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Aquaculture

Depletion of wild abalone stocks has occurred in most countries, with significant reductions in commercial harvesting over the past forty years. Abalone are vulnerable to localised overfishing and poaching which has contributed to their global stock reduction. To meet consumer demand for this delicacy, sea-based and land-based cultured abalone farming is increasing in many countries. Stock from dedicated cultured abalone hatcheries are under consideration in many countries for use in ‘ranching’ efforts to restore over exploited areas, particularly where abalone species are listed as endangered or threatened.

In some countries such as Australia, following successful spawning and fertilisation of eggs, the first week of the life cycle is spent in a specialised tank until the fertilised eggs hatch into free floating larvae. These are then transferred to a junvenile tank system with algae encrusted plates for settlement without water flow. They remain on settlement plates until large enough to be transferred to a ‘grow-out’ tank or sea-cage. Grow out tanks are varied in their size, shape and depth. Every farm utilises different methods to maintain health and promote growth of their species. Some cultured abalone farms are using selective breeding to improve their commercial product traits and grow out characteristics.

Cultured abalone farming is hampered by the quality and quantity of macroalgae sources available worldwide. Some countries in regions rich in macroalgae sources harvest wild macroalgae for their sea-based and land-based farms. However some countries are now successfully using high quality manufactured food, or a combination of macroalgae and manufactured feed depending on the developmental stage.