Sustainability assessment of the Torres Strait sea cucumber fishery (T1.4)

Task leader: Dr Timothy Skewes, CSIRO Marine Research.

The (modern) sea cucumber fishery in Torres Strait provides a substantial source of income and employment for Islander communities with catches peaking at over 1400 t (wet weight) in 1995. Sandfish on Warrior Reef provided the bulk of the early catches, until a survey in 1998 found that the population was severely depleted and it the fishery closed. Subsequent surveys in January 2000 and October 2002 found a small recovery, but the population was still considered heavily depleted. Since 1998, the fishery has mostly targeted black and white teatfish and surf redfish. A survey in March 2002 found that black teatfish and surf redfish were also overexploited, and they were closed in January 2003. Other targeted species were not considered overexploited, but it was recommended that their catches be restricted and the populations closely monitored.

This work is based on two abundance surveys, one of sandfish on Warrior Reef in early 2004 and a survey of the east Torres Strait fishery in early 2005. The survey data would provide estimates of the distribution and abundance of all commercial species in the fishery, and high resolution estimates of trends in abundance for comparison with previous surveys in 1995 and 2002.

For the sandfish population, the surveys will complete a series of 5 surveys during 1995 to 2004. The surveys will provide information on poorly understood population parameters for input into developing population models. We will then use this information for formulating robust sustainable management strategies, and for designing optimal sampling strategies for future monitoring. We will also gather information on gross environmental parameters, not only for assessing the effects of fishing, but for mapping and monitoring the environment in general.

Objectives

• Conduct surveys of the sea cucumber population and their habitats in Torres Strait.
• Provide information on stock status of all commercial species, population dynamics and recovery of depleted species, fisheries ecology and possible environmental effects of fishing.
• Recommend management strategies for sustainable harvest of sea cucumber in Torres Strait, and optimal sampling strategies for future monitoring.

Outcomes
The stock status and management recommendations will be used directly by management agencies to implement sustainable management strategies. This will be done in close consultation with Islander representative bodies.

Information on key biological and ecological parameters will be used in improving our understanding of the population dynamics of sea cucumber populations and for improved fishery models for formulating sustainable management strategies. Recommendations for future research and monitoring will be used by management and Islander bodies to set future research priorities.

The continued assessment of the sea cucumber stock, management strategy evaluation and analysis of environmental data will benefit Environmental Assessments (SA, EAR, ESD, etc.), Regional Marine Planing, and Conservation Planning.