Editor: Sean Connolly
Modelling dispersal and connectivity of broadcast spawning corals at the global scale
Article first published online: 11 AUG 2013
© 2013 The Authors. Global Ecology and Biogeography published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Global Ecology and Biogeography
Volume 23, Issue 1, pages 1–11, January 2014
How to Cite
Wood, S., Paris, C. B., Ridgwell, A. and Hendy, E. J. (2014), Modelling dispersal and connectivity of broadcast spawning corals at the global scale. Global Ecology and Biogeography, 23: 1–11. doi: 10.1111/geb.12101
- Issue published online: 3 DEC 2013
- Article first published online: 11 AUG 2013
- NERC postgraduate research grant. Grant Number: NERC/GEOG.SN1604.6525
- NSF-RAPID. Grant Numbers: OCE-10-48697, OCE-0928423
- The Royal Society
- NERC. Grant Number: NE/H017453/1
- UK Natural Environment Research Council. Grant Number: NE/D010012/1
- RCUK Academic Fellowship
- Biophysical modelling;
- coral biogeography;
- coral reefs;
- ‘Coral Triangle’;
- East Pacific Barrier;
- Indian Ocean;
- larval dispersal;
- tropical eastern Pacific
We develop the first global model of connectivity for a generic broadcast spawning coral, and compare the results to connectivity estimates from genetic studies, general biogeographic patterns and theories. We also derive various ‘connectivity indices’ describing relative isolation and source potential between locations.
Modelled oceans 47° S–47° N.
Dispersal of model coral ‘larvae’ was simulated over 8 years using an individual-based biophysical dispersal model driven by 1/12°-resolution surface ocean current data and incorporating individual trait variability (e.g. a phased pre-competency period). Source and arrival locations of modelled larvae on suitable reef habitat gave standardized dispersal paths and relative levels of connectivity.
In the model c. 50% of connections occurred within 50–100 km, with rarer dispersal between regions linking entire oceans in a ‘stepping stone’ fashion. The central Pacific was an almost complete barrier to dispersal, only rarely breached westward from the Galapagos to Marquesas Islands. Areas showing strong isolation also included Hawaii, Easter Island, the Red Sea and the eastern Atlantic. The Indo-West Pacific and Great Barrier Reef showed the highest levels of connectivity, with secondary peaks in the western Indian Ocean, corresponding to areas of enriched coral diversity. The central Indo-Pacific diversity hotspot was overall a greater source than sink for dispersal.
This study provides a global view of connectivity that complements genetic and biogeographic work as well as providing a number of novel findings relevant to biogeographic theories (e.g. the central Indo-Pacific as a dispersal source; Johnston Atoll as the sole ‘stepping-stone’ into Hawaii). Discrepancies with proposed connectivity patterns (e.g. one-way, westward, connectivity across the central Pacific) present hypotheses for future research. The model represents an effective tool for exploring the factors controlling connectivity on this scale and the effects of climate change on future connectivity, and will also aid predictions of future reef distributions.