Fisheries and Resources Monitoring System

EspañolFrançais
Tonguesole - Nigeria and Cameroon
Fact Sheet Title  Fact Sheet
CECAF Scientific advice 2020
Tonguesole - Nigeria and Cameroon
Fact Sheet Citation  
Sole (Cynoglossus spp) - Nigéria et Cameroun
Owned byFood and Agriculture Organization (FAO) – ownership
ident Blockident Blockdisplay tree map
 
Species List:
Species Ref: en - Tonguesole nei, fr - Sole-langues nca, es - Lenguas nep

Fishery Indicators
Production: Catch
ident Block Tonguesole - Nigeria and Cameroon
Aq Res
Biological Stock: Yes         Value: Regional
Management unit: No        Reference year: 2016
 
 
Aq Res State Trend
Aq Res State Trend
Aq Res State Trend
Aq Res State TrendNot applicable
Aq Res State TrendNot applicable
Aq Res State Trend
Aq Res State TrendFully exploited
Habitat Bio
Climatic Zone: Tropical.   Bottom Type: Soft bottom clean sand; Soft bottom muddy or muddy-sand.   Depth Zone: Coastal (0 m - 50 m); Shelf (50 m - 200 m).   Vertical Dist: Demersal.  

Geo Dist
Geo Dist: Shared between nations

Water Area Overview
Spatial Scale: Regional

Water Area Overview
Aq Res Struct
Biological Stock: Yes


The Working Group adopted one stock/unit for Nigeria and Cameroon for assessment purpose as they have data series from 1995 to 2016. Equatorial Guinea also provided data from 2002 to 2016 but the data sets from 2011 to 2016 were very low compared to previous data provided.
Exploit
 

CATCH: Table 4.5.3a and Figure 4.5.3a present the catches of soles in Cameroon, Nigeria and Equatorial Guinea. The trends are stable over the years for Cameroon and for Nigeria the catches increased steadily with some slight fluctuations up to 2015 and deceased slightly to 2016. Equatorial Guinean catch trends started in 2002 with a very sharp increase in 2003 and gradually decreases to 2011 this further reduced to 2016.
FISHING EFFORT: The fishing effort is the same for all demersal species. Trends in effort of these fleets are described in Section 4.3.3.
CPUE: CPUE shows fluctuations with a tendency to decrease for Cameroon and Equatorial Guinea but that of Nigeria increases in similar pattern as the catch over the years (Table 4.5.3b and Figure 4.5.3b).
Fishery Indicators
TypeMeasureValueUnitTime period
ProductionCatch 490tonnes1990
Catch 551tonnes1991
Catch 726tonnes1992
Catch 912tonnes1993
Catch 561tonnes1994
Catch 2799tonnes1995
Catch 1789tonnes1996
Catch 1686tonnes1997
Catch 2279tonnes1998
Catch 4599tonnes1999
Catch 7292tonnes2000
Catch 7234tonnes2001
Catch 980tonnes2002
Catch 8315tonnes2003
Catch 6816tonnes2004
Catch 9379tonnes2005
Catch 8524tonnes2006
Catch 7873tonnes2007
Catch 8308tonnes2008
Catch 6716tonnes2009
Catch 9005tonnes2010
Catch 11779tonnes2011
Catch 9826tonnes2012
Catch 11856tonnes2013
Catch 13325tonnes2014
Catch 13176tonnes2015
Catch 11802tonnes2016
Bio Assess
 

Assessment year: 2017
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”.
Data

To apply the assessment model the Working Group input the total catch of Cynoglossus spp. for Nigeria and Cameroon during the period 2002 to 2016. The abundance indices used are the series of CPUE of industrial trawlers (kg/fishing day) from Cameroon.
Assess Models
Type:  Biomass-aggregated
Schaefer dynamic production model

The Schaefer dynamic production model implemented in an Excel spreadsheet was used by the Working Group to assess the state of the Cynoglossus spp. stocks in Nigeria and Cameroon. The model is described in detail in FAO, 2012.
Results

No results for the assessment model. But, based on other information available the Working Group considerer that the stock is fully exploited (FAO, 2020).
RESULTS: The model fit was not satisfactory with the data available.
DISCUSSION: The data of catch and CPUE do not have sufficient contrast to be able to apply any assessment model. The catches and CPUE follow the same trends. The data series and the new data need to be analysed and improved before the next meeting.
Sci Advice

As a precautionary measure the Working Group recommends that the total catch should not exceed the mean catch of the last five years (11 000 tonnes) (FAO, 2020).
Management
Management unit: No
Sources
 
FAO. 2019. Report of the FAO/CECAF Working Group on the Assessment of Demersal Resources – Subgroup South. Libreville, Gabon, 6–15 September 2017/Rapport du Groupe de travail sur l’évaluation des ressources démersales – Sous-groupe Sud. Libreville, Gabon, 6–15 septembre 2017. CECAF/ECAF series/ FAO/COPACE COPACE/PACE séries no.18/79. Rome.  Click to openhttp://www.fao.org/3/ca2739b/ca2739b.pdf
FAO. 2019. Fishery Committee for the Eastern Central Atlantic, Report of the eighth session of the Scientific Sub-Committee, Abidjan, Côte d’Ivoire, 23–26 October 2018 / Comité des pêches pour l’Atlantique Centre-Est Rapport de la huitième session du Sous-Comité scientifique, Abidjan, Côte d’Ivoire, 23–26 octobre 2018. FAO Fisheries and Aquaculture Report / FAO Rapport sur les pêches et l’aquaculture No. 1265. Rome.  Click to openhttp://www.fao.org/3/ca5623b/ca5623b.pdf
FAO. 2020. Report of the Twenty-Second Session of the Fishery Committee for the Eastern Central Atlantic, Libreville, Gabon, 17–19 September 2019. Rapport de la vingt-deuxième session du comité des pêches pour l’Atlantique centre-est, Libreville, Gabon, 17–19 septembre 2019. FAO Fisheries and Aquaculture Report / FAO, Rapport sur les pêches et l’aquaculture No. 1303. Rome.  Click to openhttp://www.fao.org/3/ca8000b/CA8000B.pdf
Bibliography
 
All references to figures, tables and bibliography in the text are found within the source of information.
powered by FIGIS  © FAO, 2024
Powered by FIGIS
crawl