The Working Group decided to consider five stocks: the northern stock (Guinea-Bissau, Guinea, Liberia and Sierra Leone) made up of Decapterus spp., Caranx spp., Trachurus trecae and other Carangidae; the western stock (Benin, Côte d’Ivoire, Ghana and Togo) made up of the same species; the central stock (Cameroon and Nigeria), consisting of other Carangidae; the São Tomé stock consisted of Decapterus spp., and Caranx spp. and the southern stock (Angola, Congo, Democratic Republic of the Congo and Gabon) consisting of Trachurus trecae, Caranx spp., other Carangidae and Decapterus spp. for the Democratic Republic of the Congo).

TOTAL CATCH: For the group of Trachurus spp. species, most of the reported catches of Trachurus trecae corresponds to countries from the southern region, with an average of about 35 000 tonnes, mostly from the Angolan coast. Catches corresponding to the southern stock decreased from 61 000 tonnes in 1990 to 3 000 tonnes and 3 300 tonnes in 2004 and 2010, respectively, but about 70 000 tonnes in 2013 and more than 90 000 tonnes in 2015. In the northern and western regions (with averaged annual catches of 14 500 tonnes and 6 500 tonnes, respectively), the catches present noticeably annual oscillations. In the northern stock, high values of more than 30 000 tonnes in the were reported for 2016 and 2017, produced by the industrial fisheries off Guinea Bissau. In the case of the western stock, a record value on 23 000 tonnes occurred in 2014 (by the Ghanaian artisanal fishery) and, conversely, a very low value of about 5 000 tonnes was reported for 2017.
EFFORT: In Guinea and Sierra Leone these species are mainly fished by encircling gillnets and driftnets in the artisanal fishery. In Benin, Cameroon, Ghana, Nigeria and Togo, small carangids are mainly fished by beach seine and purse seine.
Most of the industrial fleets’ effort is concentrated in the Guinean EEZ. The large pelagic trawlers that target horse mackerel come from eastern European countries (the Russian Federation and Ukraine). The nominal effort of this fleet (fishing days) decreased overall from more than 600 fishing days in 1996 to about 400 days in 2004, then recovered and increased to 900 days in 2005 before falling again to 600 days in 2007; there was an increase to 5 600 days in 2017 (Table 5.2.2).
Some of the countries have reported problems in their fishery data and information collection system, and only six of them have updated the effort time series. São Tomé has not reported new data and the available data needs to be revised because of the establishment of the new database.
CPUE: The CPUE, in tonnes per fishing day or positive trip, is calculated for each species or group of species in each stock where data are available (Figure 5.2.2a, figure 5.2.2b, figure 5.2.2c, figure 5.2.2d, table 5.2.2b, table 5.2.2c, table 5.2.2d, and table 5.2.2e). Some of the time series of fishing effort do not have the same units of measurements over the years or between fisheries. Therefore, global CPUEs cannot be considered by stock. For Decapterus rhonchus and Trachurus trecae, the CPUE series is based on the nominal effort of the industrial demersal fleet in Guinea (northern stock). In Angola, Trachurus trecae and T. capensis can be found; thus, in processing the data for Angola together with the other countries, Trachurus spp. was used instead of T. trecae.

Assessment year: 2018
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”.