Principles and science of stocking marine areas with sea cucumbers

Clearly stating the goals of stocking builds an essential platform for success. The scales, methodologies, management and time frames of the interventions can then be matched to the original goals. Stock enhancement, restocking and sea ranching will involve different stocking strategies. The genetic risks to wild stocks must be minimised by preventing translocation of juvenile sea cucumbers to different locations than those where broodstock were collected, unless studies show broad genetic homogeneity of the stock. Cultured juveniles are easily marked by immersion in a fluorochrome solution (e.g. tetracycline or calcein), which provides a long-term, unequivocal means of distinguishing hatchery-produced animals from wild conspecifics. Use of open sea pens is an experimental tool that provides better estimates of early stocking success. Juvenile density can be assessed by searching through sand and mud in quadrats by hand, whereas sub-adults and adults can be surveyed visually in transects with a stratified arrangement. Proponents of sea cucumber stocking in the wild should be conservative and realistic about the expected returns; 1 in 5–10 (10–20%) of released juvenile sea cucumbers surviving to market size is a benchmark. Clear goals, use of existing technology, and realistic expectations in sea ranching and restocking of sea cucumbers will provide the foundation for success.