[PAST EVENT] A biophysical larval-fish dispersal model for the Great Barrier Reef

October 14, 2015
12pm - 1pm
VIMS - Watermen's Hall, Classroom A/B
1375 Greate Road
Gloucester Point, VA 23062Map this location
Fisheries Science Noon Seminar Series

Speaker: Jeffrey M Leis, Institute of Marine and Antarctic Studies, University of Tasmania, Hobart and Australian Museum Research Institute, Sydney, Australia

Title: GBR-Larvo: A biophysical larval-fish dispersal model for the Great Barrier Reef based on empirical larval and adult behaviour data

Abstract: Larval dispersal models increasingly include aspects of larval behaviour as advocated by Staaterman and Paris (2013) rather than simply assuming passive larvae. However, few such models include a full range of dispersal-relevant larval behaviours. In many models, adult behaviours such as the timing (seasonal, lunar and diel) of when propagules are placed into the ocean, or just where this takes place are over-generalized. Further, even if empirically-based behaviour is included, variation in behaviour among individual propagules is seldom included: rather, mean behaviour is used (e.g., only the "centre of gravity" of vertical distribution, ignoring variation around the mean), resulting in unrealistically constrained dispersal outcomes. This model for fishes that live on coral reefs of the Great Barrier Reef uses empirical measures of vertical distribution, swimming performance and orientation of larvae, and the variation in and ontogeny of these behaviours. Rather than assume that if larvae enter a "detection zone" around settlement habitat they will settle, the model allows to settle only those virtual larvae with sufficient swimming ability to overcome currents within the detection zone. The model uses empirical spawning data to release the propagules at appropriate times and places. Importantly, fish-egg buoyancy is taken into account. Although incubation periods for reef-fish eggs are typically < 24 hrs, buoyancy of eggs can strongly influence modelled dispersal outcomes. Examples of how our inclusion of behaviour influences modelled dispersal outcomes are discussed. The model's hydrodynamic component is a 3D development of the 2D model of James, Armsworth, Mason and Bode (2002). In collaboration with Geoff Jones' research team, we tested the model's predictions with genetic parentage methods, matching settled juveniles of a serranid with spawning aggregations: preliminary results will be presented.

: Jeffrey Leis has been studying the early-life history of warm-water marine fishes for over 40 years, most of it in the Indo-Pacific region in collaboration with a wide range of excellent colleagues. He is currently conducting research on larval fishes as Honorary Research Professor at the Institute for Marine and Antarctic Studies of the University of Tasmania and as Senior Fellow at the Australian Museum. Professor Leis interests include the taxonomy of marine larval fishes, the use ontogeny to assess relationships of fishes, the distributional ecology of fish larvae, and the behaviour and sensory abilities of larvae of demersal fishes, and how these influence their dispersal and settlement. He is the recipient of the K. Radway Allen Medal from the Australian Society for Fish Biology, the Bleeker Award for excellence in ecological research on Indo-Pacific fishes, and the Robert Gibbs Award for excellence in systematic research on fishes from the American Society of Ichthyologists and Herpetologists. He is continually impressed with the morphological adaptations of fish larvae for life in the pelagic environment, and with their behavioural abilities, and keen to let others know about these fascinating animals. He has published three major books on fish larvae and more than 100 papers in international journals.

[[v|ehilton,Professor Eric Hilton]]