Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

Using patterns of population structure to revive a crashed multispecies fishery

  • Christopher Bird, Hawaii Institute of Marine Biology, University of Hawaii, United States
  • Dr Brenden Holland, Center for Conservation and Research Training, University of Hawaii, United States
  • Dr Brian Bowen, Hawaii Institute of Marine Biology, University of Hawaii, United States
  • Dr Robert Toonen, Hawaii Institute of Marine Biology, University of Hawaii, United States

    • The marine environment offers few obvious barriers to dispersal for broadcast-spawning species, yet population genetic structure can occur on a scale much smaller than the theoretical limits of larval dispersal. Comparative phylogeographic studies of sympatric sister species can illuminate how differences in life history, behavior, and habitat affinity influence population partitioning. Here we use an mtDNA marker (612 bp of COI) to investigate population structure of three culturally important, commercially harvested, endemic, Hawaiian, broadcast-spawning limpets (Cellana spp.) with planktonic larvae that are competent to settle within four days. All three species exhibit significant population structure and isolation by distance, but the spatial scales of partitioning differ among the species. Cellana talcosa (n=105) exhibits strong population structure between Kauai and the other main Hawaiian Islands (MHI) where the maximum channel width is 117 km, and no shared haplotypes were observed (PhiCT=0.30, P<0.001). In contrast, populations of C. exarata (n=149) and C. sandwicensis (n=109) exhibit weaker population structure within the MHI (PhiST=0.03-0.04, P<0.05), and between the MHI and the Northwestern Hawaiian Islands (PhiST =0.03-0.09, P<0.01), where the maximum channel width is 260 km. Biogeographic range and microhabitat use were correlated with estimates of dispersal, while phylogenetic affiliation and minimum pelagic larval duration were poor predictors of population partitioning. Despite similar life histories, these closely-related limpets have contrasting patterns of population structure, illustrating the danger of relying on model species in management initiatives to predict population structure and dispersal in the context of marine protected area delineation.

    Conference Organiser - ICMS Pty Ltd