Southern Hemisphere Breeding Stock D humpback whale population estimates from North West Cape, Western Australia
MetadataShow full item record
Estimates of the abundance of Breeding Stock D humpback whales (Megaptera novaeangliae) are key to the conservation and management of what is thought to be one of the largest populations of the species. Five years (2000, 2001, 2006, 2007 and 2008) of aerial surveys carried out over an eight-year period at North West Cape (Western Australia) using line transect methodology allowed trends in whale numbers to be investigated, and provided a base for comparison with estimates made approximately 400km south at Shark Bay (Western Australia). A total of 3,127 whale detections were made during 74 surveys of the 7,043km 2 study area west of NWC. Pod abundance for each flight was computed using a HorvitzThompson like estimator and converted to an absolute measure of abundance after corrections were made for estimated mean cluster size, unsurveyed time, swimming speed and animal availability. Resulting estimates from the migration model of best fit with the most credible assumptions were 7,276 (CI = 4,993-10,167) for 2000, 12,280 (CI = 6,830-49,434) for 2001, 18,692 (CI = 12,980-24,477) for 2006, 20,044 (CI = 13,815-31,646) for 2007, and 26,100 (CI = 20,152-33,272) for 2008. Based on these data, the trend model with the greatest G2 was exponential with an annual increase rate of 13% (CI = 5.6%-18.1%). While this value is above the species' estimated maximum plausible growth rate of 11.8%, it is reasonably close to previous reports of between 10-12%. The coefficient of variation, however, was too large for a reliable trend estimate. Perception bias was also not accounted for in these calculations. Based on a crude appraisal which yielded an estimatedp(0) of 0.783 (from independent observer effort, CV = 0.973), the 2008 humpback population size may be as large as 33,300. In conclusion, the work here provides evidence of an increasing Breeding Stock D population, but further surveys are necessary to confirm whether the population is indeed increasing at its maximum rate.
Showing items related by title, author, creator and subject.
Application of a multi-disciplinary approach to reveal population structure and Southern Ocean feeding grounds of humpback whalesRiekkola, L.; Zerbini, A.; Andrews, O.; Andrews-Goff, V.; Baker, C.; Chandler, D.; Childerhouse, S.; Clapham, P.; Dodémont, R.; Donnelly, D.; Friedlaender, A.; Gallego, R.; Garrigue, C.; Ivashchenko, Y.; Jarman, Simon; Lindsay, R.; Pallin, L.; Robbins, J.; Steel, D.; Tremlett, J.; Vindenes, S.; Constantine, R. (2018)© 2018 Elsevier Ltd Obtaining direct measurements to characterise ecosystem function can be hindered by remote or inaccessible regions. Next-generation satellite tags that inform increasingly sophisticated movement models, ...
Schmitt, N.; Double, M.; Baker, S.; Gales, N.; Childerhouse, S.; Polanowski, A.; Steel, D.; Albertson, R.; Olavarría, C.; Garrigue, C.; Poole, M.; Hauser, N.; Constantine, R.; Paton, D.; Jenner, C.; Jarman, Simon; Peakall, R. (2014)In understanding the impact of commercial whaling, it is important to estimate the mixing of low latitude breeding populations on Antarctic feeding grounds, particularly the endangered humpback whale populations of Oceania. ...
Modeling the aggregated exposure and responses of bowhead whales Balaena mysticetus to multiple sources of anthropogenic underwater soundEllison, W.; Racca, R.; Clark, C.; Streever, B.; Frankel, A.; Fleishman, E.; Angliss, R.; Berger, J.; Ketten, Darlene; Guerra, M.; Leu, M.; McKenna, M.; Sformo, T.; Southall, B.; Suydam, R.; Thomas, L. (2016)© The authors 2016.Potential responses of marine mammals to anthropogenic underwater sound are usually assessed by researchers and regulators on the basis of exposure to a single, relatively loud sound source. However, ...