The maximum sustainable yield (MSY) of legal-size spiny lobsters Panulirus argus (Latreille) was estimated at 37 (±SE 7.7) × 103 animals by regression of catch per unit effort (CPUE) on total effort. A graphical plot of P. argus fishery catch and effort data for lobster seasons from 1975/76 to 1986/87 resulted in a second estimate of the P. argus MSY of 30 × 103 lobsters per season by a quadratic regression of catch on total effort. A graphical plot of catch on total fishing effort data for the Guinea chick Lobster Panulirus guttatus (Latreille), with a quadratic curve fit (R2 = 0.612), resulted in an estimate of MSY of approximately 33 × 103 lobsters per calendar year. The 1985 and 1986 fishery catches of Guinea chick lobsters were close to the MSY. There was an overall increase in the CPUE of P. argus lobsters (1975/76–1986/87), whereas there was an overall decline in the CPUE of P. guttatus spiny lobsters over the same time period.
The two species interannual patterns of change of CPUE followed that of sea temperature change on the Bermuda Platform; superimposed was a 5-year cycle of CPUE, which was particularly noticeable with P. guttatus lobsters, suggesting a causal relationship with a 5-year cycle in the annual mean temperature of sea surface waters, averaged from six temperature stations on the Platform. Annual yield of P. argus lobsters was correlated with Platform average sea temperature at the 10% level (Spearman rank test).
Both P. guttatus and P. argus yields on Platform sea temperature were parabolic in form. Platform CPUE of Guinea chicks on Hamilton Harbour temperature also suggested a parabolic relationship in the range 22–26 °C (coefficient of determination R2 = 0.43). There was clearly a parabolic association between P. argus CPUE and Hamilton Harbour temperature over the same temperature range (R2 = 0.93). It is suggested that the Lellis and Russell quadratic model for survival and growth of P. argus postlarvae may be extended to juvenile P. argus to explain these findings.
Evans, A.J.; Evans, C.R. Fisheries ecology of spiny lobsters Panulirus argus (Latreille) and Panulirus guttatus (Latreille) on the Bermuda Platform: estimates of sustainable yields and observations on trends in abundance. Fisheries Research (1995) 24 (2) 113-128. [DOI: 10.1016/0165-7836(94)00367-6]