Comparative Study of the Ichthyological Production between Two Hydrosystems under Protection and Open Access in Aby Lagoon, Côte d'Ivoire

The main objective of this study is to highlight the role of fisheries management in the productivity and sustainability of fisheries-related activities. The study ran from December 2020 to May 2021 and from December 2021 to May 2022. Sampling was carried out on catches from an artisanal fishery using purse seines in both fishing environments. The results for the reserves showed a reduction in fishing effort in year 2 compared with year 1. In terms of profit per fishing trip in the reserves. The highest Catch Per Unit Effort (CPUE) was recorded in Ehoussou (3,526.87 kg) and Abiaty (2,624 kg) during the first year, and in Bèdoubegnin/Mauricekro (1,774 kg), Abiaty (1,288.88 kg), Aby (1,283.57 kg) and Eplemlan (1,240 kg) during the second year. The largest quantities of fish caught per reserve were observed at Ehoussou (56,430 Kg) and Abiaty (39,360 Kg) during year 1, and at Aby (17,970 Kg) and Bèdoubegnin/Mauricekro (17,740 Kg) during year 2. On the portion of the Aby lagoon to which access is free, the fishing effort amounted to 2,315 trips (year 1), compared with 1,812 trips in year 2. In this free-fishing zone, the CPUE was 291.12 kg in year 1, compared with 193.17 kg in year 2. The quantity of fish produced annually in this unprotected portion was 673,935 kg in year 1, and 350,029 kg in year 2. These results showed that for the small amount of fishing effort made in the reserves (250 trips) over the sampling period, the average profit from one fishing trip was as high as possible (1,177.31 kg). The opposite was observed in the lagoon portion with free access, since with an effort of 4,127 fishing trips over the entire survey period, the average gain from one fishing trip was only 248.11 kg. This study serves to alert fisheries managers to the fact that productivity is not correlated with the increase in fishing pressure, and that the profit per fishing team in terms of biomass is higher in reserves under protection. This experiment needs to be replicated in other hydro-systems of bio-ecological interest, to better safeguard fishing in a sustainable manner.