understand the impacts of climate change on inland fish and fisheries. We welcome submissions focused on all mechanisms by which climate change is altering the biology, ecology, or fisheries of inland fishes. We also welcome talks that address management of inland fisheries under climate change and the social or economic consequences of climate change impacts.
Lead Organizer: Olaf Jensen, Center for Limnology, University of Wisconsin-Madison (olaf.p.jensen@gmail.com)
Co-organizers:
Ashley Trudeau, Center for Limnology, University of Wisconsin-Madison (ashley.trudeau@gmail.com)
Zachary Feiner, Center for Limnology, University of Wisconsin-Madison and Wisconsin Department of Natural Resources (Zachary.Feiner@wisconsin.gov)
Presentations
09:00 AM
An Introduction to the Climate Adaptation Science Centers Fish Research Program: highlighting large-scale, data-driven approaches to understand climate impacts on inland fisheries (7723)
Primary Presenter: Holly Embke, U.S. Geological Survey (hembke@usgs.gov)
The U.S. Geological Survey Climate Adaptation Science Centers (CASC) Fish Research Program is a dynamic group working collaboratively to explore the impacts of climate and other stressors on fish and aquatic systems to inform conservation and climate adaptation. We work collaboratively with diverse partners to ensure research can be directly used by resource managers and conservation practitioners to inform fisheries management. We include partners in every stage of the scientific process, specifically designing their projects to address pressing management challenges and fill in knowledge gaps. We work with everyone from individual anglers and Indigenous communities up to large professional networks, purposefully collaborating with diverse voices to create new and innovative approaches. Here, we highlight three large-scale, data-driven initiatives led by the CASC fish team to demonstrate examples of ongoing, co-produced work conducted at global and national scales. All of this work seeks to inform the sustainable and equitable use of inland fisheries in a changing climate.
09:15 AM
Smaller wins, bigger losses: asymmetric impacts of climate change on preferred thermal habitat of temperate lake fish (8169)
Primary Presenter: Luoliang Xu, University of Wisconsin-Madison (lxu287@wisc.edu)
Climate change is reshaping aquatic ecosystems and affecting fish populations. Our study focused on tracking the "preferred days" for lake fish species—days when lake temperatures align with their preferred thermal conditions. We found that cold-water species are losing preferred days more significantly than warm-water species are gaining them from 1980~2021. This imbalance is not a result of geographic distribution differences among species but is tied to the seasonal pattern in lake temperatures and the decreasing temperature differences within lakes. This uneven impact poses a challenge for fisheries management, indicating that the potential advantages of an increase in warm-water species might not fully compensate for the losses in cold-water species. This emphasizes the intricate challenges climate change presents to fisheries management.
09:30 AM
LAKE BROWNING EXACERBATES LOSS OF COLD-WATER FISH HABITAT ASSOCIATED WITH WARMING (8052)
Primary Presenter: Stephen Jane, University of Notre Dame (coachman7777@yahoo.com)
Surface warming is reducing oxythermal habitat for cold-water organisms. Lakes in many regions are also undergoing increasing dissolved organic carbon (DOC) concentrations, a process commonly referred to as “browning”. Browning is associated with both expanded cold-water volumes and reduced bottom-water dissolved oxygen (DO) during warm seasons. Expanded cold water could benefit cold-water species, which often retreat to cooler depths during summer. Yet, to serve as thermal refugia cold water must be sufficiently oxygenated. We sought to understand whether browning mitigates or exacerbates the effects of climate warming for cold-water fishes. We outfitted 15 Adirondack region lakes in New York State with high frequency temperature and DO loggers during one open-water season. Using published temperature and oxygen tolerances for cold-water brook trout, we assessed the amount of suitable oxythermal habitat and related this to DOC concentrations. Browning compressed the depth of thermally stressful surface water while shallowing the depth of low-oxygen water. In very clear lakes, limited browning expands suitable habitat. However, beyond moderate DOC concentrations, browning constricts suitable habitat; shallowing of oxygen-depleted water outpaces compression of warm water in most cases. Applying our fitted relationships to a database of 1,476 Adirondack lakes, we find that for ~ 95% of Adirondack lakes, further browning will exacerbate the loss of cold-water habitat as warming continues, reducing the available habitat for economically and ecologically important fishes.
09:45 AM
WISCONSIN’S EVOLVING MANAGEMENT RESPONSES TO OBSERVED AND PROJECTED DECLINES IN TWO VALUED SPORTFISH POPULATIONS (8376)
Primary Presenter: Alexander Latzka, Wisconsin Department of Natural Resources (alexander.latzka@wisconsin.gov)
Wisconsin’s waters are warming, and some iconic sportfish populations are struggling to adapt. Complexities in these declines and their sociopolitical contexts hinder easy solutions, especially across large scales. In Wisconsin, these issues are playing out most prominently with two native, highly valued sportfish – walleye and brook trout. The prevailing response has been to resist these declines through both traditional and experimental fisheries management techniques. Strategies that accept climate-driven changes or that direct fisheries to new, desired states have been rare. Recently, however, the magnitude and scope of climate-induced changes have stimulated both strategic long-term thinking about smarter resistance, and how, where, and when to adopt accept or direct strategies. For brook trout, we are beginning to target resources toward watersheds most likely to sustain brook trout in a warmer climate, hoping to increase resistance effectiveness. For walleye, resistance efforts have been wide-ranging, with recent intensive targeted rehabilitation efforts in critical ecosystems. Simultaneously, we are developing conceptual frameworks to help guide shifts to alternative strategies, and are beginning structured decision-making processes to inform how we can best meet multiple objectives that are inherently difficult to achieve and complex to implement. Insights from these efforts may be useful to many climate adaptation problems in fisheries and aquatic ecosystems.
SS36A - Climate Change Impacts on Inland Fish and Fisheries
Description
Time: 9:00 AM
Date: 5/6/2024
Room: Hall of Ideas I