Statistical data contained in the report of the previous Working Group on demersal resources were updated to include data for 1986–89 (Tables 3–6).
The data are broken down into types of fleet (artisanal, semi-industrial and industrial). Catch and effort data on commercial shrimpers were, until recently, added to those of the inshore vessels.
For operational reasons, some industrial vessel operators are unwilling to sort their catches of sparids into species as required. This makes the compilation of such data at the species level difficult. In Tables 4 and 5 therefore the total landings of the six most commonly caught sparids are given.
Table 6 shows that total landings of demersal fish have increased from about 47 000 t in 1983 to over 61 000 t in 1989. The highest landing of nearly 93 000 t was made in 1987.
In 1988 all three fleets recorded lower landings than in 1987. The semi-industrial fleet recorded the greatest decrease of 46.6%.
Tables 7–10 give fleet composition effort and total catches by main commercial species from 1955 to 1989, in national and foreign waters.
Standardization of effort after 1983 was done using a trawler of 160 HP considered as representative for the fleet. Effort was separated by bathymetric strata 10–50 m and 50–120 m (Table 9). Table 10 gives new effort data obtained from correcting the historical series before 1983.
Since 1985 shrimpers have been landing more finfish. The phenomenon is illustrated in the following table (landing figures are in tonnes).
| YEAR | SHRIMPS | FINFISH |
|---|---|---|
| 1985 | 218 | 0 |
| 1986 | 329 | 63 |
| 1987 | 325 | 140 |
| 1988 | 421 | 910 |
| 1989 | 411 | 1172 |
Catches from the artisanal fisheries in 1979 and 1988 using lines and landing in the Port of Abidjan are given in Table 11. Groupers (Epinephelus aeneus, E. guaza) and seabreams (Dentex spp., Sparus spp.) were the most important species groups landed by this fleet.
No new data were available to the Working Group. Appendix 7 (taken from Ssentongo and Ansa-Emmim (1986)) is included here to give an indication of the size of the marine fishing industry in Sierra Leone.
No data were available to the Working Group. Appendix 8 (taken from Ssentongo (1987)) indicates total landings and species exploited in the Liberian marine fishery.
Most of the new biological data and parameters available to the Working Group were collected during the GUINEA-90 Survey (Tables 12–15).
Some of the size frequency distribution data collected and compiled by CRO, (Abidjan) were presented to the Working Group. They formed the basis for comparison with similar data collected during the GUINEA-90 Survey.
Seven fish species were regularly measured in the port of Abidjan. These are Brachydeuterus auritus, Dentex angolensis, Pagellus bellottii, Cynoglossus canariensis, Pomadasys jubelini, Pseudotolithus senegalensis and Pseudotolithus typus. Length frequency distribution for Brachydeuterus auritus, Dentex angolensis (for April 1989) and Pagellus bellottii (for April 1989 and 1990) were compared with those of GUINEA-90 (Figures 1.1–4.2).
To complete the comparison, similar data collected during GUINEA-90 in Sierra Leone, Liberia and Ghana for the three species are also presented in the figures (Ramos et al., 1990).
Table 16 summarizes the information presented in Figures 1.1–4.2. Some data were taken from Ramos et al. (1990) to complete the table.
It is clear from Table 16 that the vessels landing in Abidjan exploit moderately large fish. The Working Group noted though, that because of gear selection and lack of market for small-sized fishes, size frequency data from commercial vessels may be biased and less indicative of population structure than data from a research vessel. The Ivorian participants commented that in Côte d'Ivoire, small fish are normally grouped together and are not made available for sampling.
The Table of upwelling indices recorded off Tema, Ghana, and compiled during the previous Working Group was updated (Table 17).
