Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic

Senegalese and Mauritanian fisheries exploit the same species of white grouper but have different exploitation histories. In Senegal, white grouper has been fished for a very long time (since the 1970s), whereas it is relatively recent in Mauritania. In addition, Senegalese small-scale fishermen exp...

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Main Authors: Beyah Meissa, Florian Quemper, Modou Thiaw, Kamarel Ba, Brahim Mohamed Tfeil, Momodou S. Jallow, Jérome Guitton, Rishi Sharma, Didier Gascuel
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Fishes
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Online Access:https://www.mdpi.com/2410-3888/10/3/98
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author Beyah Meissa
Florian Quemper
Modou Thiaw
Kamarel Ba
Brahim Mohamed Tfeil
Momodou S. Jallow
Jérome Guitton
Rishi Sharma
Didier Gascuel
author_facet Beyah Meissa
Florian Quemper
Modou Thiaw
Kamarel Ba
Brahim Mohamed Tfeil
Momodou S. Jallow
Jérome Guitton
Rishi Sharma
Didier Gascuel
author_sort Beyah Meissa
collection DOAJ
description Senegalese and Mauritanian fisheries exploit the same species of white grouper but have different exploitation histories. In Senegal, white grouper has been fished for a very long time (since the 1970s), whereas it is relatively recent in Mauritania. In addition, Senegalese small-scale fishermen exploit this species in the Gambia. Nevertheless, mainly for practical reasons, all attempts to assess the status of the stock have, until recently, been conducted at a national level except by the FAO CECAF North working group who assumed it to be a single stock for the three countries. However, their analysis gives very little attention to length frequency data, even though the fisheries have different selectivity that are likely to affect exploitation rates. In addition, management is mainly focused on length, with no TACs or quotas established at national or sub-regional levels. This work is based on a large compilation of available data from the databases of three countries complemented by the collection of length frequencies data within the framework of the European Union Demerstem/PESCAO project. Two approaches were combined (catch and length-based model) to establish a reliable diagnosis of the state of this resource, along with a spatial analysis to identify the areas most affected by fishing. The results obtained for the sub-region show a severe overexploitation of biomass revealed by the Bayesian biomass production surplus model (JABBA). Stock status indicators show overfishing with low biomass (B/Bmsy = 0.34) and high fishing mortality (F/Fmsy = 5.79). Overall, the trajectory of the state of the stock illustrated by the Kobe figure indicates that the white grouper stock has been overexploited since the 1990s. Fishing pressure reached its highest levels during the recent period of 2016–2018 and these results are consistent when considering stock assessment at the national level. However, the length-based model (LBB) indicates a deterioration in average length, particularly in Senegal and the Gambia, especially since 2014. Adults, who migrate, are more abundant in Mauritania. Therefore, due to its high market value, white grouper is increasingly targeted, resulting in an unprecedented rise in fishing mortality over the past decade, particularly among larger individuals, with the most significant pressure observed in Senegal and the Gambia. Given that the stock spans three countries, a coordinated management approach at the stock level is essential. However, management measures must also be adapted to the specific status of the population within each country. Without such a concerted effort, this trend is likely to persist, further endangering the resource.
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spelling doaj-art-8b48759df4414cf3bec696943ba5f9df2025-08-20T02:11:05ZengMDPI AGFishes2410-38882025-02-011039810.3390/fishes10030098Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central AtlanticBeyah Meissa0Florian Quemper1Modou Thiaw2Kamarel Ba3Brahim Mohamed Tfeil4Momodou S. Jallow5Jérome Guitton6Rishi Sharma7Didier Gascuel8Institut Mauritanien de Recherches Océanographiques et des Pêches, Cansado, Nouadhibou BP 22, MauritaniaUMR DECOD Institut Agro Rennes-Angers, Ifremer, Inrae, 65 rue de Saint-Brieuc, F 35042 Rennes, FranceCentre de Recherches Océanographiques de Dakar-Thiaroye, Hanne, Dakar BP 2241, SenegalCentre de Recherches Océanographiques de Dakar-Thiaroye, Hanne, Dakar BP 2241, SenegalInstitut Mauritanien de Recherches Océanographiques et des Pêches, Cansado, Nouadhibou BP 22, MauritaniaDepartment of Fisheries, 6 Marina Parade, Banjul 00220, The GambiaUMR DECOD Institut Agro Rennes-Angers, Ifremer, Inrae, 65 rue de Saint-Brieuc, F 35042 Rennes, FranceFisheries Resources Officer, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00153 Rome, ItalyUMR DECOD Institut Agro Rennes-Angers, Ifremer, Inrae, 65 rue de Saint-Brieuc, F 35042 Rennes, FranceSenegalese and Mauritanian fisheries exploit the same species of white grouper but have different exploitation histories. In Senegal, white grouper has been fished for a very long time (since the 1970s), whereas it is relatively recent in Mauritania. In addition, Senegalese small-scale fishermen exploit this species in the Gambia. Nevertheless, mainly for practical reasons, all attempts to assess the status of the stock have, until recently, been conducted at a national level except by the FAO CECAF North working group who assumed it to be a single stock for the three countries. However, their analysis gives very little attention to length frequency data, even though the fisheries have different selectivity that are likely to affect exploitation rates. In addition, management is mainly focused on length, with no TACs or quotas established at national or sub-regional levels. This work is based on a large compilation of available data from the databases of three countries complemented by the collection of length frequencies data within the framework of the European Union Demerstem/PESCAO project. Two approaches were combined (catch and length-based model) to establish a reliable diagnosis of the state of this resource, along with a spatial analysis to identify the areas most affected by fishing. The results obtained for the sub-region show a severe overexploitation of biomass revealed by the Bayesian biomass production surplus model (JABBA). Stock status indicators show overfishing with low biomass (B/Bmsy = 0.34) and high fishing mortality (F/Fmsy = 5.79). Overall, the trajectory of the state of the stock illustrated by the Kobe figure indicates that the white grouper stock has been overexploited since the 1990s. Fishing pressure reached its highest levels during the recent period of 2016–2018 and these results are consistent when considering stock assessment at the national level. However, the length-based model (LBB) indicates a deterioration in average length, particularly in Senegal and the Gambia, especially since 2014. Adults, who migrate, are more abundant in Mauritania. Therefore, due to its high market value, white grouper is increasingly targeted, resulting in an unprecedented rise in fishing mortality over the past decade, particularly among larger individuals, with the most significant pressure observed in Senegal and the Gambia. Given that the stock spans three countries, a coordinated management approach at the stock level is essential. However, management measures must also be adapted to the specific status of the population within each country. Without such a concerted effort, this trend is likely to persist, further endangering the resource.https://www.mdpi.com/2410-3888/10/3/98grouperassessmentMauritaniaSenegalThe GambiaJABBA
spellingShingle Beyah Meissa
Florian Quemper
Modou Thiaw
Kamarel Ba
Brahim Mohamed Tfeil
Momodou S. Jallow
Jérome Guitton
Rishi Sharma
Didier Gascuel
Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic
Fishes
grouper
assessment
Mauritania
Senegal
The Gambia
JABBA
title Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic
title_full Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic
title_fullStr Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic
title_full_unstemmed Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic
title_short Assessment of over Four Decades the Status of White Grouper <i>Epinephelus aeneus</i> (Geoffroy Saint-Hilaire, 1817) Population in the Eastern Central Atlantic
title_sort assessment of over four decades the status of white grouper i epinephelus aeneus i geoffroy saint hilaire 1817 population in the eastern central atlantic
topic grouper
assessment
Mauritania
Senegal
The Gambia
JABBA
url https://www.mdpi.com/2410-3888/10/3/98
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