Anthony Fischbach
Applying wildlife biology tools, including satellite imagery interpretation and telemetry, to address Pacific walrus conservation problems.
Professional Experience
2022 - Present Research Wildlife Biologist, USGS, Alaska Science Center, Anchorage, Alaska
2004 - 2022 Wildlife Biologist, USGS, Alaska Science Center, Anchorage, Alaska
2003 - 2004 Wildlife Biologist, U.S. Fish and Wildlife Service, Kodiak National Wildlife Refuge, Kodiak, Alaska
1999 - 2003 Wildlife Biologist, USGS, Alaska Biological Science Center, Anchorage, Alaska
1998 - 1999 Wildlife Biologist, Marine Mammals Management, U.S. Fish & Wildlife Service, Anchorage, Alaska
1997 - 1999 (summers) Volunteer Wildlife Biologist, Tongass Bat Habitat Project, U.S. Forest Service, Thorne Bay, Alaska
1995 - 1998 Biological Technician / Walrus Harvest Monitor, Marine Mammals Management, U.S. Fish & Wildlife Service, Anchorage, Alaska
1994 - 1995 Volunteer, Kenai National Wildlife Refuge, U.S. Fish & Wildlife Service, Soldotna, Alaska
Education and Certifications
M.A. 1994 University of Texas, Austin, TX Ecology
B.S. 1989 University of Wisconsin, Madison, WI Molecular Biology
Affiliations and Memberships*
Reviewer: BioScience, Arctic, Marine Mammal Science, Progress In Oceanography, Polar Biology
Contributor: R-sig-geo
Honors and Awards
1989-1990 Fulbright Scholar, Bayreuth, Germany
Science and Products
Filter Total Items: 28
Sex and Age Composition of Walrus Groups Hauled Out on Ice Floes in the Bering and Chukchi Seas, 2013-2015 Sex and Age Composition of Walrus Groups Hauled Out on Ice Floes in the Bering and Chukchi Seas, 2013-2015
These data are in one table with age and sex composition counts of groups of walruses on ice floes in the northern Bering and Chukchi Seas. Counts were collected by visual observations from boats.
Metabarcoding of Feces of Pacific Walruses and Autosomal DNA Sequence Data of Marine Invertebrates, 2012-2015, Alaska Metabarcoding of Feces of Pacific Walruses and Autosomal DNA Sequence Data of Marine Invertebrates, 2012-2015, Alaska
This data set describes nucleotide sequence data derived from 18S ribosomal DNA amplified in two fragments. A total of 87 feces from Pacific walrus and 57 marine invertebrates were examined for this study. Samples were collected from the Bering Sea and Chukchi Sea, Alaska. Samples used in the study originated from feces or muscle samples collected in the field from ice floes or benthic...
Pacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition Pacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition
This data release includes three datasets used to develop forecasts of autumn body condition for adult female Pacific walruses in the Chukchi Sea during mid and late century time periods. (1) The activity dataset contains daily telemetry records for 218 adult female walruses tracked for periods of 7 to 104 days during 2008-2014, in the Chukchi Sea. Records include the number of hours the...
Walrus Used and Available Resource Units for Northeast Chukchi Sea, 2008-2012 Walrus Used and Available Resource Units for Northeast Chukchi Sea, 2008-2012
Sea ice loss represents a stressor to the Pacific walrus (Odobenus rosmarus divergens), which feeds on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging walrus space use patterns. Thus, we examined walrus foraging resource selection as a function of proximity to resting substrates and prey biomass with a...
Pacific Walrus Blubber Lipid Content and Fatty Acid Composition, St. Lawrence Island, 2007-2010 Pacific Walrus Blubber Lipid Content and Fatty Acid Composition, St. Lawrence Island, 2007-2010
This dataset contains lab-measured percent lipid and fatty acid composition data from Pacific walruses harvested in waters near Saint Lawrence Island. Each row indicates data from a single layer from a blubber core sample collected from one body site (flank, rump, or sternum) from one walrus harvested by Native Alaskans during the spring walrus hunts of 2007 - 2010. Blubber cores were...
Pacific Walrus Seasonal Distribution from USGS Tracking Data, Chukchi and Bering Seas, 1987-2015 Pacific Walrus Seasonal Distribution from USGS Tracking Data, Chukchi and Bering Seas, 1987-2015
This data release includes two summary geospatial rasters in GeoTIFF format indicating the seasonal Pacific walrus distribution apparent from location tracking obtained from the temporary attachment of Argos transmitter tags to 325 adult Pacific walruses (248 female, 67 male, 10 unknown) between 1987 and 2015. We deployed tags on walruses at locations in the eastern and northern Bering...
Filter Total Items: 27
No results found.
Filter Total Items: 40
Pacific walrus coastal haulout database, 1852-2016— Background report Pacific walrus coastal haulout database, 1852-2016— Background report
Walruses are large benthic predators that rest out of water between foraging bouts. Coastal “haulouts” (places where walruses rest) are formed by adult males in summer and sometimes by females and young when sea ice is absent, and are often used repeatedly across seasons and years. Understanding the geography and historical use of haulouts provides a context for conservation efforts. We...
Authors
Anthony S. Fischbach, Anatoly A. Kochnev, Joel L. Garlich-Miller, Chadwick V. Jay
An evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus An evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus
State-space models offer researchers an objective approach to modeling complex animal location data sets, and state-space model behavior classifications are often assumed to have a link to animal behavior. In this study, we evaluated the behavioral classification accuracy of a Bayesian state-space model in Pacific walruses using Argos satellite tags with sensors to detect animal behavior...
Authors
William S. Beatty, Chadwick V. Jay, Anthony S. Fischbach
Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens) Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens)
Physiological constraints dictate animals’ ability to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind...
Authors
Shawn R. Norem, Chadwick V. Jay, Jennifer M. Burns, Anthony S. Fischbach
Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea
The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St...
Authors
Chadwick V. Jay, Jacqueline M. Grebmeier, Anthony S. Fischbach, Trent L. McDonald, Lee W. Cooper, Fawn Hornsby
Spatial genetic structure and asymmetrical gene flow within the Pacific walrus Spatial genetic structure and asymmetrical gene flow within the Pacific walrus
Pacific walruses (Odobenus rosmarus divergens) occupying shelf waters of Pacific Arctic seas migrate during spring and summer from 3 breeding areas in the Bering Sea to form sexually segregated nonbreeding aggregations. We assessed genetic relationships among 2 putative breeding populations and 6 nonbreeding aggregations. Analyses of mitochondrial DNA (mtDNA) control region sequence data...
Authors
Sarah A. Sonsthagen, Chadwick V. Jay, Anthony S. Fischbach, George K. Sage, Sandra L. Talbot
Walrus distributional and foraging response to changing ice and benthic conditions in the Chukchi Sea Walrus distributional and foraging response to changing ice and benthic conditions in the Chukchi Sea
Arctic species such as the Pacific walrus (Odobenus rosmarus divergens) are facing a rapidly changing environment. Walruses are benthic foragers and may shift their spatial patterns of foraging in response to changes in prey distribution. We used data from satellite radio-tags attached to walruses in 2009-2010 to map walrus foraging locations with concurrent sampling of benthic infauna...
Authors
Chadwick V. Jay, Jacqueline M. Grebmeier, Anthony S. Fischbach
Science and Products
Filter Total Items: 28
Sex and Age Composition of Walrus Groups Hauled Out on Ice Floes in the Bering and Chukchi Seas, 2013-2015 Sex and Age Composition of Walrus Groups Hauled Out on Ice Floes in the Bering and Chukchi Seas, 2013-2015
These data are in one table with age and sex composition counts of groups of walruses on ice floes in the northern Bering and Chukchi Seas. Counts were collected by visual observations from boats.
Metabarcoding of Feces of Pacific Walruses and Autosomal DNA Sequence Data of Marine Invertebrates, 2012-2015, Alaska Metabarcoding of Feces of Pacific Walruses and Autosomal DNA Sequence Data of Marine Invertebrates, 2012-2015, Alaska
This data set describes nucleotide sequence data derived from 18S ribosomal DNA amplified in two fragments. A total of 87 feces from Pacific walrus and 57 marine invertebrates were examined for this study. Samples were collected from the Bering Sea and Chukchi Sea, Alaska. Samples used in the study originated from feces or muscle samples collected in the field from ice floes or benthic...
Pacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition Pacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition
This data release includes three datasets used to develop forecasts of autumn body condition for adult female Pacific walruses in the Chukchi Sea during mid and late century time periods. (1) The activity dataset contains daily telemetry records for 218 adult female walruses tracked for periods of 7 to 104 days during 2008-2014, in the Chukchi Sea. Records include the number of hours the...
Walrus Used and Available Resource Units for Northeast Chukchi Sea, 2008-2012 Walrus Used and Available Resource Units for Northeast Chukchi Sea, 2008-2012
Sea ice loss represents a stressor to the Pacific walrus (Odobenus rosmarus divergens), which feeds on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging walrus space use patterns. Thus, we examined walrus foraging resource selection as a function of proximity to resting substrates and prey biomass with a...
Pacific Walrus Blubber Lipid Content and Fatty Acid Composition, St. Lawrence Island, 2007-2010 Pacific Walrus Blubber Lipid Content and Fatty Acid Composition, St. Lawrence Island, 2007-2010
This dataset contains lab-measured percent lipid and fatty acid composition data from Pacific walruses harvested in waters near Saint Lawrence Island. Each row indicates data from a single layer from a blubber core sample collected from one body site (flank, rump, or sternum) from one walrus harvested by Native Alaskans during the spring walrus hunts of 2007 - 2010. Blubber cores were...
Pacific Walrus Seasonal Distribution from USGS Tracking Data, Chukchi and Bering Seas, 1987-2015 Pacific Walrus Seasonal Distribution from USGS Tracking Data, Chukchi and Bering Seas, 1987-2015
This data release includes two summary geospatial rasters in GeoTIFF format indicating the seasonal Pacific walrus distribution apparent from location tracking obtained from the temporary attachment of Argos transmitter tags to 325 adult Pacific walruses (248 female, 67 male, 10 unknown) between 1987 and 2015. We deployed tags on walruses at locations in the eastern and northern Bering...
Filter Total Items: 27
No results found.
Filter Total Items: 40
Pacific walrus coastal haulout database, 1852-2016— Background report Pacific walrus coastal haulout database, 1852-2016— Background report
Walruses are large benthic predators that rest out of water between foraging bouts. Coastal “haulouts” (places where walruses rest) are formed by adult males in summer and sometimes by females and young when sea ice is absent, and are often used repeatedly across seasons and years. Understanding the geography and historical use of haulouts provides a context for conservation efforts. We...
Authors
Anthony S. Fischbach, Anatoly A. Kochnev, Joel L. Garlich-Miller, Chadwick V. Jay
An evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus An evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus
State-space models offer researchers an objective approach to modeling complex animal location data sets, and state-space model behavior classifications are often assumed to have a link to animal behavior. In this study, we evaluated the behavioral classification accuracy of a Bayesian state-space model in Pacific walruses using Argos satellite tags with sensors to detect animal behavior...
Authors
William S. Beatty, Chadwick V. Jay, Anthony S. Fischbach
Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens) Rapid maturation of the muscle biochemistry that supports diving in Pacific walruses (Odobenus rosmarus divergens)
Physiological constraints dictate animals’ ability to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid-buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind...
Authors
Shawn R. Norem, Chadwick V. Jay, Jennifer M. Burns, Anthony S. Fischbach
Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea Pacific walrus (Odobenus rosmarus divergens) resource selection in the northern Bering Sea
The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St...
Authors
Chadwick V. Jay, Jacqueline M. Grebmeier, Anthony S. Fischbach, Trent L. McDonald, Lee W. Cooper, Fawn Hornsby
Spatial genetic structure and asymmetrical gene flow within the Pacific walrus Spatial genetic structure and asymmetrical gene flow within the Pacific walrus
Pacific walruses (Odobenus rosmarus divergens) occupying shelf waters of Pacific Arctic seas migrate during spring and summer from 3 breeding areas in the Bering Sea to form sexually segregated nonbreeding aggregations. We assessed genetic relationships among 2 putative breeding populations and 6 nonbreeding aggregations. Analyses of mitochondrial DNA (mtDNA) control region sequence data...
Authors
Sarah A. Sonsthagen, Chadwick V. Jay, Anthony S. Fischbach, George K. Sage, Sandra L. Talbot
Walrus distributional and foraging response to changing ice and benthic conditions in the Chukchi Sea Walrus distributional and foraging response to changing ice and benthic conditions in the Chukchi Sea
Arctic species such as the Pacific walrus (Odobenus rosmarus divergens) are facing a rapidly changing environment. Walruses are benthic foragers and may shift their spatial patterns of foraging in response to changes in prey distribution. We used data from satellite radio-tags attached to walruses in 2009-2010 to map walrus foraging locations with concurrent sampling of benthic infauna...
Authors
Chadwick V. Jay, Jacqueline M. Grebmeier, Anthony S. Fischbach
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government