Lake Trout Biochronologies as Long-term Climate and Productivity Indicators in Alaska Lake Ecosystems
High latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments.
Return to Wildlife, Fish, and Habitats >> Fish and Aquatic Ecology
To address this issue we have applied dendrochronology (tree-ring analysis) techniques to growth-increment widths in otoliths from lake trout (Salvelinus namaycush). We have developed a growth record for lake trout from the Chandler Lake system in Gates of the Arctic National Park and Preserve and are currently working on a similar effort in Lake Clark National Park. Sockeye salmon are a keystone species within Lake Clark National Park and Preserve, which was established “..to protect the watershed necessary for the perpetuation of the red [sockeye] salmon fishery in Bristol Bay.” Numerous lakes in Lake Clark National Park are important salmon nurseries that are sensitive to climate change, and increasing temperatures may lead to profound changes in productivity by altering the timing of ice break-up, the timing and duration of thermal stratification, and the timing and intensity of nutrient upwelling. Given that these high-latitude landscapes are among the most likely to experience rapid climate change in the coming decades, the relationships between lake biology and climate variability must be better quantified to forecast impacts on the productivity of sockeye salmon and resident fishes. To address the implications of climate variability in lakes for fish, we borrow from the tree-ring sciences to develop multidecadal chronologies from lake trout otoliths. Just as tree-ring data capture histories of climate and productivity in terrestrial systems, we propose that lake trout otolith data will provide analogous information for lake ecosystems. A particular strength of this study is that final trout chronologies will be exactly dated, allowing us to make high quality comparisons with direct observations of climate (instrumental records) and biology (salmon escapement). Thus, we are developing lake trout otolith chronologies in lake ecosystems of Lake Clark National Park and Preserve to i) quantify long-term effects of climate on growth, ii) evaluate the influence of marine-derived nutrient input from sockeye salmon returns, and iii) compare long-term rates of change in freshwater and terrestrial ecosystems using lake trout and tree-ring chronologies.
Below are other science projects associated with this project.
Fish and Aquatic Ecology
Assessing heat stress in migrating Yukon River Chinook Salmon
Nearshore Fish Surveys in the Beaufort Sea
Condition of Forage Fish in Prince William Sound During the Marine Heatwave
Winter Habitat of Juvenile Dolly Varden in the Canning River
Arctic Lake Food Webs
Ecosystem Shifts in Arctic Seas
Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Effect of Elodea spp. on Fish Performance Mediated Through Food Web Interactions
Sockeye Salmon Migrating at the Northern Edge of Their Distribution
High latitude ecosystems are among the most vulnerable to long-term climate change, yet continuous, multidecadal indicators by which to gauge effects on biology are scarce, especially in freshwater environments.
Return to Wildlife, Fish, and Habitats >> Fish and Aquatic Ecology
To address this issue we have applied dendrochronology (tree-ring analysis) techniques to growth-increment widths in otoliths from lake trout (Salvelinus namaycush). We have developed a growth record for lake trout from the Chandler Lake system in Gates of the Arctic National Park and Preserve and are currently working on a similar effort in Lake Clark National Park. Sockeye salmon are a keystone species within Lake Clark National Park and Preserve, which was established “..to protect the watershed necessary for the perpetuation of the red [sockeye] salmon fishery in Bristol Bay.” Numerous lakes in Lake Clark National Park are important salmon nurseries that are sensitive to climate change, and increasing temperatures may lead to profound changes in productivity by altering the timing of ice break-up, the timing and duration of thermal stratification, and the timing and intensity of nutrient upwelling. Given that these high-latitude landscapes are among the most likely to experience rapid climate change in the coming decades, the relationships between lake biology and climate variability must be better quantified to forecast impacts on the productivity of sockeye salmon and resident fishes. To address the implications of climate variability in lakes for fish, we borrow from the tree-ring sciences to develop multidecadal chronologies from lake trout otoliths. Just as tree-ring data capture histories of climate and productivity in terrestrial systems, we propose that lake trout otolith data will provide analogous information for lake ecosystems. A particular strength of this study is that final trout chronologies will be exactly dated, allowing us to make high quality comparisons with direct observations of climate (instrumental records) and biology (salmon escapement). Thus, we are developing lake trout otolith chronologies in lake ecosystems of Lake Clark National Park and Preserve to i) quantify long-term effects of climate on growth, ii) evaluate the influence of marine-derived nutrient input from sockeye salmon returns, and iii) compare long-term rates of change in freshwater and terrestrial ecosystems using lake trout and tree-ring chronologies.
Below are other science projects associated with this project.