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1
LAKE ALBERT FISHERIES RESOURCES AND THEIR MANAGEMENT STRATEGY
T.O. ACERE
Uganda Freshwater Fisheries Research Organization,
P.O.Box 343, JINJA, Uganda.
And
P. MWENE-BEYANGA
Ministry of Animal Industry & Fisheries,
Planning Department,
P.O. BOX 70003,
KAMPALA, Uganda.
TECHNICAL CONSULTATION MEETING ON LAKES EDWARD AND
ALBERT/MOBUTU BETWEEN ZAIRE AND UGANDA.
21-26 MAY 1990, KAMPALA, UGANDA.
2
INTRODUCTION
Lake Albert/Mobutu lies along the Zaire-Uganda border in 43/57 per cent ratio in the faulted
depression tending south-west to the north east. It is bounded by latitudes 1o0 n to2
o 20’ N and
longitudes 30o 20’ to 31
o 20’E.
It has a width varying from 35 to 45 km (22 to 28 miles) as measured between the scarps at the
lake level. It covers an area of 5600km2 and has a maximum depth of 48m.The major inflow is
through the Semiliki, an outflow of Lake Edward, Muzizi and Victoria Nile draining lakes
Victoria and Kyoga while the Albert Nile is the outflow. The physical, chemical and biological
productivity parameters are summarized in Table 1.
The scarp is steep but not sheer and there are at least 4 tracks leading down it to villages on the
shore and scarp land scarp is a young one, formed as a result of earth movements of the
Pleistocene times, and the numerous streams come down headlong down its thousand feet drop,
more often than not in falls (Baker, 1954). Sometimes there appears to be a clean fault; and at
other places there is the appearrence of step faulting, although this may be of only a superical
nature .The escarpment’s composed of rocks belonging to the pre-Cambrian Basement complex
of the content; but the floor of the depression is covered with young sedimentary rocks, known
as kaiso beds. In their upper part these latter beds contains many pebbles; whilst low down the
occurrence fossiliferous beds is sufficiently rare phenomenon in the interior plateau of Africa.
The kaiso beds dated as possibly middle Pleistocene in age, are exposed in various flats on the
shore, and they presumably extend under the relatively shallow waters of the lake.
A feature of the shore is the development of sandpits and the enclosure of lagoons;
and these can be observed in various stages of development at kaiso, Tonya, kibiro, Buhuka and
above all, at Butiaba. On an island lake over 1100 km (700 miles) from the shores of the Indian
Ocean one can thus study some of the shore-line phenomena usually associated with the sea-
coast (Worthington, 1929). In the north, from Butiaba onwards, the flats become wider and from
a continuous lowland as the lake shore curves away from the straight edge of the escarpment.
At a height of just 610m (2000 feet) above sea-level, the rift valley floor at Butiaba
has a mean annual temperature of 25.60c (780 f), from which there is virtually no seasonal
variation; and and the mean daily range is only6.50c (130f) (E.Afr. met. Dept.1953).With a mean
annual rainfall of not much more than 762mm (309 inches) and only 92 rain days in ayear,again
to judge from Butiaba, conditions in the rift valley are semi-arid; and the vegetation cover
consists of grasses and scattered drought-resisting trees and bushes. Only near the stream courses
does the vegetation thicken.
3
The itchthyofauna of lake Albert/Mobutu comprises 47 species belonging to 28 genera seperable
into 14 families (GreenWood, 1966). The lake is rich endemic species such as lates niloticus. In
the late 1920s species of the most economic valve in order of importance included Lates
niloticus, Citharinus citherus, Oreochromis niloticus, Bargrus, Sarotherodon gailaeus,
distochodus niloticus docmac, Bagrus bayad, Labeo horie, Alestes Baremose, Hydrocynus
forskahlii,Synodontis schall and mormyrus castile (Worthington,1929 and Holden, 1963).Some
of the species have declined in artisanal catches, whilst others are rarely caught. The earlier
workers(Worthington,1929,1929a,1929b,1932; Trewavas 1933, 1938,1983; Gudger,1944;
argaca,1948;Johnels,1956;Andrerson,1956;Lowe-McConnell,1957;
Greenwood,1955,1957,1966,1971,1976; Greenwood and Howes,1975; Hamlyn,1960a,
1961,1966; Gee,1964,1969; Greenwood 1964,1964a; Stoneman and Cadwalldr,1966; Holden
,1967,1970: midgley,1968; khalil,1973; Khalil and Thurston,1973; Paperna, 1973, Paperna and
Thurston ,1969; Thurston ,1969,1970,1976a; graham, 1986) have dealt with aspects which were
mostly descriptive biology of the fish species and other related aspects . How ever the most
comprehensive study towards management based exploitation was by Holden (1939a). Other
works were carried out in the Zaire part of the lake by other scientists (Regan, 1921, 1929; poll,
1939, 1939a; Daget, 1950 1962; Hulot, 1956; Voss, 1969; etc).
FISHERIES
Lake Albert/mobutu is connected to Lake Edward by northward flowing semliki river
whose rapids, whoever, prevent free passage between the two lakes .the two lakes show marked
faunistic differences. Lake Albert/mobutu contains several non –cichlids which absent from Lake
Edward and even the cichlid fauna of the two lakes is strikingly different. in lake Albert /Mobutu
there are four species of tilapiines, the biparental brooder ,sarotherodon galilaeus, the mouth
brooders oreochromis niloticus and o. leucostictus and the substratum spawner, tilapia zillii.
The long almost parallel sides of the lake are so precipitous that over most of their
length there is a virtual absence of a shallow littoral zone, and the Tilapiine populations are very
largely confined to shallow lagoons such as those at Butiaba, Buhuka and Tonya. Steeply
shelving shores act as a barrier to species of tilapiines involved, and effective colonization of the
lake proper has not been possible (pitman, 1936). According to pitman (1936) and Worthington
(1929) Lake Albert Mobutu did not support a Tilapiine fishery in the economic sense, as it
contributed only about 2.6 per cent of the fishery, the mainstay of the fishery in ecological and
economic terms being the zooplankton-feeding characid, Alestes baremose.
4
Lake Albert/Mobutu was rich in fish, of which mputa or Nile Perch (Lates niloticus),
Mpoi, (Distochodus) and Ngenge (Oreochromis niloticus and Sarotherodon galilaeus) were some
of the most important varieties, but on the Uganda side the resources were under-exploited
(Baker, 1954). Large numbers and specimens of Nile perch which had been scarce for months
were caught particularly by beach seines with the advent of Nile perch caught in March. An
exceptionally large example of Nile perch caught in 1939 was 93.6kg (206 1bs) and later in the
year 118.0kg (260 1bs). These large specimens have continued to be caught to the present time.
The catch statistics indicate that this multi-speciesf fishery has been sustained around
13,000 tonnes per annum (Table 2 and fig. 2). However, during the last 70 years of exploitation
some fish species, such as Distochodus spp., Labeo sp. And Citharinus spp, have drastically
declined or are almost non- existent. In the late 1920s the catch per net night was1.4, 2.3, 3.0 and
2.1 catharinus in 76.2mm, 127mm, 178m and 22.6mm mesh gillnet respectively compared to 0.0
at present. The fish catches have been affected by war conditions and shortage of fishing gears at
one time or another.
FISHING METHODS AND GEARS
Fishing is the job of men and the women are occupied in fish processing at home. Early
fishing methods were of various types. At Butiaba they consisted of the following according to
Worthington (1929).
i) Harpooning large fish chiefly catfish, Bagrus spp.wascarried out from canoes. The harpoon
was attached to a line which one end was held by the fisherman, so that, if hurled at a fish in
deepwater, the harpoon could be recovered easily.
ii) Catching ngege in the Waki River, when in spate employed baskets. Each basket was
conical, widely open at the base with small hand hole at the apex. It was placed over a fish in
shallow water and the captured fish extracted through the the hand hole.
iii) Trapping in the narrow channels leading to the lagoons below Butiaba was done with traps
which were of basket work, with re-entrant mouths. They captured large numbers of Tilapiines
during the heavy rains.
iv) Headline fishing for catfish, Tilapiines and other species was a method of major importance.
5
The fishing practiced at the villages situated south of Butiaba was as follows:
1) At kibero there used to be a considerable fishery supplementary to salt industry, by 1928
fishing was only practised by small boys who caught Tilapiines on handlines,baited with
filamentous green algae(Worthington, 19 29). Earlier, fishing occupied the men folk and salt
continued (Roscoe,1923). However, although the making of salt continued to be of relative
importance of this village industry, it suffered a decline in 1950s (Baker, 1954).
ii) At Buhuka in 1928 there was a flourishing fishing population which had only returned to the
lake shore during the previous few years due to the former closure of the Buhuka flats as
sleeping sickness area. The usual method was hand-line fishing from canoes. Bundles of grass or
brushwood (a) were anchored to the bottom in 6 to 10 metres of water, about 1km (half a mile)
from the shore. Each morning these were hauled to the surface by lines buoyed with branches
from the ambatch tree (Herminiera eleapchroxylon) tree which grows in a few of water close to
the shore, usually in sheltered situation, whose wood when dry has a specific gravity
considerably less than cork. Small fish, haplchromis Albertans (b) and very young mputa (lates)
were extracted form the bundles, which they entered, no doubt to seek shelter from the ngassa,
Hydrocynus, which abounded in those waters. The small fish were used as live bait on handiness
(c) for the capture of tiger fish, Hydrocynus(d). The triggerfish when caught, was immediately
transferred to a heavy hook on a stout line (e), of lates (f). In practice lates were not often caught
in that way, but a morning’s catch would include 10 or 20 tiger fishes. Long-lines of heavy
hooks for lates fishing were also employed at Buhuka to a less extend.
Iii) At Tonya those same methods were employed and in addition, when the Hoima River was
in spate, large numbers of mail, clarias spp. were speared in the muddy water.
iv) At Kaiso there were but few fishermen; they caught Hydrocynus triggerfish on handiness.
The fishermen of panymur, at northern-western end of the lake, were more active; they employed
long-lines, each was fitted with 10 very heavy iron hooks for the capture perch. The hooks were
bated with live fish, about 23cm (9 inches) long, which obtained from basket traps set among the
papyrus and swamps of the Victoria Nile mouth. The catfish, Eutropius niloticus, was the usual
bait and the catch by this method was about one large Nile perch for each long-line of 10 hooks
set.
6
SEINE NET
The seine was the only type of European gear used round the Uganda shore (Worthington,
1929). The seine net was probably introduced on the lake before 1919 (Roscoe, 1923;
Worthington,1929).It was a net about 90m (100 yards) long by 3m(10 feet) deep of mesh76mm
(3 inches), and made of stout hemp twine. Its cost (between shs 120/- and shs 230/- in
Kampala)was prohibitive to most native fishermen, with the result that time there were not more
than 12 such nets on the lake. There were 6 seine net at Butiaba,2 at Bugungu and 3 or 4 at
panymur. They were owned by Swahili and Banyoro natives (Worthington 1929).Currently there
are very many beach seines, some of which are over 1 kilometre long and are owned by one or
more individuals.
The numer of fish per haul of a seine varied with local conditions from a very few up to
several hundred. The species usually in abundance were in the following order, Hydrocynus,
Alestes, Labeo, Tilapiines and lates .The lates caught by a usually represented but in small
numbers.
In 1928 seine –nets were by far the most important method of fishing in Uganda I waters,
there also being a few 127 mm (5-inch) gill- nets in use at the time. The seine-net remained the
most important gear until early 1950s. In 1949 there were 102 camps operating seine-nets, but
only 13 camps from which 128 fishermen, some sharing canoes and not employing more than
one assistant each operated gill-nets. In 1952 an estimated 58 per cent of the total catch was
landed by seine-net. In 1953 seine-nets accounted for only 27 per cent of total annual catch.
Currently the catch form beach seines is well over 50% of the total artisanal production.
By 1954 the native fishermen were using a type of seine net which was made from the fibres of
old motor car tyres.Currently seine net are made of synthetic webbings.
GILL-NETS
In 1927 a gillnet fishery on a very large scale was started near kasenyi, in the Zaire
(Belgian Congo), the proceeds of which were dried and transported inland to feed labourers at
kilomoto mines. The area fished forms the part of the semilki delta on the then Belgian side of
the lake. The water of that area is very shallow, little of the it being more than about5 4or 5
metres in-depth .the nets in use were 203.2 mm (8-inch) mesh and were set at night. Large
numbers of canoes, stationed near kasenyi, and a motor launch were used for this fishery, and
very many nets were set each night (Worthington, 1929).
7
Before the introduction of nylon gill-net in early 1950s, the commonly used nets were
the127 mm(5-inch)nets made of flax and locally known as Ssesse nets,76.2mm(3-inch)nets and
203.2mm (8-inch) nets made locally from cord of old motor tyres and sisal twine. Short lengths
of 406.4 mm (16-inch) nets were made in 1960sfrom synthetic twine at Ntoroko and Wanseko to
catch the larger lates sp of up to and over 91 kg (200 ib).
At present gillnets as small as 38mm (1.5-inch) are in use cropping very small and
immature Alestes. Tables4, 5, 6 and 7 give catch characteristics of different mesh sizes at present
in use.
VILLAGES
The sitting of fishing villages was determined by the sand pits and cusps, for which
prevalent winds from the south-west, sometimes accompanied by seas of considerable size, both
of the splits The major landings were Ntoroko, Buhku,Kaisa.Tonya,Kibiro,Butiaba,Bugoigo and
Wanseko. Currently there are at least 174 fishing villages, 17 of them each having up to 9
canoers, 37 villages each with 10to20 canoes and 20villages each with over 21 canoes. Bugoigo
has the largest canoe population, 78 in number and kabukanga, kyampanga and songa-Rau the
smallest each having 4 canoes.
CANOES
In a survey conducted in 1949 there were 128 fishermen operating gill-nets with not more
than assistant and often sharing canoes. Licensing of canoes first started in August 1950, and
although Licensing was never complete in any one year in total number operating on the lake.
The canoes have been increasing from 128 Licensed canoes in 1949 to around 1349 in 1989
(Table 8).
Kabalega canoe
The Kabalega canoe is named after the former kabalega Technical school in Masindi
transferred first to kichwamba outside fort portal and finally in 1967 to Entebbe fisheries
Training Institute. The Kabalega canoe is based on the tranditional planked Ssesse canoe of Lake
Victoria. The Kabalega, however, was designed for outboard motor propulsion and is built on a
much wider beam, has a double chine, and planks were copper-fastened on sawn frames. It was
first built in 1955, and they are now built by a number of progressive, trained boat- builders at
Wanseko and Masindi.
8
Congo Barque Canoe
The Congo barque canoe is aplanked, flat bottom vessel fastened with iron nails about 5-7
metres (15-20 feet) long, and was first sold to Ugandan fishermen from Kasenyi for shush 300 to
shs 400. This type of canoe soon proved popular as it was better suited to the rough conditions
often encountered on the lake than a dugout, and is far cheaper than a Kabalega or imported
sesse canoe. They were made by itinerant carpenters at various points along the lake shore and
for shs 1000 in 1965s.
Sesse canoe
The Sesse canoe in use in the early 1950s by fishermen from Buganda region who settled at
Kibiro, but in early 1965 only a very small number of them were recorded in a few villages. The
Sesse canoe is sometimes made along the lake shore from local materials, and a canoe is
imported occasionally from Lake Victoria. Soon after the introduction of the of the kabalega
canoe, a 5-7 metre (16-20 feet) craft modeled after English west-country inshore fishing vessels
was introduced as a product of the boat- building course at Kabalega Technical School Although
these crafts were in many ways better suited for the lake by 1966 they had not yet proved
popular.
The replacement of the dug- out by more advanced canoes was at first slow, but with the
existence of firms turning out several planked canoes per year, and the fact that no more dug-
outs have been made around the lake since 1963,the process became more rapid. The average
cost of a dug-out in 1953 was shs420.The large trees suitable for dug-out manufacture are now
difficult to obtain, and as a consequence fewer dug-outs are being made.
FISH MARKETING
Pitman (1936) recorded that an endeavor to develop fish –buying centre in specified
localities had met with little encouragement from the local fishermen, but that did not necessarily
imply that the scheme was deemed to failure, for the (native) fisherman was notoriously a slow
mover and normally averse from any change, especially of a sudden nature, in his mode of life
and methods.
However, in 1939 the African conducted fisheries a long the lake coast in Bunyoro
benefited enormously from the activities of a European who was permitted to undertake
systematic marketing. The European acted as a buying agent for the dried commodity which
ensured the fisherman a regular market for his produce and stimulated effort.
9
The experience gained in many years emphasized the fact that this inshore fishery was
strictly limited and that it could no support organized commercial fishing on a large scale, so was
best left to African hands. In 1939, however, 65.99 tons dried fish were exported to the Belgian
Congo, against 4.125 tons in 1938. By 1950s at Tonya the fish was dried and then sold mainly to
then Congo where there was a demand for it as food for the labourers of the kilo-Moto mines.
The fishermen in 1950s used to take fish in their own canoes directly to Kasenyi. Or they would
send it first to Butaiba ,whence it went by steamer service to mahagi port or kasneyi.Fish was
sold too in the plateau hinter land, for example at Hoima market, in exchange for other
consumer goods, but some household utensils were brought in from then Belgian Congo. Most of
the fish from the Uganda part of the lake finds its way to Zaire.
FISH KILLS AND PARASITES
One of the earliest recorded mass fish kills occurred in December 1935. For a few days
enormous numbers or caeses of Lake Mputa (lates) were seen floating over a large area on the
lake Albert/Mobutu and this wide-spread mortality extended from kibiro to panymur. From am
launch on ship hundres of gleaming white bloated carses could be seen atanyone time (pitman,
1936). It was the larger fish which were invariably affected. The occasional widespread mortality
and vast scale had also never been satisfactorily explained. Pitman (1936) further observed that
the curious mortality was evidently confined to Nile perch (lates) and no other species seemed to
be involved.
Subsequent studies have shown that Nile perch is sensitive to low oxygen and the mixing
of anoxic water from the bottom of The Lake within the whole water column should account for
the mass kills. The lake occasionally gets very rough with high seas.
Several species of fish in the lake infested. Compana-Rouget (1961) reports on nematodes
found in fish from lacs kivu, Edouard et Albert in 1952-54. Nile perch is also known to be
infested with Dalops ranorum (Acere, 1984) and Lernea bernimiana (Thurston, 1960.1970;
Acere.1984), Philometra sp larva (Nematode) and diplectanum lacustris Thurston and paperna
1969, a monogenean found in gills (Thurston, 1970) and heavily infested with Ergasilus Kandti
and moderately infested with Diplectanum lacustris (Thurston, 1970). Green (1964, 1964a)
reported two new species of parabathynella (Crustacea: synacarida) from Lake Albert,
Uganda.Khalil and Thurston (1973) have reported on the Helminths parasites of fishes including
a description of two new species of digeneans.
Some of the hosts include the tilapiines, which are abundant in the lagoons and are
infested with Nematodes in the abdominal cavity (G. Mbahinzireki, personal communication).
10
RESEARCH
Considerable amount of research work has been carried out on Lake Albert/Mbobutu,
although out continuously. On the Uganda side the most comprehensive work was done in
1962(Holden, 1963) long after the fishing survey in 1928 by Worthington (1929).Although by
1950s it was believed that the Uganda part was under-exploited (1954), this is no longer the case.
There is now need to examine the the state of the fisheries.
The biology of many species in this lake is hardly known. The Zaire part of the lake has
been studied, unfortunately the literature is not available in Uganda.
It is imperative that the long term economic viability of the fisheries of lake
Albert/Mobutu will depend upon a sound knowledge of biology, ecology and dynamics of the
constituent species in general and fish of commercial importance in particular. The dramatic
changes in the fisheries of this lake point that fish mortality of man in depleting fisheries
resources to a point of no return as demonstrated by the near disappearance of citharinus spp.
There is therefore need for a reliable and realistic study to to appraise fully the the present
state of fisheries, their potential and an understanding of those of the phenomena which have
affected their development. A number of issues need to be addressed.
1- There is a need to carry for reliable and realistic stock assessment survey in order to derive
reasonable estimates of vital statistics, standing stock and potential yield of various species.
2- There is need to conduct biological investigations on the major commercial fish species
including also the disappearing on both in the lakes and associated rivers. Among the parameters
of interest are included estimates of growth rate, age at first maturity, recruitment, and yield per
recruit and mortality rates.
3- An investigation of the ecological patterns of the lake with respect to species distribution
and abundance should be carried out.
4- An limnological survey of the lake and the associated rivers, covering phsical, chemical
and biological characteristics (productivity) of the system should be undertaken.
11
5- The impact of the various fishing methods and gears currently in use should be examined, so
that their detrimental effects are at least minimized if not eliminated.
6- socio-economic studies of the lake populations should be investigated. There have been two
reports on this subject, and both of them dealt with Jonam at north-western of the lake (Ongom,
1970; Graham, 1986).
MANAGEMENT
Migratory resources such as fish and wildlife are liable to fare badly under a system of
unregulated completion. Such resources being elusive and therefore subjects of property rights in
so far as they actually possessed, cannot be rationally exploited under a system of unregulated
competition. Any decrease in production by only a part of the abstaining preserve the resources
for the future, or for the abstaining producers, but only improves the production and profit
chances of active producers. The result is that, to safeguard their long as it is allowed by the
relationship between the prevailing prices and costs.
The fisheries of lake Albert/Mobutu have been free for all without any limit to fishing effort, and
type of gear. Although beach seines were banned in mid 1980s, throughout Uganda, their use has
continued unabated almost everywhere with the field officers keeping a blind –eye to the
practice. The use of gillnets less than 76mm were discouraged but not enforced. The area around
Butiaba Island was supposed to be a sanctuary especially for the breeding of Tilapiines, where
fishing is prohibited. This too is not enforced .fishermen continue to fish there and elsewhere
using the most dangerous method for beating the water to frighten fish into set nets. At the
confluence of the Murchison Nile, lake Albert/mobutu and Albert Nile fishing is prohibited. It is
from that point up to the Murchison fall where the biologically over exploited and now rare
species such as Citharinus spp, Distochodus spp and Labeo are still abundant. These rare species
are also still found in the Albert/Nile where they cropped at even small size. However, the
prohibition to fish from the Eastern bank in the area of park seems to protect these rare species
from extinction and should be enforced.
In absence of detailed scientific data it is only fair to make afew recommendations for
management purposes.
1-The use of beach seine nets should be prohibited because they are used and dragged in areas
suitable for breeding of the Tilapiines.
12
2-Gilnets and other fishing gears including fishing activities should not be deployed near mouths
of rivers. This measure would facilitate the eventual recovery of andromous fish such as
Citharinus, distochodus, Labeo and Claris, which breed in rivers.
3- The ban on fishing near Butiaba Island should be enforced.
4-the field staff should be p-provided with waterbourne craft and bicycles to facilitate their
mobility. This would enable the to collect catch and effort data which are the measure of fish
production. As a collorary the staff should try to provide more accurate statistics.
5- The field staff in order to be able to supply accurate information should be proviveded with
weighing scales, measuring tapes, gum-boats, rain coats and calculators.
6-Good access roads to fishing villages should be constructed or maintained. This would ensure
the supply of fish to the hinderland.
7. There is need to provide the fishing villages with fish gutting and washing slabs and also clean
water supply.
8. The fisher fork should be guaranteed the supply of fishing gears and other essential inputs.
9. The fisheries managers and research scientists from Uganda and Zaire should be constant
contact. This would alleviate some of the problems encountered on the lake such as that of
fishing gear across the border, and facilitate exchange of research findings.
10. There is need to harmonize the regulations on both sides of the shared lakes.
11. The tax stracture levied of fishermen for their canoes should be re-examined as it is now the
cause of catching more immature fish in an effort to break-even or make more profit. This
income tax seems excessive, given the hazards including thefts of gears and storage of fishing
inputs.
ACKNOWLEDGEMENTS
Our sincere thanks go to Mrs Ferry Balirwa for secretarial services and Mr. David mugerwa for
preparing statistical drawings. Most of the data and information used in this paper was collected
by the senior author when he was a consultant on the EEG financed Artisanal Fisheries
Resources Study Project No. 5100.36.47.025 Uganda.
13
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22
Table 2. Estimated Annual fish production in Lake Albert/ Mbobutu (Uganda waters) in
tones.
*= data not available. (Adopted from Ministry of Animal Industry of Fisheries, 1983;
Uganda Fisheries Department Annual Reports 1958- 1982; Okaranon and Kamanyi,
1889).
Year 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1972 1973
1000 Tonnes 12.0 14.6 18.4 18.0 * 11.3 10.2 12.4 13.2 13.5 13.7 23.4 9.5 10 4 13.0
Year 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
1000 Tonnes 18.5 18.7 12.3 20.6 20.6 17.0 13.0 6.0 10.0 4.0 4.0 3.2 8.9 * 12.5 5.6
23
Table 3: landings surveyed, number of canoes interviewed and average number of days fished in
a week in Lake Albert (Adopted from Okaronon and Kamanyi, 1989)
Landing Category Canoes Canoes Days fished
Canoe No for actually per week
Interview interviewed
Kalolo A=0-9 4 4 6.0
Kachunde B=10-20 6 6 7.0
Kitebere B=10-20 5 5 7.0
Hoima B=10-20 7 1 7.0
Runga C=20+ 8 13 5.4
24
Table 4: Catch per mesh size gillnet power night in lake Albert/Mobutu during February 1989
(Source Okaronon & Kamanyi 1989
Gillnet mesh Number of Total No. Catch (kg)
mm canoes of nets used per net
sampled
50.8 6 386 0.36
63.5 7 522 1.30
76.2 1 75 0.31
101.5 5 32 1.50
114.3 7 51 2.40
203.8 1 9 4.56
25
Table 5: Catch per unit effort per category of landing in lake Albert/Mobutu in February 1989
(Source p; Okararonon and Kamanyi, 1989).
Size of no. of Canoes Average No. Catch (kg) Catch (kg)
Landing sampled of nets per per net per
(Canoes) canoe canoe
A=0-0 4 23 1.27 29.21
B=10-20 11 47 1.37 64.21
C=20+ 13 36 0.59 21.24
A+B+C 28 38 1.03 39.14
26
Table 6: Retention Characteristics of the various mesh size gillnets per fish species in lake
Albert, in February 1989 (Source: Okarononand Kamanyi, 1989)
Species Gillnet n Total/Fork length (cm) Weight (kg)
Mesh minim. Av. Max. Min. Av. Max
(mm)
O. niloticus 101.6 63 20.80 24.90 24.50 0.14 0.58 0.64
O. niloticus 114.3 82 22.10 28.85 34.40 0.24 0.62 0.94
Bagrus spp 88.9 16 28.00 36.81 50.20 0.24 0.45 1.28
Lates spp 76.2 16 28.00 32.20 38.50 0.28 0.36 0.56
Lates spp 114.3 41 30.00 38.81 50.20 0.30 0.74 1.68
Alestes spp 63.5 58 22.30 26.72 42.40 0.10 0.21 0.52
Hydrocynus spp 50.8 149 19.80 25.61 32.30 0.08 0.21 0.72
Hydrocynus spp 63.5 114 20.30 25.49 30.30 0.12 0.20 0.33
27
Table 7: Catch per net per night for various gillnet mesh size per fish species in lake
Albert/Mobutu in February 1989 (Source ; Okararonon and Kamanyi, 1989).
Species Gillnets Total No. Catch (kg)
Mesh size of nets per net
(mm) used
O. niloticus 50.8 43 0.00
O. niloticus 63.5 72 0.00
O. niloticus 76.2 75 0.01
O. niloticus 101.6 27 1.58
O. niloticus 114.3 51 1.04
Bagrus spp 50.8 25 0.04
Bagrus spp 63.5 72 0.00
Bagrus spp 76.2 75 0.03
Bagrus spp 101.6 5 0.16
Bagrus spp 114.3 24 0.20
Clarias 114.3 4 0.8
Lates spp 50.8 163 0.03
Lates spp 63.5 150 0.00
Lates spp 76.2 75 0.23
Lates spp 101.6 5 0.74
Lates spp 114.3 41 1.07
Lates spp 203.2 9 1.39
Synodontis spp 50.8 185 0.02
Synodontis spp 63.5 244 0.65
Synodontis spp 76.2 75 0.4
Synodontis spp 114.3 24 0.10
28
Barbus spp 63.5 80 0.28
Barbus spp 76.2 75 0.01
Barbus spp 101.6 5 0.07
Barbus spp 114.3 6 0.77
Labeo spp 50.8 22 0.03
Schilbe spp 50.8 140 0.01
Schilbe spp 63.5 72 0.00
Alestes spp 50.8 246 0.06
Alestes spp 63.5 442 0.32
Alestes spp 114.3 10 0.28
Hydrocynus spp 50.8 385 0.30
Hydrocynus spp 63.5 350 1.47
Hydrocynus spp 76.2 75 0.01
Hydrocynus spp 101.6 5 0.09
Other species 50.8 22 0.01
Other species 114.3 26 0.30
Other species 203.2 9 0.17