TY - JOUR
T1 - Morphological differences between coastal bottlenose dolphin (Tursiops aduncus) populations identified using non-invasive stereo-laser photogrammetry
AU - van Aswegen, Martin
AU - Christiansen, Fredrik
AU - Symons, John
AU - Mann, Janet
AU - Nicholson, Krista
AU - Sprogis, Kate
AU - Bejder, Lars
N1 - Funding Information:
We thank C. Karniski, V. Senigaglia, D. Chabanne and the numerous research assistants who assisted with data collection in Bunbury, Mandurah and Shark Bay. We thank N. Stephens for kindly providing bottlenose dolphin measurement data collected during necropsy examinations. We thank A. Hordyk for his input on the growth curve analyses used in this study. We also thank J. Tierney and L. Spilsbury (Bunbury Dolphin Discovery Centre), S. and H. Kirby (Mandurah Dolphin Rescue Group) and Mandurah Cruises for contributing valuable long-term life history data. We thank Tim Barton and Barbara Cheney for providing technical support and advice relating to the laser equipment. Tim Barton (Barnacle Electronics) designed, manufactured and supplied the laser equipment and Barbara Cheney provided advice on laser safety, calibration, sampling, and measurement protocols. Long-term life history data were collected across several projects with different funding sources. Data obtained through the SWMRP were made possible by: Bemax Cable Sands, BHP Billiton Worsley Alumina Ltd, the Bunbury Dolphin Discovery Centre, Bunbury Port Authority, City of Bunbury, Cristal Global, the Western Australian Department of Biodiversity, Conservation and Attractions, Iluka, Millard Marine, Naturaliste Charters, Newmont Boddington Gold, South West Development Commission, Southern Ports Authority and WA Plantation Resources. Data obtained through the MDRP were made possible by: City of Mandurah, J. & B. Perry, Mandurah Cruises, Mandurah Dolphin Rescue Group, Murdoch University and Peel Development Commission. Long-term data obtained through the SBDP were made possible by funding grants to J.M.: NSF Awards: #0847922, 0820722, 9753044, 0316800, 0918308, 0941487,1559380; ONR: 10230702, Georgetown University, with special thanks to Monkey Mia Dolphin Resort and Royal Automobile Club of Australia. We thank the Western Australian Department of Biodiversity, Conservation and Attractions and Monkey Mia Dolphin Resort. This paper represents HIMB and SOEST contribution numbers 1767 and 10758, respectively.
Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Obtaining morphometric data on free-ranging marine megafauna is difficult, as traditional methods rely on post-mortem or live-capture techniques. We linked stereo-laser photogrammetry with long-term demographic data to compare length-at-age (LaA) growth curves of two well-studied populations of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in south-western (SW) and Shark Bay (SB), mid-western Australia. First, we determined the relationship between total length (TL) and blowhole-to-dorsal fin (BH-DF) length from post-mortem subjects (R2 = 0.99, n = 12). We then predicted TL from laser-derived BH-DF measurements of 129 and 74 known-age individuals in SW and SB, respectively. Richards growth models best described our LaA data. While birth length (103–110 cm) was similar between study regions, TL estimates at 1, 3, 12, and 25 years differed significantly (p < 0.001). Asymptotic length of adult males (SW = 246 cm, SB = 201 cm) and females (SW = 244 cm, SB = 200 cm) also differed significantly. Morphotypic variations likely reflect regional adaptations to local water temperatures, with the temperate SW having cooler waters than sub-tropical SB. We demonstrate the effectiveness of a non-invasive technique to understand ecological, demographic and life-history characteristics of long-lived marine megafauna, which are critical parameters for informing conservation and management actions.
AB - Obtaining morphometric data on free-ranging marine megafauna is difficult, as traditional methods rely on post-mortem or live-capture techniques. We linked stereo-laser photogrammetry with long-term demographic data to compare length-at-age (LaA) growth curves of two well-studied populations of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in south-western (SW) and Shark Bay (SB), mid-western Australia. First, we determined the relationship between total length (TL) and blowhole-to-dorsal fin (BH-DF) length from post-mortem subjects (R2 = 0.99, n = 12). We then predicted TL from laser-derived BH-DF measurements of 129 and 74 known-age individuals in SW and SB, respectively. Richards growth models best described our LaA data. While birth length (103–110 cm) was similar between study regions, TL estimates at 1, 3, 12, and 25 years differed significantly (p < 0.001). Asymptotic length of adult males (SW = 246 cm, SB = 201 cm) and females (SW = 244 cm, SB = 200 cm) also differed significantly. Morphotypic variations likely reflect regional adaptations to local water temperatures, with the temperate SW having cooler waters than sub-tropical SB. We demonstrate the effectiveness of a non-invasive technique to understand ecological, demographic and life-history characteristics of long-lived marine megafauna, which are critical parameters for informing conservation and management actions.
UR - https://www.scopus.com/pages/publications/85071187651
U2 - 10.1038/s41598-019-48419-3
DO - 10.1038/s41598-019-48419-3
M3 - Article
C2 - 31439909
AN - SCOPUS:85071187651
SN - 2045-2322
VL - 9
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 12235
ER -
