There is a broad need for population discrimination and dispersal information for the long term viability of both the wild harvest fishery and for the successful development of a sustainable sea ranching program. Internationally sea cucumber fisheries have shown themselves to be vulnerable to over fishing if not effectively managed. With little or no information on stock delineation or population dispersal, successful management must rely on very risk adverse management measures. This greatly limits the viability and productivity of the commercial wild harvest fishery. Also continuing long term to manage the stock on the assumption that it is a single entity poses considerable environmental risk if this management assumption is wrong. Understanding the population structure of H. scabra will allow for the development of far more specific management controls and also inform industry in relation to managing fishing programs towards efficienct and sustainable production. Successful management of the wild harvest fishery long term is dependent on identifying the stocks being managed.
Tasmanian Seafoods is the current sea cucumber licensee in the Northern Territory and is committed to
the development of H. scabra aquaculture and sea ranching. In addition to the fisheries management objectives outlined above there is a recognised need to understand the population genetic structure of H.scabra from the currently fished areas in order to inform the planned restocking program as part of the sustainable management of the fishery. This will ensure that the genetic structure of wild populations is taken into account when releasing hatchery produced progeny into the wild populations and is reflected in an appropriate genetic management strategy for hatchery stocks.
Accurate information on dispersal and population isolation will be crucial to the effective management
and development of the industry, and to protect genetic integrity if genetically divergent localised
populations exist along the N.T. coastline.
Sandfish (Holothuria scabra), a commercially important species of Sea Cucumber, are fished off the northern Australian coast. Elsewhere in the Asia-Pacific region, where they are commonly fished, they have been found to be particularly vulnerable to over-exploitation. Currently, as little is known about their biology and population structure, they are fished off the Northern Territory using conservative methods, by limited access, area restrictions based on an arbitrary line on the water and trigger limits based on historical data. With a view to improving their management and the sustainability of the fishery, a propagation and stock enhancement program is under development. Basic research including knowledge of the population genetic structure is required to enable informed decisions on the sustainable management of existing fisheries and to develop appropriate policies and strategies for the ranching program planned by Tasmanian Seafoods.