ANNEXE G

Portuguese Fishery in the CECAF Area (1986–88)

Contribution to the Working Group on Hakes and Deep-sea Shrimp (Northern zone of CECAF) by Manuel Lima Dias - I.N.I.P., January 1990

INTRODUCTION

In 1987 and 1988 the Portuguese fleet operated in various areas of the CECAF region, as can be seen from the following table, with catches shown in metric tonnes.

The catches realized off the African coastal countries were more or less the same in both years with 69% and 70%, in 1987 and 1988, respectively of the total catches in the whole region. The Portuguese fishery in Division 34.1.2 (Madeira waters) was, as in previous years, mainly conducted concerned with tunas and tuna-like species as shown in the following table (captures by artisanal and tuna boat).

With regard to CECAF Statistical Divisions 34.1.1, 34.1.3 and 34.3.1 information as to the origin of catches were not always reliable, specially off Mauritania and Morocco. In doubtful situations, catches and landings were refferred to more than one division, ex. 34.1.3 and 34.3.1.

The target species in the Northern Zone off the African coast have, in recent years, been not only the hake but also the seabreams, the scabbard fish (Lepidopus caudatus), the rubberlip grunt (Plectorhinchus mediterraneus), among others.

Many difficulties were encountered in obtaining reliable statistics of respective landings.

THE FISHERY

Taking into account only the fishery carried out off the African coastal countries, Table 1 shows the landings of the hakes (Merluccius spp), the seabreams (Sparidae) and the rubberlip grunt (Plectorhinchus mediterraneus) for 1949–1988. These historical statistical data of the most important species, or group of species, were previously elaborated for the CECAF Working Group and concerned only the seabreams. It is presently updated for 1985–1988 and the range of species enlarged.

Table 2, on the other hand, presents more species referring to the entire area of the CECAF and the main landings of the target fisheries report from 1979 to 1988 in Divisions 34.1.1, 34.1.3, 34.3.1 and 34.1.2. Some of the figures relating to recent years are also updated.

Table 3 presents statistics for Divisions 34.1.2 - Madeira,34.1.1-Morocco,34.1.3 + 34.3.1 Mauritania and 34.3.1 - Guinea - Bissau + Senegal +

THE HAKE FISHERY

Regarding the Portuguese hake fishery it is to be emphasized that it was impossible, with the present statistical data available, to separate data by fishing area and gear.

However, and considering that the highest percentage of catches concerns the European hake (Merluccius merluccius) fished mainly by artisanal gear (gill net and line) in the northern CECAF region, it is possible to estimate different volumes of catches, according to the two main groups of hakes and gears used.

The result of this estimation is presented on Table 4 which shows landings of each type of hake in the Morocco and Mauritania waters.

FISHING EFFORT

It is not possible to provide information on the fishing effort of the different Portuguese units operating in CECAF waters.

One of the main reasons is that exploitation was carried out by several units which at times operated in waters off the southern Portuguese coast and, fishing grounds further away (south-west of Sagres and in northern CECAF waters).

In 1988 47, 13, 5 and 18 fishing boats operated in Morocco, Mauritania, Senegal and Guinea-Bissau, respectively with the following average GRT:

Attention is however drawn to the fact that some of these fishing boats were also operating not only in these areas but also off some other coastal countries, even though this was done sporadically.

Concerning the different fishing regimes of the Portuguese fleet fishing off the northern African countries, only about 3% of all boats operated in the Mauritania waters in 1988 while 97% operated mainly off Morocco. As for the fishery conducted in these waters, 71% fished under joint venture arrangement while only 29% fished under the EEC/Morocco agreement.

Considering the main gears used by the Portuguese fleet operating in this area, the reference to “polivalente” ships means that the gears used are artisanal, mainly gill nets and long-line. Some of the units also used traps.

In spite of all difficulties encountered, with reliable data it was possible to obtain some information which, together with other data directly obtained in the fishing harbours, permitted estimation of the percentage of ships using different gears. The result can be roughly summarized as follows:

For Mauritania, it should be emphasized that at least for the last three years some of the boats also fished with traps (for crustaceans). Lines and gill nets were used in the Senegalese area.

All these informations concern the entire Portuguese fleet, independently of the fishing regime.

BIOLOGICAL STUDIES

Taking into account the insufficient knowledge on the fishing grounds and on gears used, difficulties were encountered in recent years for a collection of reliable biological data. In spite of this, it was possible to develop a sampling programme in the main fishing harbours where the hakes, fished in the CECAF region were landed.

Tables 5, 6 and 7 show the length compositions of the hakes landed (mainly Merluccius merluccius) respectively for 1986, 1987 and 1988.

In 1987, it was also possible to obtain the length composition of the European hake, apart from the most important species present in the landings (Table 8). The mean length of the fishes was 55 cm and the mean weight 1.3 kg. On the other hand, the values of the mean length and mean weight for all the hakes landed during this year was respectively 43.8 cm and 1.4 kg.

Table 4 shows the 1988 estimates of the different landings of the white and the black hakes fished off Morocco and Mauritania, with different types of gears. Sampling were carried out along 1988 in fishing harbours for length composition of the hakes caught with gill net only (mainly white hake - M. merluccius and black hake - M. senegalensis) - Table 9. On the other hand, it was also possible to find out the length composition of the main species landed - Table 10 and Figure 2. (M. merluccius was mainly caught with trawl and gill net).This figure also shows the length composition of the black hake caught with gill net - Figure 2 B.

Note should be taken of the predominance of the catches of the European hake with gill net. From the total weight landed, 500.3 tonnes were from gill nets and only 26.8 tonnes trawl fishery (Table 10 and Figure 3.)

The last column of this table and figure 30 show the length composition of the European hake fished with both gears. The different length composition of fish landed with the two different gears is quite evident. The average length of hakes fished with trawl was 34.4 cm and that fished with gill net was 52.8 cm.

Figure 2 also shows the length frequency of the landings of the black hake fished with gill net.The same information concerns the whole hake fishery.

Taking into account all the 1988 biological data (length composition) on hakes - Merluccius spp. It can be observed that two main groups attained two main peaks at 28–29 cm and between 42–43 cm and 46–47 cm classes.The first group probably concerns the total number of small fish caught by trawlers and the second by liners and by boats with gill net (Figure 1).

Referring only to the European hake landed during 1988 and fished with gill net and trawl, with an estimated 527 tonnes (Table 10) fishery with gill net comprised about 95%. Such a situation could explain the total length frequency obtained for this species with both gears (last column of Table 10 and Figure 3).

It can be seen from Table 9 that values corresponded to length composition of M. merluccius landed and caught by gill net. The total of the European hake fished with this gear is about 63%. The mean length and mean weight of the European hake were as follows:

European hake	= 57.3 cm	= 1.8 kg
Black hake	= 48.7 cm	= 1.3 kg

Table 11 also shows the length composition of the whole sampling of M. merluccius senegalensis during 1988. Such a distribution is also presented on Figure 2 (2C).

Table 5 - Size composition (total length) of european hake (Merluccius merluccius) landed in Portugal - 1986.

Classes	Merluccius merluccius
	N	Nx103	%.
28–29	-	-	-
30–31	50737	51	22.1
32–33	135638	136	59.0
34–35	186460	186	81.1
36–37	222737	223	97.0
38–39	159653	160	69.4
40–41	42619	43	18.5
42–43	67904	68	29.5
44–45	69679	70	30.3
46–47	138344	138	60.2
48–49	174367	174	75.8
50–51	180879	181	78.7
52–53	178511	179	77.6
54–55	162867	163	70.8
56–57	63506	64	27.6
58–59	48370	48	21.0
60–61	42197	42	18.3
62–63	91919	92	40.0
64–65	103420	103	45.0
66–67	54965	55	24.0
68–69	52260	52	22.7
70–71	12515	13	5.4
72–73	11670	12	5.1
74–75	7442	7	3.2
76–77	16997	17	7.4
78–79	7019	7	3.1
80–81	2621	3	1.1
82–83	338	-	0.1
84–85	4820	5	2.1
86–87	592	1	0.2
88–89	338	-	0.1
90–91	-	-	-
92–93	-	-	-
94–95	2283	2	1.0
96–97	2283	2	1.0
98–99	254	-	0.1
100–101	-	-	-
106–107	2283		1.0
TOTAL	2299487	2295	999.5
₩landed	1921 tons
	48 cm
	840 g

Table 6 - Length frequency of black hake - Merluccius spp. landed in Portugal - 1987.

	Merluccius spp
Classes	N	N×103	%
30–31	1252	1	0.7
32–33	8626	9	6.6
34–35	35179	35	25.7
36–37	75601	76	55.8
38–39	82825	83	60.9
40–41	81358	81	59.4
42–43	83366	83	60.9
44–45	86880	97	71.2
46–47	107115	107	78.5
48–49	105553	106	77.8
50–51	89389	89	65.3
52–53	67105	67	49.2
54–55	85243	85	62.4
56–57	63074	63	46.2
58–59	47769	48	35.2
60–61	28773	29	21.3
62–63	28809	29	21.3
64–65	26403	26	19.1
66–67	26946	27	19.8
68–69	29628	30	22.0
70–71	28262	28	20.5
72–73	24085	24	17.6
74–75	28993	29	21.3
76–77	33038	33	24.2
78–79	21282	21	15.4
80–81	17361	17	12.5
82–83	13403	13	9.5
84–85	6895	7	5.1
86–87	1854	2	1.5
88–89	1731	2	1.5
90–91	4653	5	3.7
92–93	2721	3	2.2
94–95	3841	4	2.9
96–97	2996	3	2.2
100–101	402	0.4	0.3
102–103	201	0.2	0.2
104–105	201	0.2	0.2
TOTAL	1362772	1363	-
= 55.2	= 1.319 Kg	WC = 1798 Tons

Table 9 - Size composition of Merluccius spp. landed from gill net fishery. 1988.

Hakes	European hake Gill net		Black hake Gill net		European and black hake Gill net
Gears
Classes 2 cm	N	Nx103	N	Nx103	N	Nx103
38–39	1227	-		-	1227	1
40–41	1254	3	13993	14	16387	17
42–43	11658	12	27866	28	39524	40
44–45	11044	11	66878	67	77922	78
46–47	21475	22	89171	89	110646	111
48–49	13148	14	61305	61	74803	75
50–51	20248	20	16720	17	36968	37
52–53	22088	22	16720	17	38808	39
54–55	18407	18	19506	20	37913	38
56–57	22088	22	16720	17	38508	39
58–59	20861	21	5573	6	26434	27
60–61	22088	22	5573	6	2761	28
62–63	15339	15	5573	6	20912	21
64–65	19020	19	2787	3	21807	22
66–67	12885	13	-	-	12885	13
68–69	14112	14	-	-	14112	14
70–71	9817	10	-	-	9817	10
72–73	7363	7	-	-	7363	7
74–75	4295	4	-	-	4295	4
76–77	1841	2	-	-	1841	2
78–79	614	1	-	-	614	1
TOTAL	272422	273	348325	351	620747	624
Weight landed 500.3 Tons			291.2 Tons		791.5 Tons
Mean length =57.3 cm			=48.7 cm		=52.5 cm
Mean weight			=0.8 Kg		=1.3 Kg

Fig. 1 - Length composition of the 1988 landgins of Merluccius spp Thousands of fish landed

Fig. 2A - Length composition of the 1988 landgins of Black Hake from gill net fishery (Thousands of fish)

Fig. 2B - Length composition of the 1988 landgins of European Hake from gill net and trawl fisheries (Thousands of fish)

Fig. 2C - Length composition of the 1988 landgins of Merluccius spp. from gill net and trawl fisheries (Thousands of fish)

Fig. 3A - Length composition of the 1988 landgins of Merluccius merluccius from gill net fishery (Thousands of fish)

Fig. 3B - Length composition of the 1988 landgins of Merluccius merluccius from trawl fishery (Thousands of fish)

Fig. 3C - Length composition of the 1988 landgins of Merluccius merluccius from gill net and trawl fisheries (Thousands of fish)

Fig. 4 - Portugues Hake fishery (Merluccius spp. ) 1988 of fish landed

Fig. 5 - Merluccius merluccius - Length composition of landings from the trawl and gill net fishery (1988) ( % of fish )

Fig. 6 - Merluccius merluccius - Length composition of landings from the trawl and gill net fishery (1988) (Thousands of fish)