High intraspecific genetic connectivity in the Indo-Pacific bonefishes: implications for conservation and management

Abstract

Bonefishes (Genus Albula) across the global tropics support premier destination catch and release fisheries. In parts of the Indo-Pacific harvest also occurs, often unregulated. Vital information on species ranges and stock structure is lacking for the Indo-Pacific bonefishes. Population declines, data deficiencies, and the absence of management plans result in conservation concerns. Research on bonefishes has also been hindered by taxonomic uncertainty stemming from morphological cryptics and inconsistent nomenclature. Genetic identification is necessary for some bonefishes, due to highly conserved morphology. This study explores verified species occurrences and genetic connectivity for six Indo-Pacific bonefishes. Samples were obtained from 210 bonefish from 16 locations across the Indian and Pacific Oceans. Genetic identification was determined through cytochrome b sequence analyses and population structure assessed with 17 microsatellite loci. Two bonefishes (A. glossodonta and A. oligolepis) are partially sympatric, suggesting multiple species may be supporting the fishery. Additional data are required to fully elucidate fishery composition at local scales and the geographic extent of species ranges. The IUCN Red List vulnerable A. glossodonta may experience increased fishing pressure due to its extensive Indo-Pacific range. Stock structure data support intraspecific genetic connectivity across broad spatial scales. Results suggested weak, non-geographic, genetic population structure in A. glossodonta, and panmixia in A. oligolepis and A. gilberti. The present study highlights the need for further research, and suggests conservation and management strategies for the Indo-Pac bonefishes may need both local and regional components to prevent further declines and localized collapse.