Project number: 2002-057
Project Status:
Completed
Budget expenditure: $195,620.00
Principal Investigator: Jeremy Lyle
Organisation: University of Tasmania (UTAS)
Project start/end date: 29 Jun 2002 - 30 Oct 2006
Contact:
FRDC

Need

The development of live fish markets in the early 1990s has created a strong demand for temperate reef species, specifically banded morwong and wrasse. Prior to these developments these species had little commercial value, often being used as bait for rock lobster. This demand has resulted in major increases in fishing pressure directed at the reef fish communities and while there has been much work on tropical species, our knowledge of how temperate reef species respond to fishing pressure is comparatively poor.

Although banded morwong and wrasse have vastly different life history characteristics (early life history, reproductive strategies and age and growth), they are basically sedentary, exhibiting population structuring at a small spatial scale. However, related to the general mis-match between the spatial scales of fishery management, fishing operations and fish population structure, there is considerable potential for localised depletion, and hence for serial depletion of the resources.

In Tasmania, steady declines in catch and catch rates have led to concerns that fishing has already significantly impacted banded morwong stocks. In Victoria, a more controlled approach to the development of the fishery has been taken, with an initial three-year developmental phase to be followed by a review to ascertain long-term sustainability.

Although key fishery indicators, catches and catch rates (analysed at state-wide or regional scales) have remained relatively stable for wrasse, there are anecdotal reports of localised depletions from Tasmania. Furthermore, the selective removal of adult male blue-throat wrasse has the potential to impact significantly on egg production even if female spawner biomass is adequate.

There is therefore an urgent need to develop robust stock assessments, appropriate performance indicators and monitoring strategies for these species if they are to be managed sustainably. However, being small-scale fisheries based on sedentary, spatially structured populations, an innovative approach to fishery and biological monitoring and data analyses is required. Since Tasmanian, Victorian and South Australian fisheries share many common characteristics there are considerable benefits from a coordinated approach to this issue. This study will also have broader implications for other small-scale and data poor fisheries.

Objectives

1. Develop appropriate and meaningful performance indicators for sedentary reef-dwelling species, using banded morwong and wrasse as models.
2. Determine minimum information requirements for the effective stock assessment of these species.
3. Develop appropriate model frameworks for testing the performance indicators developed for these fisheries.

Final report

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