Modelling dispersal and connectivity of broadcast spawning corals at the global scale

Aim 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. Location Modelled oceans 47° S–47° N. Methods 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. Results 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. Conclusions 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.

[1]  L. Levin,et al.  Reproductive Timing Alters Population Connectivity in Marine Metapopulations , 2010, Current Biology.

[2]  Claire B. Paris,et al.  Larval transport pathways from Cuban snapper (Lutjanidae) spawning aggregations based on biophysical modeling , 2005 .

[3]  R. Richmond.  Energetics, competency, and long-distance dispersal of planula larvae of the coral Pocillopora damicornis , 1987 .

[4]  N. Knowlton,et al.  Long Distance Dispersal and Connectivity in Amphi-Atlantic Corals at Regional and Basin Scales , 2011, PloS one.

[5]  P. Glynn,et al.  A biogeographic analysis and review of the far eastern Pacific coral reef region , 2000, Coral Reefs.

[6]  H. Yamano,et al.  Rapid poleward range expansion of tropical reef corals in response to rising sea surface temperatures , 2011 .

[7]  M. Hellberg,et al.  No gene flow across the Eastern Pacific Barrier in the reef‐building coral Porites lobata , 2012, Molecular ecology.

[8]  D. R. Robertson,et al.  Crossing the impassable: genetic connections in 20 reef fishes across the eastern Pacific barrier , 2006, Proceedings of the Royal Society B: Biological Sciences.

[9]  R. Grigg,et al.  Paleoceanography of the Tropical Eastern Pacific Ocean , 1992, Science.

[10]  P. Jokiel,et al.  Drift pumice at Christmas Island and Hawaii: evidence of oceanic dispersal patterns , 2003 .

[11]  Claire B Paris-Limouzy,et al.  A bio‐oceanographic filter to larval dispersal in a reef‐building coral , 2006 .

[12]  A. Baird,et al.  Early post-settlement mortality and the structure of coral assemblages , 2010 .

[13]  Claire B Paris-Limouzy.  Reef interconnectivity/larval dispersal , 2011 .

[14]  J. Kool,et al.  Population connectivity: recent advances and new perspectives , 2012, Landscape Ecology.

[15]  O. Hoegh‐Guldberg,et al.  The phylogeography and connectivity of the latitudinally widespread scleractinian coral Plesiastrea versipora in the Western Pacific , 2002, Molecular ecology.

[16]  D. Bellwood,et al.  INDO‐PACIFIC BIODIVERSITY OF CORAL REEFS: DEVIATIONS FROM A MID‐DOMAIN MODEL , 2003 .

[17]  P. Jokiel.  Ecology, biogeography and evolution of corals in Hawaii. , 1987, Trends in ecology & evolution.

[18]  D. Ayre,et al.  Protection of Genetic Diversity and Maintenance of Connectivity among Reef Corals within Marine Protected Areas , 2008, Conservation biology : the journal of the Society for Conservation Biology.

[19]  Remy Baraille,et al.  The HYCOM (HYbrid Coordinate Ocean Model) data assimilative system , 2007 .

[20]  Jason J. Roberts,et al.  Reproductive output and duration of the pelagic larval stage determine seascape-wide connectivity of marine populations. , 2012, Integrative and comparative biology.

[21]  Claire B Paris-Limouzy,et al.  Climate change and coral reef connectivity , 2009, Coral Reefs.

[22]  David A. Siegel,et al.  Lagrangian descriptions of marine larval dispersion , 2003 .

[23]  K. Black.  The relative importance of local retention and inter-reef dispersal of neutrally buoyant material on coral reefs , 1993, Coral Reefs.

[24]  Akira Okubo,et al.  Oceanic diffusion diagrams , 1971 .

[25]  D. Ayre,et al.  Climate change, genotypic diversity and gene flow in reef-building corals , 2004 .

[26]  Nicola L Foster,et al.  Connectivity of Caribbean coral populations: complementary insights from empirical and modelled gene flow , 2012, Molecular ecology.

[27]  M. Hellberg.  Footprints on water: the genetic wake of dispersal among reefs , 2007, Coral Reefs.

[28]  GENOTYPIC DIVERSITY AND GENE FLOW IN BROODING AND SPAWNING CORALS ALONG THE GREAT BARRIER REEF, AUSTRALIA , 2000, Evolution; international journal of organic evolution.

[29]  J. Gilmour,et al.  Biannual spawning, rapid larval development and evidence of self-seeding for scleractinian corals at an isolated system of reefs , 2009 .

[30]  A. Baird,et al.  Survival dynamics of scleractinian coral larvae and implications for dispersal , 2008, Coral Reefs.

[31]  P. Minchin,et al.  Correlations between sea surface temperature, circulation patterns and the distribution of hermatypic corals of Japan , 1992 .

[32]  P. Jokiel,et al.  The vortex model of coral reef biogeography , 1992 .

[33]  Eric Wolanski,et al.  ‘Sticky water’ enables the retention of larvae in a reef mosaic , 2012 .

[34]  J. E. N. Veron,et al.  Corals in space and time : biogeography and evolution of the Scleractinia , 1995 .

[35]  Claire B. Paris,et al.  Connectivity Modeling System: A probabilistic modeling tool for the multi-scale tracking of biotic and abiotic variability in the ocean , 2013, Environ. Model. Softw..

[36]  A. Baird,et al.  Synthesizing larval competence dynamics and reef-scale retention reveals a high potential for self-recruitment in corals. , 2013, Ecology.

[37]  Ray Berkelmans,et al.  Historical and contemporary factors shape the population genetic structure of the broadcast spawning coral, Acropora millepora, on the Great Barrier Reef , 2011, Molecular ecology.

[38]  Alison Green,et al.  Delineating the Coral Triangle , 2009 .

[39]  Ran Nathan,et al.  The importance of long‐distance dispersal in biodiversity conservation , 2005 .

[40]  Claire B Paris-Limouzy,et al.  Scaling of Connectivity in Marine Populations , 2006, Science.

[41]  E. Hendy,et al.  Environmental controls on the global distribution of shallow‐water coral reefs , 2012 .

[42]  Johnathan T. Kool,et al.  Connectivity and the development of population genetic structure in Indo‐West Pacific coral reef communities , 2011 .

[43]  Steven D. Gaines,et al.  Temperature or Transport? Range Limits in Marine Species Mediated Solely by Flow , 2000, The American Naturalist.

[44]  Andrew H Baird,et al.  Estimating dispersal potential for marine larvae: dynamic models applied to scleractinian corals. , 2010, Ecology.

[45]  Patrick N. Halpin,et al.  Modeling population connectivity by ocean currents, a graph-theoretic approach for marine conservation , 2007, Landscape Ecology.

[46]  V. Pizarro.  How do swimming ability and behaviour affect the dispersal of coral larvae , 2008 .