Congratulations to Dr. Phil Bouchet
Phil Bouchet, Jessica Meeuwig | Mar 17, 2016
UWA graduation ceremonies are held on the picturesque grounds of Winthrop Hall.
Our most sincere congratulations go to Dr. Phil Bouchet who was conferred the degree of Doctor of Philosophy for his thesis entitled “Submarine topography as a predictor of mobile predator hotspots: Relevance and applications to conservation planning in the pelagic ocean”.
Phil’s PhD is the product of four years of collaborative work under the National Environmental Research Programme‘s Marine Biodiversity Hub – concentrating on spatial management for large pelagic vertebrates, including oceanic sharks and fishes, cetaceans and turtles. His thesis explored the role that prominent seabed features (e.g. submarine canyons, banks and shoals) may play in aggregating wildlife and how knowledge of predictable relationships between species and their physical habitat can be harnessed for strategic conservation planning. Phil is now actively engaged as a Postdoctoral Fellow in the National Environmental Science Programme (NESP), focusing on synthesising and applying predictive models of marine biodiversity in the Australian north-west.
Dr. Bouchet and Prof. Meeuwig smile at four years of fruitful and rewarding research.
Phil also had the honour of delivering the Valedictory Address to close his graduation ceremony (Wednesday, March 16). Self-described as a “short collection of notes […] taken on the meaning of life, the universe and just about everything else”, his speech celebrated Adam Douglas’ Hitchhiker’s Guide trilogy by reminding young graduates of the value of curiosity and encouraging them to ask questions, take chances, unashamedly make mistakes, and fully embrace their fears in order to attain success. You can watch the full video below.
Many fundamental questions in marine conservation demand adequate knowledge of the spatial dynamics of faunal taxa, individually and collectively. Without robust maps of biota distributions, be they measured or predicted, informed choices about ocean use remain a significant challenge that can reduce the effectiveness of conservation interventions and leave human-wildlife conflicts unresolved. The field of conservation biogeography seeks to forge quantitative theories about global patterns of life and the underlying environmental mechanisms that cause as well as maintain them. This is a useful pursuit on both theoretical and practical grounds; by unravelling drivers of habitat preferences at a range of resolutions, species-specific needs can be better understood, conservation priorities correctly identified and aligned, reserve designs rigorously planned, and management practices optimised. Accordingly, the discipline has recently emerged as a pivotal tool in addressing the Anthropocene-induced biodiversity crisis, with particular relevance in the pelagic biome where our overall grasp of the ecological requirements of many organisms remains several degrees of magnitude coarser than on land.
In this thesis, I take a hierarchical approach to conservation biogeography in order to assess the role of seabed topography and geomorphology as determinants of pelagic predator hotspots in the eastern Indian Ocean. The prediction of animal occurrence based on landscape and other abiotic variables (termed physical surrogacy) has been pursued as a way to achieve conservation outcomes when detailed biological information is either unavailable or incomplete. It may thus be a pragmatic, though largely unvalidated, framework for identifying critical areas for oceanic fishes and sharks, which are currently amongst of the most data-deficient of extant vertebrates.
I first explore the concept of terrain complexity and find that the majority of modern geomorphometrics are mathematically redundant, meaning they can be simplified to a small set of independent characteristics that successfully capture different facets of topographic variability. Using these constructs as inputs to statistical models, I then demonstrate that they can prove influential proxies of mobile predator distributions, albeit their performance is not ubiquitously strong. Specifically, in a continental-scale analysis of historical fisheries catches, I reveal that tunas, marlins and mackerels associate closely with submarine canyons throughout parts of a dynamic and heterogeneous ocean basin. Based on regional models of a tropical seascape, I further show that fish and shark assemblages are linked to a lattice of submerged carbonate banks, with species richness rising in proximity to the features’ summits. Such examples of (potentially persistent) habitat associations have direct implications for the management of marine megafauna and the design of offshore protected areas, which currently seldom coincide with predator aggregation sites.
Insofar as documenting and disentangling these associations relies on appropriate data collection tools, I also test a novel visual monitoring technique suitable for use in topographically complex environments typically considered inaccessible for sampling. Trial of the method off the Perth coast (Western Australia) provides initial insights into the likely patterns of animal occupancy around a newly-proclaimed marine reserve, and indicates that a revision of the reserve’s boundaries may be warranted to minimise anthropogenic impacts.
Despite their charisma, economic value and ecological importance, migratory fishes and sharks face increasing threats and could benefit hugely from representative protection both within national waters and on the high seas. I suggest that topography may be harnessed as a blueprint to assist the delineation of priority conservation areas for species previously deemed too mobile to respond to static landscapes.
SEAFLOOR IN 3D
Three-dimensional models of selected areas of the West Australian seafloor reveal that sites with identical mean depths can boast drastically different terrains. Figure adapted from Bouchet et al. 2015 (Biological Reviews).
NORTHERN BLUE BACKYARD
Sample images from the NERP survey of the Oceanic Shoals Commonwealth Marine Reserve highlight rich communities of pelagic vertebrates, including sharks, rays, turtles and cetaceans. (A) Manta ray Manta birostris, (B) Killer whale Orcinus orca, (C) Australian blacktip shark Carcharhinus tilstoni and (D) Bottlenose dolphin Tursiops truncatus. Copyright: Dr. Phil Bouchet.
PUBLICATIONS ARISING FROM THIS THESIS
Bouchet PJ, Meeuwig JJ. 2015. Drifting baited stereo-videography: A novel sampling tool for surveying pelagic wildlife in offshore marine reserves. Ecosphere, 6: art137.
Bouchet P, Meeuwig JJ, Salgado Kent C, Letessier T, Jenner C. 2015. Topographic determinants of mobile predator hotspots: Current knowledge and future directions. Biological Reviews, 90(3): 699-728.
Bouchet PJ, Meeuwig JJ, Huang Z, Letessier TB, Nichol SL, Caley MJ, Watson RA. Submitted. Continental-scale models of pelagic fish hotspots: Using geomorphometry as a conservation planning tool for mobile predators in Western Australia. Global Ecology and Biogeography.
Bouchet PJ, Letessier TB, Nichol SL, Caley MJ, Meeuwig JJ. In prep. Spatial dimensions of pelagic diversity in a geodiverse offshore seascape.
Letessier TB, Bouchet PJ, Meeuwig JJ. In press. Sampling mobile oceanic fishes and sharks: Implications for fisheries and conservation planning. Biological Reviews.
Letessier TB, Bouchet PJ, Reisser, J, Meeuwig JJ. 2014. Baited videography reveals remote foraging and migration behaviour of sea turtles. Marine Biodiversity. DOI: 10.1007/s12526-014-0287-3
Letessier TB, Meeuwig JJ, Kemp K, Groves L, Bouchet PJ, Chapuis L, Vianna GM, Gollock M, Koldewey HJ. 2013. Assessing pelagic fish populations: The application of demersal video techniques to the mid-water environment. Methods in Oceanography, 8: 41-55.
FUNDING & ACKNOWLEDGEMENTS
This project was made possible by the scientific foresight and financial commitment of the National Environmental Research Program (NERP)’s Marine Biodiversity Hub, a collaborative partnership administered and supported by the Australian Government’s Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC). NERP Marine Biodiversity Hub partners include the Institute of Marine and Antarctic Studies (IMAS), the University of Tasmania (UTAS); the Commonwealth Scientific and Industrial Research Organisation (CSIRO); Geoscience Australia (GA); the Australian Institute of Marine Science (AIMS); Museum Victoria (MV); Charles Darwin University (CDU) and the University of Western Australia (UWA). Additional funding was gratefully received from the Australian Academy of Science as part of the 2013 Margaret Middleton Fund Award for endangered Australian native vertebrate animals. Phil Bouchet held a UWA scholarship for international research fees during the course of his candidature.
Rowley Shoals and Montebello Islands Expedition
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