Occurrence, distribution and abundance of cetaceans off the western Eyre Peninsula in the Great Australian Bight

Abstract

This study provides the first assessment of the occurrence, distribution and abundance of cetaceans in shelf and coastal waters off the western Eyre Peninsula, eastern Great Australian Bight, South Australia. We undertook aerial line transect surveys to estimate the abundance of common dolphins, and to assess the occurrence and distribution of other small and large cetaceans. Two along shore surveys were also flown to assess occurrence of endangered southern right whales in coastal waters. Five cetacean species were detected: seven southern right whales, three humpback whales, one minke whale (unknown species), 71 schools of common dolphins, and 14 schools of bottlenose dolphins. Abundance of common dolphins was estimated to be 20,000–22,000 using distance sampling methods with densities of 0.67–0.73 dolphin/km2. Comparisons of common dolphin densities off the Eyre Peninsula in the eastern GAB with other regions around the world show that shelf waters off the Eyre Peninsula represent an important habitat for common dolphins.