WORM FARMING IN SOUTH AUSTRALIA - PERINEREIS VALLATA SEEMS TO HAVE IT ALL?

Worm farming is somewhat removed from mainstream aquaculture and yet has much to recommend it.  There are high-value, if somewhat small and local markets for marine worms as bait for recreational fishing with retail prices up to US$150 per kg.  Looking to the future the properties and nutritional values of worms are suitable as an ingredient in specialised aquafeed diets such as for broodstock maturation, larval rearing and for aquarium fishes.  If systems could be developed for cost effective production of large-scale worm biomass it could even become a supplemental ingredient for production aquafeeds. In addition worm farming has the potential for integration into other forms of aquaculture with worm beds acting as bioremediation systems for effluent from a range of aquaculture production systems.

This presentation reviews the progress of research to comprehensively assess the potential of a temperate marine worm for aquaculture in South Australia, with an initial focus on the bait market.  Criteria for selection of bait worms for aquaculture include sourcing of founder stock, capacity to breed in captivity, survival and good growth rates in artificial systems and attractive market properties.  In the case of bait worms, market properties including achieving suitable size, ease of harvest and postharvest shelf-life and of course the capacity to catch fish.

Our research selected a southern Australian temperate species Perinereis vallata as the best candidate from a number of alternatives.  Our research has demonstrated that captive breeding is possible and can be achieved year-round in environmentally controlled facilities.  Specific growth rates of up to 4-11 % day^-1 (with the highest rates during the early growth phase) have been achieved indicating the potential to produce market sized worms of minimum weight 600 mg within less than six months.  Research has also demonstrated strong growth rates in stock fed only on waste derived from a commercial abalone farm.  Recent research has indicated that a post-harvest shelf-life of over two weeks is achievable using a range of different media under certain specified conditions, which would be adequate to supply worms for use by recreational fishers.  Supplementary research has indicated that the worms have the capacity to synthesise their own highly unsaturated fatty acids (HUFAs) demonstrating their potential nutritional value as an ingredient in specialised aquafeeds.

The presentation will summarise achievements to date and discuss some of the challenges for commercialisation of the farming of this species.