A new species of electric ray of the genus Narcine Henle, 1834 from the South-Western Indian Ocean (Chondrichthyes: Torpediniformes: Narcinidae)     

《African Journal of Marine Science》2013,35(1):135-144

The Namibian linefishery is a multisector fishery, with recreational and commercial sectors targeting overlapping species. Prior to 1990, catch data were recorded for the boat sector, but little research was done on the population dynamics of any of the species. Hence, none of the stocks were assessed owing to the lack of parameter estimates for fisheries modelling. Current management regulations for the Namibian linefishery are therefore not based on scientific investigations but, for historical reasons, were adapted from South African legislation for similar species. From 1994, linefish research in Namibia focused on the life history and population dynamics of silver kob Argyrosomus inodorus and West Coast steenbras Lithognathus aureti, important species in both commercial and recreational sectors. A roving-roving creel survey was used to determine effort and catches of recreational shore-anglers. Both species were assessed using yield-per-recruit models. Based on the results, reduced daily bag limits and the implementation of size limits for the recreational sector were proposed. For the commercial sector, the introduction of a total allowable catch would seem to be the best option. Results from an economic survey indicated that the recreational sector earns six times more for the country annually than the commercial sector.  相似文献   

An economic comparison of the commercial and recreational linefisheries in Namibia     

《African Journal of Marine Science》2013,35(3):577-584

The most important Namibian linefish species, the silver kob Argyrosomus inodorus, is currently heavily exploited, and in order to ensure its survival catch restrictions are being introduced. However, kob are exploit ed oth by recreational anglers and by commercial vessels, and it is important to examine the economics of these fisheries in order to determine where catch restrictions will do the least harm to the economy. Data from a survey of commercial fishing vessels are compared with results from earlier surveys of recreational anglers to determine economic values and impacts from both fisheries. The economic benefits are shown to be greatest in recreational angling, less in commercial fishing by large vessels and least in commercial skiboat fishing. This sudy also shows that catch restrictions would do less harm to the economy if applied to the commercial linefishing sector rather than to recreational angling.  相似文献