Fisheries and Resources Monitoring System

Scads - Guinea-Bissau, Guinea, Sierra Leone and Liberia
Marine Resource  Fact Sheet
CECAF Scientific advice 2016
Scads - Guinea-Bissau, Guinea, Sierra Leone and Liberia
Fact Sheet Citation  
Decapterus spp - stock nord (Guinée-Bissau, Guinée, Sierra Leone et Libéria)
Owned byFood and Agriculture Organization (FAO) – More
Related observationsLocate in inventorydisplay tree map
FAO Names: en - Scads nei, fr - Comètes nca, es - Macarelas nep, ru - Ставриды десятиперные (=ставриды сигарные)

Fishery Indicators
Production: Catch
Geographic extent of Scads - Guinea-Bissau, Guinea, Sierra Leone and Liberia
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 = 176% ; Fcur/FMSY = 158%Not applicable
Abundance levelBcur/B0.1 = 73%Not 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.
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: Tropical.   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 0tonnes1990
Catch 0tonnes1991
Catch 0tonnes1992
Catch 0tonnes1993
Catch 135tonnes1994
Catch 2070tonnes1995
Catch 6319tonnes1996
Catch 4801tonnes1997
Catch 7281tonnes1998
Catch 4976tonnes1999
Catch 5535tonnes2000
Catch 4132tonnes2001
Catch 4527tonnes2002
Catch 3866tonnes2003
Catch 2833tonnes2004
Catch 5438tonnes2005
Catch 3577tonnes2006
Catch 3120tonnes2007
Catch 2739tonnes2008
Catch 5630tonnes2009
Catch 2960tonnes2010
Catch 3758tonnes2011
Catch 6679tonnes2012

Assessment year: 2014
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 dynamic global model was applied to the total catch of Decapterus spp. with data from the CPUEs of the industrial pelagic trawlers of Guinea (period 1995–2011). As data from Sierra Leone were not available to the Working Group, and the data series from Liberia was not continuous, the Working Group decided to disaggregate the northern stock to assess the Decapterus spp. stock of Guinea only. The initial parameters were: - Decapterus spp. stock of Guinea: r = 0.50, K = 50 000 tonnes and B/K = 60 percent.
Overall Assessment Results

The results of the model show that the Decapterus spp. stock in Guinea is overexploited. This species is not targeted by the fishery in Guinea, and is mainly caught as a bycatch in the industrial fishery.
Scientific Advice

Catches should be decreased and the Working Group retains the 2009 recommendation that catches should not exceed 3 000 tonnes.
Management unit: Yes
Source of information
FAO. 2016. 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. 2015. Report of the FAO/CECAF Working Group on the Assessment of Small Pelagic Fish – Subgroup South. Pointe Noire, Congo, 17–23 March 2014. Rapport du Groupe de travail FAO/COPACE sur l’évaluation des petits poissons pélagiques – Sous-groupe Sud. Pointe Noire, Congo, 17-23 mars 2014. CECAF/ECAF Series / COPACE/PACE Séries No. 15/75 Rome, FAO. 157 pp.  Click to open
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