Larval connectivity patterns of the North Indo-West Pacific coral reefs

PLoS One. 2019 Jul 23;14(7):e0219913. doi: 10.1371/journal.pone.0219913. eCollection 2019.

Abstract

Coral reefs of the North Indo-West Pacific provide important ecosystem services to the region but are subjected to multiple local and global threats. Strengthening management measures necessitate understanding the variability of larval connectivity and bridging global connectivity models to local scales. An individual-based Lagrangian biophysical model was used to simulate connectivity between coral reefs for three organisms with different early life history characteristics: a coral (Acropora millepora), a sea urchin (Tripneustes gratilla), and a reef fish (Epinephelus sp). Connectivity metrics and reef clusters were computed from the settlement probability matrices. Fitted power law functions derived from the dispersal kernels provided relative probabilities of connection given only the distance between reefs, and demonstrated that 95% of the larvae across organisms settled within a third of their maximum settlement distances. The magnitude of the connectivity metric values of reef cells were sensitive to differences both in the type of organism and temporal variability. Seasonal variability of connections was more dominant than interannual variability. However, despite these differences, the moderate to high correlation of metrics between organisms and seasonal matrices suggest that the spatial patterns are relatively similar between reefs. A cluster analysis based on the Bray-Curtis Dissimilarity of sink and source connections synthesized the inherent variability of these multiple large connectivity matrices. Through this, similarities in regional connectivity patterns were determined at various cluster sizes depending on the scale of interest. The validity of the model is supported by 1) the simulated dispersal kernels being within the range of reported parentage analysis estimates; and, 2) the clusters that emerged reflect the dispersal barriers implied by previously published population genetics studies. The tools presented here (dispersal kernels, temporal variability maps and reef clustering) can be used to include regional patterns of connectivity into the spatial management of coral reefs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Distribution
  • Animals
  • Anthozoa / growth & development
  • Anthozoa / physiology*
  • Cluster Analysis
  • Coral Reefs*
  • Larva / physiology
  • Models, Biological*
  • Pacific Ocean
  • Seasons

Grants and funding

PRP received an MSc scholarship for the period of January 2016 to June 2017 through the Capturing Coral Reef and Related Ecosystem Services (CCRES) project (www.ccres.net), funded by the Global Environment Facility, the World Bank and The University of Queensland. Additional funding was provided by the Office of the Vice Chancellor for Research and Development Outright Research Grant for the Project entitled "Assessing coral reef condition and connections for MPA network development” under the Program “Enhancing coral reef management through tools assessing coral reef conditions and connections.” The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.