Analysis of the chokka squid : Loligo reynaudi d`Orbigny, 1845 : log-book data in South Africa

Abstract

The total annual catch from the log-book and Food & Agriculture Organization were compared. Annual catch per unit effort of the Loligo reynaudi was investigated. There were five vessel size groups and eight fishing areas identified. A Simple Analysis of Variance was used to test the effect of the year, quarter, region, area on the CPUE and General Linear Model was used to standardize the CPUE. The trend in the annual biomass from the surveys and the standardized CPUE were examined and compared.

The log-book data had highest annual catch in 2004 and lowest in 2001. While the FAO statistics had the highest peak in 2005. Closed season imposed from October to November and different peaks in the spawning periods had an influence on the monthly CPUE. Vessel size group 5 had the highest CPUE, while, size group 1 had the lowest. Port Alfred showed higher and Seal Bay lower CPUE. The relationship between the survey biomass and standardized annual CPUE revealed an increase in the biomass in the surveys and a fluctuation in the CPUE