ANNEXE 7

PAPER PRESENTED AT AD HOC GROUP MEETING ON SARDINELLA
IN THE NORTHERN ZONE OF CECAF

National Report of the Gambia

by Asberr N. Mendy

THE GEOGRAPHY AND BIO-PHYSICAL INFORMATION

The Gambia is located on the west coast of Africa between the 13th and 14th parallel North. The River Gambia flows through the country and the estuarine ecology is found up to 200km inland from the mouth. The country is narrow and the coastline stretches only some 50km north to south.

The Gambia's continental shelf of 3855km2 is relatively rich in marine fish resources, with small pelagics such as sardinellas and mackerels predominating. Such stocks migrate through waters of Senegal, Mauritania and Guinea Bissau. More localized stocks comprise bonga (E. fimbriata) which is the species mainly caught by artisanal fisherman. Coastal waters also contain high value demersal fish such as groupers, sea breams and lobsters.

Current estimates of potential sustainable yields are 50,000 to 60,000 metric tonnes of small pelagics ( excluding bonga of about 10,000 tonnes), and 15,000 to 16,000 tonnes of demersal species. Demersal resources are believed to be fully or even over-exploited while there are still potential harvests of small pelagic species. High value shrimp and lobster resources are also believed to be fully or over-exploited.

The fisheries sector is both contibutor and victim, of increasing harvesting rates of natural resources and of environmental changes and degradation. It is also affected by spatial conflicts on land and in the sea and river. Despite the negative and potentially damaging factors mentioned above, there is no hard evidence of a decline in the stocks of bonga and other small pelagics such as sardinella and mackerel spp. available to the artisanal canoe fishery and industrial fishing vessels. It must be mentioned that Gambia has yet to fully exploit and utilize the economic potentials of its estuarine and marine fisheries. Out of an estimated annual fisheries potential of 75000 metric tons, only about 20000 metric tonnes are being exploited. The pelagic fishes of its marine fishing zone are not fully exploited and the full benefits of fishing under a reciprocal fishing agreement with senegal are yet to be achieved.

PHYSICAL PROFILE OF THE MARINE AND ESTUARINE ENVIRONENT

Sea temperatures are 15 to 20c in November through June, when days are sunny and warm and evenings cool. From july to October, the climate is hot and humid, with rain, and sea temperatures are about 27oc. Surface temperatures and hydrological profiles suggest a situation characteristic of nothern winter with cold inshore surface water, revealing an up-welling north of about 12oN (Cruise Report “Dr. Fridtjorf Nansen,” 1992). The Cap-Vert profile shows isolines rising towards the surface over the inner shelf. While the profile off the Gambia shows lifting of intermediate water onto the shelf, a profile off nothern Guinea Bissau shows lifting isolines in the upper 100m.

According to Dr. Fridtjof Nansen's Report¹, estimates of shelf areas (nm2) of the Gambia by depth ranges are as follows, see table.

¹ Survey of the pelagic fish resources off North West AfricaPart 3 SENEGAL - THE GAMBIA (19 February - 4 March 1992)

FISHERIES SUD-SECTORS

The fisheries sector is seen as a major potential source of employment: domestic food supply and export earnings. The sector is divided into industrial and artisanal fisheries with the industrial subsector being characterised by large scale private investment in export-oriented production, based entirely in Banjul. The artisanal sub-sector is characterised by low levels of investment and operation from many dispersed, and often isolated, landing sites. Industrial vessels tend to be large offshore vessels, often of foreign ownership, whereas the artisanal craft are locally built wooden canoes.

INDUSTRIAL SECTOR

Industrial fishery in the Gambia can be divided into two groups: The national fleet consists of shrimp trawlers and some finfish bottom trawlers. The foreign industrial fleet is composed of vessels from Senegal, Spain, USA, Brazil, Sierra Leone, Greece, France, Korea, Honduras, Kaliningrad, Latvia, Russia, Japan and Ghana of which only the latter used to fish pelagic species. The operators of this pelagic fishery vessels have now ceased operations in the Gambia. The industrial fleet of all nationals that operated during the period June 1991–1992 were 159 vessels. In annex VI is a table showing number of vessels by country and their GRTs.

The vessels were of the following types:

1. Freezer trawlers
2. Shrimp & Stern trawlers
3. Shrimp trawlers
4. Tuna purse seiners
5. Trawlers
6. Stern trawlers
7. Pole & Line (tuna)

Production, processing and marketing by the industrial sector is aimed at export and it is centralised and capital intensive. The industrial sub-sector comprises a few companies with high level of investment and is dominated by large scale private sector production, processing and domestic export-marketing companies of Gambia and or/foreign ownership. The onshore processing plants operating in this sector mainly receive demersal species including crustaceans (mainly deep and shallow water shrimps). The now liquidated Seagull Fisheries Co. Ltd was the only company that produced and processed small pelagics (these include sardinella and mackerel spp.). The industrial production during the period 1985– 1992 are given in annex I. The annual total catch of small pelagics are given in table 2a and graph 2a. From table one could see that the total catches of sardinella and mackerel have not exceeded 40% of the overall species caught. Catches of these species may be as low as 1% or less.

DATA COLLECTION

It is the department's policy to deploy observers on all fishing vessels licenced to fish in Gambian waters. The observers keep records of name of vessel, the latitude and longitude, whether the vessel was engaged in fishing or otherwise, catches by species, position of fishing, duration of hauls etc. The data recorded for each vessel is sent to the department for further processing. Not all vessels are provided with observers. Operators of vessels operating under the Gambia/EEC Fishing Agreement are responsible for recording and forwarding of their catch and effort data. The rate of return of such data continues, however, to be surprisingly low and the information provided not detailed enough to be useful.

The implementation of the Luxembourg Development Project (AFR/004) funded by the Government of Luxembourg and concerns aerial surveillance of fishing ground (mainly demersal gounds), and it is expected that it will improve industrial catch and effort estimation. Estimates of annual catches by the industrial fleet are grossly misrepresented, and it is highly probable that fishing efforts and catches are over-estimated. The data collection system is being reviewed. The new data collection and estimation systems are being put in place with 1992 as the base year. The annual fishing effort was determined as 5,363 vessel-days and a total catch for all species groups of 6050 metric tonnes.

ARTISANAL SUBSECTOR

Grant² proposed the geographical stratification of fishing villages into four strata:

• Stratum 1 Northern coast
• Stratum 2 Southern coast
• Stratum 3 Lower river
• Stratum 4 Upper river

It was observed that Stratum 1 had only one fishing village, Barra, which is located along the coast. Grant's Stratum 1 and Stratum 2 were merged to form the Marine Coast Stratum, yielding three Fishery Administrative Areas in the Gambia, Namely:

• Stratum 1 Marine Coast
• Stratum 2 Lower River
• Stratum 3 Upper River

The artisanal sub-sector provides about 95% of the locally consumed fish supply and employ approximately 1,500 people in the harvesting side and a further 13,000–18,000 on related boat bulding, fish handling, processing, transportation and marketing activities. However, many fishermen operating in this sector are not Gambian nationals and there is a considerable degree of seasonality in employment. Some of those employed in the processing of fish are women who may also be involved in some other activities, i.e, agriculture.

A frame survey is a sort of inventory survey of the fishery economic units, such as fishing canoes and fishermen. The purpose of the survey can be summarized as follows:

1. to prepare a complete list of fish landing sites (frame) for the catch assessment survey;

2. to collect basic statistics on the number of fishing canoes, fishermen and types of fishing gears used.

This survey is normally conducted by enumerators (staff members of the department) who visit all the landing sites existing in the three strata and ask a few wel-informed fishermen on required information. Frame Survey is conducted once every other year and at the shortest time period possible inorder to avoid duplication of information. The peak season for artisanal fisheries is from January to March, as a result mid-January up till the end of February is the period most suitable for the frame survey.

² FAO consultant who designed statistical data collection system for Fisheries Department in 1976

From the 1990 and 1992 frame surveys one could see that artisanal fishery is not equally divided between the three Fishery Administrative Areas, in fact in the Lower River Stratum are concentrated 44% of the fishermen and 48% of the total number of canoes³, see tables 3a and 3b for further details. The level of motorization also vary from one stratum to another, infact, in the Marine Coast about 98% of all the canoes are motorised while in both the Lower and Upper River Strata have only 8–12% motorization, see table 3b. Nine major types of gears are used in artisanal fishery. These gears are encircling net, gillnet, stow net, cast net, drift net, long line, hand line and purse seine. Tables 3a and 3c give the distribution by gear type in the three Fisheries Administrative Areas (1990/1992 frame survey results).

CATCH ASSESSMENT SURVEY

Catch assessment survey is a statistical survey for collecting the catch statistics (fishing efforts and fish catches) of small scale fisheries and is designed as a sample survey. Field Staff are deployed to identified sample landing sites where they weigh catches of sample canoes, usually six and make note of total number of canoes that went fishing on the sample day. The sample days are six, three in the first and second half of the month.

³ From 1992 Frame Survey results

ESTIMATION OF CATCHES (RAISING FACTORS)

As it was explained earlier, Grant's proposals for the raising factors to obtain estimated total landings by the artisanal sector are still being used to obtain monthly instead of bi-monthly estimates. The raising factors are as follows (to be applied to all fishing gear employed):

• Landing factor = Total number of canoes by the fishing method/number of landing sampled with the fishing method

• Frame factor = Total number of canoes in the stratum/Total number of canoes in the selected sample village

• Time factor = Number of days in the survey round/Number of survey days (usually 6 days)

• Overall = Landing × Frame × Time

The total catch during the six days by the selected landings of the fishing method multiplied by the overall raising factor gives an estimate of the total catch by that type of fishing gear. Due to the decision to include all the fishing villages along the marine coast into the sampling plan, the frame factor for this stratum is negligible; the frame factor automatically becomes 1/1 = 1 due to the complete enumeration of all fishing. Annex I gives annual catches by species.

FISHING EFFORT

Fishing effort is estimated using the frame survey results for the three Fisheries Administrative Areas, Marine Coast, Lower and Upper River Strata. The number of canoes seems to be the most feasible measure of effort. In practice we will have to choos a measure for effort we believe is related to fishing mortality or fishing power. In general a measure which can be shown to be linearly related to the catch rate is suitable measure. That is, if can be shown that two units of effort catch twice as much as one unit of effort when operating under egual conditions the effort measure is a suitable one. It most be bored in mind there are considerable difficulties in defining suitable measure of effort for a single gear let alone multi gear fishery.

Processing and marketing within the artisanal sector are, however, at a very low level of technological development and are very labour intensive. Artisanal production is aimed at both the domestic market and the export markets within the region and Europe through their supply of catch to the industrial companies.

Although the artisanal sub-sector has the potential to increase its contrbution to economic and social development is constrained by many factors. These are related mainly to poor shore-based infrastural development, inefficient and environmentally damaging processing techniques, lack of skilled gambian fishermen and poor recruitment to the sub-sector, low levels of credit availability, and limited village level organisation of the fishery. This is reflected in the low catch and heavy postharvest losses caused by poor handling.

Fish and other seafoods are very important source of protein for urban and coastal population. The fish per caput supply is about 20 kg and this represents about 19% of the total protein supply for the country.

BIOLOGICAL DATA

The Department of Fisheries as at present, is only able to record catches by species but has plans to incorporate other biometrics such as length frequency on selected species of commercially valuable species. The department is aware of the importance of size and weight limits in the catches as well as the size at maturity and the spawning period. Due to lack of funds and the necessary manpower, Department of Fisheries may require to solicit funds/assistance to carry out studies outlined above, including distribution and migration pattern of stocks.

In the absence of sufficiently long time series on length and age composition of the main species in the catches, growth parameters, mortality rates, long-term abundance cycles in relation to environmental changes, parasites and selectivity, application of stock assessment models will prove futile.

The biomass of pelagic stocks as contained in Dr Fr..Nansen' report are given in table 4.

According to the report aggregations of sardinellas and horse mackerel were found in the northern and south extremes of the Senegal-Gambia shelf which the report say may indicate the existence of sub stocks of these species. The report went further to state that at around February March the fish are likely to be at the southern part of their range and the distribution area of the sub stocks would then be West Sahara, Mauritania, Northern Senegal and Senegal south of Cap vert with Gambia respectively. It concluded that the sardinella stocks are in a healthy condition.

BIOLOGICAL CHARACTERISTICS

SARDINELLA AURITA Valenciennes, 1847

This species can reach 35cm but are common to 20cm. The sardinella aurita sp. are found in upwelling areas (cold and saline water). It is a pelagic species and is found from 16 to 50 metres of depth. They are fish by both the artisanal and the industrial fisheries fleets. The main gear used in small pelagics fishery are pusre seine (poli nets), gillnets, beach seines and midwater trawls. Sardinella aurita like all other sardinella spp. is highly migratory; it migrates through waters of Senegal, Mauritania and Guinea Bissau. No information on growth, fecundity, spawning and size at maturity are collected.

SARDINELLA MADERENSIS(Lowe, 1839)

Sardinella maderensis can reach 30 cm but are common to 25cm. This species is found in warm coastal waters, from the surface to 50 depth, sometimes in estuaries and lagoons. The species highly migratory and follows the same route as sardinella aurita; and mainly caught by ringnets, purse seines beach seines, cast nets and midwater trawls.

TRACHURUS TRACHURUS (Linnaeus, 1758)

Atlantic hore mackerel can reach about 40cm (fork lenght) but are common to 25cm. They are found in sandy bottoms from 100 to 200m depth, sometimes pelagic; and they sometimes form schools. The main gear used to fish horse mackerels are pelagic and bottom trawls and purse seines. This species migrates through waters of Senegal, Mauritania and Guinea Bissau.

The Fisheries resources of the Gambia are under tremendous fishing pressure from the industrial fleet which is more concerned with the harvesting of demersal stocks. These stocks are believed to be fully exploited if not over-exploited. Contrary to the demersal fishery, the pelagic fishery is still in a very good condition as less fishing pressure is exerted on it. Both artisanal and industrial catch data received from observers and field/staff are insufficent and not enough detailed to be useful. These data are mostly in the form of catch weight (production) and effort data are normally not explicit. As previously mentioned, no other biometric data are collected. The department is incorporating length frequency measurement of selected species of commercial importance in the near future.

ANNEX I

Fisheries Department
Statistics Unit
Industrial Sector

ANNEX II

FISHERIES DEPARTMENT
Statistics Unit
ARTISANAL SECTOR

ANNEX III

FISHERIES DEPARTMENT
Statistics Unit

ARTISANAL SECTOR

ANNEX IV

Fisheries Department
Statistic Unit

Abstracts of 1992 Frame Survey Results

Abstracts of the 1990 Frame Survey Results

ANNEX V

Table 3B

The table shows abstract (fishermen and canoes) from the 1990 and 1992 frame survey

ANNEX VI

Table shows number of vessels by country and GRT