Aq Res State Trend
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 Bio
Climatic Zone: Tropical. Bottom Type: Soft bottom clean sand; Soft bottom muddy or muddy-sand. Depth Zone: Coastal (0 m - 50 m). Horizontal Dist: Littoral. Vertical Dist: Demersal.
Geo Dist
Geo Dist: Shared between nations
Aq Res Struct
Biological Stock: Yes
The Galeoides decadactylus is found primarily in shallow water in Guinea-Bissau and Guinea. This species can be considered as forming a single stock.
Bio Assess
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”.
Assess Models
Type: Biomass-aggregated
Schaefer dynamic production model
The total catch of Galeoides decadactylus for Guinea-Bissau and Guinea as well as the abundance indices from scientific surveys carried out in Guinea were used for the period 1997-2009. The catches of Guinea-Bissau were estimated7 for the periods 1998-1999 and 2002-2004. Catches of Guinea for the year 2009 were estimated assuming that exploitation was the same as in 2008. The initial input parameters were, r (intrinsic growth rate) = 2.70; K (initial biomass) = 17 000 and BI/K (biomass of the stock at the beginning of the data series, compared with the initial biomass) = 80 percent.
Results
The model provides a satisfactory fit to the data. The results of the model indicate that the stock is fully exploited.
Sci Advice
Not to exceed the 2009 fishing effort. The total catch should not be greater than the average of the last three years (5 000 tonnes).
Sources
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.
http://www.fao.org/3/I5301Bi/i5301bi.pdfFAO. 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.
http://www.fao.org/3/a-i5138b.pdf
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