The USGS Alaska Science Center conducts long-term research on the Pacific walrus to provide scientific information to Department of Interior management agencies and Alaska Native co-management partners. In addition, the USGS Pacific walrus research program collaborates with the U.S. Fish and Wildlife Service (USFWS) and the State of Alaska’s Department of Fish and Game and Alaska Native co-management partners to deliver scientific products that advance knowledge of walrus ecology and the importance of walrus in northern ecosystems. Because addressing population-level questions requires collaboration between U.S. and Russian scientists, many USGS studies have relied on Russian partnership.
Return to Ecosystems >> Marine Ecosystems
Population dynamics
Department of Interior partner agencies require information on Pacific walrus survival, reproduction, population abundance, and population trend to inform management decisions and address statutory responsibilities. US and Russian partners conducted aerial surveys in 1975, 1976, 1980, 1985, and 1990 to estimate population abundance. In 2006, USGS collaborated with US Fish and Wildlife Service (USFWS) and Russian partners to estimate population abundance from an offshore aerial survey that accounted for the proportion of walruses that were in-water and therefore unavailable to be counted, and was the first to rigorously account for uncertainty in the population abundance estimate. Because these offshore survey efforts resulted in large uncertainty in the estimated population size, development began on alternative abundance estimation methods. The USFWS has led an effort, with USGS support, to estimate Pacific walrus population abundance using genetic mark-recapture methods. USGS efforts developing methods to determine sex and age of walruses from remotely collected biopsies support this effort. USGS developed methods to estimate regional population size at a large coastal haulout and has refined these methods through use of unoccupied aerial systems (UAS or survey drones) through support of the USGS National Uncrewed Systems Office to estimate the regional walrus abundance in the U.S. Chukchi Sea autumn waters during 2018 and 2019.
Age structure surveys provide information on population demographics required by USFWS statutory responsibilities under the Marine Mammal Protection Act (MMPA). In the 1950’s, F.H. Fay pioneered methods for collecting walrus sex and age structure data by observing facial and tusk characteristics. These methods were applied to collect age structure data on offshore surveys from 1981-1999 with Department of the Interior support. The State of Alaska’s Department of Fish and Game evaluated these methods and found them to provide invaluable information on population demographics.
USGS developed integrated population models that estimated Pacific walrus survival, reproduction, and population trend. These models used all available age structure and population survey data to estimate population parameters required by the MMPA. These models found the age structure data to strongly influence estimated population trends, prompting USGS and FWS with support from the Alaska Department of Fish and Game to collect additional age structure data during 2013 - 2017. USGS is pursuing further age structure data collection beginning in 2023. Development of integrated population models has allowed USGS and collaborators to evaluate threats posed to the Pacific walrus population from climate related changes in the Arctic. For example, an increase in deaths of young walruses resulting from disturbances at large coastal haulouts can affect population trend.
Seasonal distribution and habitat use
Pacific walruses primarily consume invertebrates that live in bottom sediments of the shallow continental shelf waters that extend across the Bering and Chukchi seas. In response to the understanding that sea ice loss causes walruses to change their movement and foraging behavior in ways that may affect survival and reproduction, USGS has developed minimally invasive methods to track walruses with small satellite-linked tags and has collected behavior and movement data from walruses across the Bering and Chukchi seas in support of numerous studies. These studies include correcting aerial survey estimates for walruses in-water and therefore unavailable to be counted; understanding how walruses move within their habitat relative to sea ice movement in the northern Bering Sea; identifying how they move relative to sea ice and benthic biomass distributions in the Bering, and Chukchi Seas; and understanding how their resting and foraging efforts change when summer sea ice disappears. The tracking data have also revealed walrus foraging areas within the Chukchi Sea and contributed to a broader understanding of marine mammal seasonal distributions in the Pacific Arctic. The tracking data are currently being analyzed to better understand how Pacific walruses utilize the largest coastal haulout in northwestern Alaska.
Recorded Talk: Pacific Walruses: Responding to Change? Strait Science, April 2023
Monitoring large coastal haulouts
Walruses haul out of the water and rest between foraging bouts. They rest on sea ice when it is available but use land when waters are ice free. The Chukchi Sea continental shelf has been ice-free during most summers since 2007, and the seasonal duration of ice-free conditions will increase in the decades ahead. When walruses gather in large numbers to rest on shore at locations that are termed “haulouts”, they are at risk from large mortality events resulting from disturbances that cause stampedes. They are also at increased risk from any vessel spill events because walrus distributions are so densely concentrated at and around coastal haulouts. To reduce these risks, managers require an understanding of the distribution and occurrence of large coastal haulouts. USGS has partnered with the USFWS and a Russian collaborator to document the occurrence and distribution of Pacific walrus haulouts. USGS is supporting a revision of the Pacific Walrus Haulout Database in collaboration with USFWS.
Graphic by: Andres A. Aceves for USGS through the Virtual Student Federal Service program.
USGS has developed methods to monitor walruses resting on shore through use of Earth observing satellite imagery. USGS is supporting local management of haulouts by providing satellite imagery analysis to local managers during the haulout season. USGS has worked with Russian partners to extend these methods at haulout sites with complex substrates and terrain and plans to continue this work at Alaskan study sites with State of Alaska, FWS and academic partners. To support that effort, the USGS Advanced Research Computing center is using trail camera ground-truth imagery collected by partner agencies to teach deep neural networks to recognize walruses so they can more rapidly detect walruses remotely. USGS is also collaborating to automate interpretation of the walrus haulouts apparent in optical Earth observing imagery so that information can be transferred to management partners in real-time, and USGS has supported harmonization of aerial survey imagery collection efforts conducted in the U.S. and Russia so that haulout monitoring studies and results may be unified range-wide.
Consequences of shifting prey base and increased energetic demands
The loss of sea ice has caused shifts in walrus space use, is forecasted to increase the energetic demands for lactating walruses and may cause changes to walrus prey. By coupling walrus behavior models with an understanding of the energy demands throughout the reproductive life of female walruses, USGS evaluated the energetic consequences of forecasted sea ice loss over the next century. This study found that continued sea ice loss will increase walrus energetic demands, but there was uncertainty about the impact increased energetic demands might have on body condition and how that may affect reproduction rates. To understand how the walrus population may respond to the increased energetic demands, USGS is evaluating methods to monitor possible changes in walrus reproductive success over time as environmental conditions change. Using information collected by Native Alaskan communities in the Bering Strait region, from captive walruses in zoos and aquaria, and from aerial imagery from drones at coastal haulouts, USGS is investigating different methods to monitor walrus body condition and how variation in body condition may affect female reproductive success.

In support of this study USGS has (1) collaborated to determine how to reliably measure fat stores from harvested walruses; (2) evaluated the condition and composition of walrus fat stores; (3) collaborated to evaluate energetic costs for resting walruses across the range of reproductive conditions and across juvenile age-classes; (4) collaborated to evaluate energetic cost of swimming, diving, and resting in water; and (5) explored the development of diving capabilities in young walruses. Finally, the loss of sea ice may cause changes to walrus prey and understanding the consequences of a shift in the prey base requires methods to understand walrus diet. So, USGS developed non-invasive methods to monitor walrus diet.
Potential effects of increased vessel traffic
Arctic marine mammals have historically had low exposure to vessel traffic and noise, but sea ice loss has increased accessibility of Arctic waters to vessels. Thus, Arctic vessel traffic is expected to increase, yet its effect on walruses is unknown. Vessel exposure has the potential to change walrus population dynamics by altering how much time walruses use to rest, travel, and forage. Such changes may require walruses to consume more calories or reduce their energy stores which are needed to support growth, reproduction, and maintenance. The USGS conducted an initial study of effects of vessel exposure on Pacific walrus behavior in the Chukchi Sea using data from satellite-tagged walruses (collected by USGS, Russian collaborators, and the State of Alaska’s Department of Fish and Game) and vessel locations. Foraging walruses were no more likely to stop foraging and start traveling when they were within 17 km of vessels than when they were greater than 17 km from vessels. Due to the small number of walruses exposed to vessels at close distances, this study did not determine at what distance vessel exposure affects walrus behaviors; however, it provided an upper bound on the distance at which the vessels encountered may disturb foraging walruses. Furthermore, USGS developed extensive analytical methods that will help detect the effect of vessel exposure on walrus behavior when sufficient walrus tracking data are available with improved resolution. USGS also supported a study to evaluate walrus in-air hearing range.
Stock Definition
The Marine Mammal Protection Act requires an understanding of whether there are distinct stocks within the Pacific walrus sub-species. Pacific walruses range across the shallow waters of the continental shelf that extends between Alaska and the Russian Far East. Three distinct breeding areas are known to develop during the sea ice maximum season each spring: in the eastern Bering Sea of the outer Bristol Bay region; south of Saint Lawrence Island in the central northern Bering Sea; and within the Gulf of Anadyr in the northwestern Bering Sea. USGS investigated whether these distinct breeding regions may result in distinct stocks that may merit separate management efforts. Investigations based on signatures from heavy metal isotopes characteristic of the two western breeding regions suggested that walruses in these regions had distinct isotopic signatures, suggesting that each region hosted walruses that habitually returned to that region. However, genetic characterization of walruses from the three breeding regions determined that walruses freely moved amongst breeding regions, indicating that the Pacific walrus sub-species may be considered as a single stock.
Below are other science projects associated with this project.
USGS Alaska Science Center Wildlife Tracking Data Collection
Changing Arctic Ecosystems
Below are data or web applications associated with this project.
Pacific Walrus Coastal Haulout Occurrences Interpreted from Satellite Imagery, 2023
Data Supporting Walrus Areas of Use in the Chukchi Sea During Sparse Sea Ice Cover
Walrus Haulout and In-water Activity Levels Relative to Vessel Interactions in the Chukchi Sea, 2012-2015
Pacific Walrus Coastal Haulout Occurrences Interpreted from Satellite Imagery
Metabolic Rates Measured in Three Captive Adult Female Walruses (Odobenus rosmarus divergens) While Resting and Diving
Tracking Data for Pacific Walrus (Odobenus rosmarus divergens)
Walrus Haulout Aerial Survey Data Near Point Lay Alaska, Autumn 2018 and 2019
Behavior of Pacific Walruses (Odobenus rosmarus divergens) Hauled Out on Sea Ice During UAS Overflights, Eastern Chukchi Sea, 2015
Walrus Haulout Outlines Apparent from Satellite Imagery Near Point Lay Alaska, Autumn 2018-2020
Walrus Haulout Outlines and Count Data Apparent from Aerial Survey Images Collected Near Point Lay Alaska, Autumn 2018 and 2019
Sex and Age Composition of Walrus Groups Hauled Out on Ice Floes in the Bering and Chukchi Seas, 2013-2015
Metabarcoding of Feces of Pacific Walruses and Autosomal DNA Sequence Data of Marine Invertebrates, 2012-2015, Alaska
Below are publications associated with this project.
Effects of feeding and habitat on resting metabolic rates of the Pacific walrus
Exploring effects of vessels on walrus behaviors using telemetry, automatic identification system data and matching
Estimating Pacific walrus abundance and survival with multievent mark-recapture models
Regional walrus abundance estimate in the United States Chukchi Sea in autumn
Subsurface swimming and stationary diving are metabolically cheap in adult Pacific walruses (Odobenus rosmarus divergens)
Evaluation of satellite imagery for monitoring Pacific walruses at a large coastal haulout
Variability of lipids and fatty acids in Pacific walrus blubber
DNA metabarcoding of feces to infer summer diet of Pacific walruses
A multi-species synthesis of satellite telemetry data in the Pacific Arctic (1987–2015): Overlap of marine mammal distributions and core use areas
Demography of the Pacific walrus (Odobenus rosmarus divergens) in a changing Arctic
Forecasting consequences of changing sea ice availability for Pacific walruses
Evaluation of a method using survey counts and tag data to estimate the number of Pacific walruses (Odobenus rosmarus divergens) using a coastal haulout in northwestern Alaska
Tagged Animal Movement - Mammals
This project contains data collected by the Argos System from 921 satellite transmitters attached to adult Pacific walruses in the Bering and Chukchi Seas, in U.S. and Russian waters, 1988-2019.
R script for email delivery of sea ice imagery and charts to users with limited bandwidth
Below are news stories associated with this project.
- Overview
The USGS Alaska Science Center conducts long-term research on the Pacific walrus to provide scientific information to Department of Interior management agencies and Alaska Native co-management partners. In addition, the USGS Pacific walrus research program collaborates with the U.S. Fish and Wildlife Service (USFWS) and the State of Alaska’s Department of Fish and Game and Alaska Native co-management partners to deliver scientific products that advance knowledge of walrus ecology and the importance of walrus in northern ecosystems. Because addressing population-level questions requires collaboration between U.S. and Russian scientists, many USGS studies have relied on Russian partnership.
Return to Ecosystems >> Marine Ecosystems
Population dynamics
Department of Interior partner agencies require information on Pacific walrus survival, reproduction, population abundance, and population trend to inform management decisions and address statutory responsibilities. US and Russian partners conducted aerial surveys in 1975, 1976, 1980, 1985, and 1990 to estimate population abundance. In 2006, USGS collaborated with US Fish and Wildlife Service (USFWS) and Russian partners to estimate population abundance from an offshore aerial survey that accounted for the proportion of walruses that were in-water and therefore unavailable to be counted, and was the first to rigorously account for uncertainty in the population abundance estimate. Because these offshore survey efforts resulted in large uncertainty in the estimated population size, development began on alternative abundance estimation methods. The USFWS has led an effort, with USGS support, to estimate Pacific walrus population abundance using genetic mark-recapture methods. USGS efforts developing methods to determine sex and age of walruses from remotely collected biopsies support this effort. USGS developed methods to estimate regional population size at a large coastal haulout and has refined these methods through use of unoccupied aerial systems (UAS or survey drones) through support of the USGS National Uncrewed Systems Office to estimate the regional walrus abundance in the U.S. Chukchi Sea autumn waters during 2018 and 2019.
Walruses in the Chukchi Sea during a tagging survey onboard the Norseman II in June 2010. Age structure surveys provide information on population demographics required by USFWS statutory responsibilities under the Marine Mammal Protection Act (MMPA). In the 1950’s, F.H. Fay pioneered methods for collecting walrus sex and age structure data by observing facial and tusk characteristics. These methods were applied to collect age structure data on offshore surveys from 1981-1999 with Department of the Interior support. The State of Alaska’s Department of Fish and Game evaluated these methods and found them to provide invaluable information on population demographics.
USGS developed integrated population models that estimated Pacific walrus survival, reproduction, and population trend. These models used all available age structure and population survey data to estimate population parameters required by the MMPA. These models found the age structure data to strongly influence estimated population trends, prompting USGS and FWS with support from the Alaska Department of Fish and Game to collect additional age structure data during 2013 - 2017. USGS is pursuing further age structure data collection beginning in 2023. Development of integrated population models has allowed USGS and collaborators to evaluate threats posed to the Pacific walrus population from climate related changes in the Arctic. For example, an increase in deaths of young walruses resulting from disturbances at large coastal haulouts can affect population trend.
Seasonal distribution and habitat use
Pacific walruses primarily consume invertebrates that live in bottom sediments of the shallow continental shelf waters that extend across the Bering and Chukchi seas. In response to the understanding that sea ice loss causes walruses to change their movement and foraging behavior in ways that may affect survival and reproduction, USGS has developed minimally invasive methods to track walruses with small satellite-linked tags and has collected behavior and movement data from walruses across the Bering and Chukchi seas in support of numerous studies. These studies include correcting aerial survey estimates for walruses in-water and therefore unavailable to be counted; understanding how walruses move within their habitat relative to sea ice movement in the northern Bering Sea; identifying how they move relative to sea ice and benthic biomass distributions in the Bering, and Chukchi Seas; and understanding how their resting and foraging efforts change when summer sea ice disappears. The tracking data have also revealed walrus foraging areas within the Chukchi Sea and contributed to a broader understanding of marine mammal seasonal distributions in the Pacific Arctic. The tracking data are currently being analyzed to better understand how Pacific walruses utilize the largest coastal haulout in northwestern Alaska.
Recorded Talk: Pacific Walruses: Responding to Change? Strait Science, April 2023
Monitoring large coastal haulouts
Walruses haul out of the water and rest between foraging bouts. They rest on sea ice when it is available but use land when waters are ice free. The Chukchi Sea continental shelf has been ice-free during most summers since 2007, and the seasonal duration of ice-free conditions will increase in the decades ahead. When walruses gather in large numbers to rest on shore at locations that are termed “haulouts”, they are at risk from large mortality events resulting from disturbances that cause stampedes. They are also at increased risk from any vessel spill events because walrus distributions are so densely concentrated at and around coastal haulouts. To reduce these risks, managers require an understanding of the distribution and occurrence of large coastal haulouts. USGS has partnered with the USFWS and a Russian collaborator to document the occurrence and distribution of Pacific walrus haulouts. USGS is supporting a revision of the Pacific Walrus Haulout Database in collaboration with USFWS.
This is a graphical abstract for a publication by the USGS that evaluates satellite imagery for monitoring large Pacific walrus haulouts in northwestern Alaska.
Graphic by: Andres A. Aceves for USGS through the Virtual Student Federal Service program.USGS has developed methods to monitor walruses resting on shore through use of Earth observing satellite imagery. USGS is supporting local management of haulouts by providing satellite imagery analysis to local managers during the haulout season. USGS has worked with Russian partners to extend these methods at haulout sites with complex substrates and terrain and plans to continue this work at Alaskan study sites with State of Alaska, FWS and academic partners. To support that effort, the USGS Advanced Research Computing center is using trail camera ground-truth imagery collected by partner agencies to teach deep neural networks to recognize walruses so they can more rapidly detect walruses remotely. USGS is also collaborating to automate interpretation of the walrus haulouts apparent in optical Earth observing imagery so that information can be transferred to management partners in real-time, and USGS has supported harmonization of aerial survey imagery collection efforts conducted in the U.S. and Russia so that haulout monitoring studies and results may be unified range-wide.
Consequences of shifting prey base and increased energetic demands
The loss of sea ice has caused shifts in walrus space use, is forecasted to increase the energetic demands for lactating walruses and may cause changes to walrus prey. By coupling walrus behavior models with an understanding of the energy demands throughout the reproductive life of female walruses, USGS evaluated the energetic consequences of forecasted sea ice loss over the next century. This study found that continued sea ice loss will increase walrus energetic demands, but there was uncertainty about the impact increased energetic demands might have on body condition and how that may affect reproduction rates. To understand how the walrus population may respond to the increased energetic demands, USGS is evaluating methods to monitor possible changes in walrus reproductive success over time as environmental conditions change. Using information collected by Native Alaskan communities in the Bering Strait region, from captive walruses in zoos and aquaria, and from aerial imagery from drones at coastal haulouts, USGS is investigating different methods to monitor walrus body condition and how variation in body condition may affect female reproductive success.
Sources/Usage: Public Domain. Visit Media to see details.Indianapolis Zoo marine mammal trainers, Erika Allen and Sydney Pitts, measure a healthy female walrus in support of a USGS study that seeks to develop methods to monitor walrus body condition from survey drones flown high above walruses where they rest on shore. With this new tool, USGS intends to examine the environmental factors that affect walrus body condition in order to better understand how they are responding to the changing arctic ecosystem. In support of this study USGS has (1) collaborated to determine how to reliably measure fat stores from harvested walruses; (2) evaluated the condition and composition of walrus fat stores; (3) collaborated to evaluate energetic costs for resting walruses across the range of reproductive conditions and across juvenile age-classes; (4) collaborated to evaluate energetic cost of swimming, diving, and resting in water; and (5) explored the development of diving capabilities in young walruses. Finally, the loss of sea ice may cause changes to walrus prey and understanding the consequences of a shift in the prey base requires methods to understand walrus diet. So, USGS developed non-invasive methods to monitor walrus diet.
Potential effects of increased vessel traffic
Arctic marine mammals have historically had low exposure to vessel traffic and noise, but sea ice loss has increased accessibility of Arctic waters to vessels. Thus, Arctic vessel traffic is expected to increase, yet its effect on walruses is unknown. Vessel exposure has the potential to change walrus population dynamics by altering how much time walruses use to rest, travel, and forage. Such changes may require walruses to consume more calories or reduce their energy stores which are needed to support growth, reproduction, and maintenance. The USGS conducted an initial study of effects of vessel exposure on Pacific walrus behavior in the Chukchi Sea using data from satellite-tagged walruses (collected by USGS, Russian collaborators, and the State of Alaska’s Department of Fish and Game) and vessel locations. Foraging walruses were no more likely to stop foraging and start traveling when they were within 17 km of vessels than when they were greater than 17 km from vessels. Due to the small number of walruses exposed to vessels at close distances, this study did not determine at what distance vessel exposure affects walrus behaviors; however, it provided an upper bound on the distance at which the vessels encountered may disturb foraging walruses. Furthermore, USGS developed extensive analytical methods that will help detect the effect of vessel exposure on walrus behavior when sufficient walrus tracking data are available with improved resolution. USGS also supported a study to evaluate walrus in-air hearing range.
Stock Definition
The Marine Mammal Protection Act requires an understanding of whether there are distinct stocks within the Pacific walrus sub-species. Pacific walruses range across the shallow waters of the continental shelf that extends between Alaska and the Russian Far East. Three distinct breeding areas are known to develop during the sea ice maximum season each spring: in the eastern Bering Sea of the outer Bristol Bay region; south of Saint Lawrence Island in the central northern Bering Sea; and within the Gulf of Anadyr in the northwestern Bering Sea. USGS investigated whether these distinct breeding regions may result in distinct stocks that may merit separate management efforts. Investigations based on signatures from heavy metal isotopes characteristic of the two western breeding regions suggested that walruses in these regions had distinct isotopic signatures, suggesting that each region hosted walruses that habitually returned to that region. However, genetic characterization of walruses from the three breeding regions determined that walruses freely moved amongst breeding regions, indicating that the Pacific walrus sub-species may be considered as a single stock.
- Science
Below are other science projects associated with this project.
USGS Alaska Science Center Wildlife Tracking Data Collection
Understanding the short- and long-distance movements of wildlife is critical for a wide variety of ecological research questions and management decisions. Since the mid-1980s, the USGS Alaska Science Center has used information from telemetry devices on wildlife species to determine locations of animals throughout their annual cycles, understand patterns of habitat use, quantify time spent on...Changing Arctic Ecosystems
Arctic regions of Alaska are important for cultural and economic sustainability and host a wide variety of wildlife species, many of which are of conservation and management interest to the U.S. Department of the Interior. The USGS and collaborators provide information about Arctic ecosystems that are used by Arctic residents, management agencies, and industry. - Data
Below are data or web applications associated with this project.
Filter Total Items: 20Pacific Walrus Coastal Haulout Occurrences Interpreted from Satellite Imagery, 2023
This data release contains maps, geospatial files, and a table of the satellite imagery types with the dates when they were collected and examined to interpret the presence of, and area occupied by, walruses at terrestrial haulouts. Estimates of the land area occupied by walruses are provided based on interpretation by experienced image reviewers. The images are from a variety of Earth observing sData Supporting Walrus Areas of Use in the Chukchi Sea During Sparse Sea Ice Cover
The dataset consists of geospatial files depicting the estimated June-to-November distribution of walrus foraging and occupancy during a four year period of sparse sea ice cover above the Chukchi Sea continental shelf (2008-2011). The walrus distribution and utilization estimates are based on location data from satellite-linked radio-tracked walruses in the Chukchi Sea (2008-2011). Compared to preWalrus Haulout and In-water Activity Levels Relative to Vessel Interactions in the Chukchi Sea, 2012-2015
These data were used to evaluate effects of vessel exposure on Pacific walrus (Odobenus rosmarus divergens) behaviors. We obtained greater than 120,000 hours of location and behavior (foraging, in-water not foraging, hauled out) data from 218 satellite-tagged walruses and linked them to vessel locations from the marine Automated Information System. This yielded 206 vessel-exposed walrus telemetryPacific Walrus Coastal Haulout Occurrences Interpreted from Satellite Imagery
This data release contains maps, geospatial files, and a table of the satellite imagery types with the dates when they were collected and examined to interpret the presence of, and area occupied by, walruses at terrestrial haulouts. Estimates of the land area occupied by walruses are provided based on interpretation by experienced image reviewers. The images are from a variety of Earth observing sMetabolic Rates Measured in Three Captive Adult Female Walruses (Odobenus rosmarus divergens) While Resting and Diving
This dataset contains measurements of oxygen consumption and carbon dioxide production of 3 adult female walruses (Odobenus rosmarus divergens) while resting and diving at the Oceanografic Aquarium in Valencia, Spain. Oxygen consumption and carbon dioxide production was measured for walruses via a respiratory dome while resting at the water surface and after swimming and diving.Tracking Data for Pacific Walrus (Odobenus rosmarus divergens)
This metadata document describes the data contained in the "processedData" folder of this data package. This data package contains all data collected by the Argos System from 921 satellite transmitters attached to adult Pacific walruses in the Bering and Chukchi Seas, in U.S. and Russian waters, 1988-2019. The raw data were processed to accomplish two goals: flag implausible location estimates andWalrus Haulout Aerial Survey Data Near Point Lay Alaska, Autumn 2018 and 2019
This dataset consists of the complete set of aerial imagery and data from walrus haulouts collected by unoccupied aerial system (UAS) surveys near Pt. Lay, Alaska, during the autumns of 2018 and 2019. The data include: 1) georeferenced digital aerial imagery and flight logs from UAS surveys, and 2) orthoimages derived from the aerial imagery and flight logs by standardized structure from motion alBehavior of Pacific Walruses (Odobenus rosmarus divergens) Hauled Out on Sea Ice During UAS Overflights, Eastern Chukchi Sea, 2015
This dataset is comprised of three tables showing the reaction of walruses hauled out on sea ice of the Chukchi Sea to overflights by rotary wing Unoccupied Aircraft Systems (UAS). Data include behavior of walruses before, during, and after overflights, and environmental conditions during flights.Walrus Haulout Outlines Apparent from Satellite Imagery Near Point Lay Alaska, Autumn 2018-2020
These data are in three folders of Keyhole Markup Language (KML) geospatial polygons representing the outlines of walrus herds apparent in satellite imagery. Each KML file contains one or more geospatial polygons of walrus herd outlines created by one observer who visually interpreted the images. The attribute values from all KML files are collected in a CSV table included with this data package.Walrus Haulout Outlines and Count Data Apparent from Aerial Survey Images Collected Near Point Lay Alaska, Autumn 2018 and 2019
This dataset provides walrus haulout group outlines, systematic grids cast over the outlines, and digitized points at the centroids of the individual walruses identified inside a randomly selected subset of grid cells. These data are based on visual interpretation of unpublished imagery from 26 aerial surveys by an Unoccupied Aerial System (UAS) operated by the U.S. Geological Survey, Alaska ScienSex 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
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 van Veen gr - Multimedia
- Publications
Below are publications associated with this project.
Filter Total Items: 56Effects of feeding and habitat on resting metabolic rates of the Pacific walrus
Arctic marine mammals live in a rapidly changing environment due to the amplified effects of global warming. Pacific walruses (Odobenus rosmarus divergens) have responded to declines in Arctic sea-ice extent by increasingly hauling out on land farther from their benthic foraging habitat. Energy models can be useful for better understanding the potential implications of changes in behavior on bodyAuthorsKaryn D. Rode, Joan Rocabert, Alicia Borque-Espinosa, Diana Ferrero-Fernández, Andreas FahlmanExploring effects of vessels on walrus behaviors using telemetry, automatic identification system data and matching
Arctic marine mammals have had little exposure to vessel traffic and potential associated disturbance, but sea ice loss has increased accessibility of Arctic waters to vessels. Vessel disturbance could influence marine mammal population dynamics by altering behavioral activity budgets that affect energy balance, which in turn can affect birth and death rates. As an initial step in studying these lAuthorsRebecca L. Taylor, Chadwick V. Jay, William S. Beatty, Anthony S. Fischbach, Lori T. Quakenbush, Justin A. CrawfordEstimating Pacific walrus abundance and survival with multievent mark-recapture models
Arctic marine ecosystems are undergoing rapid physical and biological change associated with climate warming and loss of sea ice. Sea ice loss will impact many species through altered spatial and temporal availability of resources. In the Bering and Chukchi Seas, the Pacific walrus Odobenus rosmarus divergens is one species that could be impacted by rapid environmental change, and thus, populationAuthorsWilliam S. Beatty, Patrick R. Lemons, Jason P. Everett, Cara J. Lewis, Rebecca L. Taylor, Robert J. Lynn, Suresh A. Sethi, Lori T. Quakenbush, John J. Citta, Michelle Kissling, Natalia Kryukova, John K. WennburgRegional walrus abundance estimate in the United States Chukchi Sea in autumn
Human activities (e.g., shipping, tourism, oil, gas development) have increased in the Chukchi Sea because of declining sea ice. The declining sea ice itself and these activities may affect Pacific walrus (Odobenus rosmarus divergens) abundance; however, previous walrus abundance estimates have been notably imprecise. When sea ice is absent from the eastern Chukchi Sea, walruses in waters of the UAuthorsAnthony S. Fischbach, Rebecca L. Taylor, Chadwick V. JaySubsurface swimming and stationary diving are metabolically cheap in adult Pacific walruses (Odobenus rosmarus divergens)
Walruses rely on sea-ice to efficiently forage and rest between diving bouts while maintaining proximity to prime foraging habitat. Recent declines in summer sea ice have resulted in walruses hauling out on land where they have to travel farther to access productive benthic habitat while potentially increasing energetic costs. Despite the need to better understand the impact of sea ice loss on eneAuthorsAlicia Borque-Espinosa, Karyn D. Rode, Diana Ferrero-Fernandex, Anabel Forte, Romana Capaccioni-Azzati, Andreas FahlmanEvaluation of satellite imagery for monitoring Pacific walruses at a large coastal haulout
Pacific walruses (Odobenus rosmarus divergens) are using coastal haulouts in the Chukchi Sea more often and in larger numbers to rest between foraging bouts in late summer and autumn in recent years, because climate warming has reduced availability of sea ice that historically had provided resting platforms near their preferred benthic feeding grounds. With greater numbers of walruses hauling outAuthorsAnthony S. Fischbach, David C. DouglasVariability of lipids and fatty acids in Pacific walrus blubber
The variability of lipid content and fatty acid (FA) composition across blubber depth and body sites are important considerations for condition and diet studies of marine mammals. We investigated lipid and FA variability among inner and outer blubber layers, three body sites, four study years, and lactation status of adult female Pacific walruses (Odobenus rosmarus divergens) using blubber samplesAuthorsChadwick V. Jay, Sara J. Iverson, Anthony S. FischbachDNA metabarcoding of feces to infer summer diet of Pacific walruses
Environmental conditions in the Chukchi Sea are changing rapidly and may alter the abundance and distribution of marine species and their benthic prey. We used a metabarcoding approach to identify potentially important prey taxa from Pacific walrus (Odobenus rosmarus divergens) fecal samples (n = 87). Bivalvia was the most dominant class of prey (66% of all normalized counts) and occurred in 98% oAuthorsSarah A. Sonsthagen, Chadwick V. Jay, Robert S. Cornman, Anthony S. Fischbach, Jacqueline M. Grebmeier, Sandra L. TalbotA multi-species synthesis of satellite telemetry data in the Pacific Arctic (1987–2015): Overlap of marine mammal distributions and core use areas
We collated available satellite telemetry data for six species of ice-associated marine mammals in the Pacific Arctic: ringed seals (Pusa hispida; n = 118), bearded seals(Erignathus barbatus, n = 51), spotted seals (Phoca largha, n = 72), Pacific walruses (Odobenus rosmarus divergens, n = 389); bowhead whales (Balaena mysticetus, n = 46), and five Arctic and sub-arctic stocks of beluga whales (DelAuthorsJohn J. Citta, Lloyd F. Lowry, Lori T. Quakenbush, Brendan P. Kelly, Anthony S. Fischbach, Josh M. London, Chadwick V. Jay, Kathryn J. Frost, Gregory O'Corry Crowe, Justin A. Crawford, Peter L. Boveng, Michael Cameron, Andrew L. Von Duyke, Mark Nelson, Lois A. Harwood, Pierre Richard, Robert Suydam, Mads Peter Heide-Jørgensen, Roderick C. Hobbs, Dennis I. Litovka, Marianne Marcoux, Alex Whiting, Amy S. Kennedy, John C. George, Jack Orr, Tom GrayDemography of the Pacific walrus (Odobenus rosmarus divergens) in a changing Arctic
The Pacific walrus (Odobenus rosmarus divergens) is a candidate to be listed as an endangered species under United States law, in part, because of climate change‐related concerns. While the population was known to be declining in the 1980s and 1990s, its recent status has not been determined. We developed Bayesian models of walrus population dynamics to assess the population by synthesizing informAuthorsRebecca L. Taylor, Mark S. Udevitz, Chadwick V. Jay, John J. Citta, Lori T. Quakenbush, Patrick R. Lemons, Jonathan A. SnyderForecasting consequences of changing sea ice availability for Pacific walruses
The accelerating rate of anthropogenic alteration and disturbance of environments has increased the need for forecasting effects of environmental change on fish and wildlife populations. Models linking projections of environmental change with behavioral responses and bioenergetic effects can provide a basis for these forecasts. There is particular interest in forecasting effects of projected reducAuthorsMark S. Udevitz, Chadwick V. Jay, Rebecca L. Taylor, Anthony S. Fischbach, William S. Beatty, Shawn R. NorenEvaluation of a method using survey counts and tag data to estimate the number of Pacific walruses (Odobenus rosmarus divergens) using a coastal haulout in northwestern Alaska
Increased periods of sparse sea ice over the continental shelf of the Chukchi Sea in late summer have reduced offshore haulout habitat for Pacific walruses (Odobenus rosmarus divergens) and increased opportunities for human activities in the region. Knowing how many walruses could be affected by human activities would be useful to conservation decisions. Currently, there are no adequate estimatesAuthorsBrian Battaile, Chadwick V. Jay, Mark S. Udevitz, Anthony S. Fischbach - Web Tools
Tagged Animal Movement - Mammals
This project contains data collected by the Argos System from 921 satellite transmitters attached to adult Pacific walruses in the Bering and Chukchi Seas, in U.S. and Russian waters, 1988-2019.
- Software
R script for email delivery of sea ice imagery and charts to users with limited bandwidth
This software package represents an effort to enable access of sea ice charts and imagery in support of daily logistics planning where internet bandwidth and geoprocessing abilities are limited. The script acquires, processes and delivers these data in a format that may be manipulated by openly available virtual globe software, be visualized by software commonly installed on all smart phones and c - News
Below are news stories associated with this project.