| Popis: |
Summary Management of fish resources in the Western Indian Ocean is complicated due to the lack of data on the basic biology and landing statistics for exploited fish species. In this paper, a database including biological parameters, length frequency distributions and catches of Epinephelus gabriellae in Oman according to fleet components has been established to develop a management plan for its sustainable exploitation. Length cohort analyses and yield per recruit were examined by simulating changes in fishing effort in length at first capture and by introducing a seasonal ban for trawlers. The results showed a high sensitivity to the applied value of natural mortality (M). (i) With M = 0.40, a healthy status of the stock is observed; however, with M values of 0.20 and 0.15 the stock appears slightly overexploited, and actual F exceeds 10 and 30% of the F01 level, respectively. (ii) A moderate increase of length at first capture would not significantly affect the long-term yield or stock spawning biomass; however, a substantial length increase would in the long-term lead to a decrease in yields for the artisanal fleet using traps. (iii) A seasonal ban regulation for trawlers would not have a significant effect on the sustainable yield, but if the fishing effort were to increase considerably, a significant long-term gain in yield would be obtained with a closed season from April-September. |
