A fishery’s long-term profitability is intrinsically linked to its sustainability. We know that pipi populations are patchily distributed, display large natural fluctuations in abundance, and that overharvesting can drive localised depletion. Careful management is needed to ensure Victoria’s pipis remain a sustainable resource.

Sustainable fisheries management requires an understanding of how harvested populations are structured (population connectivity), and the spatio-temporal dynamics in their abundance and demography (assessed by monitoring). Previous work indicates that Australian pipi stocks consist of two large, reproductively isolated, groupings occurring on Australia’s east and south coasts, however, we lack information on more relevant finer-scale stock structure. Our study will provide novel research that will determine the spatial and temporal patterns in harvestable pipi biomass, the recruitment potential of individual stocks, and connectivity / genetic stock structuring among Victorian populations. We will identify pipi populations that can sustain ongoing commercial harvest, and those that are vulnerable to over-exploitation. Our project outputs will help set objective and informed catch quotas.

We need information on local-scale pipi demography because: the abundance, reproductive characteristics and size structure of pipis provides essential information to set sustainable catch rates. Stock biomass and individual size are indicators of recruitment variation, and a direct measure of harvest impact, together determining the sustainability of the fishery.

We need information on pipi stock structure and connectivity because: if certain stocks are isolated and largely dependent on local recruitment, they likely have reduced recruitment potential and are vulnerable to over-fishing. Conversely, if pipi stocks across the state are highly connected, then they are expected be more resilient to harvesting pressure due to their greater potential for recruitment and replenishment from external sources.

We need to develop fishery-dependent and fishery-independent survey methods because: sound fisheries management relies on the cost-effective and accurate estimation of biomass and abundance.