Table 2 presents catch details for sparids for division 34.1.1 by country for the period 1964–1984 taken from CECAF Statistical Bulletins No. 1 and 4 and some notes on the derivation of these data are given below :
the Moroccan data have been revised (Source : ISPM),
a data series for Portugal is included, taken from the Spanish Progress Report for 1982–1982,
Japanese data for 1964–1969 have been updated using information from Ikeda and Sato, in FAO Fisheries Report 109 (Appendix 8), and are given in Table 3.
Polish data have been updated using data in Appendix 6 (Table 4).
No general effort estimate could be made, but some effort data are available and details are given below :
For trawlers, the number of fishing day s times the engine power was used for 1982 (Hake Working Group), based on data for the Port of Casablanca only.
Thiam (Appendix 7, Table 2) presents fishing effort in number of trips from 1961 to 1979 and 1983.
Table 5 gives the total number and tonnage of all Moroccan trawlers for the periods 1960–1984.
Table 6 gives ehe number of longliners/gillnetters and the corresponding number of fishing trips for the perios 1961–1980, for the port of casablanca.
It should be noted that as from 1984 detailed catch and effort data are available for the Port of Casablanca. These consist of catches by species by vessel by fishing trip; effort in number of trips; number of trips times length of trip; and number of trips times engine power or number of trips times tonnage.
Figure 5 shows the geographical distribution of fishing effort in the Moroccan waters.
Thiam (Appendix 7) presents for 1981/1982 the effort of the Spanish trawlers expressed in terms of the number of fishing days.
Effort data exist from 1964–1969, separated by vessel category and are given in Table 3 (source: FAO Fisheries Report 109, Appendiz 5).
The number of trawlers for the years 1975/1976–1985 was about 50. The average CPUE of the longliners/gillnetters is given en Lima Dias (Appendix 8, Table 2)presents fishing effort from 1949–1984, for Portuguese trawlers. Until 1975/1976 fishing was mainly in statistical divisions 34.1.3 and 34.1.3 but afterwards it was mainly in division 34.1.1.
Effort data are available for the period 1968–1970 and are listed in Table 6 (FAO Fisheries Report 109).
Another data series is given in Appendix 6 valid for the whole CECAF area.
No information on discards is avalable for division 34.1.1.
Table 8 gives statistical data for sparids from division 34.1.2, by country. Reported catches were high in the early seventies. The catch of sparids dropped from about 11.000 T in 1974 to 200 T in 1982. Dentex macrophthalmus the principal species caught between 1972 and 1976. The Soviet catch of D.ma crophtalmus increased from 735 T in 1972 to 7, 019 T in 1974, followed by a sharp drop to 446 in 1975.
Brfore 1982, no detailed catch statistics of effort data were collected from the artisanal boats operating from the Canary Islands, but limited data exist for 1982 (Table 54 and 55). Data Collection for these boats has been discontinued since 1983 because of logistic problems. Spanish catches in 1973 and 1974 were mainly Pagellus spp. and Dentex spp.
Statistics collected from Portuguese artisanal boats operating from the Madeira Islands give no species breakdown.
No information on discards is available for division 34.1.2
The nominal catches of seabream in statistical division 34.1.3 are summarized in Table 9 for the period 1964–1982 (CECAF Statistical Bulletins Nos. 1 and 4).
For a number of fleets which operated in this division, catch and effort data are known.
For the Ghanaian trawl fleet (Table 10) catch statistics are available for 3 groups of species :A)consisting of all seabreams, B) of Carangidae, Scomber, snappers, threadfin, spadefish, etc. and C)psettode,Epinephelus and Pseudotolithus (Zei and Ansa-Emmin, 1970). In the period 1965–1967, the percentage of seabreams in the total landings decreased from 18.0% to 10.0%.
The evolution of the landingsof the Polish fleet is summarized in Table 11. In the beginning of the fishery (1963), the sparids represented 36% of the landings.
The Polish fishery statistics for the several statistical divisions in the Northern CECAF area are presented in Appendix 6. Table 12 shows different vessel types.
During research activities on board the fishing vessel RAMADA in 1967,the percentages of sparids were calculated by depth intervals (see Table 13,after Klimaj, 1970).
Details of catch and effort data are available since 1982, and these are presented in Table 14.
Monthly catch data are available for different groups of seabreams for 1984 (Table 15). Species of the genera Dentex, Pagellus and most abun dant in the landings. In the period 1982–1984, the percentage of seabreamas varied between 12 and 18%. The distribution of effort within the Moroccan waters is given in Figure 5.
Some CPUE data of large Soviet factory trawlers are available for the pe riod 1961–1967 (Domanevsky ,1970). Best sparid catches were made from September to February. The average yields per hour for the main sparid season are presented in Table 16.
For the period 1964–1969, detailed CPUE data are available for several types of Japanese fishing vessels (Table 17 and 18).
Catches for three categories of seabreams are available for the northern part of Mauritania (between Cape Blanc and Cape Timiris), for the period 1981–1983. The percentage of all the sparids in the total demersal landings varied between 11% and 16%. The catch data are presented in Table 19.
For the years 1981 and 1982, detailed catch and effort data are presented in Table 20. In 1981 and 1982, 1.6 and 3.9% of the total catches respectively consisted of sparids.
Scattered data exist on seabream catches. A summary is presented in Table 21.
Fishery statistics exist for all the fleets fishing cephalopods and seabreams. All catches are landed in Las Palmas (Yamamoto and Ansa-Emmin, 1979; Shimura, 1980, 1981, 1983, 1984, Roest and Frielink, 1985). Detailed CPUE and effort data for GRT classes for two important fishing areas are presented in Table 22.
For the period July 1981–December 1983, catch and effort data exist for the four fishing fleets operating in statistical division 34.1.3. For the cephalopod and hake ice carrying trawlers, the freezer trawlers and the artisanal fishing units,the total catches are presented in Table 23. For each fleet, data are available for the sparid landings and these are shown in Tables 24–27.
The artisanal Canary fleet operating in 34.1.3 has been studied since 1975 (Balguerias,1983). The numbers of fishing units, days-at-sea, days fishing and days -per -trip are shown in Table 28,while in Table 29 the catches of the main species group caught by the artisanal fleet are presented. Table 30 shows the yields in kg/day fishing for the different species groups.
Tables 31 and 32 show detailed catches of sparids by the hook-and -line and trap fishermen fishing in 34.1.3 for the years 1983 and 1984. In Table 33 total sparid catches landed by the different fleets are summarized. Figure 7 shows the location of the fishing grounds frequented by Spanish artisanal vessels.
During three trips on commercial freezer -trawlers,Bravo de Laguna et al. (1976,1977) studied by -catches and discards in the Spanish cephalopod fishery between 21°30'N and 24°20'N on four main fishing ground.
At Villa Cisneros (Dakhla) in shallow waters,invertebrates made up 50% of the total catch during the first cruise. Sparids constituted 38%of the discard fish, and of these, pagellus bellottii made up 47%, Diplodus se negalensis 26% and Spondyliosma cantharus 22%. Discarded fish place, during which invertebrates constituted only 9% of the total catch. Percentages of sparids in the discards were respectively 42 and 18%,the main species discarded being p.bellottii (59%, 55%), D.senegalensis (26%, 34%). pangellus erythrinus (12%), Spondyliosoma canthaarus (3%, 4%). Most numerous sizes discarded were 8–13 cm for p.bellottii, 8.5–16.5 cm for senegalensis and 9.5–13.5 cm for spondyliosoma.
At Cape Barbs, where fishing grounds are deepeer than 50 m, the percentages of sparids during two cruises were 7 and 8%, and in these cruises p.bellottii made up 66% and 28% respectivly and P. acarne 29% and 26% respectively. During the second cruise, Dentex macrophtlamus was the most abundant sparid,making up 30% of the discars. The lengths discards were mostly 7–10.5 cm.
Table 34 summarizes detailed catch and discard comppsitions per species and per cruise.
The CECAF Statistical Bulletins 1–4, covering the period 1964–1982, summarize nominal catches by statistical division, fishing country, species or species groups and year. For statistical division 34.3.1 sparid catches are summarized in Tables 35–38. species distinguished in these statistics are Dentex macrophtlamus, Dentex anglensis, Dentex dpp. Pangellus acarane, pagellus bellottii, pagellus spp.,spondyliosma cantharus and unidentified sparids (sparidae NET). Fiuger 6 illustrates the trends in total catches which were below 25.000 T in 1964–1970 and since 1979. Higher catches of the order of 30.ooo–45.000 T were attained in 1972–1975. Details of species composition are lacking for an average of 80% of the total sparid catches, and this limits the usefullness of the species breakdown given by some coutries.
National and industrial demersal fisheries in Mauritania have only existed since 1981, but for 1981–1983 the total industrial demersal fish catch and the sparid catch for the statistical division 34.3.1 are given in Table 39 (Source: CNROP Bulletins and FAO, 1984). For the calculation of the total catch in 34.3.1 it was assumed that one third of the catches from unknown fishig areas were taken in this division. The total landings declined over this period from about 31.000 T to 10.000 T, of which the sparids declined from 7.500 to 1.000 T. Data on artisanal catches of sparids were not available to the Working Group.
Landing statistics for the Dakar-based trawl fleet as given in Thiam (Appendix 7) were reised by the Working Group, to take into account the percentage of Dentex macrophtalmus in the commercial category “pageot” which consists mostly of Pagellus bellottii. Table 40 summarizes the revised time series for P.bellottii nad other red seabreams (“dorades roses”) for the period 1971–1984. Total seabreams catches of the Dakar-based fleet increased from about 450 T in 1971 to 3800 T in 1976. It then fluctuated around 5300–5900 in 1977–1980 and again around 7100–7500 T in 1981–1984.
Artisanal fisheries landings for four groups of sparids are given in Table 41 for the period 1977–1984. They comprise the commercial categories “pageot” (P. bellottii), “pagres” (Sparus caeruleostictus, Sparus pagrus, etc) “dentes” (Dentex spp.) and other sparids. In order to take into account catches made at the artisanal fishing centres of Mbour and Joal (which were not included) in the catch assessment survey until 1980) available artisanal catch data for the years 1977–1980 have been increased by 20% (this being the proportion of sparids caught at these centres in the immediately succeeding years).
Total sparid catches by all fisheries on the Senegalese commercial shelf are given in Table 42. Artisanal landings prior to 1977 were estimated from the statistics of P. bellottii given in Franqueville (1983) nad based on the average proportion of this species in the sparid landings between 1977 and 1984. Statistics of foreign fleet fishing in Senegalese waters before 1980 were obstained using the same method. The resulting estimates of the total sparid catches in Tables 42 which increased from 4865 T in 1971 to 16008 T in 1984 differ considerably from the nominal catches given in Table 37.
Tables 43–45 summarize, for the period 1964–1970, the available catch per unit of effort data for the Japanese and Polish fleets by vessel type. Except in the case of the largest Japanese trawlers (2 501–3 000 GRT) where sparids made up 23–41% of the landings, sparids contributed in widely varying percentages to the total catch. Between 1966 and 1969 sparid catches tended to decline when cephalopod stocks were fished by Japan and Polish fleets shifted their attention to pelagic fishing (Figure 8).
For Senegal, several series of effort units are available (days at sea, number of trips) for 10 GRT classes for the years 1971–1983. Because of the very frequent changes in the fishing strategy of many of the various vessels, the members of the Working Group were of the opinion that the CPUE of the pair trawlers was probably the best index of sparid abundance available for the Senegalese continental shelf.
Since 1974, these pair trawlers have exploited all species of the sparid community, and their landings of sparids represent 10–25% of the total quantities of sparids caught on the Senegalese shelf. Although the principal target species of the pair trawlers has at all times been cuttlefish (Sepia officinalis hieredda), most by-catch species (groupers, mullet and especially sparids) have been target species during period of low catch rates of cuttlefish.
For the pair trawl fishery, only CPUE data for 1976 to 1983 were compiled as the period 1974–1975 represented an exploratory fishing phase mainly oriented toward the capture of cuttlefish. The series in Table 46 shows a clear downward trend in time of the CPUE of the sparids. It is difficult to determine to what extent this trend in pair trawl CPUE is a valid index of changes in abundance.
Figure 4 illustrates the relations between total catch and effort and CPUE and effort. Franqueville (1983 and Appendix 5) presents a time series for 1972–1984 of landings and catches of Pagellus bellottii as well as of standardized effort (200 HP red mullet trawler fishing days) and CPUE value. These times series are illustrated in Figures 2–5 as well as in Table 3 of Appendix 5.
In Senegal, in 1975–1981, trawl surveys were made with R/V LAUTENT AMARO on commercial fishing grounds for P. bellottii during the main fishing season for this species and using the same mesh size as the commercial trawlers. Catches were then compared with commercil landings to determine yhe expected percentages of descards. Estimated percentages of discards over the survey period were of the order of 35–42% (Franqueille , 1983). In 1972–1974, these percentages were thought to hae been somewhat higher. There has been a general tendency fot dis cardpercentages to decrease, but this can be explained by marketing developments rather than by the effect of fishing. Frenqueville (1983 and Appendix 5, Table 3) based his assessment of the P. bellottii stocks on estimated catches from corrected landings statistics.
In Senegal and Mauritania, the CECAF Project did some discard studies on board several different types of vessels, of which the preliminary results indicated high discard rates for sparids (Monoyer and Bellemans, 1982).