Long-term Trends in Demersal Fishery Resources

A brief review is presented of the structure of the Ghanaian fishing fleet, and of the changes they induced on their resource base since the 1960s. These change consist of a reduction of the biomass of longer lived fishes, particularly in shallower waters, and in conjunction with environmental fluctuation, the creation of opportunities for invasive species of fish (triggerfish Balistes carolinensis) and invertebrates (e.g., scallops) to experience short-lived population outburst. The relative impacts of fishing and environmental changes in generating these outbursts are difficult to disentangle. It is evident, however, that the effort jointly exerted by several Ghanaian fleets onto their supporting fisheries resources is excessive and that the country would benefit from a reduction of that effort.