Abstract
The production models previously used to describe the Western Australian rock lobster fishery have been re-examined with more recent data in order to assess the effects of recent management changes. Stock-recruitment and catchability parameters were also estimated by fitting a Schnute/Deriso delay-difference model to the catch/effort time series. Observed abundance indices for recruitment to the fishery were introduced to reflect environmental variation affecting pre-recruits. Parameters estimated from the delay-difference model suggest that recruitment is independent of the spawning stock for the range of spawning stock sizes which have been experienced. At equilibrium, the average biomass associated with the reduced pot quota is estimated to be 5% greater than that which might have resulted with the original pot quota, but the annual catch is expected to be approximately 6% less. The study suggests that improved handling may have increased annual recruitment, and that introduction of multiple escape gaps may have further enhanced recruitment.