USGS Changing Arctic Ecosystems: Enhancing forecasts of polar bear and walrus population response to a rapidly changing Arctic ecosystem (Modeling walrus-habitat associations and foraging energetics)

This project develops and integrates models of walrus movement patterns, habitat associations, and bioenergetics to assess and forecast status of the Pacific walrus population.

Abstract

The loss of sea ice during summer over the continental shelf of the Chukchi Sea over the past decade has affected walrus distribution and behavior, most notably, the movement of tens of thousands of walruses from offshore to a large onshore haulout in autumn each year. To estimate the approximate number of walruses that may be affected by this behavioral change in the eastern Chukchi Sea, a new 3-year project was initiated to use a drone to count the number of walruses at the haulout. The use of a drone results in little to no apparent disturbance to walruses and allows for frequent surveys to be made for more precise abundance estimates. In addition, the use of the land haulout by female and young walruses has resulted in direct calf mortality from walrus trampling events and affects the ability of walruses to forage effectively. Recent work has modeled linkages between future sea ice availability, walrus activity levels and energy requirements to forecast female body condition. A similar modeling framework can be used to investigate other potential effects on walrus condition, such as ship traffic. To estimate the effect of the presence of ships on walrus activity levels, an ongoing 3-year project is using data from walrus telemetry data and AIS vessel tracking data in the Chukchi Sea to quantify activity budgets (time spent resting and foraging) of walruses relative to their proximity to ship traffic. Information from these projects provide Department of the Interior management partners greater certainty about how walruses respond to stressors and human activities so they can craft regulations that meet wildlife conservation goals, and yet do not place undue burden on resource users.

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Products

Title	Type
Pacific Walrus Behavior Data and Associated Chukchi Sea Ice Observations and Projections for use with Bioenergetics Models to Forecast Walrus Body Condition	Data
Walrus used and available resource units for northeast Chukchi Sea, 2008-2012	Data
An evaluation of behavior inferences from Bayesian state-space models: A case study with the Pacific walrus	Publication
Walrus Bayesian State-space Model Output from the Bering Sea and Chukchi Sea, 2008-2012	Data
Pacific Walrus Research	Organization Website
Changing Arctic Ecosystems	Project Website

Contacts

Jay, Chadwick V., 907-786-7414

Status: completed
Start Year: 2010
End Year: 2019

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Project Sites

USGS Mission Area and Program

Ecosystems → Wildlife Program

Major Initiatives

USGS - Changing Arctic Ecosystems Initiative
USGS - Marine and Freshwater Ecology

Keywords

Biosphere > Ecological Dynamics > Species/Population Interactions > Use/Feeding Habitats