An Overview of the Current Status of Lake Naivasha Fishery: Challenges and Management Strategies

Abstract

Lake Naivasha a shallow, freshwater body and a Ramsar site is found in the eastern arm of the Kenyan Rift Valley. This paper used published, unpublished and analyzed data to assess the status, challenges and management options for the fishery. Lake Naivasha fishery is based on exotic species that fluctuates depending on fishing regime, lake water level and aquatic plant concentrations. The fishery has been dominated by different species with the current catch contribution consisting mainly of common carp, Cyprinus carpio, Nile tilapia, Oreochromis niloticus, blue-spotted tilapia, O. leucostictus and African catfish, Clarias gariepinus. The minimum and maximum catch of 21 t yr -1 and 1181 t yr -1 was reported in 1997 and 2015, respectively. The main threats to the lake fishery are anthropogenic influences emanating from within the lake and its basin. The factors include intense fishing, exotic species introductions, water abstraction, lake level fluctuations, wetland utilization, eutrophication, and land degradation. There are also several conflicts of interest amongst the stakeholders in agriculture, fisheries, wildlife, tourism, conservation and geothermal electricity generation. There is fear that if the current trend persists, the lake and its fishery may be headed for extinction. The management measures instituted in the lake do not seem to have arrested reduction in fish catches nor reversed deterioration in water quality. For sustainable utilization of Lake Naivasha and its fishery, there is a need to consider a holistic ecosystem approach of the basin management. Additionally, all the relevant stakeholders should be involved in formulation and implementation of the decisions to manage the fishery.

Polyphyletic Origins of Schizothoracinae Fishes (Cyprinidae) in Respect to Their Mitochondrial Protein-Coding Genes

“…Kolding and Zwieten [11] extended the notion that while the national/regional management institutions see the BMUs primarily as their new implementation tools for centrally decided harmonized regulations adopted from elsewhere the fishers see them as fora for solving local problems and conflicts, and particularly as instruments for reducing theft and piracy (which is rampant and increasing around the lake).…”

Has the Latest Fish Introduction in Lake Naivasha Improved Income of Fishermen? The Economics of Nile Tilapia (Oreochromis niloticus) in Lake Naivasha

“…Between 2007 and 2008 the catches were dominated by C. carpio, 81.7%, O. leucostictus 9.7%, M. salmoides 8.3% and C. zilli 0.3% [7]. Currently the fishery is dominated by O. niloticus, C. carpio, O. leucostictus and African catfish Clarias gariepinus [5][6][7][8][9]. In 2015, the contributions were 83.4%, 7.3%, 6.0% and 19% and 1.7% for these species respectively [5][6][7][8][9].…”

“…Currently the fishery is dominated by O. niloticus, C. carpio, O. leucostictus and African catfish Clarias gariepinus [5][6][7][8][9]. In 2015, the contributions were 83.4%, 7.3%, 6.0% and 19% and 1.7% for these species respectively [5][6][7][8][9]. "The notable decline in carp in the first four months of 2016 was attributed to overexploitation in the previous year which was occasioned by gillnets of 3.5'' and below being deployed targeting the smaller sized O. niloticus, O. leucostictus and C. zilli [5][6][7][8][9].…”

“…In 2015, the contributions were 83.4%, 7.3%, 6.0% and 19% and 1.7% for these species respectively [5][6][7][8][9]. "The notable decline in carp in the first four months of 2016 was attributed to overexploitation in the previous year which was occasioned by gillnets of 3.5'' and below being deployed targeting the smaller sized O. niloticus, O. leucostictus and C. zilli [5][6][7][8][9]. This practice has rendered common carp as a by-catch of the tilapia fishery and hence resulted in , fishermen have been landing higher numbers of the fish in every subsequent year.…”

“…Data used for this study was collected routinely by Kenya Marine and Fisheries Research Institute and Nakuru County Government Fisheries Department between January 2011 and April 2016 from four landing beaches along the shores of Lake Naivasha; Central, Karagita, Kamere and Tarambete. Lake Naivasha (Figure 1), a shallow freshwater lake with a surface area of approximately 139 km 2 is situated in the Eastern arm of the Great Rift Valley, about 100 km north-west of Nairobi, Kenya [3,9]. It has an average depth of 3.35 m with the deepest area being 7 m [4] though these values vary with change in rainfall patterns.…”