Humpback whales, Megaptera novaeangliae (Cetaceaa : Balaenopteridae), in Hervey Bay, Queensland .

Abstract

Humpback whales, Megaptera novaeangliae, of the Antarctic Area V stock, pass through Hervey Bay, Queensland, during their southward migration. As part of an investigation of the impact of commercial whalewatching in the bay, aerial surveys were conducted during the 1988-90 whalewatching seasons, and a photo-identification project was run over the 1988 season. In 1988,60 pods containing 127 whales were observed. All pods were sighted on the transects in the eastern section of Hervey Bay, so surveys in 1989 and 1990 were confined to this area. In 1989, 223 whales in 121 pods were counted, and in 1990, 105 whales in 60 pods were observed. There was annual variation in the temporal pattern of the migration through Hervey Bay. Pods tended to occur in shallow water close to the western coast of Fraser Island and, on days when several whales were observed in the bay, pods were not distributed in a regular fashion. Mother-calf pods were the final cohort to migrate through the Bay. The recorded sizes of whale pods varied between observation platforms and averaged 1.75-2.81. In all, 100 whales were identified from photographs of natural marks. Most were photographed once only, although individual whales were sighted up to seven times. Of the 34 whales identified on more than one occasion, 24 were observed over a one- or two-day period. Pod sizes and residence times of whales in Hervey Bay resemble those of whales recorded at tropical breeding grounds. However, there are no data suggesting that Hervey Bay is of particular importance to any class of the humpback whale population migrating off the eastern coast of Australia.