Effects of Stream Type and Extreme Flow Events on Riverine Ecosystems and Salmon in Southeast Alaska
Streams in Southeast Alaska are changing rapidly due to climate change. Warmer temperatures are bringing more rain, less snow, and causing glaciers to retreat, all of which affects stream flow and food sources for young salmon. Researchers supported by this Alaska CASC project will study whether juvenile salmon can adapt by moving between different types of streams (including rain-, snow-, or glacier-fed streams) to find food. The resulting data about salmon behavior, movement, and growth can help resource managers predict how climate change may affect salmon and support better tools for managing salmon populations and protecting food security, culture, and ecosystems in Southeast Alaska.
Project Summary
High latitude northern ecosystems are rapidly warming, leading to shifts in watershed hydrologic cycles. In Southeast Alaska (SEAK), climate change is expected to bring more rain, less snow at sea level, and cause glaciers to retreat —leading to more frequent high streamflow events and flooding, as well as longer and more severe dry periods. These changes could affect stream food webs that support salmon populations, which are critical for food security and the culture of coastal communities.
Previous CASC-funded research helped this research team understand the how different types of streams – (glacier-, snow-, and rain-fed streams) and stream flows (high and low flows) provide distinct foraging opportunities for young salmon. However, whether this could benefit young salmon that move between stream types, or even if young salmon can actually move between stream types is unknown.
This project will conduct three follow-up studies to address knowledge gaps and synthesize current research: Study 1 will synthesize current knowledge about how shifting stream conditions in SEAK watersheds impacts salmon and their food sources; Study 2 will assess how periods of extreme high and low flows impact juvenile salmon behavior, movement, and foraging success; Study 3 will quantify the growth and movement of young salmon to determine whether they move between streams with distinct flow regimes, tracking distinct feeding opportunities previously documented in glacier-, snow-, and rain-fed streams.
The outcomes of these studies will produce new data on fish behavior, stream food webs, and climate-driven changes to freshwater ecosystems. These data can be used to refine predictive models that explore the impacts of climate change on salmon population in SEAK. By better understanding how climate change will affect salmon in Southeast Alaska, this research can help inform fisheries management, habitat restoration, and conservation strategies, which is critical for communities that depend on healthy salmon runs for food, culture, and economic well-being.
- Source: USGS Sciencebase (id: 6724d247d34e4f57573f26ed)
Streams in Southeast Alaska are changing rapidly due to climate change. Warmer temperatures are bringing more rain, less snow, and causing glaciers to retreat, all of which affects stream flow and food sources for young salmon. Researchers supported by this Alaska CASC project will study whether juvenile salmon can adapt by moving between different types of streams (including rain-, snow-, or glacier-fed streams) to find food. The resulting data about salmon behavior, movement, and growth can help resource managers predict how climate change may affect salmon and support better tools for managing salmon populations and protecting food security, culture, and ecosystems in Southeast Alaska.
Project Summary
High latitude northern ecosystems are rapidly warming, leading to shifts in watershed hydrologic cycles. In Southeast Alaska (SEAK), climate change is expected to bring more rain, less snow at sea level, and cause glaciers to retreat —leading to more frequent high streamflow events and flooding, as well as longer and more severe dry periods. These changes could affect stream food webs that support salmon populations, which are critical for food security and the culture of coastal communities.
Previous CASC-funded research helped this research team understand the how different types of streams – (glacier-, snow-, and rain-fed streams) and stream flows (high and low flows) provide distinct foraging opportunities for young salmon. However, whether this could benefit young salmon that move between stream types, or even if young salmon can actually move between stream types is unknown.
This project will conduct three follow-up studies to address knowledge gaps and synthesize current research: Study 1 will synthesize current knowledge about how shifting stream conditions in SEAK watersheds impacts salmon and their food sources; Study 2 will assess how periods of extreme high and low flows impact juvenile salmon behavior, movement, and foraging success; Study 3 will quantify the growth and movement of young salmon to determine whether they move between streams with distinct flow regimes, tracking distinct feeding opportunities previously documented in glacier-, snow-, and rain-fed streams.
The outcomes of these studies will produce new data on fish behavior, stream food webs, and climate-driven changes to freshwater ecosystems. These data can be used to refine predictive models that explore the impacts of climate change on salmon population in SEAK. By better understanding how climate change will affect salmon in Southeast Alaska, this research can help inform fisheries management, habitat restoration, and conservation strategies, which is critical for communities that depend on healthy salmon runs for food, culture, and economic well-being.
- Source: USGS Sciencebase (id: 6724d247d34e4f57573f26ed)