Fisheries and Resources Monitoring System

Senegalese hake, Benguela hake - Mauritania, Senegal and Gambia
Marine Resource  Fact Sheet
CECAF Scientific advice 2016
Senegalese hake, Benguela hake - Mauritania, Senegal and Gambia
Fact Sheet Citation  
Merlu noir (Merluccius senegalensis et Merluccius polli) - Mauritanie, Sénégal et Gambie; Black hake (Merluccius senegalensis and Merluccius polli) - Mauritania, Senegal and Gambia
Owned byFood and Agriculture Organization (FAO) – More
Related observationsLocate in inventorydisplay tree map
Geographic extent of Senegalese hake, Benguela hake - Mauritania, Senegal and Gambia
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Regional
Management unit: Yes        Reference year: 2012
Biological State and Trend
State & Trend Descriptors
Exploitation rateFcur/F0.1 = 50% ; Fcur/FMSY = 45%Not applicable
Abundance levelBcur/B0.1 = 127% ; Bcur/BMSY = 140%Not applicable
Aq Res State Trend
Exploitation stateNot fully exploited

Fcur/F0.1: Ratio between the observed fishing mortality coefficient during the last year of the series and F0.1.
Fcur/FMSY: Ratio between the observed fishing mortality coefficient during the last year of the series and the coefficient that would give a maximum sustainable yield over the long term.
Bcur/B0.1: Ratio between the estimated biomass for the last year and the biomass corresponding to F0.1.
Bcur/BMSY: Ratio between the estimated biomass for the last year and the biomass corresponding to FMSY.
Unless otherwise indicated, the indicators were based on the Schaefer dynamic production stock assessment model.
Habitat and Biology
Climatic zone: Tropical.   Bottom type: Soft bottom clean sand; Soft bottom muddy or muddy-sand.   Depth zone: Shelf (50 m - 200 m); Slope (200 m - 1000 m).   Horizontal distribution: Neritic; Oceanic.   Vertical distribution: Demersal.  

Geographical Distribution
Jurisdictional distribution: Shared between nations

Water Area Overview
Spatial Scale: Regional

Geo References
Resource Structure
Considered a single stock: Yes

No detailed studies on black hake stock identity are available. The two black hake species are found in Moroccan, Mauritanian and Senegalese waters. The Senegalese hake (Merluccius senegalensis), found exclusively in the Eastern Central Atlantic, is caught between 33° N and 10° N, whereas the tropical African hake (Merluccius polli) is fished between 25° N and 18.5° S (Fernández et al., 2008; Lloris, et al., 2003). Due to their morphological resemblance and overlapping occurrence at certain depths, both species are mixed in catches and are commonly marketed as Merluccius spp. Stock assessment is therefore carried out as a single stock.
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 21033tonnes1983
Catch 15598tonnes1984
Catch 11558tonnes1985
Catch 12861tonnes1986
Catch 11960tonnes1987
Catch 11648tonnes1988
Catch 14534tonnes1989
Catch 13380tonnes1990
Catch 13464tonnes1991
Catch 20217tonnes1992
Catch 22606tonnes1993
Catch 16091tonnes1994
Catch 19037tonnes1995
Catch 16281tonnes1996
Catch 16795tonnes1997
Catch 18538tonnes1998
Catch 17080tonnes1999
Catch 15354tonnes2000
Catch 18150tonnes2001
Catch 17430tonnes2002
Catch 13624tonnes2003
Catch 12307tonnes2004
Catch 10238tonnes2005
Catch 8744tonnes2006
Catch 8300tonnes2007
Catch 8219tonnes2008
Catch 8363tonnes2009
Catch 6476tonnes2010
Catch 7763tonnes2011
Catch 6883tonnes2012

Assessment year: 2013
The CECAF Working Groups have adopted the following Biological Reference Points (BRPs):
- Limit Reference points: BMSY and FMSY
- Target Reference Points: B0.1 and F0.1
Stock status is assigned based on current estimates of fishing mortality (Fcur) and biomass (Bcur) relative to these target and limit reference points (Bcur/BMSY, Fcur/FMSY, Bcur/B0.1, Fcur/F0.1). The results from the stock assessment of this stock are found under the “Biological state and trend section”.
Assessment Model
Type:  Biomass-aggregated
Schaefer dynamic production model

For the assessments of black hake in Mauritania, total catch and abundance indices of Spanish trawlers targeting fresh hake were used. The CPUE series of this fleet was used as abundance index since it is the most complete and representative of the resource abundance. Although these data cover the whole period 1983-2012, the latest years from 2000 to 2012 are representative of the new fishing strategy period.Two assessment tests were carried out with the global model for the Mauritanian zone:<br/> - A first test with the total catch and CPUE abundance indices from 1983 to 2012. To fit this long data series to the models, the environmental effect was taken into account.<br/> - A second test with the latest total catch and CPUE abundance indices from 2000 to 2012, considering the most recent fishing strategy. No environmental effect was used. The parameters used were r= 0.50 per year, K=50 000 tonnes and BI/K=30 percent.<br/>
Assessment Model
Type:  Size-structured
Length Cohort Analysis (LCA)

Data on length structure collected by the IEO teams from landings of hake vessels in 1991–2012 were available. However, in view of several uncertainties about the middle of the series (this is explained in the 2010 WG), only the 2004-2012 data were used to run the LCA analytical model (see Section 2.4.3 of FAO 2016b).
Yield per Recruit Analysis (Y/R)
Scientific Advice

Taking into consideration the contradictory results of the assessments, the Working Group recommends obtaining information on the catches of black hake as bycatch from other fleets (retained and discarded) and their sizes through an observation programme. The current fishing effort should be increased by 10 percent, whilst waiting for confirmation on the state of the stocks.
Management unit: Yes
Source of information
FAO. 2016a. Fishery Committee for the Eastern Central Atlantic, Report of the seventh session of the Scientific Sub-Committee, Tenerife, Spain, 14–16 October 2015 / Comité des pêches pour l’Atlantique Centre-Est Rapport de la septième session du Sous-Comité scientifique. Tenerife, Espagne 14-16 octobre 2015. FAO Fisheries and Aquaculture Report / FAO Rapport sur les pêches et l’aquaculture No. 1128. Rome, Italy.  Click to open
FAO. 2016b. Report of the FAO/CECAF Working Group on the Assessment of Demersal Resources – Subgroup North. Fuengirola, Spain, 18–27 November 2013. / Rapport du Groupe de travail FAO/COPACE sur l’évaluation des ressources démersales – Sousgroupe Nord. Fuengirola, Espagne, 18-27 novembre 2013. CECAF/ECAF Series/COPACE/PACE Séries. No. 15/77. Rome, Italy/Italie.  Click to open
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