Dispersal has a major effect on ecological and evolutionary dynamics. We are interested in better understanding dispersal in the coral reef environment, characterizing dispersal potential in a way that facilitates better predictive modelling of dispersal patterns, and understanding the demographic and community-level implications of dispersal. Projects include:
Existing models of dispersal typically make very crude assumptions about the growth and development of larvae of larvae. We have formulated and calibrated models for the survival, and the acquisition and loss of settlement competence in coral larvae, which better capture within-cohort variability in those dynamics, with implications for both recruitment back to the natal reef, and also very long-distance dispersal. For fishes, we are developing models that realistically characterize the development of swimming ability in reef fishes.
Many models of larval dispersal characterize hydrodynamics on a relatively coarse scale – to coarse to resolve mesoscale hydrodynamic features, like lee reef eddies, that are known to concentrate larvae and hypothesized to be mechanisms that reduce the dispersal of coral larvae. We are investigating the extent to which fish swimming strategies may exploit even transient eddies to reduce their energy expenditure and reduce their dispersal distances. We are also developing and evaluating methods to approximate the retention times expected for particular reef sizes, shapes, and circulation regimes.
In many organisms with lecithotrophic (non-feeding) larvae, delayed settlement has adverse effects on post-settlement survival and growth. We are quantifying these effects in corals.
For lecithotrophs living in a warm environment, coral larvae are incredibly long-lived. We are testing hypothesized mechanisms for very extended coral longevity, and for the effects of delayed settlement, by quantifying metabolic rates and depletion of energy stores throughout larval lifetimes.
Graham, E. M., A. H. Baird, and S. R. Connolly. 2008. Survival dynamics of scleractinian coral larvae and implications for dispersal. Coral Reefs 27: 529-539.
Connolly, S.R. and A.H. Baird. 2010. Estimating dispersal potential for marine larvae: dynamic models applied to scleractinian corals. Ecology 91: 3572-3583.
Cetina-Heredia, P. and S. R. Connolly. 2011. A simple approximation for larval retention around reefs. Coral Reefs 30: 593-605.