An industry based mark recapture program to provide stock assessment inputs for the Western Rock Lobster Fishery following introduction of quota management
The recent change to quota management for the Western Rock Lobster fishery has resulted in significant changes in fishing behaviour which has affected the ability to use the long standing empirical catch rate indices that have been a major component of the assessment of lobster stocks (e.g. catch rates of legal, undersize and breeding lobsters). A recent FRDC funded study (2009/019) examined the possibility of using alternative data sources unbiased by effort to monitor biomass levels and exploitation rates using change-in-ratio techniques. The project concluded that:
1. The current data sources available to the fishery had too many unknowns including size and sex specific timing of growth and movement to enable the assessment of exploitation rates using these techniques.
2. A robust tag-recapture study using multiple release periods across different fishing seasons could generate independent assessments of legal biomass and exploitation rates providing an additional baseline level to improve the interpretation of post quota catch rate indices.
A comprehensive tag-recapture study would also provide increased resolution of the movement dynamics of lobsters, especially the rate of migration between management zones. Such information is considered vital by industry in their discussions of the potential benefits of voluntarily reducing quotas to generate increased localised catch rates.
Final report
Fishery-independent survey of the breeding stock and migration of the western rock lobster (Panulirus cygnus)
Evaluating the potential use of change-in-ratio and index removal techniques for determining harvest rates and efficiency increases in the Western Rock Lobster Fishery
Seafood CRC: decision-support tools for economic optimisation of western rocklobster
Mitigation measures to reduce entanglements of migrating whales with commercial fishing gear
Whale entanglements in the western rock lobster (WRL) fishery have increased dramatically with changes in fishing times from a move to a quota. The recent commonwealth Department for the Environment (DE) assessment removed the fishery from five-year export approval, granting a two-year Wildlife Trade Order (WTO) with conditions on whale entanglements. Subsequent correspondence from the Department of Fisheries (DoF) and DE requested information from industry as to what actions will undertaken for the 2014 and 2013 humpback migrations respectively. DoF correspondence indicated a seasonal closure may be implemented ‘in the absence of specific alternative action(s)’. A closure during the humpback migration (1 May-30 Nov) would concentrate fishing into the remaining 5 months resulting in a reduced beach price. Winter beach prices are ~$70/kg, with a move from this high value period into a condensed season reducing GVP by ~$50 million.
TRF project (2013-037) addresses the immediate aspects of the WTO conditions, required by 31 March 2014. Industry groups, while cognizant of the need to address the issue of whale
entanglements are reluctant to proceed with the introduction of gear modifications without a clear scientific rationale behind their testing.
Project 2013-037 is a preliminary study and with its initiations after the 2013 humpback migration has begun, detailed gear testing and migration information was not possible. However it is planned to identify a number of viable mitigation options that are worthy of detailed evaluation in 2014. This project extends on Project 2013-037 addresses the longer term (2014-2015) DE conditions, which would enable year-round market access.