Acoustic detection and satellite-tracking leads to discovery of rare concentration of endangered North Pacific right whales

Abstract

The North Pacific right whale, Eubalaena japonica, is one of the most endangered species of whale in the world. On 10 August 2004, two right whales were located in the Bering Sea using headings to right whale calls provided by directional sonobuoys. A satellite-monitored radio tag attached to one of these whales functioned for 40 days. Over the 40-day period, this whale moved throughout a large part of the southeast Bering Sea shelf, including areas of the outer-shelf where right whales have not been seen in decades. In September, multiple right whales were acoustically located and subsequently sighted by another survey vessel approaching a near-real-time position from the tag. An analysis of photographs confirmed at least 17 individual whales (not including the tagged whales). Genetic analysis of biopsy samples identified 17 individuals: 10 males and 7 females. The discovery of seven females was significant, as only one female had been identified in the past. Genetics also confirmed the presence of at least two calves. Although the future of this population is highly uncertain, the discovery of additional females and calves gives some hope that this most critically endangered of all whale populations may still possess the capacity to recover.

Validating the reliability of passive acoustic localisation: a novel method for encountering rare and remote Antarctic blue whales

“…In addition to blue whales, DIFAR systems have already been used for tracking right (McDonald & Moore 2002, Wade et al 2006, fin (McDonald & Fox 1999, Gedamke & Robinson 2010, and humpback whale calls (Swartz et al 2003, Garland et al 2013, and could likely be used to track other baleen whale calls (McDonald 2004), though few of these prior studies acoustically localised whales in real-time. The success of this study, coupled with the decreasing cost and size of computing hardware and ongoing improvements of automated detection and classification software (e.g.…”

“…Barlow & Taylor 2005, Baumgartner et al 2013, or it can comprise the primary means of locating cryptic or critically endangered animals that may be dispersed over large or rarely accessed areas (e.g. Wade et al 2006, Klinck et al 2012, Rone et al 2012). …”

“…Wade et al 2006, Clark et al 2010, Klinck et al 2012, Rone et al 2012, Baumgartner et al 2013. Real-time acoustic detection can be used along with adaptive survey designs in order to increase the amount of time spent with animals during studies that rely on visual observations and/or contact with animals (e.g.…”

Management and research applications of real-time and archival passive acoustic sensors over varying temporal and spatial scales

“…The upcall, or contact call, is typically the call type used for diagnostic detection of right whale species (Wade et al 2006, Clark et al 2007). This call is highly stereotypic making it ideal for species recognition.…”

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

“…Individual calling rates for North Pacific right whales were estimated from recordings made during vessel-based cetacean surveys in the southeastern Bering Sea. (Wade et al 2006). Right whale calls were recorded using directional sonobuoys (type AN/SSQ-53D), and species identification was confirmed and group size estimated by visual observers.…”