Thesis: Fish recruitment in coastal habitats of north-west Australia.
Recruitment in fish is commonly cited as the time at which larvae settle into juvenile or adult habitat from their planktonic stage. Fish recruitment and post-settlement survival are key ecological processes that help sustain viable populations and despite their importance we have little understanding of these processes in NW Australia. Focusing on ecological and indigenously important fish species, and working with local indigenous rangers and traditional owners, this project will explore latitudinal and temporal gradients in the timing of recruitment using published literature to build a global picture of the process, and fish otolith microstructure to generate baseline data for NW Australia. Juvenile reef fish often settle into ‘nursery’ habitat so the relative significance of mangrove, seagrass and coral reef biotopes to Kimberley fish populations will be explored using remote underwater video techniques and comprehensive morphometric and diet analysis to quantify the advantages of ontogenetic shifts in habitat and diet.
Why my research is important
The Northwest Australia coast, and the Kimberley region in particular, is increasingly under pressure from fisheries, industry and acute disturbance events. Recruitment variability is directly relevant to ecosystem-based fisheries policy and management, and to developing adaptive management strategies in the face of climate change. A multi-faceted approach using novel techniques to investigate fish recruitment will provide invaluable baseline data and improve our understanding of the intricate ecological relationships present in recruitment. Knowledge on how fish use different habitats during, and post- recruitment and of the advantages of such behaviour could give insight into the mechanisms behind evolutionary speciation in marine fishes. These data are essential for the processes involved in the development of marine protected areas, stock management and in assessing the impact of fisheries, inshore development and climate change on these remote and unique ecosystems.