Sea cucumbers are valuable export products. Technology on their culture is expanding rapidly to help meet market demand in China, and to help relieve exploited fisheries. The sandfish. Holothuria scabra, is the most valued of tropical species. It is the focus of a restocking research project in New Caledonia, funded by ACIAR, provincial governments and the government of France. Sandfish are deposit-feeding detritivores of shallow muddy/sandy habitats, thus earthen ponds provide suitable conditions.
The sandfish, Holothuria scabra, is a heavily exploited sea cucumber species. Minimising stress in the transportation of hatchery-produced sandfish juveniles to release sites is critical for successful restocking. Replicate groups (n=4) of 20 hatchery-produced juveniles (1–5 g) were held in plastic bags with oxygen under 6 transport durations (0, 2, 4, 8, 12 and 24 h), two media (water or saturated sponge), and two temperature regimes (ambient and cool). Subsequent deaths and sand burrowing of the groups in release chambers were monitored for 5 days.
This study investigated the daily activities of juvenile sea cucumbers Holothuria scabra Jaeger.
Fisheries management personnel and other stakeholders need a means of ensuring consistency when identifying the various species exploited within a fishery. We conducted a questionnaire-based survey to evaluate the usefulness of SPC’s “Pacific Island sea cucumber and beche-de-mer identification cards”. Quality photographs of live animals were the most valuable information. The usefulness of other information depended on the user group, and whether users were from large, developed countries or small Pacific Island nations.
Conservative management should be the key to sustainable sea cucumber fisheries, and the release of hatchery-produced juveniles could speed the recovery of depleted stocks. Advances in methods for culturing sea cucumbers have allowed juveniles to be produced in high numbers for restocking. However, the lack of research on release methods and assessment of stock recovery jeopardizes the success of restocking programs. A key criterion before releasing juveniles should be genetic similarity of stocks at release sites and sites of broodstock collection.
ICLARM – The World Fish Center recently completed a three-year project in Solomon Islands, which found that H. scabra is the species most suited to restocking in the tropical Pacific and South Asia. The project established the methods for rearing juvenile sandfish en masse in simple, landbased nursery systems.
Small-scale fishers are often believed to receive marginal earnings for seafood relative to other value- chain actors but proportionate incomes across different traded species are rarely compared. This study compares value chains for 15 species of sea cucumbers between Fiji and Kiribati using data collected on sale prices of dried products (bêche-de-mer) from fishers to middlemen and exporters, export prices and market retail prices in China.
Over a 3-year period (1996–1998), reproduction of the commercial sea cucumber Holothuria scabra (Jaeger, 1833) was investigated in the Solomon Islands to determine the spawning pattern and whether gametogenesis is continuous or seasonal. The gonad consisted of a single cohort of tubules that developed uniformly. Macroscopic examination of the gonads revealed that mature gametes were present throughout the year. Individuals with gonads at different stages of maturity were present in most samples. Partly spawned gonads were prevalent in females, whereas mature gonads were prevalent in males.
The International Centre for Living Aquatic Resources Management (ICLARM) in the Solomon Islands has a 5-year project to develop methods for mass rearing of tropical sea cucumbers for the purpose of enhancing wild stocks (ICLARM, 1995). The project is now in its third year and has produced over 150,000 juveniles up to 120 mm in length. The detachment of settled juveniles has been a technical constraint to the culture of H. scabra in Solomon Islands. The aim of the study was to examine whether the methods used for detachment of S. japonicus were appropriate for H. scabra.
The aim of the current study was to describe the distribution and population structure of newly-settled juveniles, young and adults of H. scabra with respect to the characteristics of their habitat, and to investigate the aggregative and burrowing behaviours that might influence the population structure and spatial distribution. Recruitment over a yearly period, and movement and growth of juveniles on different substratum types were also monitored to determine their influence on the spatial distribution of H. scabra in the Solomon Islands.