Estimating North Pacific right whale (Eubalaena japonica) density using passive acoustic cue counting

• Published in: Endangered Species Research
• Main Authors: Marques, Tiago Andre Lamas Oliveira, Munger, Lisa, Thomas, Len, Wiggins, Sean, Hildebrand, John
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Bering Sea; Point transects; Distance sampling; Normal mode propagation; Abundance estimation; Acoustic recording package; ARP; High frequency acoustic package; HARP; Pacific; Sea Point; Eubalaena japonica; North Pacific right whale
• Online Access: https://risweb.st-andrews.ac.uk/portal/en/researchoutput/estimating-north-pacific-right-whale-eubalaena-japonica-density-using-passive-acoustic-cue-counting(b41d8279-1978-4f1c-bebd-5c8bc9f32f99).html; https://doi.org/10.3354/esr00325

We present a method for estimating animal density from fixed passive acoustic detectors, and illustrate it by estimating the density of North Pacific right whales Eubalaena japonica in the areas surrounding 3 hydrophones deployed in the southeastern Bering Sea in 2001 to 2002 and 2005 to 2006. Input data were the distances to detected right whale calls, estimated using a normal mode sound propagation model, and call production rate, estimated from encounters by survey vessels with right whale groups. Given the scarcity of information about this highly endangered species, we also extrapolate our results to provide a tentative estimate of the total population size in shelf waters of the eastern Bering Sea. This gives a point estimate of 25 animals (CV 29.1%; 95% confidence interval 13–47), which agrees well with what little is known for this species. We discuss the assumptions underlying the method. Obtaining more reliable values requires a larger sample of randomly located hydrophones, together with improved estimates of call rate.