Minke whale abundance estimation from the NASS 1987 and 2001 aerial cue–counting surveys taking appropriate account of distance estimation errors

  • David L Borchers RUWPA, The Observatory, University of St Andrews, Fife, KY16 9LZ
  • Daniel G Pike 21210 Ski Club Road, North Bay, Ontario, P1B 8E5
  • Thorvaldur Gunnlaugsson Marine Research Institute, P.O. Box 1390, IS-121, Reykjavík
  • Gísli A Víkingsson Marine Research Institute, P.O. Box 1390, IS-121, Reykjavík
Keywords: minke whales, Balaenoptera physalus, surveys, abundance,

Abstract

We estimate the abundance of minke whales (Balaenoptera acutorostrata) from the Icelandic coastal shelf aerial surveys carried out as part of the 1987 and 2001 North Atlantic Sightings Surveys (NASS). In the case of the 1987 survey, the probability of detecting animals at distance zero (g(0)) is very close to 1 but there is substantial random measurement error in estimating distances. To estimate abundance from these data, we use methods which assume g(0)=1 but which includea distance measurement error model. In the case of the 2001 survey, measurement errors were sufficiently small to be negligible, and we use double platform methods which estimate g(0) and assume no measurement error to estimate abundance. From the 1987 survey, we estimate abundance to be 24,532 animals, with 95% CI (13,399; 44,916). From the 2001 NASS survey data, minke whale abundance is estimated to be 43,633 animals, with 95% CI (30,148; 63,149).
Published
2009-09-01
How to Cite
Borchers, D. L., Pike, D. G., Gunnlaugsson, T., & Víkingsson, G. A. (2009). Minke whale abundance estimation from the NASS 1987 and 2001 aerial cue–counting surveys taking appropriate account of distance estimation errors. NAMMCO Scientific Publications, 7, 95-110. https://doi.org/10.7557/3.2708