Fish Ecologist Mike Carey studies the impacts beavers have on warming Alaskan permafrost landscapes.
The range expansion of the North American beaver (Castor canadensis) has implications for water quality, aquatic ecosystems, and fisheries in Arctic streams.
Return to Ecosystems >> Fish and Aquatic Ecology
Landscape change in the Arctic has altered the historical range and distribution of terrestrial mammals, including moose and snowshoe hares, which have moved northward into tundra ecosystems during the 20th century. Recent field and remote sensing observations indicate that beavers (Castor canadensis) have also expanded their range from boreal forest to tundra ecosystems over the past 15 to 30 years. Extensive research from boreal and temperate regions show that beavers dramatically alter stream hydrology and water quality by building dams, creating impoundments, and modifying the transport of particulates and solutes downstream of the dam. However, little is known about beaver impacts to streams and rivers draining arctic tundra catchments, and how changing environmental conditions or management practices are driving beaver range expansion.
Compared to impacts in other regions and biomes, beaver range expansion in tundra ecosystems is unique as impoundments from beaver dams triggers rapid permafrost thaw due to inundation of valley bottom soils. Permafrost stores large reservoirs of organic carbon (C), nutrients, and mercury (Hg) in perennially frozen soils. Permafrost degradation will impact terrestrial and aquatic ecosystems by altering catchment hydrology, water temperatures and biogeochemical processes. Soil inundation increases wetland extent, which is critical for the production of dissolved organic C and the formation of toxic methylmercury. Further, enhanced hydrologic connectivity following inundation drives the mobilization of these constituents to surface waters and downstream ecosystems, where they can alter water quality and be taken up by stream food webs. Beaver dams may impact fish directly by restricting migration and movement or altering habitat for foraging and spawning, and indirectly by altering water quality through the release of C, nutrients and Hg from inundated permafrost soils. The more variable aquatic thermal habitat created by beavers may also have positive impacts on fish species. Ponded water may lead to warmer stream temperatures, providing greater unfrozen habitat in winter and warmer and more constant water temperatures throughout the year.
![Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >2 5rKM from coast](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/Rabbit%20Creek%20BP4_Mike%20and%20Fish.jpg?itok=LSB0el-u)
![Beaver dams on Rabbit Creek, Cape Krusenstern National Monument](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/Rabbit%20Creek%20BP2_complex%20photo%20from%20bluff_2.jpg?itok=Wev7M9Qh)
Below are other science projects associated with this project.
Fish and Aquatic Ecology
Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Below are multimedia items associated with this project.
![Climate Science Champions, Season 1: Mike Carey, Research Fish Ecologist Misty pine trees overlaid with photo of smiling white man in a red and white striped beanie](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/Climate%20Champions_Michael%20Carey.png?itok=pPoZlkDO)
Fish Ecologist Mike Carey studies the impacts beavers have on warming Alaskan permafrost landscapes.
Beaver dam and lodge on the Wrench Creek, Noatak National Preserve
Beaver dam and lodge on the Wrench Creek, Noatak National Preserve
Beaver dam complex and lodge at the confluence of Wrench Creek and Kelly River, Noatak National Preserve
Beaver dam complex and lodge at the confluence of Wrench Creek and Kelly River, Noatak National Preserve
![Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >2 5rKM from coast](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Rabbit%20Creek%20BP4_Mike%20and%20Fish.jpg?itok=2ykLL4Hk)
Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >25 rKM (river KM) from coast.
Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >25 rKM (river KM) from coast.
Measuring temperature and dissolved oxygen in impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Measuring temperature and dissolved oxygen in impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Arctic grayling (Thymallus arcticus) and Dolly varden (Salvelinus malma) from impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Arctic grayling (Thymallus arcticus) and Dolly varden (Salvelinus malma) from impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Gnawed tree from beaver activity on tributary of the Agashashok River, Noatak National Preserve
Gnawed tree from beaver activity on tributary of the Agashashok River, Noatak National Preserve
![Beaver dams on Rabbit Creek, Cape Krusenstern National Monument](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Rabbit%20Creek%20BP2_complex%20photo%20from%20bluff_2.jpg?itok=ugM1R3Sj)
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dam crossing mainstem of Rabbit Creek near the headwaters, Cape Krusenstern National Monument
Beaver dam crossing mainstem of Rabbit Creek near the headwaters, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
![Beaver dams on Rabbit Creek, Cape Krusenstern National Monument](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Rabbit%20Creek%20BP1%20Pond_3.jpg?itok=Rm40ndD1)
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver swimming near dam on Rabbit Creek, Cape Krusenstern National Monument
Beaver swimming near dam on Rabbit Creek, Cape Krusenstern National Monument
Measuring the amount of water impounded by a beaver dam on Rabbit Creek, Cape Krusenstern National Monument.
Measuring the amount of water impounded by a beaver dam on Rabbit Creek, Cape Krusenstern National Monument.
Impounded water above beaver dam on the Wrench Creek, Noatak National Preserve
Impounded water above beaver dam on the Wrench Creek, Noatak National Preserve
Beaver lodge and drained impoundment in tributary of the Noatak River, Noatak National Preserve
Beaver lodge and drained impoundment in tributary of the Noatak River, Noatak National Preserve
Beaver dam and lodge on the Ahaliknak Creek, Noatak National Preserve
Beaver dam and lodge on the Ahaliknak Creek, Noatak National Preserve
Publications related to this project.
Comparing sediment microbial communities of Arctic beaver ponds to tundra lakes and streams
How beavers are changing Arctic landscapes and Earth’s climate
The range expansion of the North American beaver (Castor canadensis) has implications for water quality, aquatic ecosystems, and fisheries in Arctic streams.
Return to Ecosystems >> Fish and Aquatic Ecology
Landscape change in the Arctic has altered the historical range and distribution of terrestrial mammals, including moose and snowshoe hares, which have moved northward into tundra ecosystems during the 20th century. Recent field and remote sensing observations indicate that beavers (Castor canadensis) have also expanded their range from boreal forest to tundra ecosystems over the past 15 to 30 years. Extensive research from boreal and temperate regions show that beavers dramatically alter stream hydrology and water quality by building dams, creating impoundments, and modifying the transport of particulates and solutes downstream of the dam. However, little is known about beaver impacts to streams and rivers draining arctic tundra catchments, and how changing environmental conditions or management practices are driving beaver range expansion.
Compared to impacts in other regions and biomes, beaver range expansion in tundra ecosystems is unique as impoundments from beaver dams triggers rapid permafrost thaw due to inundation of valley bottom soils. Permafrost stores large reservoirs of organic carbon (C), nutrients, and mercury (Hg) in perennially frozen soils. Permafrost degradation will impact terrestrial and aquatic ecosystems by altering catchment hydrology, water temperatures and biogeochemical processes. Soil inundation increases wetland extent, which is critical for the production of dissolved organic C and the formation of toxic methylmercury. Further, enhanced hydrologic connectivity following inundation drives the mobilization of these constituents to surface waters and downstream ecosystems, where they can alter water quality and be taken up by stream food webs. Beaver dams may impact fish directly by restricting migration and movement or altering habitat for foraging and spawning, and indirectly by altering water quality through the release of C, nutrients and Hg from inundated permafrost soils. The more variable aquatic thermal habitat created by beavers may also have positive impacts on fish species. Ponded water may lead to warmer stream temperatures, providing greater unfrozen habitat in winter and warmer and more constant water temperatures throughout the year.
![Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >2 5rKM from coast](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/Rabbit%20Creek%20BP4_Mike%20and%20Fish.jpg?itok=LSB0el-u)
![Beaver dams on Rabbit Creek, Cape Krusenstern National Monument](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/Rabbit%20Creek%20BP2_complex%20photo%20from%20bluff_2.jpg?itok=Wev7M9Qh)
Below are other science projects associated with this project.
Fish and Aquatic Ecology
Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Below are multimedia items associated with this project.
![Climate Science Champions, Season 1: Mike Carey, Research Fish Ecologist Misty pine trees overlaid with photo of smiling white man in a red and white striped beanie](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/Climate%20Champions_Michael%20Carey.png?itok=pPoZlkDO)
Fish Ecologist Mike Carey studies the impacts beavers have on warming Alaskan permafrost landscapes.
Fish Ecologist Mike Carey studies the impacts beavers have on warming Alaskan permafrost landscapes.
Beaver dam and lodge on the Wrench Creek, Noatak National Preserve
Beaver dam and lodge on the Wrench Creek, Noatak National Preserve
Beaver dam complex and lodge at the confluence of Wrench Creek and Kelly River, Noatak National Preserve
Beaver dam complex and lodge at the confluence of Wrench Creek and Kelly River, Noatak National Preserve
![Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >2 5rKM from coast](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Rabbit%20Creek%20BP4_Mike%20and%20Fish.jpg?itok=2ykLL4Hk)
Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >25 rKM (river KM) from coast.
Adult Pacific salmon (Oncorhynchus nerka) caught in impounded water above beaver dam. >25 rKM (river KM) from coast.
Measuring temperature and dissolved oxygen in impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Measuring temperature and dissolved oxygen in impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Arctic grayling (Thymallus arcticus) and Dolly varden (Salvelinus malma) from impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Arctic grayling (Thymallus arcticus) and Dolly varden (Salvelinus malma) from impounded water of beaver dam on the Wrench Creek, Noatak National Preserve.
Gnawed tree from beaver activity on tributary of the Agashashok River, Noatak National Preserve
Gnawed tree from beaver activity on tributary of the Agashashok River, Noatak National Preserve
![Beaver dams on Rabbit Creek, Cape Krusenstern National Monument](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Rabbit%20Creek%20BP2_complex%20photo%20from%20bluff_2.jpg?itok=ugM1R3Sj)
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dam crossing mainstem of Rabbit Creek near the headwaters, Cape Krusenstern National Monument
Beaver dam crossing mainstem of Rabbit Creek near the headwaters, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
![Beaver dams on Rabbit Creek, Cape Krusenstern National Monument](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Rabbit%20Creek%20BP1%20Pond_3.jpg?itok=Rm40ndD1)
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver dams on Rabbit Creek, Cape Krusenstern National Monument
Beaver swimming near dam on Rabbit Creek, Cape Krusenstern National Monument
Beaver swimming near dam on Rabbit Creek, Cape Krusenstern National Monument
Measuring the amount of water impounded by a beaver dam on Rabbit Creek, Cape Krusenstern National Monument.
Measuring the amount of water impounded by a beaver dam on Rabbit Creek, Cape Krusenstern National Monument.
Impounded water above beaver dam on the Wrench Creek, Noatak National Preserve
Impounded water above beaver dam on the Wrench Creek, Noatak National Preserve
Beaver lodge and drained impoundment in tributary of the Noatak River, Noatak National Preserve
Beaver lodge and drained impoundment in tributary of the Noatak River, Noatak National Preserve
Beaver dam and lodge on the Ahaliknak Creek, Noatak National Preserve
Beaver dam and lodge on the Ahaliknak Creek, Noatak National Preserve
Publications related to this project.