Enhancing the performance of quota managed fisheries using seasonality information: The case of the Portuguese artisanal dredge fleet

Several fisheries across the world are managed by a quota regime. These quotas can be set yearly, monthly, weekly or daily. However, for some fish species demand seasonality may occur, which should be taken into consideration in the establishment of the quota (especially in those fisheries managed by daily or monthly quotas). This would allow fishermen to catch more fish at times of the year with higher demand in detriment of periods when demand is low. The present work investigates the existence of demand seasonality for bivalves from the artisanal dredge fleet. This fleet operates along the entire coast of the Portugal mainland. The analysis of fleets' revenue efficiency is assessed with Data Envelopment Analysis models, and the monthly seasonality effects on the revenue efficiency were tested using a Tobit regression. The results revealed that on the South coast there is a strong demand in the summer whereas on the western coast (northwest and southwest fishing areas) demand increases during Christmas and New Year festivities. Since this fishery is managed by weekly/daily quotas, it is proposed that these quotas should be redistributed in order to adjust them to periods of higher demand, thereby increasing the profitability of the vessels. The approach followed could be applied to similar fisheries worldwide. •Monthly seasonality effects on the vessels’ revenue efficiency were tested using a Tobit regression.•It was shown that revenue efficiency in the dredge fleet is related to demand.•In the South coast revenue efficiency of the fleet was higher in the summer.•It is proposed to redistribute daily/weekly fishing quotas to periods of higher demand.•The approach followed can be applied to similar fisheries worldwide.