Seascape genetics and genomics refute long-standing assumptions of recruitment patterns in a commercially important mollusc

Genetic markers provide an effective way of assessing the stock structure and spatial patterns of recruitment of commercial fisheries, assisting in their management and long term sustainability. Current management of the... [ view full abstract ]

Genetic markers provide an effective way of assessing the stock structure and spatial patterns of recruitment of commercial fisheries, assisting in their management and long term sustainability. Current management of the economically important blacklip abalone, Haliotis rubra, in Australia assumes that stock viability is dictated by local recruitment, but genetic data supporting this assumption are lacking for most regions where this species is harvested.
We investigated patterns of gene flow and local genetic structure across the Victorian coastline using microsatellite and genome-wide SNP markers, and a replicated hierarchical sampling regime guided by high definition LIDAR bathymetric imagery. Results indicate high levels of gene flow and no significant genetic structure across 1868 km of the coastline, in contrast to patterns local genetic structure in Tasmanian fisheries. These findings refute previous ecological and genetic studies that indicate larval dispersal is limited and a major reason for trends of slow recovery in depleted fisheries. Our results point to spatially variable patterns of larval supply in this fishery with implications for recruitment essential for long-term recovery from stock depletion. We discuss potential physical and ecological factors that may influence the extent of larval movement and establishment in the fishery, and the implications of our findings with respect to future fisheries management