Habitat Bio
Climatic Zone: Tropical. Bottom Type: Soft bottom muddy or muddy-sand. Depth Zone: Coastal (0 m - 50 m); Shelf - Uppershelf (up to 100 m). Horizontal Dist: Littoral. Vertical Dist: Demersal/Benthic.
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
For the catch data series, the Working Group used the series of total catch estimated for the country, for the period 1995 to 2008 (shrimpers and other trawlers). For the abundance index, the CPUE series from the Guinean shrimp trawl fleet was used. The Working Group considered that this series best reflects the trends in abundance of Penaeus notialis in Guinea.
Results
The fit of the model to the data is not acceptable, and therefore, no conclusions can be made based on the model results. The trends for observed and predicted CPUE reveal strong fluctuations and inconsistencies with the catches, and a decline in stock abundance in the three last years. Doubts were raised about the fishing strategy. There are strong differences in the results from the last Working Group. Given the uncertainties about the exploitation of this stock, the assessment was not accepted.
Sci Advice
Not to exceed the 300 tonne level until new information is made available to the Working Group
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
to turn layers on and off 