Fisheries and Resources Monitoring System

Sardinella - Northwest Africa
Marine Resource  Fact Sheet
CECAF Scientific advice 2016
Sardinella - Northwest Africa
Fact Sheet Citation  
Sardinelles (Sardinella aurita, Sardinella maderensis) - Afrique nord-occidentale
Owned byFood and Agriculture Organization (FAO) – More
Related observationsLocate in inventorydisplay tree map
Geographic extent of Sardinella - 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 = 250%Not applicable
Abundance levelUncertain/Not assessedNot applicable
FAO Categories
Exploitation stateOverexploited

Fcur/F0.1: Ratio between the observed fishing mortality coefficient during the last year of the series and 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; Littoral.   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
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 423902tonnes1990
Catch 280326tonnes1991
Catch 332328tonnes1992
Catch 282723tonnes1993
Catch 219034tonnes1994
Catch 254247tonnes1995
Catch 527019tonnes1996
Catch 479283tonnes1997
Catch 592471tonnes1998
Catch 478614tonnes1999
Catch 473621tonnes2000
Catch 469237tonnes2001
Catch 460883tonnes2002
Catch 521712tonnes2003
Catch 457444tonnes2004
Catch 537057tonnes2005
Catch 427267tonnes2006
Catch 623524tonnes2007
Catch 674950tonnes2008
Catch 635261tonnes2009
Catch 728170tonnes2010
Catch 787079tonnes2011
Catch 743313tonnes2012
Catch 663315tonnes2013
Catch 801043tonnes2014

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:  Size-structured
Length Cohort Analysis (LCA)

For the LCA model, the Working Group used the length frequency data derived from the sampling of catches and landings from 2012-2014 carried out in the zones North, A and B in Morocco, Mauritania and Senegal. For each year, the length structures of each zone were extrapolated to the total catch of the zone concerned. Then, the averages of the annual length compositions were used. The lengths of the individuals in the final matrix obtained vary between 10 and 40 cm. The growth and mortality parameters used are presented in Table 3.6.1 of FAO, 2016b.
Yield per Recruit Analysis (Y/R)

The LCA results are then used as input data for the yield per recruit model.
Overall Assessment Results

The Working Group considered the results of the models (Figures 3.6.1 and 3.6.2 of FAO, 2016b) acceptable. The LCA results show an exploitation phase of the younger fish (21-25 cm) and another for the adults (29-35 cm). The mean fishing mortality for the length groups considered fully recruited (24-36 cm) is estimated at 0.94 year-1. The diagnosis of the yield per recruit model indicates that the current fishing mortality Fcur is higher than that corresponding to F0.1. The results show that the stock of S. aurita in the sub-region is overexploited.
Scientific Advice

The Working Group notes that in the absence of acoustic estimates for recent years and the deterioration of CPUE series the production model traditionally applied could not be used. However improved length frequency data made possible the application of an LCA model and a yield per recruit analysis. The results of the assessments indicate that the stock is overexploited. The Working Group further notes that the catches in recent years (since 2007) are high, despite the state of overexploitation indicated by the Working Group. The increase of catches over a longer period, despite a stock being overexploited, could be linked to an increase in the level of recruitment during this period. There is no guarantee that such a high level of recruitment will continue in the future and high catches do not necessarily reflect the state of the stocks. As a precautionary mesure, the Working Group retains its recommendation of previous years to reduce fishing effort for all fleet segments. The Working Group could not make a catch recommendation as at present it does not dispose an adequate index of abundance and is unable to predict future recruitment.
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
All references to figures, tables and bibliography in the text are found within the source of information.
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