Widespread Dispersal of the Crown-of-Thorns Sea Star, Acanthaster planci, across the Hawaiian Archipelago and Johnston Atoll

Abstract EN

The population structure of marine species is variable along the Hawaiian Archipelago; thus, it is important to understand dispersal and recruitment patterns for economically and ecologically important taxa to inform Ecosystem-based Management.

Connectivity of the coral-eating crown-of-thorns sea star, Acanthaster planci, was examined from Johnston Atoll and 12 locations across the Hawaiian Archipelago.

Sequences of mitochondrial DNA from 383 individuals were analyzed to infer patterns of gene flow among the Northwestern Hawaiian Islands (NWHIs), the main Hawaiian Islands, and Johnston Atoll.

Population samples were genetically similar across the Hawaiian Archipelago with the exception of the west side of the Big Island of Hawaii, which was significantly differentiated from the majority of Hawaiian samples (pairwise ΦST=0.0607–0.1068, P<.05).

Although differentiated, Hawai`i West shares haplotypes with every other site across the Hawaiian Archipelago.

Johnston Atoll was genetically distinct from every location (pairwise ΦST=0.064–0.13, P<.05) except French Frigate Shoals (ΦST=0.03, P=.10), supporting connectivity between the central NWHIs and Johnston Atoll.

Taken together with the lack of geographic population structure and haplotypes shared among all populations, these results indicate widespread larval dispersal with few restrictions to gene flow along the archipelago.