Fisheries and Resources Monitoring System

Atlantic chub mackerel - Northwest Africa
Marine Resource  Fact Sheet
CECAF Scientific advice 2016
Atlantic chub mackerel - Northwest Africa
Fact Sheet Citation  
Maquereau (Scomber colias) - Afrique nord-occidentale
Owned byFood and Agriculture Organization (FAO) – More
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FAO Names: en - Atlantic chub mackerel, fr - Maquereau espagnol atlantique, es - Estornino del Atlántico, ru - Скумбрия японская

Fishery Indicators
Production: Catch
Geographic extent of Atlantic chub mackerel - Northwest Africa
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Regional
Management unit: Yes        Reference year: 2014
Biological State and Trend
State & Trend Descriptors
Exploitation rateFcur/F0.1 = 101% ; Fcur/FMSY = 91%Not applicable
Abundance levelBcur/B0.1 = 135% ; Bcur/BMSY = 148%Not applicable
FAO Categories
Exploitation stateFully exploited

Fcur/F0.1: Ratio between the observed fishing mortality coefficient during the last year of the series and F0.1.
Fcur/FSYcur: Ratio between the observed fishing mortality coefficient during the last year of the series and the coefficient that would give a sustainable yield at the current biomass level.
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.
Unless otherwise indicated, the indicators were based on the Schaefer dynamic production stock assessment model.
Habitat and Biology
Climatic zone: Temperate; Tropical.   Depth zone: Coastal (0 m - 50 m); Shelf (50 m - 200 m); Slope (200 m - 1000 m).   Horizontal distribution: Neritic; Oceanic.   Vertical distribution: Pelagic.  

Geographical Distribution
Jurisdictional distribution: Shared between nations

Water Area Overview
Spatial Scale: Regional

Geo References
Resource Structure
Considered a single stock: Yes

The Working Group maintained the assumption of two stocks of chub mackerel (Scomber colias): the northern stock between Cape Bojador and the north of Morocco in the Atlantic, and the southern stock between Cape Bojador and the south of Senegal. Nevertheless, owing to a lack of more information on migration and possible exchanges between the two stocks, the Working Group since its 2003 meeting has proceeded with a joint assessment of the two stocks in its general distribution area.
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 49295tonnes1990
Catch 20052tonnes1991
Catch 35867tonnes1992
Catch 41711tonnes1993
Catch 92445tonnes1994
Catch 147174tonnes1995
Catch 184936tonnes1996
Catch 214357tonnes1997
Catch 205056tonnes1998
Catch 142383tonnes1999
Catch 191727tonnes2000
Catch 158585tonnes2001
Catch 136557tonnes2002
Catch 182237tonnes2003
Catch 222784tonnes2004
Catch 182050tonnes2005
Catch 206266tonnes2006
Catch 257544tonnes2007
Catch 268325tonnes2008
Catch 243931tonnes2009
Catch 224608tonnes2010
Catch 321941tonnes2011
Catch 226726tonnes2012
Catch 278425tonnes2013
Catch 343906tonnes2014

Assessment year: 2015
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

The catch data used by the Working Group were the total catch series of the whole sub-region for the period 1999–2014. Previously the biomass indices used for the model run have been the acoustic biomasses from the “Nansen series”, initiated by the RV DR. FRIDTJOF NANSEN, started in 1999 and continued by the national research vessels. However, as no coordinated acoustic survey has been carried out since 2011, no value for this index was reported to the Working Group in 2014. Thus, the Group proceeded with a model run using the standardized CPUE series from Russia. The Russian CPUEs for 2012 were not used because the 2012 index was only for the month of December and was not representative of the annual index. The initial parameters for the carrying capacity K and the intrinsic growth rate r used as starting points for the model runs were the following: - Intrinsic growth rate r = 1.55 - Carrying capacity K (in thousands of tonnes) = 602
Assessment Model
Type:  Age-structured
Length Cohort Analysis (LCA)
Extended Survivor Analysis (XSA)
Overall Assessment Results

The adjustment of Russian CPUEs for the year 2014 was considered satisfactory by the Working Group for the stock assessment using the Schaefer dynamic production model. The current stock biomass is 35 percent higher than the target biomass B0.1. The current Fishing Mortality is more or less the same as equal to F0.1 and slightly below the level of FMSY. The combination of these results show that the chub mackerel stock is fully exploited.
Scientific Advice

The Working Group adopted, based on the results of both the production model and the analytical model that the stock is fully exploited. The Working Group recommends not to exceed the mean level over the last five years 280 000 tonnes in 2014 for the whole sub-region.
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 Working Group on the Assessment of Small Pelagic Fish off Northwest Africa. Casablanca, Morocco, 20–25 July 2015 / Rapport du Groupe de travail de la FAO sur l’évaluation des petits pélagiques au large de l’Afrique nord-occidentale. Casablanca, Maroc, 20-25 juillet 2015. FAO Fisheries and Aquaculture Report/FAO Rapport sur les pêches et l’aquaculture No. 1122. Rome, Italy/Italie.  Click to open
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