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Cuttlefishes - Ghana
Marine Resource  Fact Sheet
CECAF Scientific advice 2016
Cuttlefishes - Ghana
Fact Sheet Citation  
Seiche (Sepia spp) - Ghana
Owned byFood and Agriculture Organization (FAO) – More
Monitoring periodPreviously monitored as: Cuttlefish - Ghana and Benin
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Related observationsLocate in inventorydisplay tree map
 
Species:
Geographic extent of Cuttlefishes - Ghana
Main Descriptors
Considered a single stock: Yes        Spatial Scale: National
Management unit: Yes        Reference year: 2010
 
 
Biological State and Trend
State & Trend Descriptors
PartnerFIRMS
Exploitation rateFcur/F0.1 = 246%; Fcur/FMSY = 222%Not applicable
Abundance levelBcur/B0.1 = 36% ; Bcur/BMSY = 40%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/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); Shelf - Uppershelf (up to 100 m).   Vertical distribution: Demersal.  

Geographical Distribution
Jurisdictional distribution: National

Water Area Overview
Spatial Scale: National

Geo References
Resource Structure
Considered a single stock: Yes
Exploitation
 
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 1908tonnes1990
Catch 2663tonnes1991
Catch 1496tonnes1992
Catch 1495tonnes1993
Catch 2287tonnes1994
Catch 2751tonnes1995
Catch 2936tonnes1996
Catch 3247tonnes1997
Catch 2981tonnes1998
Catch 3249tonnes1999
Catch 1362tonnes2000
Catch 2585tonnes2001
Catch 3529tonnes2002
Catch 4548tonnes2003
Catch 3351tonnes2004
Catch 2057tonnes2005
Catch 3217tonnes2006
Catch 2540tonnes2007
Catch 2504tonnes2008
Catch 1877tonnes2009
Catch 2186tonnes2010
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

Information used to assess the Ghanaian cuttlefish stock was the total catch (Ghanaian demersal trawlers and pair trawlers) and the abundance indices used to fit the model were the annual CPUEs of the demersal trawling fleet for the period 1990–2010. Note that there is no catch from pair trawlers in 2009 and 2010. The initial parameter values of the Biodyn model are: r = 1.00; K = 10 000 tonnes: BI/K = 80 percent.
Overall Assessment Results

The results of the model obtained are satisfactory. They indicate that the stock of Sepia spp. is overexploited and its situation seems to be worse than the 2008 assessment both in terms of biomass and fishing mortality. The current biomass is 40 percent of that corresponding to the maximum sustainable yield (MSY). Fishing effort, and consequently fishing mortality, has continued increasing during the last six years (2005–2010) despite the recommendation made by the 2005 and the 2008 Working Groups to reduce the fishing effort in order to avoid a more severe overexploitation. In 2010 the increase in effort was 65 percent compared to 2004.
Scientific Advice

The situation seems to be worse than in 2008 assessment. In 2010 the effort increase was 65% compared to 2004. Fishing effort should be reduced and catches limited to a maximum of 2 000 tonnes per year.
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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