Holly Smith, PhD Candidate, is carrying out research on the population abundance, social structure, ranging patterns and habitat use of bottlenose dolphins in Bunbury.
The primary goal of this research is to examine the status of the dolphin population to assist with long-term conservation and management.
Specific aims include to:
- Calculate accurate abundance estimates and determine how many dolphins are in the Bunbury population.
- Describe group composition, including each animal’s sex and age.
- Investigate associations and interactions between dolphins.
- Determine seasonal residency and extent of home ranges.
- Identify benthic habitat types available to Bunbury dolphins.
Field methods:
Between March 2007 and February 2010, year-round standard boat-based photo-identification techniques were used as a capture-recapture method for documenting individual bottlenose dolphins, based on nicks and marks on the dorsal fin and body surface, encountered along pre-determined transect lines.
Figure 1
The study area was divided into three transect zones (Zone 1: Buffalo Beach; Zone 2: Back Beach; and Zone 3: Bunbury Inner waters; Figure 1). Surveys were conducted from a 5 m centre console research vessel driven at a speed of 8 -12 kn along transect lines. Transects followed a predetermined track in a zigzag pattern within one nautical mile from shore.
Figure 1. Map of the 120km2 study area in the near-shore environment around the Bunbury, Western Australia, showing the extent of the three transect zones and zig-jag patterns of each transect line. Zone 1: the northern area off Buffalo Beach; Zone 2: the southern area off Back Beach; and Zone 3: Bunbury inner waters including the Leschenault Estuary and Inlet, Inner and Outer Harbour, Koombana Bay and the lower reaches of the Collie River.
Holly Smith is currently writing-up her PhD and submission is eminent.
