Vanessa von Biela (USGS – ASC) examines the empty cod end of a surface trawl net while looking for fish in the Beaufort Sea, Alaska.
Does fish prey influence red-throated loon productivity?
This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success to differences in the relative abundance, composition, and nutritional content of nearshore fish communities that vary in space and time.
Return to Ecosystems >> Terrestrial Ecosystems or Fish and Aquatic Ecology
Red-throated loon (Gavia stellata) populations have declined on the North Slope of Alaska, an area requiring ongoing and new management decisions related to oil and gas development. Given that adult red-throated loons have high survival rates, the declining population suggests that reproductive success is poor. Nesting red-throated loons forage in marine waters, unlike sympatric freshwater feeding loon species with stable or increasing populations. The USGS Alaska Science Center is conducting an integrative study of fish and loons at two locations along the Beaufort Sea coast over three field years (2021–2023). This study will not only evaluate possible drivers of the decline in loon numbers on the North Slope but inform the Bureau of Ocean Management (BOEM) about loon and fish habitats.
This work will necessitate two separate, coordinated field efforts (see study area map). One field effort will take place at loon nesting sites on small coastal lakes and include installing time-lapse cameras to estimate loon breeding success, loon captures to deploy GPS transmitters to record loon movements and foraging activities, and tissue collections to assess loon diet. A second field effort will take place in the nearshore and coastal marine areas where breeding loons forage. Boat based sampling in river plume and marine waters will quantify fish catch rates and community composition along beaches and in coastal waters up to 20 m deep. All fish sampling will include concurrent measurements of temperature and salinity. A subset of fish will be sacrificed for tissue collections to support loon diet assessment.
Specific study questions include:
- What is the reproductive success of red-throated loons nesting along the Beaufort Sea coastline?
- Where are the important Beaufort Sea nearshore and offshore feeding areas for red-throated loons?
- What is the diet of red-throated loons during the breeding season?
- What is the relative quality of common fish prey?
- Is loon reproductive success related to diet composition?
- Is loon diet composition similar to the fish community composition?
- Are there differences in loon foraging activity budgets between study sites?
Below are other science projects associated with this project.
Data related to this project.
Photos related to this research project.
Vanessa von Biela (USGS – ASC) examines the empty cod end of a surface trawl net while looking for fish in the Beaufort Sea, Alaska.
A saffron cod (front, Eleginus gracilis) and an Arctic cod (behind, Boreogadus saida) from the Beaufort Sea, Alaska.
A saffron cod (front, Eleginus gracilis) and an Arctic cod (behind, Boreogadus saida) from the Beaufort Sea, Alaska.
Alaska Native Science and Engineering Program (ANSEP) student Austin Bergerson attaching a coded metal band to the leg of red-throated loon (Gavia stellata).
Alaska Native Science and Engineering Program (ANSEP) student Austin Bergerson attaching a coded metal band to the leg of red-throated loon (Gavia stellata).
Alaska Native Science and Engineering Program (ANSEP) student Jakob Sipary holds a red-throated loon on the Canning River Delta, Alaska, July 2019 as part of a USGS study on loon marine habitat use areas. Jakob was an intern for the summer with the U.S. Geological Survey.
Alaska Native Science and Engineering Program (ANSEP) student Jakob Sipary holds a red-throated loon on the Canning River Delta, Alaska, July 2019 as part of a USGS study on loon marine habitat use areas. Jakob was an intern for the summer with the U.S. Geological Survey.
Below are publications associated with this project.
Below are partners associated with this project.
This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success to differences in the relative abundance, composition, and nutritional content of nearshore fish communities that vary in space and time.
Return to Ecosystems >> Terrestrial Ecosystems or Fish and Aquatic Ecology
Red-throated loon (Gavia stellata) populations have declined on the North Slope of Alaska, an area requiring ongoing and new management decisions related to oil and gas development. Given that adult red-throated loons have high survival rates, the declining population suggests that reproductive success is poor. Nesting red-throated loons forage in marine waters, unlike sympatric freshwater feeding loon species with stable or increasing populations. The USGS Alaska Science Center is conducting an integrative study of fish and loons at two locations along the Beaufort Sea coast over three field years (2021–2023). This study will not only evaluate possible drivers of the decline in loon numbers on the North Slope but inform the Bureau of Ocean Management (BOEM) about loon and fish habitats.
This work will necessitate two separate, coordinated field efforts (see study area map). One field effort will take place at loon nesting sites on small coastal lakes and include installing time-lapse cameras to estimate loon breeding success, loon captures to deploy GPS transmitters to record loon movements and foraging activities, and tissue collections to assess loon diet. A second field effort will take place in the nearshore and coastal marine areas where breeding loons forage. Boat based sampling in river plume and marine waters will quantify fish catch rates and community composition along beaches and in coastal waters up to 20 m deep. All fish sampling will include concurrent measurements of temperature and salinity. A subset of fish will be sacrificed for tissue collections to support loon diet assessment.
Specific study questions include:
- What is the reproductive success of red-throated loons nesting along the Beaufort Sea coastline?
- Where are the important Beaufort Sea nearshore and offshore feeding areas for red-throated loons?
- What is the diet of red-throated loons during the breeding season?
- What is the relative quality of common fish prey?
- Is loon reproductive success related to diet composition?
- Is loon diet composition similar to the fish community composition?
- Are there differences in loon foraging activity budgets between study sites?
Below are other science projects associated with this project.
Data related to this project.
Photos related to this research project.
Vanessa von Biela (USGS – ASC) examines the empty cod end of a surface trawl net while looking for fish in the Beaufort Sea, Alaska.
Vanessa von Biela (USGS – ASC) examines the empty cod end of a surface trawl net while looking for fish in the Beaufort Sea, Alaska.
A saffron cod (front, Eleginus gracilis) and an Arctic cod (behind, Boreogadus saida) from the Beaufort Sea, Alaska.
A saffron cod (front, Eleginus gracilis) and an Arctic cod (behind, Boreogadus saida) from the Beaufort Sea, Alaska.
Alaska Native Science and Engineering Program (ANSEP) student Austin Bergerson attaching a coded metal band to the leg of red-throated loon (Gavia stellata).
Alaska Native Science and Engineering Program (ANSEP) student Austin Bergerson attaching a coded metal band to the leg of red-throated loon (Gavia stellata).
Alaska Native Science and Engineering Program (ANSEP) student Jakob Sipary holds a red-throated loon on the Canning River Delta, Alaska, July 2019 as part of a USGS study on loon marine habitat use areas. Jakob was an intern for the summer with the U.S. Geological Survey.
Alaska Native Science and Engineering Program (ANSEP) student Jakob Sipary holds a red-throated loon on the Canning River Delta, Alaska, July 2019 as part of a USGS study on loon marine habitat use areas. Jakob was an intern for the summer with the U.S. Geological Survey.
Below are publications associated with this project.
Below are partners associated with this project.