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Bobo croaker - Guinea-Bissau and Guinea
Marine Resource  Fact Sheet
CECAF Scientific advice 2016
Bobo croaker - Guinea-Bissau and Guinea
Fact Sheet Citation  
Bossus (Pseudotolithus elongatus) - Guinée-Bissau et Guinée
Owned byFood and Agriculture Organization (FAO) – More
Related observationsLocate in inventorydisplay tree map
 
Species:
FAO Names: en - Bobo croaker, fr - Otolithe bobo, es - Corvina bobo

Fishery Indicators
Production: Catch
Geographic extent of Bobo croaker - Guinea-Bissau and Guinea
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Regional
Management unit: Yes        Reference year: 2009
 
 
Biological State and Trend
State & Trend Descriptors
PartnerFIRMS
Exploitation rateFcur/F0.1 = 121% ; Fcur/FMSY = 109%Not applicable
Abundance levelBcur/B0.1 = 76% ; Bcur/BMSY = 84%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.
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.   Depth zone: Coastal (0 m - 50 m).   Horizontal distribution: Estuarine.   Vertical distribution: Demersal/Benthic.  

Geographical Distribution
Jurisdictional distribution: Shared between nations

Water Area Overview
Spatial Scale: Regional

Geo References
Resource Structure
Considered a single stock: Yes
Exploitation
 
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 7244tonnes1994
Catch 7743tonnes1995
Catch 6833tonnes1996
Catch 9679tonnes1997
Catch 7880tonnes1998
Catch 7467tonnes1999
Catch 12081tonnes2000
Catch 13086tonnes2001
Catch 13559tonnes2002
Catch 2123tonnes2003
Catch 7196tonnes2004
Catch 7120tonnes2005
Catch 4922tonnes2006
Catch 1315tonnes2007
Catch 15590tonnes2008
Catch 9225tonnes2009
Assessment
 

Assessment year: 2011
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 total catch of Pseudotolithus elongatus for Guinea-Bissau and Guinea for the period 2000-2009 was used for the model fit. The catch for Guinea-Bissau has been estimated5 for the period 2002-2004. That for Guinea for 2009 was estimated assuming that exploitation was the same as in 2008. The abundance indices used were the CPUE from the scientific surveys carried out in Guinea. The Working Group estimated that these data better reflected the abundance of the species than the CPUE from the other types of fleets of the two countries. The initial values of the parameters were, r (intrinsic growth rate) = 1.40; K (initial biomass) = 30 000 tonnes and BI/K (stock biomass at the beginning of the data series, compared with the initial biomass) = 60 percent.
Overall Assessment Results

The model provides a satisfactory fit. The overall results show that the stock is fully exploited. The current fishing mortality is above that which would give a maximum sustainable yield over the long term. Thus, if the catch remains at the 2009 level, the biomass of the stock will decrease.
Scientific Advice

The fishing effort should not exceed the current level and the total catch should be above the average of the last three years (9 000 tonnes).
Management
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 openhttp://www.fao.org/3/a-i5301b.pdf
FAO. 2015. Report of the FAO/CECAF Working Group on the Assessment of Demersal Resources – Subgroup South. Accra, Ghana, 15–24 November 2011 / Rapport du Groupe de travail FAO/COPACE sur l’évaluation des ressources démersales – Sous-groupe Sud. Accra, Ghana, 15-24 novembre 2011. CECAF/ECAF Series/COPACE/PACE Séries. No. 15/76. Rome, Italy/Italie.  Click to openhttp://www.fao.org/3/a-i5138b.pdf
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