001. ANDERSSON, R. AND OHLSSON, C.S. (1963)
Fishing boats for Lake Chad. Report to the Government of Nigeria. FAO (Rome),
EPTA Project Report No. 1711. 64p. En.
FISHING TECHNOLOGY; Lake Chad; fishing boats; traditional boat designs; new boat designs; construction materials; mechanisation; research vessels; fisheries development; commercialization; future recommendations.
Detailed report including a review of African boatbuilding practices and craft designs and construction materials used on Lake Chad. A design for mechanized craft which could be used to develop the commercial fishery is provided.
002. ARDIZZONE, G. (1975)
A bibliography on hydrobiology and fisheries of the Chad, Niger and Senegal
Basins. FAO (Rome), Report of the consultation on fisheries problems in the
Sahelian zone, Bamako, Mali, 13–20 November 1974. CIFA Occas. Doc. No. 4:
220–242. En. Fr.
GENERAL APPRAISAL (FISHERIES); Chad Basin; bibliography.
The Chad Basin is included as a significant component of this bibliography covering the areas of fisheries biology and hydrology..
003. AUBRAY, R. (1978)
Rapport national d'ensemble: Tchad, (developpement des peches). [Country study:
Tchad, fisheries development.] FAO (Rome); CILSS/CAS (Permanent Interstate
Committee for Drought Control in the Sahel, Ouagadougou (Upper Volta))
Consultation to Promote the Fishery Development Programme in the Sahel,
Meeting Report, Rome, Italy, April 1978. 58p. Fr. 39 ref.
GENERAL APPRAISAL (FISHERIES); Chad Basin (Chad); fisheries resources and production; fisheries development.
The potential for fisheries development in the Sahel region of Chad, especially Lake Chad, is considered at all levels: production, processing and marketing.
004. AZEZA, N.I. (1979a)
Fish processing technology and production. Annual Report of the Lake Chad
Research Institute, Maiduguri, Nigeria. 1979/80. Pp. 35–37. En.
FISH PROCESSING; Lake Chad; processed fish products; handling; transportation; post-harvest losses; insect infestation; Dermestes beetle; product value.
Surveys indicated that the Dermestes beetle is the major cause of post-harvest fish losses at Lake Chad processing and landing sites. Breakage of processed fish during sorting, grading and transport halved the market value of the product.
005. AZEZA, N.I. (1979b)
Improvement of traditional methods of fish processing. Annual Report of the
Lake Chad Research Institute, Maiduguri, Nigeria. 1979/80. Pp. 37–42. En.
FISH PROCESSING; Lake Chad; processed fish products; post-harvest losses; insect infestation; improved processing methods; brining & smoking.
Soaking fish in brine (5–10% salt solution) for between 12 and 80 minutes, depending on the species, before smoking can reduce insect infestation significantly. However resmoking every 5–7 days proved to most effective, allowing storage for up to 5 weeks.
006. AZEZA, N.I. (1982)
Quality assessment in processed fish from Lake Chad destined for (Nigerian)
southern markets. Proceedings of the Expert Consultation on Fish Technology in
Africa, Casablanca, Morocco, 7th June 1982. FAO Fish Report No. 268 (suppl.):
75–83. En.
FISH PROCESSING; Lake Chad; processed fish products; post-harvest losses; insect infestation; quality control; fish commerce and marketing; Nigerian markets.
Sample surveys of processed fish from Lake Chad destined for southern Nigerian markets revealed that product quality is variable. Significant post-harvest losses occur in transit associated with insect infestation and internal rotting promoted by the inadequately-dried state of the fish. The impact on marketing and the possibilities for quality control are examined.
007. AZEZA, N.I. (1983)
Incidence of the use of chemicals applied as techniques for protecting Lake Chad
processed fish against insect infestation. Annual Report of the Lake Chad
Research Institute, Maiduguri, Nigeria. 1983. Pp. 66–67. En.
FISH PROCESSING; Lake Chad; processed fish products; post-harvest losses; insect infestation; insecticide (synthetic) use; product quality; fish commerce and marketing.
Preliminary results show that agricultural pesticide residues are not present in Lake Chad processed fish. It is suspected though that pesticides are sometimes used by traders to protect against insect infestation.
008. AZEZA, N.I. (1986)
The problem of choice of safer methods of reducing post-harvest losses in Lake
Chad processed fish. In Fish Processing in Africa, Proceedings of the FAO expert
consultation on fish technology in Africa, Lusaka, Zambia, 21 – 25th Jan. 1985,
FAO (Rome), pp. 340–349. FAO Fish. Rep. 329 (Suppl) 747p. En. 9 ref.
FISH PROCESSING; Lake Chad; processed fish products; post-harvest losses; improved processing methods; brining and smoking; product quality; nutritional value.
Some of the technological approaches available to the Lake Chad fish processors with a view to reducing post-harvest losses and providing products with a better nutritive value are discussed. These include drying, smoking, brining, salting, improved packaging and better hygiene.
009. AZEZA, N.I. AND MAEMBE, T.W. (1981)
Report on the meeting of fish preservation and processing organisations in
Nigeria. Fed. Inst. of Ind. Res. (Lagos, Nigeria). En.
FISH PROCESSING; Nigeria; Research Organistions; research priorities; fisheries development.
Basic summary of the work of each organisation, identification of research priorities (investigations of new processing methods) and strategies for future fisheries development.
010. BENECH, V. (1974)
Données sur la croissance Citharinus citharus dans la bassin tchadien. [Data on
the growth of Citharinus citharus in the Chad Basin.] Cah. ORSTOM., sér.
Hydrobiol., 8: 23–33. Fr. 17 ref.
FISH BIOLOGY; Citharinus citharus; Lake Chad Archipelago; fish growth.
Growth in length of Citharinus citharus in the south-east archipelago of Lake Chad is investigated. Back-calculated mean standard length (L1) at the end of the first growth period is 115mm. Growth is compared to that recorded in other African basins for the same species.
011. BENECH, V. (1975a)
Effets de la sécheresse sur les peuplements de poissons dans le lac Tchad et le
delta du Chari. [Effect of drought on the fish populations of Lake Chad and the
Chari Delta.]. Notes techniques du Centre ORSTOM., N'Djamena, Tchad No.9.
15p. Fr. 7 ref.
FISHERIES ECOLOGY; Chad Basin; fish population structure; species abundance; stock assessment; hydrological cycle; Sahel drought.
012. BENECH, V. (1975b)
Croissance, mortalité et production de Brachysynodontis batensoda (Pisces,
Mochocidae) dans l'archipel sud-est du Lac Tchad. [Growth, mortality amd
reproduction of Brachysynodontis batensoda (Pisces, Mochocidae) in the south-eastern
archipelago of Lake Chad.] Cah. ORSTOM., sér. Hydrobiol., 9 (2):91–103.
Fr. 15 ref.
FISH BIOLOGY; Brachysynodontis batensoda; Lake Chad Archipelago; fish growth; fish mortality; fish reproduction; fish population structure; stock assessment; hydrological cycle.
Study based on monthly gill-net and seine-net fishing during period of falling lake level (drought). Length/weight regressions, mortality and productivity estimates presented. Winter growth stop noted. Water recession and overcrowding also produced further growth stops. Condition factor indicated increase in weight with flood of October 1973 onwards.
013. BENECH, V. (1978)
Recherche de solutions pour l'échantillonnage quantitatif en milieu tropical.
[Search for solutions to the problem of quantitative sampling in tropical
environments.] In Symposium on River and Floodplain Fisheries in Africa,
Bujumbura, Burundi, November 1977. Review and Experience Papers, ed. R.L.
Welcomme, pp. 92–107. FAO (Rome): CIFA Tech.Pap. 5: 92–106. Fr. 4 ref.
RESEARCH METHODOLOGY; Chad Basin; sampling techniques; net fishing; electrified nets; trawls and purse-seines; performance analysis.
After a review of sampling methods employed in different biotopes of the Chad Basin, the use of an electrified net is described and the researches into the improvement of this method. A new type of trawling with this net is described. The selectivity and efficiency of these nets is examined with reference to the use of purse-seine and electrified nets for certain species.
014. BENECH, V., DURAND, J.R., FRANC, J., LOUBENS, G., QUENSIERE,J. (1974) Résultats des pêches aux filets maillants dans l'archipel du lac Tchad, de 1971 à 1974. [Results of net fishing in the archipeligo region of Lake Chad, from 1971 to 1974]. Rapport du Centre ORSTOM., N'Djamena, Tchad (miméo). 91p. Fr.
FISH RESOURCE SURVEYS; Lake Chad Archipelago; net fishing; tabulated statistics.
Results of fishing surveys in the archipelago region (Lafia-Bol-Berim) of Lake Chad are presented in table form. Details also given of sampling methodology.
015. BENECH, V., DURAND, J.-R. AND QUENSIERE, J. (1983)
Fish Communities of Lake Chad and associated rivers and floodplains. In Lake
Chad: Ecology and productivity of a shallow tropical ecosystem, Carmouze, J.-P.,
Durand, J. R., Lévêque, C. (Eds), pp. 293–357, Monographiae Biologicae 53, The
Hague: Dr. W.Junk. En.Fr. 28 ref.
FISHERIES ECOLOGY; Chad Basin; fish population structure; stock assessment; fish population composition; hydrological cycle; Sahel drought; lacustrine-swamp species transition.
A detailed examination of the fish communities based on the extensive field-work undertaken by ORSTOM between 1965–1975, including discussion of the influence of the drought, the transition from “Normal” to “Lesser Chad” and the replacement of lacustrine species by swamp species.
016. BENECH, V. AND FRANC, J. (1975a)
Résultats de l'ensemble des pêches à la senne de rivage, de 1966 à 1974. [Overall
results for shore-seining, from 1966 to 1974]. Rapport du Centre ORSTOM.,
N'Djamena, Tchad. 46p.(miméo). Fr.
FISH RESOURCE SURVEYS; Chad Basin; net fishing; tabulated statistics.
Tabulated results of all fishing surveys undertaken between 1966 and 1974 in the Chad Basin.
017. BENECH, V. AND FRANC, J. (1975b)
Résultats des pêches au filets maillant dans la cuvette nord du lac Tchad de 1971
à 1975. [Results of net fishing in the northern basin of Lake Chad from 1971 to
1975]. Rapport du Centre ORSTOM., N'Djamena, Tchad. 60p.(miméo). Fr.
FISH RESOURCE SURVEYS; Lake Chad (N. Basin); net fishing; tabulated statistics.
Results of fishing surveys undertaken in the northern basin between 1971 and 1975 presented in tables.
018. BENECH, V. FRANC, J. AND MATELET, P. (1978)
Utilisation du chalut électrifie pour l'échantillonnage de poissons en milieu
tropical (Tchad). [Use of an electrified trawl-net for sampling fish in the tropical
environment (Chad).] Cah. ORSTOM., sér. Hydrobiol., 12, 197–224. Fr. 12 ref.
RESEARCH METHODOLOGY; Chad Basin; sampling techniques; net fishing; electrified nets; trawls; performance analysis.
019. BENECH, V. and LEK, S. (1981)
Résistance à l'hypoxie et observations écologiques pour seize espèces de poissons
du Tchad. [Resistance to deoxygenation and ecological observations in sixteen fish
species from Chad.] Rev. Hydrobiol. trop., 14 (2): 153–168. Fr. 43 ref.
FISHERIES ECOLOGY; Lake Chad; fish population structure; fish population composition; species abundance; stock assessment; lacustrine-swamp species transition; hydrological cycle; Sahel drought; deoxygenation; deoxygenation resistance; Brachysynodontis batensoda.
Resistance to hypoxia is enhanced by morphological and ethological features facilitating the use of the oxygenated surface film; this seems clear in Brachysynodontis batensoda. Deoxygenation appears to be the main factor responsible for drastic changes in fish species abundance. Observations related to the effect of drought on Lake Chad. Other ecological factors acting on spawning or feeding promote certain species among those which are most resistant to deoxygenation.
020. BENECH, V., LEMOALLE, J. AND QUENSIERE, J. (1976)
Mortalités de poissons et conditions de milieu dans le lac Tchad au cours d'une
période de sécheresse. [Fish mortalities and environmental conditions in Lake
Chad during the severe drought.] Cah. ORSTOM., sér. Hydrobiol., 10 (2): 119–130. Fr. 25 ref.
FISHERIES ECOLOGY; Lake Chad; fish mortality; species abundance; stock assessment; hydrological cycle; Sahel drought; critical water level; water quality; deoxygenation.
Fish mortality in Lake Chad during the Sahelian drought of 1972–74 is described. Water level was greatly reduced and Lake became divided into three separate basins. Variations in water quality parameters are presented. Mass mortalities occurred due to water turbulence and anoxia produced by macrophyte decomposition. Relative CPUE data given for some species. A critical water level below which mortalities occurred has been determined for the two main basins.
021. BENECH, V. AND QUENSIERE, J. (1979)
Etudes des potentialities du bassin conventionnel du lac Tchad. [Studies of the
potential of the Lake Chad Basin]. Rapport, ORSTOM (Paris), 135p. Fr. 19 ref.
GENERAL APPRAISAL (FISHERIES); Chad Basin; fisheries resources and production; hydrological cycle; fisheries development; fishing practices; fishing gear; fish commerce and marketing; commercialization; ethnicity.
Detailed report which examines the history, present status and future potential for fisheries development in the Chad Basin and including: the evolution of the fisheries (1953–70); estimation of lake production and commerce in processed fish products (banda and salanga); fish populations of the associated floodplain areas, their dynamics and exploitation; status report on the present fisheries (hydrological characteristics, fishing communities - tribal and social aspects, principal fishing gears and techniques, seasonal activity in the fishery, and production estimates). Many interesting maps and diagrams provided.
022. BENECH, V. AND QUENSIERE, J. (1981)
Migrations de poissons dans le bassin tchadien. [Fish migrations in the Chad
Basin.] Bull.Inf.Mus.Nat.Hist.Nat. no.23: 29–42.
FISHERIES ECOLOGY; Chad Basin; fish population structure; fish migration.
023. BENECH, V. AND QUENSIERE, J. (1982)
Migrations de poissons vers le lac Tchad à la décrue de la plaine inondée du
Nord- Cameroun. I. Méthodologie d'échantillonnage et résultats généraux. [Fish
migrations from Lake Chad, during a drop in water-level to the floodplain of
North Cameroun. I.Sampling methods and general results.] Rev. Hydrobiol.trop.,
15 (3): 253–270. Fr. 11 ref.
FISHERIES ECOLOGY; Chad Basin; hydrological cycle; fish migration; resear ch methodology; juvenile fish; fisheries resources and production.
Water flooding the N. Cameroun plains (Yaere) drains into Lake Chad through the El Beid channel. Young fish also follow this route during their migration. The methodology used to undertake a study of this activity is presented and discussed. Prevalent traditional fishing techniques are also described as well as the impact of changing hydrological patterns.
024. BENECH, V. AND QUENSIERE J. (1983)
Migrations de poissons vers le lac Tchad à la décrue de la plaine inondée du
Nord-Cameroun. II. Comportement et rythme d'activité des principales espéces.
[Fish migrations from Lake Chad, during a drop in water-level, to the floodplain
of North Cameroun II. Behaviour and rhythm of activity of the principal species].
Rev. Hydrobiol. trop., 16 (1): 79–101. Fr. 25 ref.
FISHERIES ECOLOGY; Chad Basin; fish migration; fish migration order; hydrological cycle.
The results of the sampling regime described in Benech and Quensiere (1982) are presented. Downstream fish migrations appear to be organised on three levels: seasonal, lunar and diurnal. The interaction between these is discussed.
025. BENECH, V. AND QUENSIERE J. (1983)
Migrations de poissons vers le lac Tchad a la decrue de la plaine inondee du
Nord-Cameroun. III. Variations annuelles en fonction de l'hydrologie. [Fish
migrations from Lake Chad, during a drop in water-level, to the floodplain of
North Cameroun. III. Annual variations as a function of hydology.] Rev.
Hydrobiol. trop., 16(3): 287–316. Fr. 35 ref.
FISHERIES ECOLOGY; Chad Basin; fish migration; migration order; hydrological cycle; fish habitats.
As a follow-on from Benech and Quensiere (1982, 1983) the annual variations in fish migrations between the lacustrine and riverine habitats is related to the hydrological patterns.
026. BLACHE, J., MITON, F. AND STAUCH, A. (1962)
Première contribution à la connaissance de la pêche dans le bassin
hydrographique Logone-Chari-Lac Tchad. [First contribution to knowledge of the
fisheries in the Logone-Chari-Lac Tchad hydrographic Basin]. Mém. ORSTOM.,
Paris, 4, 143p. Fr. 19 ref.
GENERAL APPRAISAL (FISHERIES); Chad Basin; fisheries resources & production; fishing practices; fishing gear; hydrological cycle; ethnicity; fish commerce and marketing; commercialization.
An early overview of the Chad Basin fisheries including detailed descriptions and maps of the variation in fishing activity with hydrological cycles, distribution of this activity according to geography and ethnic grouping, post-harvest processing and trade. There is also a large section detailing the numerous fishing techniques of the region with many fine illustrations.
027. BLACHE, J., MITON, F., STAUCH, A., ILTIS, A. AND LOUBENS, G. (1964)
Les poissons du bassin du Tchad et du bassin adjacent du Mayo Kebbi. [The fish
of the Chad Basin and the adjacent Mayo Kebbi Basin.]. Mém. ORSTOM., Paris,
483p. Fr. Ref(4p).
FISH BIOLOGY; Chad Basin; Mayo Kebbi Basin; fish species (general); identification keys; systematics; fish biology (general); morphology; vernacular fish names.
Detailed systematic and biological information on the main fish species including morphological characteristics, growth and size, condition factor, reproduction, distribution. Also including detailed drawings of species, vernacular names and essential bibliography.
028. BUKAR, T.A. (1979)
Experimental fishing conducted 30km offshore (East of Baga) in Lake Chad.
Annual Report of the Lake Chad Research Institute, Maiduguri, Nigeria. 1979/80.
Pp. 47–49. En.
FISHING TECHNOLOGY; Lake Chad; gear trials; longlines; gillnets; tabulated statistics.
The effectiveness of different gear is determined and the results presented in table form. Longlines caught mainly Clarias catfish and Heterotis, whereas various gillnets were more effective for all other species.
029. BUKAR, T.A. (1985)
The effects of the changing hydrology of the Lake Chad on it's fisheries resources.
Paper presented at the International Conference on Arid Zone Hydrology and
Water Resources, 23 – 26th Sept. 1985, Univ. of Maiduguri, Nigeria. En.
FISHERIES RESOURCES AND PRODUCTION; Lake Chad; hydrological cycle; Sahel drought; fishing practices; catch estimate; species abundance; stock assessment; lacustrine-swamp species transition; swamp fisheries.
Recent effects of drought are discussed including the fall in total catch, decline of many fish species associated with open lake waters and emerging dominance of swamp species such as Clarias catfish and tilapias and the modification of fishing practices. Prospects for the future are also considered.
030. BUKAR, T.A. AND GUBIO, A.K. (1985)
The decline of the commercially important species of fish and predominance of
Clarias lazera in Lake Chad. Paper presented at the Fisheries Society of Nigeria
(FISON) Annual Conference, November 27–29, 1985, Port Harcourt, Nigeria. 12p.
En. 5 ref.
FISHERIES RESOURCES AND PRODUCTION; Lake Chad; hydrological cycle; Sahel drought; fish resource survey; species abundance; stock assessment; lacustrine-swamp species transition; swamp fisheries.
Based on the results of a sampling programme conducted by the Lake Chad Research Institute (Nigeria). It was demonstrated that as the amount of open water declined with the onset of drought, fish more adapted to swamp conditions became predominant.
031. CARLETON, C.R.C. (1980)
The reduction of insect infestation and spoilage of fish products from Lake Chad:
An analysis of the processing, handling, distribution and marketing of fish from Lake Chad with suggestions as to how improvements can be achieved. FAO
(Rome) Project: NIR/74/001 - Nautilus Consultants (Edinburgh). 9p. En.
FISH PROCESSING; Lake Chad; processed fish products; post-harvest losses; fish commerce & marketing; research priorities.
Investigation report quantifying the production and distribution patterns of processed fish, spoilage problems, associated economic data and recommendations for future research and development.
032. CARMOUZE, J.-P., DURAND, J.R. AND LEVEQUE, C. (1983) (Eds) Lake Chad: Ecology and productivity of a shallow tropical ecosystem. Monographiae Biologicae 53, The Hague: Dr. W. Junk. 575p. En. Fr.
FISH RESOURCES AND PRODUCTION; Lake Chad; Chad Basin; fish ecology; ecosystems; fisheries development.
The most important publication about Lake Chad resulting from the research activity of ORSTOM. Includes important chapters on fish communities (see No. 015: Benech et al.), trophic relations of fish (see No. 111: Lauzanne) and fisheries exploitation (see No. 57: Durand).
033. CHOURET, A. (1978)
La persistance des effets de la sécheresse sur le Lac Tchad [The persistance of the
effects of drought on Lake Chad]. In Symposium on River and Floodplain
Fisheries in Africa, Bujumbura, Burundi, November 1977. Review and Experience
Papers, ed. Welcomme, R.L., pp.74–92. FAO (Rome). CIFA Tech.Pap./Doc.Tech.
CPCA, 5. Fr. 12 ref.
FISHERIES RESOURCES AND PRODUCTION; Lake Chad; hydrological cycle; Sahel drought.
The hydrological characteristics of Lake Chad are described and the effects of recent drought conditions described in the context of recent historial evidence of Lake level fluctuations. The outlook for a return to a “normal” Lake is examined.
034. CHRISTENSEN, H.C. (1969)
Fishing boats for Lake Chad. Third Report to the Government of Nigeria. FAO
(Rome), UNDP Project Report TA No. 2690. 36p. En.
FISHING TECHNOLOGY; Lake Chad; fishing boats; new design; fisheries development; economic analysis.
Expert Report on the status of boat-building at Lake Chad, boatyards and training courses. Specifications and design are given for a new low priced open boat.
035. COUTY, P. (1964a)
Le commerce du poisson dans le Nord Cameroun. [The fish trade in North
Cameroun]. Mém. ORSTOM., 5, 222p. Fr.
FISH COMMERCE AND MARKETING; Chad Basin (N. Cameroun); processed fish products; trade statistics; trade routes; markets; distribution; transportation; trading practices; retailing; commercialization; fisheries development; economic analysis.
A comprehensive survey of fish commerce in North Cameroun including details of markets, activities of merchants and fish-sellers, trade routes, evaluation of trade and economic significance. Future prospects also examined.
036. COUTY P. AND DURAN, P. (1968)
Le commerce du poisson au Tchad. [The fish trade in Chad]. Mém. ORSTOM.,
5, 252p. Fr. 78 ref.
FISH COMMERCE AND MARKETING; Chad Basin (Chad); processed fish products; trade statistics; trade routes; markets; distribution; transportation; trading practices; retailing; commercialization; fisheries development; economic analysis.
A comprehensive survey of fish commerce in Tchad including details of major markets, the activities of merchants and fish-sellers, trade routes, evaluation of trade and economic significance. Future prospects also examined.
037. COUTY, P. (1968)
Le poisson sale-seche du Lac Tchad et du Bas-Chari - Prix et debouches. [Dried
and salted fish from Lake Chad and the Lower Chari - Prices and Markets.]
FAO (Rome), UNDP/SF Project AFR/REG/79, Survey of the water
resources of the Chad Basin for development purposes (Cameroon, Chad,
Nigeria). 97p. Fr. 8 ref.
FISH COMMERCE AND MARKETING; Chad Basin; processed fish products; trade routes; markets; distribution; prices.
Expert Report on dried and salted fish trade from Chad Basin in Nigeria, Chad and Cameroon, including cost analysis (production and distribution), prices and pricing policies, and potential markets.
038. COUTY, P. (1980)
Nécessité fertile ou le pêcheur sans arbres. [Woodland conservation in opposition
to the needs of fishermen]. Cah. ORSTOM., série sciences humaines; TS L'Arbre
en Afrique Tropicale, 17 (3–4): 223 – 226. Fr. 8 ref.
FISHING TECHNOLOGY; Chad Basin; fishing boats; construction materials.
The modern trend demonstrated by fishermen of using wood for boat construction in preference to papyrus grasses for the building of traditional kadei craft is discussed in the context of local wood availability.
039. DAJET, J. (1962)
Situation et evolution de la peche au Niger (Niger - Situation and trends in the
fishing industry). Report to the Government of Niger. FAO (Rome), EPTA
Project Report No. 1525. 57p. Fr.
GENERAL APPRAISAL (FISHERIES); Chad Basin (Niger; Lake Chad); Lake & swamp fisheries; fisheries resources and production; fishing practices; fishing gear; fish processing; fish commerce & marketing.
General appraisals of the Lake Chad fisheries and Chad Basin swamp fisheries are included in this status report on fisheries resources in Niger.
040. DAJET, J. (1966)
Note sur les Micralestes du bassin tchadien (Pisces, Characidae). [Note on the
Micralestes of the Chad Basin.] Bull. du Museum nat. d'Histoire naturelle, 38(2),
129–131. Fr.
FISH BIOLOGY; Micralestes spp.; Chad Basin; morphology.
041. DAJET, J. (1969)
Sur la présence de Clarias albopunctatus (Pisces, Clariidae) dans le bassin
tchadien. [On the presence of Clarias albopunctatus (Pisces, Clariidae) in the
Chad Basin.] Cah. ORSTOM., sér. Hydrobiol., 3 (2): 75–79. Fr. 13 ref.
FISH BIOLOGY; Clarias albopunctatus; Clarias angolensis; Chad Basin; morhology; systematics.
The occurrence of Clarias albopunctatus in the Chad Basin is pointed out for the first time. This species also exists in the Benue System. It is very close to Clarias angolensis from which it can be distinguished by fewer gillrakers on the anterior arch.
042. DAJET, J. AND DURAND, J.-R. (1981)
Poissons. In Flore et Faune aquatique de l'Afrique Sahelo-Soudienne. [Fish in
Aquatic Flora and Fauna of the Sudan-Sahel of Africa.], Vol.2, ed.Durand, J.-R.
& Lévêque, C., pp. 688–771, ORSTOM, Paris. Fr. 43 ref.
FISH BIOLOGY; Chad Basin; fish species (general); systematics; fish ecology; biogeography.
A detailed account of the fish species found in the Chad Basin including treatment of systematics, ecology and biogeography, and accompanied by lined diagrams.
043. DAJET, J. AND ECOUTIN, J.M. (1976)
Modèles mathématiques de production applicables aux poissons tropicaux
subissant un arrêt annuel prolongé de croissance. [Mathematical production
models as applied to tropical fish having a long annual pause in reproductive
pattern.] Cah. ORSTOM., sér. Hydobiol., 10 (2): 59–69. Fr. 10 ref.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin (River Chari); Polypterus senegalus; stock assessment; fish growth; fish mortality; mathematical models.
Using Polypterus senegalus from the river Chari as an example, the authors explain how mathematical stock assessment models, taking into account an annual prolonged interruption of growth, could be determined. The most influential parameter, but also the difficult to assess, total mortality, is examined in detail.
044. DEGAND, J., MUELLER, M.D. AND REKLEWSKI, M. (1974)
Survey of the water resources of the Chad basin for development purposes. Lake
Chad Basin Commission (Cameroun, Chad, Niger, Nigeria): Economic aspects of
the agricultural sector, Technical Report 3. (Authors: FAO (Rome) Land and
Water Development Division). 80p. En, Fr. 65 ref.
GENERAL APPRAISAL (FISHERIES); Chad Basin; water resources; agricultural development; economic analysis; fisheries development.
Fisheries are also considered in this appraisal of the agricultural development potential of the Chad Basin with reference to available water resources.
045. DEJOUX, C AND CARMOUZE, J.P. (1979)
Hydrobiological evaluation of the side effects of larvicide treatments against
Simulium damnosum in West Africa (v.9). The hydrochemical regulation of the
Lake Chad (v.10). Reunion de Travail sur la Limnologie Africaine, Nairobi,
Kenya, 16–23 December 1979. En.
FISH RESOURCES AND PRODUCTION; Chad Basin; limnology; fish biology; fish population dynamics; stock assessment.
The general characteristics of the Chad Basin ecosystem are reviewed and reference to made to the fish resource biomass and dynamics.
046. DE MERONA, B., ECOUTIN, J.M., LEVEQUE, C., ALBARET, J.J. (1979)
Zonation ichtyologique des rivieres en Afrique (v.1.) [Zonation of fish populations
in African rivers]; La croissance des poissons d'eau douce Africains; revue
bibliographique et essai de generalisation (v.2) [Growth of African freshwater fish;
bibliographic review and general account.]; Revue des estimations de stocks de
poissons d'eau douce Africains (v.3) [Review of fish stock assessment in African
freshwaters.]; Revue des recherches entreprises sur la fecondite des poissons d'eau
douce Africains (v.4) [Review of research activity on the fecundity of African
freshwater fish.]. Reunion de Travail sur la Limnologie Africaine, Nairobi, Kenya,
16–23 December 1979. Fr.
FISHERIES ECOLOGY; Chad Basin; fish population composition; fish population structure; fish population distribution; fish growth; stock assessment; research methodology (review); fish reproduction.
In these four symposium review papers, Chad Basin aquatic habitats and fish populations are cited as examples in examining fish population distribution, fish growth, stock assessment techniques and reproduction (fecundity).
047. DUPUIS, J. AND PORTIER, P. (1977)
Modernisation des techniques de peche, Tchad, Rapport Final. [Modernisation of
fishing techniques, Chad, Final Report.] FAO (Rome), Fisheries Div. 46p. Fr.
FISHING TECHNOLOGY; Chad Basin (Chad); fishing gear; fishing nets; construction materials; nylon nets; gillnets; fishing practices; modernisation; mechanization; training.
Final report on an initiative to promote the use of modern fishing gear and techniques at Lake Chad including nylon nets and engined fishing craft, and the need for training.
048. DURAND, J.-R. (1970a)
Les peuplements ichtyologiques de l'El Beid. Première note. Présentation du
milieu et résultats généraux. [The ichthyological populations of the El Beid. First
Note. Introduction to the environment and general results.] Cah. ORSTOM., sér.
Hydrobiol., 4 (1): 3–26. Fr. 14 ref.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin; fishing practices; catch estimation; catch composition; hydrological cycle; fish migration; juvenile fish; fish population identification.
The El Beid is an intermittent river that connects the large north Cameroun flood-plain (Yaere), 5–6,000km2 and Lake Chad with the annual riverine flood. Intensive traditional fishing is practised there for 3 or 4 months. Observations made during the 1968–69 indicate that 95% catch is juvenile fish (< 1 year old), catches decline as water level drops and two distinct fish populations may be defined (correlated with high and low water). Other hydrological observations are presented together with a discussion of the important part played by the El Beid in the migration cycle: Yaere - Lake - River.
049. DURAND, J.-R. (1970b).
Les peuplements ichtyologiques de l'El Beid. Observations sur les rendements.
[The ichthyological populations of the El Beid. Observations on the yield.]
Rapport de Centre ORSTOM., N'Djamena, Tchad. 14p (miméo). Fr.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin (El Beid); fishing practices; catch estimation; hydrological cycle; fish migration; juvenile fish.
Results of this study are included in no. 46 (above).
050. DURAND, J.-R. (1971a)
Le peuplements ichtyologiques de l'El Beid. 2éme note. Variations inter et
intraspécifiques. [The ichthyological populations of the El Beid. Second note.
Inter- and intraspecific variations.] Cah. ORSTOM., sér. Hydrobiol., 5 (2): 147–159. Fr. 8 ref.
FISHERIES ECOLOGY; Chad Basin; fish population composition; fish population structure; inter- and intra-specific variations; hydrological cycle; fish migration; sampling techniques; poison fishing.
Inter- and intraspecific variations were studied by means of Kendall's Rank Correlation. There are two main groups of multi-specific samples. The first group is not a steady one and is connected with the discharge of Logone waters. The second one is gradually homogenised during the drop in water level and the low water period. Fishing with poison in the Yaere during the dry season enabled definition of the corresponding sedentary stocking and its connections with the El Beid stockings. The cycle Logone - North Cameroun flooded plain - El Beid - Lake Chad is a general one and affects the first group and second group species as well.
051. DURAND, J.-R. (1971b)
Note sur les pêches de l'El Beid. [Note on the fisheries of the El Beid.] ORSTOM,
N'Djamena, Tchad. 6p.(miméo). Fr.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin (El Beid); fishing practices; catch estimation; catch composition; hydrological cycle; fish migration; juvenile fish.
Observations are given on the seasonal fishery: 95% catch is young fish, catch decreases as the river level falls and species composition changes depending on the source of the water (river or floodplain). The El Beid route is very important in the cyclical migration of fish from floodplain to lake.
052. DURAND, J.-R. (1973a)
Application de l'analyse des correspondances à l'étude de certains peuplements
ichtyologiques du lac Tchad. [Application of correspondance analysis to the study
of certain ichthyological populations of Lake Chad.] Cah. ORSTOM., sér.
Hydrobiol., 7 (1): 55–62. Fr. 5 ref.
RESEARCH METHODOLOGY; Lake Chad; catch composition; hydrological cycle; biotopes; fish migration; correspondance analysis.
Since 1965 fish populations in Lake Chad have been sampled using 2 (0.5 inch) gillnets. Results expressed as mean nightly catch per 100m2 have been studied by means of correspondance factorial analyses. Catch composition depends on biotype (archipelago & open water), seasonal variations connected with migrations and interannual changes (due to fall in lake level).
053. DURAND, J.-R. (1973b)
Note sur l'évolution des pêcheries du lac Tchad (1963–71). [Note on the evolution
of the fisheries of Lake Chad (1963–71)]. ORSTOM., N'Djamena, Tchad.
9p.(miméo). Fr. 7 ref.
FISHERIES RESOURCES AND PRODUCTION; Lake Chad; catch estimation; total effort; optimum yield; fish commerce and marketing; commercialisation; fisheries management; fisheries regulation.
Between 1963 and 1971 total catch rose from 20,000 tonnes to over 100,000 tonnes due an increase in total effort and the development of a strong trade in fish products within Nigeria. Intensive fishing is likely to continue in the future, whereas the possibilities for controlling exploitation are limited from the start by a lack of fundamental information. The relationship between the unstable lake environment and the optimal yield is a major problem.
054. DURAND, J.-R. (1973c)
Note sur l'évolution des prises par unité d'effort dans le lac Tchad. [Note on the
evolution of catch per unit effort in Lake Chad]. Cah.
ORSTOM., sér. Hydrobiol., 7 (3/4): 195 – 207. Fr. 14 ref.
FISH RESOURCES AND PRODUCTION; Lake Chad (N. Basin); catch per unit effort; total effort; catch estimation; hydrological cycle; fish resource surveys.
Comparing landing data for the gill-net fishery in the northern part of the Lake between 1968 and 1972 with experimental fishing results for 1963 to 1967, it can be shown that CPUE decreased quickly between 1963 and 1967, but then stabilized. This is explained by an increase in total fishing effort. The decline in lake level between 1970 and 1973 had an influence on total production, which trebled between 1969 and 1972.
055. DURAND, J.-R. (1977)
Situation actuelle des pecheries dans la région du lac Tchad. [The status of
fisheries in the Lake Chad region]. PNUD/FAO/CBLT, 29p. (multigr.).
GENERAL APPRAISAL (FISHERIES); Chad Basin; fisheries development
056. DURAND, J.-R. (1978)
Biologie et dynamique des populations d'Alestes baremoze (Pisces, Characidae) du
bassin Tchadien. [Biology and population dynamics of Alestes baremoze (Pisces,
Characidae) in the Chad Basin.] Trav.Doc. ORSTOM, 98, 332p. (Thes. Sc. Nat.
Paris). Fr. 158 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; population dynamics; stock assessment; fish growth; fish reproduction; larval development; fish recruitment; fish nutrition; diet; feeding habits; fish migration; fish mortality; fish production models.
Fishery and main biological aspects of this species described, including: reproduction, larval development, feeding habits, migrations, growth, variation in stock, mortalities. A stock assessment study and a production model are presented.
057. DURAND, J.-R. (1980)
Evolution des capture totales (1962 – 1977) et devenir des pêcheries de la région
du lac Tchad. [Evolution of total catch (1962 – 1977) and the future of fisheries
in the Lake Chad region]. Cah. ORSTOM., sér. Hydrobiol., 13 (1–2): 93–111. Fr.
13 ref.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin; catch estimate; stock assessment; total effort; hydrological cycle; Sahel drought; predicted fish yield; fisheries development.
Recent trends in fish catches in the Chad Basin are presented based largely on road traffic census of processed fish. Between 1962 and 1970 total catches rose from 40,000 to 80,000t, and total effort increased by a factor of 30. Between 1971 and 1974 the yearly catches rose even faster, reaching a maximum of 220,000t in 1974 corresponding to the period of severe Sahel drought. Post 1975, total catch has remained at about 100,000t - a level sustainable by the “small state” of the Lake (8–10,000 km2). Given a yield of 100–120kg/hectare, a rejuvenated Lake (20,000km2) could sustain a catch of 180,000t.
058. DURAND, J.-R. (1983)
The exploitation of fish stocks in the Lake Chad region. In Lake Chad: Ecology
and productivity of a shallow tropical ecosystem, Carmouze, J,-P., Durand, J.-R.,
Leveque, C.(Eds), pp.425–482, Monographiae Biologicae 53, The Hague:
Dr.W.Junk. En.Fr. 30 ref.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin; fishing practices; catch estimation; stock assessment; total effort; fisheries management; fish processing; fish commerce and marketing; hydrological cycle; Sahel drought; Alestes baremoze; fish population dynamics; fisheries development.
A detailed account of the fisheries of the region based on the research of the ORSTOM team, charting the evolution of exploitation patterns and the effect of drought. A large section is devoted to the studies undertaken on Alestes baremoze including population dynamics and the effect of exploitation. Information also given on commercial activities and processing, with a concluding discussion on the future prospects of the fishery.
059. DURAND, J.-R., FRANC, J. AND LOUBENS, G. (1972)
Résultats des pêches aux filets maillants et à la senne (1966 – 1970). [Gill- and
seine-net fishing results (1966 – 1970)]. ORSTOM., N'Djamena, Tchad. 97p.
(mimeo). Fr.
FISH RESOURCE SURVEYS; Chad Basin; net fishing; catch composition; tabulated statistics.
Results of fishing surveys are presented in table form for both riverine (Mailao, Logone-Gana, El Beid, Djimtilo) and lacustrine (Sud, L'est, Archipel est) environments of the Chad Basin. Details also given of sampling methods and gear.
060. DURAND, J.-R., FRANC, J. AND LOUBENS, G. (1973)
Clefs longeur-poids pour 58 espèces de poissons du Bassin du lac Tchad. [Length-weight
keys for 58 fish species in the Lake Chad Basin.] Rapport, Centre
ORSTOM., N'Djamena, Tchad. 35p. (miméo). Fr. 7 ref.
FISH BIOLOGY; Chad Basin; fish species (general); fish growth; length-weight keys.
061. DURAND, J.-R. AND LOUBENS, G. (1967)
Première observations sur la biologie d'Alestes baremoze (Pisces, Characidae) dans
le Bas-Chari et la partie est du lac Tchad. [First observations on the biology of Alestes baremoze(Pisces, Characidae) in the lower Chari and the eastern part of
Lake Chad.] Rapport, Centre ORSTOM., N'Djamena, Tchad. 74p.(miméo). Fr.
12 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; fish growth; condition coefficient; fish reproduction; meristic characteristics; larval development.
This preliminary work presents certain key aspects including studies of growth (length), condition, sexuality and reproduction, meristic characteristics and larval stages.
062. DURAND, J.-R. AND LOUBENS, G. (1969)
La croissance en longeur d'Alestes baremoze (Joannis, 1835) (Poisson, Characidae)
dans le Bas-Chari et le lac Tchad. [Growth in length of Alestes baremoze (Joannis,
1835) (Pisces, Characidae) in the Lower Chari and Lake Chad.] Cah. ORSTOM,
sér. Hydrobiol., 3 (1): 59–105. Fr. 38 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; fish growth; scale readings; length-frequency analysis; Peterson's method; fish population identification.
Results presented for the lower parts of the Chari and Logone rivers, and the southern and eastern regions of Lake Chad. Length growth studied with the aid of scale measurements and Petersons method. Evidence that there might be two populations of this species - one sedentary in the Lake and the other fluvial-lacustrine and migratory. Comparisons made with Dajet's work at Central Niger Delta indicates growth checks are related to temperature and food availability.
063. DURAND, J.-R. AND LOUBENS, G. (1970a)
Variations du coefficient de condition chez les Alestes baremoze (Pisces,
Characidae) du Bas-Chari et du lac Tchad. [Variations in the condition coefficient
of Alestes baremoze (Pisces, Characidae) in the lower Chari and Lake Chad.] Cah.
ORSTOM, sér. Hydrobiol., 4 (1): 27–44. Fr. 6 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; condition coefficient; size variation; fish reproduction; fish migration; hydrological cycle.
Variations in the condition coefficient of A. baremoze from the lower Chari and Lake Chad as a function of fish sizes, sexes and sexual stages. Condition improves from January to April, followed by a decline and minimum value in September associated with breeding. There is an improvement thereafter. Breeding migration of the large adults during the flood is confirmed.
064. DURAND, J.-R. AND LOUBENS, G. (1970b)
Observations sur la sexualité et la reproduction des Alestes baremoze du Bas-Chari
et du Lac Tchad. [Observations on the sexuality and reproduction of Alestes
baremoze in the lower Chari and Lake Chad.] Cah. ORSTOM., sér. Hydrobiol.,
4 (1): 61–81. Fr. 7 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; fish reproduction; sexual maturity; spawning habits; hydrological cycle.
Maturation of the ovaries lasts 3 months (May, June, July). Laying of eggs takes place in August and September. In the river fish reproduce for first time when 2 years old, and all adults spawn. In the Lake most adults are sexually dormant during the breeding season. Spawners only form small groups. Spawning occurs in major part of the river system and in Lake archipelago. Fecund females have up to 230,000 eggs/kg.body wt.
065. DURAND, J.-R. AND LOUBENS, G. (1971a)
Développement embryonnaire et lárvaire d'Alestes baremoze. [Embryonnic and
larval development of Alestes baremoze.] Cah. ORSTOM., sér. Hydrobiol., 5: 137–145. Fr. 6 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; embryonic development; larval development.
066. DURAND, J.-R. AND LOUBENS, G. (1971b)
Etudes de certain caractères méristiques chez les Alestes baremoze du Bas-Chari
et du Lac Tchad. [Study of certain meristic characters of Alestes baremoze in the
lower Chari and Lake Chad.] Cah. ORSTOM., sér.
Hydrobiol., 5 (2): 113–136. Fr. 17 ref.
FISH BIOLOGY; Alestes baremoze; Chad Basin; fish population identification; meristic characteristics; spawning habits; fish migration; fisheries resources and production.
Meristic characters (vertebrae, fin-ray counts) and spawning habits were used to identify 4 populations of Alestes baremoze in the Lake which make a spawning run, but the presence of separate sub-species could not be confirmed. Lake acts a shelter to populations since most fishing occurs in rivers during spawning runs.
067. DURAND, J.-R., LOUBENS, G. AND FRANC, J. (1969)
Courbes longeur-poids de 46 espèces de poissons du bassin tchadien. [Length-weight
curves for 46 species of fish from the Chad Basin.] Rapport, Centre
ORSTOM., N'Djamena, Tchad. 48p. Fr.
FISH BIOLOGY; Chad Basin; fish species (general); length-weight keys.
Length-weight curves for the 46 main species, continuing the work of Blache (1964) and designed to be used as a practical tool.
068. FAO (1973)
Lake Chad Basin Commission, Cameroon, Chad, Niger, Nigeria. Survey of the
water resources of the Chad Basin for development purposes. Report on project
results, conclusions and recommendations. Terminal report. FAO (Rome), Land
and Water Development Div., Report. 71p. En, Fr.
GENERAL APPRAISAL (FISHERIES); Chad Basin; water resources; agricultural development; fisheries development; economic analyses.
The fisheries of the Chad Basin are also considered in this report on the prospects for developing the water resources of the region; main focus are the possibilities for irrigation agriculture and a livestock industry.
069. FAO (1974)
Commission du Bassin du Lac Tchad. Programme a moyen terme de lutte contre
la secheresse. [Lake Chad Basin Commission. Medium-term programme on
drought control.] FAO (Rome), Report. 80p. Fr.
GENERAL APPRAISAL (FISHERIES); Chad Basin; fisheries development; project appraisal; finance; development aid; drought control.
Programme report on the 14 development projects (including fisheries) operating in the Chad Basin area with reference to drought control. Detailed account of projects including finance and development aid.
070. FAO (1975)
A brief review of the status of the inland fisheries of the Sahelian zone. FAO
(Rome), Fisheries Dept., Report of the Consultation on Fisheries Problems in the
Sahelian Zone, Bamako, Mali, 13–20 Nov. 1974. CIFA Occas. Pap. no. 4: 271–282.
Fr.
GENERAL APPRAISAL (FISHERIES); Chad Basin; fisheries resources and production; fish commerce and marketing.
A brief review is given of the Chad Basin fisheries including annual catches and the trade in fish by country.
071. FAO (1982)
Improvement of Fish Processing and Transport on Lake Chad, Nigeria.
Project findings and recommendations. Terminal Report. FAO (Rome), Fisheries
Dept. 40p. En. (Restricted access).
FISH PROCESSING; Lake Chad; processed fish products; improved processing methods; fisheries development; transportation.
072. FEDERAL DEPARTMENT OF FISHERIES, NIGERIA (1986)
Situation Study of Fish Demand and Supply in Nigeria and Survey of Production
and Economics of Operation of Fishermen Community in Uta-Ewa, Ikot Abasi,
Cross River State. Report prepared by Saphe (Nigeria) Consortium, Lagos,
Nigeria. 140p. En.
GENERAL APPRAISAL (FISHERIES); Chad Basin (Nigeria); fish resources production; economic analysis; fisheries development.
A brief overview of the fishery is included in this national survey. Information on the work of FAO in the region and a proposed development plan including an economic evaluation are provided.
073. FRANC, J. (1975a)
Résultats des pêches au filet maillant dans le delta du Chari de 1971 à 1972.
[Results of net-fishing in the Chari Delta between 1971 and 1972.] Rapp. Centre
ORSTOM., N'Djamena, Tchad. 44p. (miméo). Fr.
FISH RESOURCE SURVEYS; Chad Basin (River Chari Delta); net fishing; tabulated statistics.
Fishing survey results presented in tables.
074. FRANC, J. (1975b)
Les techniques de pêche pratiquées dans la région du Lac Tchad et du Bas-Chari.
[Fishing techniques used in the Lake Chad and Lower River Region.] Note Tech.
Centre ORSTOM, N'Djamena, Tchad, 10. 44p. (miméo). Fr. 7 ref.
FISHING TECHNOLOGY; Chad Basin; fishing practices; fishing gear; modernisation; sampling techniques.
075. FYSON, J. (1966)
Fishing boats for Lake Chad. Second Report to the Government of Nigeria. FAO
(Rome), UNDP Report. 18p. En.
FISHING TECHNOLOGY; Lake Chad; fishing boats; new designs; fishing practices; modernisation; mechanisation; training; finance; future recommendations; fisheries development.
Recommendations and building data for 18ft fishing boats for fisheries development at Lake Chad. Also including details of proposed fishing operations, maintenance and repair, mechanization, training and finance (loan scheme).
076. GRAS, R. (1962)
Etude biométrique des Alestes baremoze du bassin du Chari. [Biometric study of
Alestes baremoze in the River Chari Bassin.] Bull. IFAN., ser., A, 24, I, pp.245–261.
FISH BIOLOGY; Alestes baremoze; River Chari Basin; biometry.
077. GRAS, R., LAUZANNE, L. AND SAINT-JEAN, L. (1981)
Régime alimentaire et sélection des proies chez Brachysynodontis batensoda (Pisces,
Mochodikae) du lac Tchad en période de basses eaux.
[Diet and prey selection by Brachysynodontis batensoda (Pisces, Mochokidae) from Lake Chad during a period of low water.] Rev. Hydrobiol. trop. 14: 223–231. Fr. 16 ref.
FISH BIOLOGY; Brachysynodontis batensoda; Lake Chad; fish nutrition; diet; feeding habits; prey selection; hydrological cycle; fish population dynamics; trophic relationships.
078. GRAS, R. AND SAINT-JEAN, L. (1982)
Comments about Ivlev's electivity index. Rev. Hydrobiol. trop. 15 (1): 33–37. En.
11 ref.
RESEARCH METHODOLOGY; Lake Chad; Ivlev's electivity index; zooplanktivorous fish; prey selection.
The authors show that the absolute value of the Ivlev's electivity index and its sign do not represent accurately the degree of prey selection; the index is markedly influenced by the abundance of prey in the natural environment. They propose a new index which allows, under certain conditions, the calculation of the proportion of zooplankton biomass which can readily be used by a predator, according to its prey selection characteristics.
079. GUBIO, A. AND SAGUA, V.O. (1982)
Preliminary Analysis of Catches from Malian Fishing Traps in Lake Chad.
Annual Report of the Lake Chad Research Institute, Maiduguri, Nigeria. 1982. Pp.
67–69. En.
FISHING TECHNOLOGY; Lake Chad; fishing gear; Malian fish traps; juvenile fish; overfishing.
This newly-introduced trap can be used in a range of habitats with some modification and is believed to be responsible for destructive fishing of Clarias catfish juveniles. Traps constructed with a nylon net cover of 25.4mm mesh size will retain a large percentage of immature Clarias.
080. GUILLAND, J. (1955)
Etudes et travaux sur la pêche dans le bassin Camerounais du Logone. [Studies
and work on the fisheries in the Logone basin of Cameroun]. Rapport, CMR.,
Archives de l'Inspection Forestière du Nord, Garoua (Cameroun) (dactylogr.).
FISHERIES RESOURCES AND PRODUCTION; River Logone Basin;
081. GULBRANDSEN, O. AND IVENGAR, H.D.R. (1968)
Report on travel to Chad, Niger, Nigeria and Cameroon from 3 to 19 March 1968
to study the existing administrative structure and boat-building facilities around
Lake Chad. FAO (Rome), Fish. Travel Report and Aide
Memoire No. 159. 26p. En.
FISHING TECHNOLOGY; Chad Basin (Lake Chad); fishing boats, construction facilities (boats); economic analysis; fisheries administration; fisheries development; future recommendations.
Assessment of the boat-building facilities and fishery administration. Recommendations for a pilot boat-building project and notes on the economic aspects.
082. HERMAN, C. (1982)
Design and implementation of certain fisheries statistical surveys: Nigeria. A
report prepared for the Improvement of Fish Processing and Transport on Lake
Chad Project. FAO (Rome), Fisheries Dept. 29p. En.
FISH PROCESSING; Lake Chad; statistical surveys; fisheries development.
083. HILL, B. (1976)
Analysis of fisheries development potential in Chad. For Multi-national
Agribusiness Systems Inc., Washington DC (USA). Published by MASI,
Washington DC (USA), 1976, 60p. PN-RAB-636. Available from the AID R & D
Report Distribution Center, 300 North Zeeb Road, Ann Arbor, MI 48106 (USA).
En.
GENERAL APPRAISAL (FISHERIES); Chad Basin (Chad); fish resources and production; fishing practices; fishing gear; hydrological cycle; Sahel drought; fish commerce & marketing; fish processing; Chadian Fisheries Service; infrastructural problems; fisheries development; finance; training; development aid; cooperative formation; fishing boats.
A detailed evaluation of fisheries in Chad including fish resources, fishing methods, potential production, the effect of the drought, marketing, conservation and preservation, the status of the Chadian National Fisheries Service, and infrastructural problems which hinder development. Specific A.I.D. responses are recommended including: education and training, expatriate intervention, development of the National Fisheries Service, fishermens co-ops and the development of a new fishing canoe construction method.
084. HOPSON, A.J. (1965)
Winter Scale Rings in Lates niloticus (Pisces: Centropomidae) from Lake Chad.
Nature, London, 208: 1013 –1014. En. 3 ref.
FISH BIOLOGY; Lates niloticus; Lake Chad; fish growth; scale readings; water temperature; hydrological cycle.
First report of winter scale rings in L. niloticus. Correlated with significant temperature decrease during winter months at Lake Chad. It is noted that scale ring marks in tropical savannah fish have previously always been correlated with periods of physiological stress such as spawning and dry-season water level fluctuations.
085. HOPSON, A.J. (1967)
Fisheries of Lake Chad. In Reed, W. et al. Fish and Fisheries of Northern Nigeria,
pp. 188–201, The Ministry of Agriculture Northern Nigeria, Kaduna, Nigeria. 225
p. En. 21 ref.
GENERAL APPRAISAL (FISHERIES); Chad Basin (Niger); fish resources and production; fishing practices; fishing gear; catch composition; fish processing; fish commerce and marketing; fisheries development.
A general overview of the fishery including an anotated checklist of the species caught, the fishing methods and gear employed, processing methods and a note on the role of government.
086. HOPSON, A.J. (1967a)
B1. Fish Population Studies & B2. Gear Trials. Annual Report, 1966–67, Federal
Fisheries Services, Lake Chad Research Station, Malamfatori, Borno State,
Nigeria, pp.7–8. En.
FISHERIES RESOURCES AND PRODUCTION; Lake Chad; catch composition; fishing practices; fishing gear; fish resource surveys; catch per unit effort; total effort; fisheries development.
A decline in CPUE is recorded for experimental fishing since 1963. Observations presented on changing fish size and species composition, the intensification of fishing effort by local fishermen and the comparative effectiveness of different gears.
087. HOPSON, A.J. (1968)
The gill-net fisheries of Lake Chad. Federal Fisheries Service, Maiduguri, Nigeria.
64 p. En.
GENERAL APPRAISAL (FISHERIES); Lake Chad; fishing practices; fishing gear; gillnets; catch composition; fish processing; fish commerce & marketing; fisheries development.
Detailed observations of fishing practices, community and activity organisation, species composition, catch seasonality, processing, trade. Present development trends also discussed.
088. HOPSON, A.J. (1969c)
A description of pelagic embryos and larval stages of Lates niloticus (L.) (Pisces,
Centropomidae) from Lake Chad with a review of early development in lower
percoid fishes. Zool. J. Linn. Soc. London. 48: 117–134. En.
FISH BIOLOGY; Lates niloticus; Lake Chad; life cycle; embryonic development; larval development; percoid fishes (a review).
089. HOPSON, A.J. (1972b)
A study of the Nile Perch (Lates niloticus L.) (Pisces, Centropomidae) in Lake
Chad. Overseas Research Publication 19, HMSO (London). 93p. En. 81 ref.
FISH BIOLOGY; Lates niloticus; Lake Chad; fish growth; fish reproduction; spawning habits; life-cycle; fish nutrition; diet; trophic relationships; fish habitats; hydrological cycle.
A detailed account of the biology of Lates niloticus in Lake Chad based on investigations over six years (1963–69). Including the study of growth (no differences between males and females), reproduction (peak spawning occurs in January and February in peripheral areas, pelagic larvae move to open water locations, post-larvae return to shallow areas) and nutrition (marked changes occur with size, season and habitat; prawns and characins are the most important prey for Lates up to 80cm in length.). The trophic relationship between Lates and other species is discussed. Lates is a top predator in the ecosystem.
090. HOPSON, J. (1969)
A preliminary study on the biology of Alestes baremoze in the Malamfatori area.
Annual Report, 1966–67, Federal Fisheries Service, Lake Chad Research Station,
Malafamtori, Borno State, Nigeria, pp. 50–83. En.
FISH BIOLOGY; Alestes baremoze; Lake Chad; fish growth; scale readings; fish reproduction; sexual maturity; fisheries resources and production.
Details are given of the fishery, age and growth studies using scale readings, reproduction and maturity. Further work in progress includes study of condition factor, identifying different races of the species and assessment of body fat reserves.
091. HOPSON, J. (1972)
Breeding and growth in two populations of Alesetes baremoze (Joannis) (Pisces,
Characidae) from the northern Basin of Lake Chad. Overseas Research
Publication 20, 55p. HMSO (London). En.
FISH BIOLOGY; Alestes baremoze; Lake Chad (Northern Basin); fish population identification; morphology; fish growth; scale readings; fish reproduction; fish migration.
Two distinct populations of A. baremoze were recognised in the northern basin on the basis of scale type and fin-ray number. Age determination was carried out with the aid of winter scale rings, growth parameters were estimated for both populations. Age composition of commercial catches was also analysed. Breeding was studied in detail. Migration of populations is discussed.
092. ILTIS, A. (1974)
L'Ensemble Yaéré-Bas Chari-Lac Tchad et la production piscicole au Tchad. [The
Yaéré floodplain-Lower Chari-Lake Chad system as a whole and fisheries
production in Tchad.] Note Tech. ORSTOM, N'Djamena, 1. 6p. (miméo). Fr. 9
ref.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin; fish population dynamics; fish habitats; hydrological cycle; fish migration; fish lifecycle; fish recruitment; agricultural development.
The important relationship which exists between the floodplain/riverine habitats and Lake Chad is emphasized. The floodplain in particular represents an important breeding area for fish and a source of juveniles to replenish exploited riverine and lake stocks. Developments (e.g. agriculture) which might limit the area of seasonal inundation could have serious repercussions on overall fisheries production and need to examined carefully.
093. IM, B.H. (1974)
Rapport de diplôme d'études approfondies (Hydrobiologie). [Diploma report of
detailed studies in hydrobiology.] Rapport, Centre d'ORSTOM, N'Djamena, Chad.
34p. Fr. 40 ref.
FISHERIES RESOURCES AND PRODUCTION; Chad Basin; fish population dynamics; stock assessment; fish nutrition; limnology.
A summary of diploma research undertaken by the author on aspects of Chad Basin fish populations including stock assessment and nutrition. Relevant aspects of limnology also covered.
