University of Cape Town
MARAM_Tristan_2023_MAY_06 (Nightingale assessment update 2023).pdf (1.36 MB)

Nightingale island rock lobster (Jasus tristani) assessment updated for 2023

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posted on 2023-09-19, 06:53 authored by Susan HollowaySusan Holloway, Doug ButterworthDoug Butterworth

This paper provides an updated assessment of the rock lobster resource at Nightingale island. This assessment includes updated data from both the commercial fishery and the biomass surveys. The continued recent (2013+) high GLM standardised CPUE values (and biomass survey index values) at the island, which were not anticipated earlier, suggest that the possible negative impact of the OLIVA incident on adults was overestimated previously and that the associated additional mortality on juveniles was much less than originally assumed. The 2023 Reference Case (RC) assessment assumes zero adult mortality in 2011 due to the OLIVA incident, but continues to assume an associated additional 20% once off juvenile mortality in 2011. The current spawning biomass is estimated to be at a healthy 99% of its pristine level.



Department of Mathematics and Applied Mathematics, University of Cape Town