Pond grow-out trials for sandfish (Holothuria scabra) in New Caledonia

Sandfish (Holothuria scabra) is a high-value tropical sea cucumber widely distributed in the shallow waters of the Indo-Pacific. In New Caledonia, sandfish are locally called ‘gris’ and have been harvested since the 1840s. The WorldFish Center in New Caledonia grew cultured juvenile sandfish in earthen ponds to assess the potential for farming the species. In this paper, we report on pond culture grow-out of sandfish from small juveniles to market size in a 21-month trial. Sandfish in two ex-shrimp ponds reached mean weights of 390 and 441 g after 19 and 21 months, respectively. The overall average weight gains were estimated to be 0.60 g and 0.77 g per animal per day, and overall survival to be 69% and 41%, respectively. Some mortality occurred in ponds due to high water temperature and salinity. Beche-de-mer produced from the pond-grown sandfish had a darker skin colour and most was classified as grade-A, although cultured animals lost twice as much weight as the wild sandfish during processing. Positive features were the homogeneous sizes of pond-grown animals and the potential for reduced fluctuations in numbers. Recommendations for improving sandfish farming in ponds centre on the management of animal density and the practice of alternating earthen ponds.