1. Are habitats important in mediating range shifts in tropical fishes? Hayden Beck PhD Candidate Supervisors: Prof. David Booth and Dr David Feary

2. GREAT BARRIER REEF EAST AUSTRALIAN CURRENT Recruitment of tropical reef fishes along SE Australian coast during summer Hotspot of climate change: establishment of permanent populations Importance of physical habitats for early life stages of tropical fishes? Model System: SE Australia 1500km AUSTRALIA

3. 1.Selection for habitat generalists (i.e. no coral dwellers) Predictions: importance of habitats in core range 2. Larger-scales: organisation of distributions by interactions between wave-exposure and swimming abilities 3. Finer-scales: association with specific benthic habitats

4. Result 1. Only habitat generalists observed 5695 individuals belonging to 30 species (Underwater surveys: 2 years, 4 latitudes, estuarine and coastal reef sites – 100s m apart) NO CORAL DWELLERS Planktivores (51%) Invertivores (24%) Grazers (24%)Piscivores (1%) Images: D. Harasti and Australian museum

5. Result 2. Association with wave-exposure Significant correlation of densities of tropical fishes with wave-exposure on larger-scales

6. Result 2. Association with wave-exposure Significant correlation of species richness of tropical fishes with wave-exposure on larger-scales No correlation with water temperatures, benthic complexity, predator densities or substrate composition

7. Result 3: Swimming modes match wave-exposure * * Coastal reefs High swimming performance * Poor swimming performances Estuarine reefs

8. Result 4. Association with sea urchin barrens 1028 individuals belonging to 15 species (Underwater surveys: 2 years, 7 coastal reef sites; barrens and kelp habitats - 10s m apart) NO species associated with kelp habitat Images: D. Harasti

9. Conclusions 4 Within new range lacking coral: Habitat generalists successful Wave-exposure: strong structuring mechanism on larger-scales Benthic habitat: organise finer-scale distribution