Measuring sperm whales at sea
Photogrammetry has proven to be a useful technique to estimate remotely the size of free-ranging cetacean species. A boat-based digital photogrammetric system has been designed, calibrated, and assessed for the purpose of measuring free ranging sperm whales. Results of assessment have shown that a relative error of less than 1% could be achieved (Growcott et al., 2012). This sytem was used to validate an acoustic method to derive their length (Growcott et al., 2011). Find out about the system with the animation below.
Collaborations
This project has been conducted in collaboration with the Department of Marine Science at the University of Otago (www.otago.ac.nz/marinescience).
This project has been supported by the New Zealand Whale and Dolphin Trust (www.whaledolphintrust.org.nz).
Selected publications and outcomes
Growcott, A.; Miller, B.; Sirguey, P.; Slooten, E. & Dawson, S. (2011), 'Measuring body length of male sperm whales from their clicks: the relationship between inter-pulse intervals and photogrammetrically measured lengths', Journal of the Acoustical Society of America 130(1), 568-573.