Biological State and Trend
Habitat and Biology
Climatic zone: Tropical. Bottom type: Hard rocky bottom. Depth zone: Shelf (50 m - 200 m). Horizontal distribution: Neritic. Vertical distribution: Demersal.
Geographical Distribution
Jurisdictional distribution: National
Resource Structure
Considered a single stock: Yes
In Cape Verde waters, the Esmoregal (Seriola spp.) family consists of three species, and is thus considered as a shared stock.
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 Working Group used the total artisanal catch series for Esmoregal (Seriola spp) for the period 1996 to 2009. The abundance indices used were the CPUE of the artisanal lines (kg/trip). The initial input parameters were: r (intrinsic growth rate) = 1.50; K (initial biomass) = 700 tonnes and BI/K (biomass of the stock at the start of the data series, compared with the initial biomass) = 50 percent.
Overall Assessment Results
The data do not fit the model for Esmoregal (Seriola spp.), and thus no conclusion can be drawn from the results of the model. The abundance indices seem to be quite similar, and do not allow for a conclusion to be drawn.
Scientific Advice
The Working Group decided to adopt a precautionary approach, and recommends an analysis of the data on the abundance index series (CPUE) and that new analysis models should be tried.
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.
http://www.fao.org/3/a-i5301b.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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