983 resultados para Lake-sediments
Resumo:
Fish smoking, as a traditional occupation of fishermen and women in Kainji Lake Area (Nigeria) is done using simple traditional ovens called 'Banda', the fuel for the smoking being almost hundred percent dependent on wood. A simple modification was made to the traditional 'Banda' oven using a damper to prevent burning of the fish. A comparison of the improved and the traditional 'Banda' was made. The results indicate that fuel wood consumption was reduced 52 percent by using the improved 'Banda', which implied that 50 percent of fish processor's income could be saved through the adoption of this technology. The most important advantage of the improved kiln, fuel wood conservation, represents for fishers a problem of an economic importance. Whilst they are aware that it is becoming much more difficult to get the needed fuel wood, the children can still conveniently collect enough wood for both home use and processing activities. The cost of the components of the improved kiln, when compared with the traditional version may be considered quite significant, and hence the reluctance of the fish processors in constructing similar ones. Selected blacksmiths were trained to continue the fabrication of the kiln component. The training was carried out to assure that the improved kiln will be constructed even after the project will end to support the fabrication
Resumo:
Kainji Lake, the first man-made lake in Nigeria is one of the most researched water bodies in Africa. Earlier studies indicated that there was no systematic management of the lake fisheries involving the participation of the fishers in the decision-making processes before 1993. In 1993, the Nigeria-German Kainji Lake Fisheries Promotion Project (KLFPP) started the introduction of a bottom-up approach in the management of the fishery resources through a random selection of some fishers representatives for the decision making body of the project. The paper traces the democratization process of the management approach to the lake fisheries culminating in the systematic selection, appointment, training and assignment of responsibilities to twenty-four Wakilis covering the 316 fishing communities around Lake Kainji
Resumo:
Sex ratio and fecundity variations of Chrysichthys nigrodigitatus and Chrysichthys walkeri from Asejire Lake (Nigeria) were examined. The Logarithm transformation of weight (W) against standard length (SL) gave a straight-line graph represented by the following equations: 1) C. nigrodigitatus LogW =-0.66 + 2.13 Log SL; = 0.854; (P < 0.001) n = 209; 2) C. walkeri LogW = -1.23 + 2.63 Log SL; = 0.759; (P < 0.001) n = 237. Males were generally more than females in both species. The ratio of males:females was higher in C. nigrodigitatus (1:0.18) than in C. walkeri (1:0.8). C. walkeri attained sexual maturity at a smaller size of 20.0 g (12.0 cm Standard Length) compared with C. nigrodigitatus maturity size of 45.0 g (14.0 cm Standard Length). Relative fecundity was not dependent on body weight and standard length for C. walkeri but it was significant at P < 0.05 and P < 0.01 respectively for C. nigrodigitatus
Resumo:
Five fishing villages in Lake Chad Basin region of Borno State (Nigeria) were assessed for the roles of children in fishing activities in the area. The villages surveyed include: Bundaram, Yobe, Daba masara, Dumba and Doro. The results show that the children were largely between 12-18 years of age in the villages. Generally, the younger children (less than 12 years) participate in activities that require no technicality and little physical strength, while the older children (12 years and above) engage in skillful fabrication of gear and fishing activities. Some activities in the surveyed villages were gender specific. Such activities include fish processing (smoking) which is exclusive for female and few male children, who carry out preliminary cleaning of fish before any processing method is applied. 80% of the children in the five fishing villages claimed proper understanding of the techniques and procedure involved in most fishing activities. About 65% of the children sampled showed willingness to become full time fishermen while 22% were uncertain and claimed that they do not know what the future holds for them. 15% of them resolved to migrate to town so that they could live a city life
Resumo:
The paper describes the uniqueness and invasiveness of water hyacinth (Eichhornia crassipes) on Lake Kainji (Nigeria). The mechanical blocking device design concept based on the Kainji Lake flooding regime is also highlighted. Water hyacinth coverage, that was over 23% at high water in level in 1994, was reduced to 0.75% in the same period in 2000. Although this feat cannot be wholly ascribed to mechanical control effort alone, the first year of the device's full operation more than 1.04 million kg of fresh weight of water hyacinth were trapped, collected and deposited in two separate dumping pits, each at about 1 km off the shoreline of either side of the Lake. On further analysis over a period of one year of uncleared inflow of water hyacinth indicated the effectiveness of the bloom. Recommendations are advanced for the use of such local but highly technical knowledge to control floating water hyacinth that is vastly taking over the intricate network of Nigerian water systems and within the West African sub-region
Resumo:
An overview is provided of the literature of socio-economic relevance to the fisheries of Lake Victoria. It covers the following areas: marketing studies; management; changes to the structure of the fishery; and, base-line studies. The bibliography provides a guide to the more important documents on Lake Victoria's socio-economy and includes a total of 177 references
Resumo:
The list provides addresses of institutions in Kenya, Tanzania and Uganda which are of managerial relevance to the fisheries of Lake Victoria, indicating the relevant area covered
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The findings are presented of a survey conducted regarding the fishers of Lake Victoria, which examined the relationships affecting supply flows of raw material on to the market, and also the characteristics of fishing activities and their effects on fish quality and distribution. Fish marketing plays a vital role in the lives of much of the lake basin's population, both in terms of employment and nutrition. The results of the survey comprise, in part, a base-line data set which will facilitate further research, analysis and management decision-making in relation to stakeholders of the lake's resources. Data collection, methods and research difficulties encountered are described and details given of a profile of a boat owner/renter and aslo of a profile of a crew member. The survey shows that Lake Victoria's fishery is one of very limited diversity. The fishers recount that they consistently target one or more of the 3 most common species within the lake (Nile perch, tilapia and dagaa) and very rarely consider any other species type. The largest proportion of fishers on the lake are Nile perch fishers; there is considerable demand for this species, and hence fishers have little incentive to either target alternative fish species, not to try and establish firm marketing outlets through the creation of arrangements with their principal buyers. In Kenyan waters, however, the number of Nile perch fishers is equaled by the number of dagaa fishers; this fish now commands a considerable portion of the market for fish from Lake Victoria through its availability as well as its relatively low prices. The tilapia fishery is in decline, and all 3 riparian states would not appear to be attracting investment almost certainly as a result of declining catches. For many of those working in Lake Victoria's fishery, the problems faced appear most often to be associated with the vagaries of an unstable market which may rise or fall depending on the state of the international market or the state of access roads to fish landings. (PDF contains 42 pages)
Resumo:
Limnological studies in Lake Victoria (Kenyan portion) have been sporadic. Water quality and nutrient dynamics studies are being undertaken in fifteen sampling sites that have been divided into four ecological zones namely: Nyanza Gulf, Rusinga Channel, open waters inshore and open waters. The ongoing study will show how the physical and chemical paramenters affect fish distribution and abundance.
Resumo:
For a long time, the Tanzanian Fisheries Department has managed Tanzanian fisheries without incorporating other stakeholders within its management framework. On lake Victoria, the persistent use of illegal fishing gear and declining catches have led the government to realize that this system of fisheries management may no longer be viable, and have sought to incorporate fishing communities into the management structure. Through the creation of beach management units (BMUs), the Fisheries Departments have sought to persuade fishing communities to implement and enforce Tanzania's fishing regulations and to monitor the fishery. In this paper we explore a recently gathered data set that yields information on, amongst others, how Tanzanian fishing communities perceive the state of their resource base, how they view their relationship with the Fisheries Department, the efficacy of fishing regulations and other variables. We draw on a series of criteria developed by Ostron (1990) for institutional 'robustness' to explore various areas of institutional development on Lake Victoria, and to try and anticipate how the BMUs will fare. We argue there are many socio-political and economic factors that will determine how communities will receive and perceive their responsibilities towards government-imposed administrative structures at the local level, these will become 'socialized' such that they will vary from place to place. While this may bode well for problems of heterogeneity, it does not necessarily mean that fisheries management objective on Lake Victoria will be met
Resumo:
This paper sets out to explore how Uganda's lake Victoria fishery has been managed. It explores the management of the fishery during the protectorate period, and argues that the apparent success of regulation during this time may be attributed to the very heightened controls arising from Sleeping Sickness Controls. Once these were removed, entry into the fishery was rapid and uncontrolled, and the resultant impact on fish stocks was quickly felt. With its huge area, considerable shoreline, and innumerable islands, the lake Victoria fisheries service was quickly overwhelmed and disbanded as a result. In the early independence years, the Republic's government focused on developing the fishery, plans thwarted by turmoil of, and following, Idi Amin's reign. More recently, the fishery has prospered from Uganda's entry into the Nile perch fillet export market, which ahs adversely affected stocks. We present and comment on recently collected data that considers fishers' impressions of the status of the fishery, regulations and future managerial possibilities, and comment on these in the light of recent changes to Uganda's fisheries administration
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This paper provides an overview of fisheries legislation in Kenya, Uganda and Tanzania as far it concerns the administration of Lake Victoria's fishery. It also provides brief comment on the structure of these nations' fisheries departments and how they have evolved in recent years. The administration of Kenya's Lake Victoria fishery has changed very little since the introduction of the 1988 Fisheries Act. In Tanzania and Uganda, however, government policies of decentralization have had a profound impact on fisheries administration at a local level. This paper examines these changes and speculates about possible future management scenarios for these two countries
Resumo:
This study concentrated on the reproductive biology of the small pelagic cyprinid Rastrineobola argentea. The results indicate that this fish is an inshore spawning species, which agrees with other recent studies. It was also found that in areas where fishing intensity was likely to be relatively high, the size at first maturity of R. argentea was reduced, which is likely to be an effect of the fish altering its reproductive strategy according to life history theory. The CPUE results showed a general trend of decreasing with distance from shore, however areas less than one kilometer from the shore were not sampled. Evidence was also found suggesting that the cestode parasite, Ligula intestinalis had an adverse effect on the maturation and fecundity of R. argentea. Some management options concerning the findings in this study are also briefly discussed. (PDF has 82 pages)
Resumo:
The fisheries of Lake Kainji, Nigeria, experienced a boom year following impoundment, then decline post impoundment and now is in a period of stabilisation of the fish resources. Several reasons have been advanced on factors responsible for these changes, but two outstanding factors are those of nutritional status and fishing methods of the lake. Two important fish families however continue to dominate the lake fisheries in daily fisherman catches: Clupeidae and Cichlidae (tilapias). Recent studies have also shown that the dominance of the tilapias and clupeids is an important factor in the understanding of the stability of fisheries of Lake Kainji. One area which has remained undiscussed concerns the parasites and non-fish predators of tilapias which can affect the population dynamics of tilapias. This paper examines therefore some aspects of the fisheries of Lake Kainji and the potential roles that parasites and non-fish predators of tilapias can contribute in developing strategies for consideration in the sustainable management of the fisheries
Resumo:
The carbohydrate, protein and lipid contents of the food ingested and their absorption in the intestine of Sarotherodon melanotheron inhabiting Awba lake in Ibadan, Nigeria, were investigated. Total carbohydrates of the ingested food ranged from 39.33 to 55.38% (mean = 48.70% while total protein and total lipid ranged from 10.10 to 17.13% (mean = 12.91%) and 7.79 to 8.96% (mean = 8.28%) dry weight, respectively. Calculated total percentages absorbed were 54.86-62.01 (mean 58.07) carbohydrates 47.33-54.06 (mean = 50.43) protein and 43.27-52.23% (mean 46.56) lipid. Absorption of protein and carbohydrate occurred mostly in the fore-gut (the first one-third of the intestine), while lipid was mostly absorbed in the mid-gut (the second one-third of the intestine). Dietary carbohydrate, protein and lipid contents of the food as well as the absorptive capacity of the intestine for these components of the food varied with size of fish