Sandfish hatchery techniques - English version - ACIAR

PROMISING APPLICATIONS FOR HATCHERY-REARED
SANDFISH
Provided methods can be developed for releasing cultured sandfish in the wild that ensure a high proportion
of them survive, hatchery-reared juveniles could be used for restocking, stock enhancement and sea ranching
programmes.
h Restocking involves releasing cultured juveniles to restore the spawning biomass of a severely depleted
fishery to a level where it can once again provide regular, substantial yields.
h Stock enhancement is designed to increase the productivity of a fishery that is still operating reasonably
well by overcoming shortfalls in the natural supply of juveniles.
h Sea ranching differs from restocking and stock enhancement in that there is no intention of allowing the
released animals to augment spawning biomass or particular age-classes within the population. Instead,
animals are placed in the wild to be gathered at a larger size in ‘put and take’ operations.
The availability of cultured juvenile sandfish also provides potential for farming this species in earthen ponds or sea
pens. However, sandfish should not be reared in ponds together with shrimp because shrimp prey on sandfish.
The following questions need to be answered to fully assess the potential for pond farming of sandfish:
h What is the optimal density for stocking sandfish into ponds including those previously used to farm
shrimp?
h Do sandfish have a beneficial effect on the sediments of recently harvested and filled shrimp ponds?
h Do sandfish need to be thinned out, or does food have to be added, later in the production cycle to
maintain good growth rates?
h If enrichment of sediments is needed, what is the best method?
h Are some sediments better than others for rearing sandfish?
Figure 52. Hatchery-reared sandfish.
PROMiSiNG APPLiCATiONS FOR HATCHERY-REARED SANDFiSH
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