New Zealand Journal of Marine and Freshwater Research abstracts
Evolution of operational management procedures for the South African
West Coast rock lobster (Jasus lalandii) fishery
S. J. Johnston
D. S. Butterworth
Marine Resource Assessment and Management Group
Department of Mathematics and Applied Mathematics
University of Cape Town
Rondebosch, 7701
South Africa
Abstract The commercial fishery for Jasus lalandii,
the South Africa West Coast rock lobster, began in the late 1800s and at
its peak in the early 1950s yielded an annual catch of 18 000 t. Although
this annual catch has dropped to only some 2000 t over recent years, the
fishery remains South Africa’s third most valuable for landed value. The
primary reason for the low total allowable catch (TAC) over these recent
years has been a marked drop in somatic growth rate that occurred at the
end of the 1980s, for reasons that remain unexplained. A key problem in formulating
TAC recommendations with longer-term objectives in mind, has been uncertainties
about likely future trends, particularly in somatic growth and recruitment.
To address this problem, an “operational management procedure” (OMP) was
adopted in 1997 and has twice been re-evaluated and modified (in 2000 and
2003) in the light of further data and changing perceptions of resource dynamics.
The history of this process is reviewed, concentrating on the most recent
modification. In particular, a summary is given of the process by which the
merits of alternative management procedures were evaluated over a range of
important uncertainties about the dynamics of the resource. This summary
includes a discussion of the key trade-offs between resource rebuilding,
future TAC trends and TAC variability, and the eventual choice that was made.
The paper concludes by listing a number of lessons learnt concerning best
practice for OMP development as this process evolved.
Keywords rock lobster; Jasus lalandii; management
procedure; uncertainty; trade-off
M04015; Online publication date 8 June 2005 Received 8 February 2004;
accepted 4 November 2004
New Zealand Journal of Marine and Freshwater Research, 2005, Vol. 39:
687-702
0028-8330/05/3903-0687 © The Royal Society of New Zealand 2005
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