Abstract: Shallow-water tropical seascapes typically include a range of habitat types such as coral reefs, mangroves, macroalgal and seagrass beds. These habitats can occur in close proximity and are interconnected, yet they are often studied as discrete entities. While some species of coral reef fishes are known to use multiple habitat types during their lifecycle, we still know very little about the extent of non-reef habitat use among reef fishes and how the spatial patterning of seascapes might influence fish-habitat relationships or ecological processes on reefs. My thesis examines the use of tropical seascapes by reef-associated fishes through a global synthesis, and field studies in Kavieng, Papua New Guinea. Results from both the global synthesis and field based research in Papua New Guinea show that non-reef habitat use by reef fishes is common and widespread. A multiscale analysis of fish assemblages within shallow seagrass beds revealed that for 62% of taxa examined, the surrounding seascape had a greater influence on distribution patterns than within-habitat variables. Finally, I examine how the surrounding seascape influences a key ecological process (i.e., macroalgae browsing) in shallow reef habitats. Overall my thesis highlights the need to broaden our horizons beyond a habitat or patch-centric approach and incorporate a wider seascape perspective when investigating patterns and processes within coral reef seascapes.

Biography: Katie hails from the UK and began diving as soon as she was able, spending many happy but rather cold weekends exploring the underwater seascapes of the UK south coast. Katie completed a BSc in Marine Biology & Zoology at Bangor University, Wales in 2013, and, thanks to an Australian Government Endeavour Scholarship, fulfilled a lifelong dream to complete an MSc in Marine Biology & Ecology at James Cook University. She enjoyed the experience so much, she decided to stick around a little longer and embark on a PhD. During her time in academia so far, she has worked on a broad range of topics including non-native species, coral recovery, coral spawning, edge effects and the impacts of habitat loss and fragmentation on reef fish communities. For her PhD project, Katie has been investigating how the seascape structure surrounding reefs can influence fish communities and ecological processes on reefs, under the supervision of Professor Andrew Hoey, Professor Serge Andréfouët, Dr Mary Bonin, Professor Graeme Cumming and Dr Stephanie Duce.