The aim of this research is to better understand the food habits and foraging behaviour of the population of bottlenose dolphins in Bunbury waters. The specific aims of this research project are to:
- Estimate the relative abundance, composition, and energy content of prey species in the nearshore waters of Bunbury in summer and winter months.
- Compare the presence of prey species with stomach contents of stranded dolphins
- Investigate trophic level interactions of dolphins and prey using stable isotope analyses.
- Develop a spatially explicit model of environmental drivers in the coastal region that influence dolphin movement and behavior.
Three fishing gears (seine, trap, and gillnet) were used to sample fish from sites within three habitats (ocean, bay, and estuary) during summer and winter months from 2008-2010. Over 45,000 fish were caught and identified! (The majority of fish were released alive after being weighed and measured).
The most commonly captured fish were burned in a bomb calorimeter to determine energy content per gram. Stomachs from 12 stranded dolphins were dissected and prey parts identified.
Samples from plankton, algae, fish, crabs, and dolphins were analyzed for signatures of carbon and nitrogen to determine approximate feeding locations and trophic levels.
Shannon McCluskey is currently analysing her data and writing up her PhD dissertation.