Genetic Analyses and Simulations of Larval Dispersal Reveal Distinct Populations and Directional Connectivity across the Range of the Hawaiian Grouper (Epinephelus quernus)

Malia Ana J Rivera,Kimberly R Andrews,George K Roderick,Donald R Kobayashi,Christopher Kelley,Johanna L K Wren,Robert J Toonen

doi:10.1155/2011/765353

Abstract

Integration of ecological and genetic data to study patterns of biological connectivity can aid in ecosystem-based management. Here we investigated connectivity of the Hawaiian grouperEpinephelus quernus, a species of management concern within the Main Hawaiian Islands (MHI), by comparing genetic analyses with simulated larval dispersal patterns across the species range in the Hawaiian Archipelago and Johnston Atoll. Larval simulations revealed higher dispersal from the MHI to the Northwestern Hawaiian Islands (NWHI) than in the opposite direction and evidence for a dispersal corridor between Johnston and the middle of the Hawaiian Archipelago. Genetic analyses using mitochondrial DNA (mtDNA) control region sequences and microsatellites revealed relatively high connectivity across the Hawaiian Archipelago, with the exception of genetically distinct populations and higher mtDNA diversity in the mid-Archipelago. These analyses support the preservation of the mid-archipelago as a source of genetic diversity and a region of connectivity with locations outside the Hawaiian Archipelago. Additionally, our evidence for directional dispersal away from the MHI lends caution to any management decisions that would rely on the NWHI replenishing depleted MHI stocks.

Highlights

Growing numbers of studies are integrating ecological and genetic data to investigate population connectivity [1,2,3]
We investigated connectivity of the Hawaiian grouper Epinephelus quernus, a species of management concern within the Main Hawaiian Islands (MHI), by comparing genetic analyses with simulated larval dispersal patterns across the species range in the Hawaiian Archipelago and Johnston Atoll
Our evidence for directional dispersal away from the MHI lends caution to any management decisions that would rely on the Northwestern Hawaiian Islands (NWHI) replenishing depleted MHI stocks

Summary

Introduction

Growing numbers of studies are integrating ecological and genetic data to investigate population connectivity [1,2,3] These techniques have the potential to facilitate ecosystembased management by increasing our understanding of the interactions between organisms and their environment. For marine species, these techniques may be valuable because population genetic studies of these species are often thought to suffer from low power and to be of limited value for management [4,5,6]. Studies of marine species commonly reveal weak population genetic structure that is described as “chaotic” due to its apparent unpredictability over space and time [7,8,9,10]. Violations of the assumptions of commonly used population genetic statistical models are thought to be strong for marine populations; many of these populations have spatial and temporal heterogeneity in abundance and settlement rates which violate the assumptions of constant population

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Discussion

Conclusion