Genetics and Connectivity

Genetic approaches are helping us:

  • positively identify fish species caught by local fishermen
  • definitively associate scientific names with local names
  • understand the potential ecological connections between reefs
  • learn about the role of typhoons in the spread of a weedy species of coral

Connectivity and Management

If each island has populations that are unique genetically, then these populations are more sensitive to fishing, and management needs to be locally focused. On the other hand, if populations from across an atoll, or even across the entire Outer Island chain are related, it means that the populations are larger in scale and management could be more regional in scope.

Our work to date has focused on samples of fish caught by local fishers, as well as a weedy species of Montipora coral, Holothuria atra sea cucumbers, and clownfishes.

This work has involved local science teams, the One People One Reef science team, and classes at Cabrillo College and University of California Santa Cruz.


Crane, N.L., Paddack, M.J., Nelson, P.A., Abelson, A., Rulmal, J. & Bernardi, G. (2016) Corallimorph and Montipora Reefs in Ulithi Atoll, Micronesia: documenting unusual reefs. Journal of the Ocean Science Foundation, 21, 10–17.

Bernardi, Giacomo; Peter Nelson, Michelle Paddack, John Rulmal Jr, and Nicole Crane. 2018. Genomic islands of divergence in the Yellow Tang and the Brushtail Tang Surgeonfishes. Ecology and Evolution DOI: 10.1002/ece3.4417

  • We found that pairs of siblings were found on the east and west sides of the atoll of Ulithi, with relationships going north to south.

  • At the scale of the outer islands, we found that islands east of Sorol were more connected to each
    other than any of them were connected to the west of Sorol (Yap and Ulithi). The large ocean
    gap at Sorol might give a plausible explanation for the lowered gene flow levels between these
    two regions

  • Youth from Ulithi Atoll teaching their peers on Woleai Atoll how to sample sea cucumbers

  • Weedy species of Montipora overgrowing other corals

  • Classes at Cabrillo College and University of California at Santa Cruz have helped with lab work and analysis.