Water quality and nutrient dynamics - Lake Victoria, Kenya

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.

Fisheries management in the social domain: perspectives from Tanzania's Lake Victoria fishery

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

Regulation in Uganda's Lake Victoria fishery: historical and contemporary conditions

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

Fisheries legislation of Lake Victoria: present legislation and new developments

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

Some aspects of the ecology and reproduction of the small pelagic cyprinid, Rastrineobola argentea in Lake Victoria

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)

Parasites and non-fish predators of tilapia with particular reference to the sustainable management of fisheries of Lake Kainji Nigeria

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

Absorption of food in the black-jaw tilapia, Sarotherodon melanotheron (Ruppell) from a small tropical man-made lake in Ibadan, Nigeria

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

Assessment of post-harvest losses in Nigeria fishery: the Kainji Lake model

The paper provides a description of a methodology used for quantitative assessment of post harvest losses in the Kainji Lake Fishery (Nigeria). The sample population was made up of 314 fisherfolk, 115 processors, 125 fish buyers and 111 fish sellers. For the determination of handling losses, 24,839 fishes weighing 2,389.31 kg belonging to 43 species were examined of which 10% by number and 9% by weight deteriorated at checking and 4% by number and 3% by weight at landing. Processing losses recorded 22% by number and 16% by weight deteriorated prior to and during smoking with the traditional 'Banda' kiln. During marketing, 16% of fish sold had deteriorated and 6% by weight of fish bought also deteriorated, mainly due to insect infestation during storage. Based on the 1995 yield estimate for Kainji Lake fishery, approximately 1000 tons of fish estimated at 80 million Naira were lost during handling alone. This figure would be much higher if the level of losses during processing and marketing are included. This assessment technique is recommended for use in obtaining quantifiable data on post harvest losses from other water bodies in Nigeria

A preliminary investigation into the post harvest losses of fish in Shiroro Lake area

The findings are presented of a study conducted to assess the post harvest losses in Shiroro Lake, Nigeria. The major objectives were to identify and quantify the types of losses, to provide recommendations that would enhance formulation of policy guidelines for utilization and exploitation of the declining fishery resources of the lake

Lake Kainji water hyacinth infestation and the control strategies

The paper documents the aquatic vascular plants situation of Lake Kainji, particularly with the invasion of water hyacinth (Eichhormia crassipes) hitherto alien to the lake system. The frequency of occurrence of some aquatic plants on Lake Kainji have increased whilst a few decreased over the period between 1984 and 1995. More than 53.6% of the lake surface has now been covered by aquatic vascular plants of which water hyacinth alone covered 30.6% (16.4% of the system). Apart from the characteristic rapid multiplication and biomass build-up of the plant, more than 9.1 clumps with a diameter range between 0.8-4cm enter the lake per minute. Thus more than 16.4ha per day or annually 6000ha of water hyacinth are added as drifts. Because of the peculiar hydrological cycle of the lake and the plant aggressiveness and invasiveness, NIFFR (with the support of the GTZ) had developed an approach of control which combines manual, biological, natural, boom construction and chemical measures. These are discussed

The distribution and abundance of Copepoda and Cladocera in the Lake Victoria, Kenya

Fourteen stations were sampled in the Kenyan waters of Lake Victoria in order to assess distribution and abundance of zooplankton. Seven stations were selected in the Nyanza gulf while the rest were in the open waters of the lake. Zooplanktons samples were collected monthly from November 1998 to January 1999, using a 1.5 m long Nansen type plankton net of 243 mu m mesh size and 50 cm diameter. Representative specimens were dissected and identified to species level

Community-based organizations on Lake Victoria: a lesson from the Tweyambe Fishing Enterprise in Muleba District, Kagera Region, Tanzania

This paper is aimed at government, non-government organizations, intergovernmental organizations and the general public as they work toward the development of their individual strategies and action plans. It has been recognized that community-based organizations have a particular relevance to the pursuit of sustainable resource management and may well contribute to the foundations of self-sustenance. Women on Lake Victoria, Tanzania presently face great challenges within the fishery. These include the lack of capital, interference by men, theft of fishing gear, time constraints and socio-cultural problems. In recent years, the fish trading and marketing sectors of the fishery, which have traditionally been dominated by women, have seen large incursions by male entrepreneurs. This move has endangered the role of women within the fishery. This paper focuses on the Tweyambe Fishing Enterprise (TFE), a well-known women's group based in Kasheno village in the Muleba District of Kagera Region in northwestern Tanzania. Inhabitants from the Haya ethnic group who make up some 95% of the population of Kagera Region dominate this village. The TFE has a series of initiatives aimed towards ecologically sound self-development

Ownership and co-management: towards the integrated management of Lake Victoria

The management of Lake Victoria is a high priority to the riparian countries that benefit directly from its resources. Management regulations have been formulated and implemented with the aim of maintaining the lake's ecological quality as well as sustaining fisheries exploitation for economic gain. Results indicate, however, that the regulations have not been successful in maintaining the state of the lake's ecosystem nor the fisheries. There has been a continuing decline in fish catches as well as declining biodiversity. Currently, the riparian countries are considering the introduction of a co-management regime as an alternative managerial strategy to address the lake's problems. In this paper it is argued that the failure of the former management regulations was because ownership of the lake was not clearly defined. It is further argued that even if co-management were to be successfully instituted, it will yield very minimal results if the problem of ownership is not properly addressed. This paper explores the ownership status of the lake based on data collected in Tanzania, and examines the relationship between, and significance of, ownership and co-management. The research makes recommendations for how these concepts can contribute to an integrated management of the lake

An assessment of co-management potentials in the Lake Victoria fisheries of Kenya

Co-management is a system or a process in which responsibility and authority for the management of common resources is shared between the state, local users of the resources as well as other stakeholders, and where they have the legal authority to administer the resource jointly. Co-management has received increasing attention in recent years as a potential strategy for managing fisheries. This paper presents and discusses results of a survey undertaken in the Kenyan part of Lake Victoria to assess the conditions - behaviour, attitude and characteristics of resource users, as well as community institutions - that can support co-management. It analyses the results of this survey with respect to a series of parameters, identified by Pinkerton (1989), as necessary preconditions for the successful inclusion of communities involvement in resource management. The survey was implemented through a two-stage stratified random sampling technique based on district and beach size strata. A total of 405 fishers, drawn from 25 fish landing beaches, were interviewed using a structured questionnaire. The paper concludes that while Kenya's lake Victoria fishery would appear to qualify for a number of these preconditions, it would appear that it fails to qualify in others. Preconditions in this latter category include the definition of boundaries in fishing grounds, community members' rights to the resource, delegation and legislation of local responsibility and authority. Additional work is required to further elaborate and understand these shortcomings

Who's doing what sustainably? Fishermen's perceptions of managerial responsibility on Lake Victoria, East Africa

This paper examines the data recently collected from Lake Victoria (SEDAWOG, 2000a). In the first section, it provides the results from the survey that examines fishermen's perceptions of the status of the resource base. In the second section, it starts with an examination of boundaries, followed by an examination of these data insofar as they relate to fishermen's understanding of roles. We conclude the paper with a brief discussion of what these findings mean for fisheries management on Lake Victoria in particular, and our understanding of co-managerial applications more generally