A bucket holds an assortment of forage-sized fishes from Lion Bay on the Beaufort Sea, Alaska. Species include saffron cod (Eleginus gracilis), Arctic cod (Boreogadus saida), fourhorn sculpin (Myoxocephalus quadricornis), and Arctic smelt (Osmerus mordax), among others.
Does fish prey influence red-throated loon productivity? Active
By Alaska Science Center
December 9, 2022
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
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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.
Sources/Usage: Public Domain. View Media Details
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?
Sources/Usage: Public Domain. View Media Details
Below are other science projects associated with this project.
Loon Research
Scientists at the USGS Alaska Science Center have conducted research on Alaska’s three loon species since the late 1970s. Loons rely on freshwater lakes for nesting habitat and fish and invertebrates inhabiting lakes and marine ecosystems for food. All three loon species in Alaska occur within the National Petroleum Reserve-Alaska (NPR-A) on Alaska’s northern coast. Research by the USGS is...
Fish and Aquatic Ecology
Fish and aquatic habitats in Alaska support important commercial, sport, and subsistence fisheries and provide forage fish that support wildlife populations. The USGS Alaska Science Center conducts interdisciplinary research to inform local, state, federal, and international policy makers regarding conservation of fish, aquatic species, and their habitats. We work collaboratively with hydrologists...
Photos related to this research project.
Filter Total Items: 25
Assortment of fishes in bucket
A bucket holds an assortment of forage-sized fishes from Lion Bay on the Beaufort Sea, Alaska. Species include saffron cod (Eleginus gracilis), Arctic cod (Boreogadus saida), fourhorn sculpin (Myoxocephalus quadricornis), and Arctic smelt (Osmerus mordax), among others.
Saffron cod and Arctic cod, Beaufort Sea, Alaska
A saffron cod (left, Eleginus gracilis) and Arctic cod (right, Boreogadus saida) sit on a measuring board for comparison.
A saffron cod (left, Eleginus gracilis) and Arctic cod (right, Boreogadus saida) sit on a measuring board for comparison.
Forage sized fishes, Beaufort Sea, Alaska
An assortment of forage sized fishes from the Beaufort Sea, Alaska lie on a measuring board.
An assortment of forage sized fishes from the Beaufort Sea, Alaska lie on a measuring board.
A fourhorn sculpin
Fourhorn sculpin, Beaufort Sea, Alaska. A fourhorn sculpin sits in a net pen underwater.
Fourhorn sculpin, Beaufort Sea, Alaska. A fourhorn sculpin sits in a net pen underwater.
Eroding and slumping shoreline, Beaufort Sea, Alaska
An eroding and slumping shoreline adjacent to a fyke net fishing site in Lion Bay, Beaufort Sea, Alaska.
An eroding and slumping shoreline adjacent to a fyke net fishing site in Lion Bay, Beaufort Sea, Alaska.
Slender eelblennys and fourhorn sculpin
Six slender eelblennys (Lumpenus fabricii) and two fourhorn sculpin (Myoxocephalus quadricornis) lie on a measuring board. Fish collected from Beaufort Sea, Alaska.
Six slender eelblennys (Lumpenus fabricii) and two fourhorn sculpin (Myoxocephalus quadricornis) lie on a measuring board. Fish collected from Beaufort Sea, Alaska.
Pacific capelin (Mallotus villosus)
A pacific capelin (Mallotus villosus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A pacific capelin (Mallotus villosus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A juvenile Dolly Varden
A juvenile Dolly Varden (Salvelinus malma) from the Beaufort Sea, Alaska, during the first summer at sea following freshwater rearing. Dolly Varden return to freshwater overwinter areas each winter because freshwater temperatures are warmer.
A juvenile Dolly Varden (Salvelinus malma) from the Beaufort Sea, Alaska, during the first summer at sea following freshwater rearing. Dolly Varden return to freshwater overwinter areas each winter because freshwater temperatures are warmer.
Deploying a CTD, Beaufort Sea, Alaska
Vanessa von Biela (USGS-ASC) deploys a CTD to measure conductivity, temperature, and density of seawater in the Beaufort Sea, Alaska.
Vanessa von Biela (USGS-ASC) deploys a CTD to measure conductivity, temperature, and density of seawater in the Beaufort Sea, Alaska.
Pulling in a surface trawl net
Vanessa von Biela (USGS – ASC) pulls in a surface trawl net in the Beaufort Sea, Alaska.
Vanessa von Biela (USGS – ASC) pulls in a surface trawl net in the Beaufort Sea, Alaska.
Fyke net, Beaufort Sea, Alaska
A fyke net is installed adjacent to Flaxman Island in the Beaufort Sea, Alaska.
A fyke net is installed adjacent to Flaxman Island in the Beaufort Sea, Alaska.
Four Arctic cod
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Two juvenile broad whitefish
Two juvenile broad whitefish (Coregonus nasus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Two juvenile broad whitefish (Coregonus nasus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A caribou stands next to a pipeline
A caribou (Rangifer tarandus) stands next to a pipeline. This photo was taken while conducting field work in Northern Alaska.
A caribou (Rangifer tarandus) stands next to a pipeline. This photo was taken while conducting field work in Northern Alaska.
Two Red-throated loons
Two Red-throated loons (Gavia stellata) in a pond near the Beaufort Sea, Alaska.
Two Red-throated loons (Gavia stellata) in a pond near the Beaufort Sea, Alaska.
Arctic smelt
Arctic smelt (Osmerus mordax), Beaufort Sea, Alaska. An Arctic smelt or rainbow smelt, (Osmerus mordax) from the Beaufort Sea, Alaska.
Arctic smelt (Osmerus mordax), Beaufort Sea, Alaska. An Arctic smelt or rainbow smelt, (Osmerus mordax) from the Beaufort Sea, Alaska.
Four Arctic cod (Boreogadus saida)
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A saffron cod
A saffron cod (Eleginus gracilis) captured in the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A saffron cod (Eleginus gracilis) captured in the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Scenic view of the Beaufort Sea, Alaska
A scenic view of the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A scenic view of the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Ice floating in the Beaufort Sea, Alaska
Chucks of ice floats in the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Chucks of ice floats in the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Surface trawl retrieval
The field crew pulls in a surface trawl net in the Beaufort Sea, Alaska on the back deck of the R/V Proteus.
The field crew pulls in a surface trawl net in the Beaufort Sea, Alaska on the back deck of the R/V Proteus.
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
Remote image Url
Sources/Usage: Public Domain. View Media Details
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.
Sources/Usage: Public Domain. View Media Details
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?
Sources/Usage: Public Domain. View Media Details
Below are other science projects associated with this project.
Loon Research
Scientists at the USGS Alaska Science Center have conducted research on Alaska’s three loon species since the late 1970s. Loons rely on freshwater lakes for nesting habitat and fish and invertebrates inhabiting lakes and marine ecosystems for food. All three loon species in Alaska occur within the National Petroleum Reserve-Alaska (NPR-A) on Alaska’s northern coast. Research by the USGS is...
Fish and Aquatic Ecology
Fish and aquatic habitats in Alaska support important commercial, sport, and subsistence fisheries and provide forage fish that support wildlife populations. The USGS Alaska Science Center conducts interdisciplinary research to inform local, state, federal, and international policy makers regarding conservation of fish, aquatic species, and their habitats. We work collaboratively with hydrologists...
Photos related to this research project.
Filter Total Items: 25
Assortment of fishes in bucket
A bucket holds an assortment of forage-sized fishes from Lion Bay on the Beaufort Sea, Alaska. Species include saffron cod (Eleginus gracilis), Arctic cod (Boreogadus saida), fourhorn sculpin (Myoxocephalus quadricornis), and Arctic smelt (Osmerus mordax), among others.
A bucket holds an assortment of forage-sized fishes from Lion Bay on the Beaufort Sea, Alaska. Species include saffron cod (Eleginus gracilis), Arctic cod (Boreogadus saida), fourhorn sculpin (Myoxocephalus quadricornis), and Arctic smelt (Osmerus mordax), among others.
Saffron cod and Arctic cod, Beaufort Sea, Alaska
A saffron cod (left, Eleginus gracilis) and Arctic cod (right, Boreogadus saida) sit on a measuring board for comparison.
A saffron cod (left, Eleginus gracilis) and Arctic cod (right, Boreogadus saida) sit on a measuring board for comparison.
Forage sized fishes, Beaufort Sea, Alaska
An assortment of forage sized fishes from the Beaufort Sea, Alaska lie on a measuring board.
An assortment of forage sized fishes from the Beaufort Sea, Alaska lie on a measuring board.
A fourhorn sculpin
Fourhorn sculpin, Beaufort Sea, Alaska. A fourhorn sculpin sits in a net pen underwater.
Fourhorn sculpin, Beaufort Sea, Alaska. A fourhorn sculpin sits in a net pen underwater.
Eroding and slumping shoreline, Beaufort Sea, Alaska
An eroding and slumping shoreline adjacent to a fyke net fishing site in Lion Bay, Beaufort Sea, Alaska.
An eroding and slumping shoreline adjacent to a fyke net fishing site in Lion Bay, Beaufort Sea, Alaska.
Slender eelblennys and fourhorn sculpin
Six slender eelblennys (Lumpenus fabricii) and two fourhorn sculpin (Myoxocephalus quadricornis) lie on a measuring board. Fish collected from Beaufort Sea, Alaska.
Six slender eelblennys (Lumpenus fabricii) and two fourhorn sculpin (Myoxocephalus quadricornis) lie on a measuring board. Fish collected from Beaufort Sea, Alaska.
Pacific capelin (Mallotus villosus)
A pacific capelin (Mallotus villosus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A pacific capelin (Mallotus villosus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A juvenile Dolly Varden
A juvenile Dolly Varden (Salvelinus malma) from the Beaufort Sea, Alaska, during the first summer at sea following freshwater rearing. Dolly Varden return to freshwater overwinter areas each winter because freshwater temperatures are warmer.
A juvenile Dolly Varden (Salvelinus malma) from the Beaufort Sea, Alaska, during the first summer at sea following freshwater rearing. Dolly Varden return to freshwater overwinter areas each winter because freshwater temperatures are warmer.
Deploying a CTD, Beaufort Sea, Alaska
Vanessa von Biela (USGS-ASC) deploys a CTD to measure conductivity, temperature, and density of seawater in the Beaufort Sea, Alaska.
Vanessa von Biela (USGS-ASC) deploys a CTD to measure conductivity, temperature, and density of seawater in the Beaufort Sea, Alaska.
Pulling in a surface trawl net
Vanessa von Biela (USGS – ASC) pulls in a surface trawl net in the Beaufort Sea, Alaska.
Vanessa von Biela (USGS – ASC) pulls in a surface trawl net in the Beaufort Sea, Alaska.
Fyke net, Beaufort Sea, Alaska
A fyke net is installed adjacent to Flaxman Island in the Beaufort Sea, Alaska.
A fyke net is installed adjacent to Flaxman Island in the Beaufort Sea, Alaska.
Four Arctic cod
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Two juvenile broad whitefish
Two juvenile broad whitefish (Coregonus nasus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Two juvenile broad whitefish (Coregonus nasus) from the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A caribou stands next to a pipeline
A caribou (Rangifer tarandus) stands next to a pipeline. This photo was taken while conducting field work in Northern Alaska.
A caribou (Rangifer tarandus) stands next to a pipeline. This photo was taken while conducting field work in Northern Alaska.
Two Red-throated loons
Two Red-throated loons (Gavia stellata) in a pond near the Beaufort Sea, Alaska.
Two Red-throated loons (Gavia stellata) in a pond near the Beaufort Sea, Alaska.
Arctic smelt
Arctic smelt (Osmerus mordax), Beaufort Sea, Alaska. An Arctic smelt or rainbow smelt, (Osmerus mordax) from the Beaufort Sea, Alaska.
Arctic smelt (Osmerus mordax), Beaufort Sea, Alaska. An Arctic smelt or rainbow smelt, (Osmerus mordax) from the Beaufort Sea, Alaska.
Four Arctic cod (Boreogadus saida)
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Four Arctic cod (Boreogadus saida) from the Beaufort Sea, Alaska This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A saffron cod
A saffron cod (Eleginus gracilis) captured in the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A saffron cod (Eleginus gracilis) captured in the Beaufort Sea, Alaska. This study will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Scenic view of the Beaufort Sea, Alaska
A scenic view of the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
A scenic view of the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Ice floating in the Beaufort Sea, Alaska
Chucks of ice floats in the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Chucks of ice floats in the Beaufort Sea, Alaska. This study site will evaluate the nearshore marine feeding areas of breeding adult red-throated loons and assess the response of loon reproductive success and nutritional content of nearshore fish communities.
Surface trawl retrieval
The field crew pulls in a surface trawl net in the Beaufort Sea, Alaska on the back deck of the R/V Proteus.
The field crew pulls in a surface trawl net in the Beaufort Sea, Alaska on the back deck of the R/V Proteus.