Assessment over Four Decades the Status of White Grouper Population in the Eastern Central Atlantic

The Senegalese and Mauritanian fisheries exploit the same white grouper species but have relatively different exploitation histories. In Senegal, the white grouper fishery is very old (since the 1970s), while it is relatively recent in Mauritania. Nevertheless, mainly for practical reasons, all attempts to assess the status of the stock have, until recently, been conducted at national scale. For the assessment and management of the white grouper stock, we assumed a single stock in the two countries, like the FAO CECAF North working group. This work is so based on a large compilation of the data available in the databases of the two countries in addition to the collection of new data within the framework of the European DEMERSTEM/PESCAO project. Two models are using to establish a reliable diagnosis of the state of this resource in addition to a spatial analysis to determine the areas most affected by fishing. The results obtained, at the scale of the two countries, show a severe overexploitation of biomass is revealed by the Bayesian biomass production surplus model (JABBA). Stock status indicators show a state of overfishing (B/Bmsy=0.24) with high fishing mortality (F/Fmsy=7.7). Overall, the trajectory of the state of the stock illustrated by the Kobe figure indicates an overexploitation of the biomass of the white grouper stock since the 90s except that the fishing pressure has never been as high as its level over the recent period 2016 -2018. This species is particularly targeted by the different artisanal gears, unfortunately, apart from the measures edited in the fishing code (first catch size of 30 cm TL), there is no management of this resource by TACs or quotas and the fishing effort is slowly monitored. However, given its market value, White grouper is increasingly sought after, which explains the unprecedented level of fishing mortality during the last decade.