MMS ENVIRONMENTAL STUDIES PROGRAM: ONGOING STUDIES
MMS OCS Region: Alaska
Title: Correction Factor for Ringed Seal Surveys in Northern Alaska (AK-93-48-23)
Total Cost: $174,854 Period of Performance: FY 1998-2001
Conducting Organization: University of Alaska at Fairbanks, Coastal Marine Institute
MMS Contact:

Chief, Alaska Environmental Studies Section
Description:
Background
A protocol for monitoring ringed seal distribution and relative densities in Arctic waters has already been developed for MMS and implemented over 6 field seasons during spring basking periods when the greatest number of seals are hauled out on the ice. This study will augment previous monitoring by permitting estimation of true ringed seal densities based on the number visible from an airplane. Good information exists on ringed seal ecology and distribution in industrial versus control areas, but not enough to estimate true densities correctly. Correction factors developed for harbor seals have been found to be applicable to other years, as long as they and the survey estimates were developed in the same areas at similar times of the year. Most aerial surveys for ringed seals have attempted to standardize by surveying from late May to early June and not past mid-day. The correction factor will facilitate re-analysis of historical data collected in GIS-compatible formats.
Objectives
The goal of the study is to estimate a correction factor for the proportion of ringed seals not visible during aerial surveys and thereby, enhance the protocol for estimating Arctic ringed seal densities from aerial monitoring results. Useful quantitative information on ringed seal behavior will also be obtained, as identified in the methods section.
Methods
Subnivean lairs will be located by dogs trained to alert handlers to ringed seal scents on command. Each year, the use of 20 subnivean lairs by seals will be monitored using air temperature recorded in lairs by thermistor sensors connected to data loggers. The cumulative frequency of lair use by date will be compared among years. During each aerial survey, the proportion of lairs still active will be calculated based on the temperature records. A sample of seals will be instrumented with radio- and ultrasonic-transmitters and their behaviors recorded by observers stationed on the ice surface. Ringed seals not visible during aerial surveys will be partitioned into those under the ice and those in subnivean lairs. Quantitative information will be obtained, including:
  1. The temporal pattern in which ringed seals abandon lairs and begins to bask.
  2. The proportion and variance of the out-of-water population of ringed seals concealed within subnivean lairs during aerial surveys.
  3. The proportion and coefficient of variation of the population visible during aerial surveys.
  4. The frequency distribution of distances traveled between winter home ranges and sites occupied during the spring basking period.
  5. The relationships between date, distance to ambush cover, and group size for seals visible next to basking holes and cracks.
Importance to MMS
Offshore production of oil in the Beaufort Sea is planned for the Northstar and Liberty. Post-lease undersea-pipeline construction is expected to result in additional acoustic and visual disturbance of ringed seals in marine areas due to increased vessel and helicopter traffic. Such disturbance has the potential for causing some long-term abandonment of industrial areas. Providing a means to determine the true densities of seals observed in aerial monitoring will help us estimate the number of seals affected by such industrial activity. Also, estimates of absolute population size require a correction factor for the proportion of seals not visible during surveys.
Current Status:
The Draft Final Report has been submitted to MMS and is under review.
Final Report Due: June 2001
Publications: Kelly, B. and L. Quakenbush. 1998. Correction Factor for Ringed Seal Surveys in Northern Alaska. In: University of Alaska Coastal Marine Institute. Annual Report No. 5, OCS Study MMS 98-0062. Fairbanks, AK: University of Alaska, Coastal Marine Institute and USDOI, MMS, Alaska OCS Region; p. 62

Kelly, B. and L. Quakenbush. 2000a. Correction Factor for Ringed Seal Surveys in Northern Alaska. In: University of Alaska Coastal Marine Institute. Annual Report No. 6, OCS Study MMS 2000-046. Fairbanks, AK: University of Alaska, Coastal Marine Institute and USDOI, MMS, Alaska OCS Region; p. 51.

Kelly, B. and L. Quakenbush. 2000b. Correction Factor for Ringed Seal Surveys in Northern Alaska. In: University of Alaska Coastal Marine Institute, Annual Report No. 7, OCS Study MMS 2000-070. Fairbanks, AK: University of Alaska, Coastal Marine Institute and USDOI, MMS, Alaska OCS Region; p. 14.
Affiliated WWW Sites: Mammals and Sea Turtles Observations from GOM- NMFS Cruises (1998 - 2001) (GM-98-X11)
Revised date: March 2002
ESPIS

ESPIS - All completed ESP Studies:
Full Text, Online, Right Now!
 Environmental Studies Program Information System