Project Description
Despite the fact that bearded, ribbon, ringed, and spotted seals (collectively called ice seals) represent important subsistence resources for the native peoples of northern and western Alaska, and are key ecological components of the arctic and sub-arctic marine ecosystems, relatively little is known of their abundances and distributions, seasonal migrations and habitat requirements, diving and foraging behaviors. Such information is critical for NMFS to fulfill its stewardship mandates described by the Marine Mammal Protection Act. This project is aimed at addressing this lack of basic knowledge of ice seal ecology. We will use abundance and distribution surveys and Satellite Data Recorders (SDRs) to investigate various aspects of ice seal ecology, and determine potential impacts resulting from the loss of sea ice and other anthropogenic effects.
Issues & Justification
Relatively little is known of the abundances and distributions, seasonal migrations and habitat requirements, diving and foraging behaviors, genetic discreteness and stock structures of the four species of ice seals. Many of these attributes are likely highly sensitive to suitable habitats and sea ice conditions and may be particularly vulnerable to climatic change and other disruptions from more direct anthropogenic effects such as offshore oil and gas development. Changes in the extent and concentration of sea ice have been non-uniform; and so the effects on seals are likely to occur on regional scales. Our ability to predict and manage for such impacts, however, is limited by our inadequate knowledge of ice seal ecology. To fulfill its stewardship mandates described by the Marine Mammal Protection Act, NMFS is required to have information on these species abundance, population trend, and extent of interactions with fisheries, seasonal movements, and distribution and harvest pressures. This project is aimed at addressing this lack of basic knowledge of ice seal ecology.
Goals
- Estimate the seasonal movements and patterns of distribution and behavior of the four species of ice seals.
- Identify specific marine habitats associated with key life history events of ice seals, such as breeding, pup rearing, foraging, and molting, and rank them according to importance of use.
- Improve the accuracy and precision of estimates of ice seal abundance developing a haul-out correction factor that can be used to adjust existing survey counts for the proportion of seals that are at sea and not observed during aerial surveys.
- To develop a working relationship with the native members of villages along the coastline of arctic and sub-arctic Alaska.
Methods
We will use population surveys and Satellite Data Recorders (SDRs) to investigate various aspects of ice seal ecology. We will conduct multiple surveys from various aerial and shipboard platforms to collect data necessary for calculating the abundances, and describing the distributions, of the four ice seal populations in U.S. waters. Satellite telemetry is a powerful tool for addressing many other aspects of ice seal ecology and behavior. SDRs can provide data on a seal's location, and on the timing and depths of its dives. We will capture ice seals and instrument them with SDRs. Data from instrumented animals will be analyzed to: 1) provide haul-out correction factors for past and future abundance and distribution sightings surveys, 2) assess the seasonal movements and patterns of distribution and diving/foraging behavior, and 3) identify and determine the priority of importance for specific marine habitats associated with key bearded seal life history events such breeding, pup rearing, and foraging and molting. Finally, we will collaborate with other researchers and organizations to analyze tissue samples collected during capture activities to assess nutritional status, health, and contaminant load.