Landscape Ecology

, Volume 23, Supplement 1, pp 19–36 | Cite as

Modeling population connectivity by ocean currents, a graph-theoretic approach for marine conservation

  • Eric A. TremlEmail author
  • Patrick N. Halpin
  • Dean L. Urban
  • Lincoln F. Pratson
Research Article


The dispersal of individuals among marine populations is of great importance to metapopulation dynamics, population persistence, and species expansion. Understanding this connectivity between distant populations is key to their effective conservation and management. For many marine species, population connectivity is determined largely by ocean currents transporting larvae and juveniles between distant patches of suitable habitat. Recent work has focused on the biophysics of marine larval dispersal and its importance to population dynamics, although few studies have evaluated the spatial and temporal patterns of this potential dispersal. Here, we show how an Eulerian advection–diffusion approach can be used to model the dispersal of coral larvae between reefs throughout the Tropical Pacific. We illustrate how this connectivity can be analyzed using graph theory—an effective approach for exploring patterns in spatial connections, as well as for determining the importance of each site and pathway to local and regional connectivity. Results indicate that the scale (average distance) of dispersal in the Pacific is on the order of 50–150 km, consistent with recent studies in the Caribbean (Cowen, et al. 2006). Patterns in the dispersal graphs highlight pathways for larval dispersal along major ocean currents and through island chains. A series of critical island ‘stepping stones’ are discovered providing potential pathways across the equatorial currents and connecting distant island groups. Patterns in these dispersal graphs highlight possible pathways for species expansions, reveal connected upstream/downstream populations, and suggest areas that might be prioritized for marine conservation efforts.


Coral dispersal Graph theory Marine protected areas Networks Tropical Pacific 



The authors thank the members of the Landscape Ecology Lab and the Marine Geospatial Ecology Lab at Duke University for their technical support and insightful comments. Don Olson, University of Miami, RSMAS, and two anonymous reviewers provided helpful comments. Data and assistance was also provided by Yi Chao, Jet Propulsion Laboratory, California. Funding for this research was provided by the Fagatele Bay National Marine Sanctuary, the American Samoa Coral Reef Advisory Group, and the David and Lucile Packard Foundation. Initial work on modeling marine connectivity was supported by an International Society for Reef Studies/Ocean Conservancy fellowship awarded to E. A. Treml.


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Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Eric A. Treml
    • 1
    Email author
  • Patrick N. Halpin
    • 1
  • Dean L. Urban
    • 2
  • Lincoln F. Pratson
    • 3
  1. 1.Marine Geospatial Ecology Lab, Nicholas School of the Environment and Earth SciencesLSRC, Duke UniversityDurhamUSA
  2. 2.Landscape Ecology Lab, Nicholas School of the Environment and Earth SciencesLSRC, Duke UniversityDurhamUSA
  3. 3.Nicholas School of the Environment and Earth SciencesOld Chem, Duke UniversityDurhamUSA

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