Current Stock Status Relative to the stock’s lowest point in 1993/94 there has been significant rebuilding in terms of exploitable biomass. This rebuilding has been so successful, with significant increases in catch rates and biomass, that none of the original performance measures (except area-based egg production) provide useful insights into the stock status and how it is performing over more recent years. The fishery performance measures are currently under formal review and consequently, for this year, more details are given in this assessment of model based performance measures in order to characterize the status of the resource. The distribution of effort and catch (the fleet dynamics) continues to exhibit strong trends which appear to be related to a particular sequence of recruitment events. Effort peaked in 1992/1993 (2.07 million pot lifts), with current effort only 60.6% of that amount (1.25 million pot lifts). Current effort is 65.7% of a secondary peak of pre-quota effort in 1996/1997 (1.90 million pot lifts), and 78.7% of effort in 1998/1999, the first year of the quota management system (1.59 million pot lifts). The level of rebuilding is evident in the reduced amount of effort required to catch the TAC; this is especially significant given that there has also been a shift to more winter fishing, when catch rates are generally lower. The geographical distribution of effort is changing with the amount of effort dropping significantly in assessment areas 2 to 6 and rising significantly in areas 1, 7, and 8 (dropping in the north and rising in the south). At the same time, catches are dropping or stable in the Northern four assessment areas and are rising in the Southern four areas. Combining these trends in effort and catch, catch rates are dropping or stable in the Northern four areas and rising in the southern four assessment areas. Consequently the stock is continuing to rebuild in the south while rebuilding appears to have slowed in the north. The number of vessels reporting any catches of rock lobster in 2005/2006 is down to 224 from 344 in 1994/1995.
History
Publication title
Fishery Assessment Report
Commissioning body
Tasmanian Aquaculture and Fisheries Institute
Issue
2007
Pagination
63
Department/School
Institute for Marine and Antarctic Studies
Publisher
Tasmanian Aquaculture and Fisheries Institute
Place of publication
Hobart, Tasmania
Rights statement
Copyright 2006 Tasmanian Aquaculture and Fisheries Institute, Institute of Marine and Antarctic Studies, University of Tasmania.