scholarly journals A review on the status of some major fish species in Lake Victoria

2019 ◽  
Author(s):  
Nicholas Outa ◽  
Edwin Yongo ◽  
Jameslast Keyombe ◽  
Namwaya David
Keyword(s):  
Fish Species ◽  
Lake Victoria ◽  
Nile Perch ◽  
Management Measures ◽  
Ecological Changes ◽  
The Status ◽  
Domestic Use ◽  
Food Fish ◽  
Labeo Victorianus ◽  
Alien Fish Species

Lake Victoria, the second largest freshwater lake in the world supports a huge flora and fauna with a large human population around the Lake. The Lake is a source of food (fish), water for domestic use and crop and livestock production, transportation, tourism among others. Due to its varied uses, human intervention within the lake and its catchment has caused several ecological changes in the recent years with profound effects on the resource resources. One of the most notable change is the reduction and risk of extinction of some fish species, including the endemic tilapiine species (Oreochromis esculentus and O. variabilis), catfishes (Xenoclarias eupogon), haplochromines and cyprinids (Labeo victorianus and Barbus altinialis) within the lake. The reduction in biodiversity and extinctions within the lake has been ascribed to the introduction of alien fish species (Nile perch (Lates niloticus) and Nile tilapia (O. niloticus) into the lake, habitat loss and the cultural eutrophication. These changes if left unchecked will have devastating effects on the lake’s resources and at large to people living around the lake and beyond who depend on the lake for their livelihood. There is, therefore, an urgent need for management measures based on sound scientific research to be taken in order to curb the loss of ichthyodiversity within the lake and to save livelihoods of the direct and indirect dependents of the lake

scholarly journals The status of research on Lake Victoria fisheries: Historical and current data on fisheries and the lake environment

2019 ◽  
Author(s):  
Dan Mungai ◽  
Nicholas Outa ◽  
Paul Obama ◽  
Fredrick Ondemo ◽  
Erick Ogello
Keyword(s):  
Fish Species ◽  
Lake Victoria ◽  
Large Population ◽  
Ecosystem Approach ◽  
Current Data ◽  
Lake Ecosystem ◽  
Nile Perch ◽  
The People ◽  
Ecological Changes ◽  
The Status

Lake Victoria which is the second largest freshwater lake in the world supports a large population living around it through provision of food; fish and employment; both directly and indirectly. Due to its varied uses, human intervention within the lake and its catchment has caused several ecological changes in the recent years which have had profound effects on its resources. Historical and recent data within the lake show an enormous change in the diversity of the fish species as well as environmental and ecological changes. Some of the reasons cited for the changes in biodiversity within the lake are: the introduction of alien fish species like Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus) into the lake, habitat loss and the cultural eutrophication. Several research projects like Lake Victoria Management programme (LVEMP) and Lake Victoria Fisheries Organization (LVFO) have been formed to help address some of these problems with varied levels of success. There is therefore an urgent need for management measures based on sound scientific research to be taken in order to curb this loss of ichthyodiversity within the lake and to save the livelihoods of the people who are dependent on the lake. Owing to the importance of the lake to the livelihoods of the people around the lake and beyond, there is need for concerted effort by all stakeholders in trying to halt the degradation and other negative environmental and ecological changes within the lake. Ecosystem approach to conservation is the way forward in the management and sustainable utilization of the fisheries and other resources within the lake.

scholarly journals A review on the status of some major fish species in Lake Victoria and possible conservation strategies

2020 ◽  
Vol 25 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Nicholas Otieno Outa ◽  
Edwine Omollo Yongo ◽  
James Last A. Keyombe ◽  
Erick O. Ogello ◽  
David Namwaya Wanjala
Keyword(s):  
Fish Species ◽  
Lake Victoria ◽  
Conservation Strategies ◽  
The Status

scholarly journals The impacts of introduced species on lake ecosystems: A case of Lakes Victoria and Naivasha, Kenya.

2019 ◽  
Author(s):  
Nicholas Outa ◽  
Dan Mungai ◽  
James Last A. Keyombe
Keyword(s):  
Introduced Species ◽  
Fish Species ◽  
Largemouth Bass ◽  
Water Hyacinth ◽  
Native Species ◽  
Nile Tilapia ◽  
Lake Victoria ◽  
Nile Perch ◽  
Lake Naivasha ◽  
Lake Ecosystems

Fish and other aquatic organisms have been introduced into new environments for various reasons. Provision of sports fishery, supplemental to stocks, to fill empty niches, control weeds, and disease vectors and even create a commercial fishery are some of the reasons why fish species are introduced into new ecosystems. Lake Victoria and Lake Naivasha in Kenya have seen several introductions as discussed in this paper. In Lake Victoria for example, some of the species introduced include Nile perch, Lates niloticus, Nile tilapia, Oreochromis niloticus, Tilapia zilii, and Oreochromis esclentus among others. The most successful introductions have been that of the Nile perch, Nile tilapia and water hyacinth. Lake Naivasha too has witnessed a number of introductions into its fisheries too. Some of the successful introductions into the lake are those of the Common carp, Cyprinus carpio, the largemouth bass, Micropterus salmoides, the Nile tilapia, O. niloticus and Louisiana red swamp crayfish, Procambarus clarkia. Aside from the fish species mentioned, some invasive plant species have also been introduced into these two lake ecosystems. Of notable success and impacts have been the water hyacinth, Eichhornia crassipes and Nile cabbage, Pistia stratiotes. These introductions have had both negative and positive impacts on the fisheries and the ecology of the two lakes. Some of the impacts have been predation on the native species by the introduced species like in the case of Nile perch and largemouth bass in Lake Victoria and Naivasha respectively. Competition for resources and hybridization with the native species has also been witnessed in the case of the tilapiines in the two lakes with undesirable results. Blockage of navigation routes caused by the invasive plants has been a major problem in the two lakes sometimes leading to massive postharvest losses by the fishermen. On the other hand, some introduced species have led to an increase in fish landings as well as utilization of the niches that were initially vacant within these ecosystems. It can therefore be concluded that introduced species often have more negative effects on the native species and therefore such introductions should be based on sound scientific research in order to minimize their effects within the new environments.

Are fisheries management, measures in Lake Victoria successful? The case of Nile perch and Nile tilapia fishery

2007 ◽  
Vol 45 (3) ◽  
pp. 315-323 ◽  
Author(s):  
M. Njiru ◽  
P. Nzungi ◽  
A. Getabu ◽  
E. Wakwabi ◽  
A. Othina ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Nile Tilapia ◽  
Lake Victoria ◽  
Nile Perch ◽  
Management Measures

scholarly journals Socio-Economic Drivers of Fish Species Consumption Preferences in Kenya’s Urban Informal Food System

2021 ◽  
Vol 13 (9) ◽  
pp. 5278
Author(s):  
Oscar Ingasia Ayuya ◽  
Katrine Soma ◽  
Benson Obwanga
Keyword(s):  
Fish Species ◽  
Nile Tilapia ◽  
Food System ◽  
Lake Victoria ◽  
Informal Settlement ◽  
Clarias Gariepinus ◽  
Future Market ◽  
African Catfish ◽  
Nile Perch ◽  
Haplochromine Cichlids

In an effort to contribute to resilient food and nutritional security in urban slums, a food system approach was applied to understand the key socio-economic factors driving fish species consumption in Kibera, the largest informal settlement in Africa located in Nairobi, Kenya. Data were collected from 385 randomly selected households using a structured questionnaire. A multivariate probit model was applied to estimate the relationship between the variables in order to determine the socio-economic drivers of preferences for different fish species. The results indicated that Lake Victoria sardine (Rastrineobola argentea) had the highest preference (73%) among the respondents, followed by Nile tilapia (Oreochromis niloticus) (70%) and Nile perch (Lates niloticus) (23%), respectively, with other fish species at 12%, including African catfish, marbled lungfish, common carp, fulu and tuna (Clarias gariepinus, Protopterus aethiopicus, Cyprinus carpio, Haplochromine cichlids and Thunnus sp., respectively). Large household size showed an increase in preference for the Lake Victoria sardine, while higher income influenced preference for Nile tilapia and Nile perch positively, implying that when more income is available, Nile tilapia is the preferred fish over other fish species. Increased fish prices positively influenced preference for Nile tilapia, which is explained by the willingness to pay extra for quality and origin, for instance, to avoid the cheaply cultivated Chinese fish. In the case of the Lake Victoria sardine, lower prices positively affected the preferences. Religious and cultural practices and beliefs influenced preference for species and consumption of fish. Residents who migrated from western Kenya had a higher preference for the Lake Victoria sardine, while residents born and raised in Kibera had a higher preference for Nile tilapia. Neighbourhood effects reduced the preference for consuming Nile perch. These findings provide insights into future market opportunities for specific target groups. For instance, given that small-sized fish like the Lake Victoria sardine is highly demanded, in order to increase resiliency in food and nutrition security, small-sized cheap Nile tilapia will have a large potential in the future, with ever higher demand specifically from the residents born and raised in Kibera.

Are fisheries management, measures in Lake Victoria successful? The case of Nile perch and Nile tilapia fishery

2006 ◽  
Vol 0 (0) ◽  
pp. 061206032120001-???
Author(s):  
M. Njiru ◽  
P. Nzungi ◽  
A. Getabu ◽  
E. Wakwabi ◽  
A. Othina ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Nile Tilapia ◽  
Lake Victoria ◽  
Nile Perch ◽  
Management Measures

scholarly journals Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Agnes Robert ◽  
Prosper Mfilinge ◽  
Samwel M. Limbu ◽  
Chacha J. Mwita
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Human Health ◽  
Fish Species ◽  
Lake Victoria ◽  
Nile Perch ◽  
Commercial Fish ◽  
Tilapia Zillii ◽  
Significant Difference ◽  
Commercial Species

Fatty acids (FAs) particularlyω3 andω6 polyunsaturated fatty acids (PUFAs) play important role in human health. This study aimed to investigate the composition and levels of selectedω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus),Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and eicosatetraenoic acids.O. niloticushad the highest composition of FAs (34) compared toL. niloticus(27),T. zillii(26), andR. argentea(21). The levels of EPA differed significantly among the four commercial fish species(F=6.19,  P=0.001). The highest EPA levels were found inR. argenteafollowed byL. niloticusandO. niloticusand the lowest inT. zillii. The DPA levels showed no significant difference among the four fish species studied(F=0.652,  P=0.583). The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, butR. argenteais the best for consumption because it contains higher levels ofω3 FAs, mainly EPA.

The Nile Perch in Lake Victoria: Local Responses and Adaptations

Africa ◽  
2005 ◽  
Vol 75 (4) ◽  
pp. 510-538 ◽  
Author(s):  
Robert M. Pringle
Keyword(s):  
Species Diversity ◽  
Global Economy ◽  
Lake Victoria ◽  
Nile Perch ◽  
Ecological Ethics ◽  
Social Scientists ◽  
Ecological Processes ◽  
Local Responses ◽  
Local Livelihoods ◽  
Ecological Changes

AbstractIntroduced into Lake Victoria in the 1950s, the Nile perch has gained fame for prompting rapid regional economic growth and for driving scores of endemic fish species into extinction. This study uses oral and archival data to trace the historical development of the Nile perch fishery on Lake Victoria. Particular emphasis is placed on local responses and adaptations to (1) the Nile perch itself; (2) the abrupt integration of the Lake Victoria fishery with the global economy; and (3) the ecological changes that the Nile perch has precipitated. I also attempt to situate Lake Victoria's history in the larger debate about environment and African livelihoods. Because so much of Lake Victoria's species diversity has been lost within one generation – biologist E. O. Wilson (1992) has called this process ‘the most catastrophic extinction episode of recent history’ – the lake is an ideal case study with which to examine ‘local’ perceptions of biodiversity. The data suggest that species diversity is important and highly resolved in the worldviews of Lake Victoria's fishermen; yet, although the will for conservation is present, poverty obstructs its realization. These findings are discussed in relation to other work on indigenous environmental knowledge and ecological ethics. I argue that ‘intrinsic’ valuation of species diversity and ecological processes may be more widespread in rural societies than has traditionally been assumed by natural and social scientists, and that the preponderance of social studies highlighting oppositions between Western science and ethno-science, and between conservation concerns and local livelihoods, may have blinded us to synergies between them. More effort is needed to understand fully the nuances in these complex local ecological worldviews, perhaps via ‘social histories of extinction’ that explore the local consequences of species loss.

scholarly journals A review on the status of Tilapiine species in Lakes Victoria and Naivasha, East Africa

2020 ◽  
Author(s):  
Edwine Yongo ◽  
Cishahayo Laurent ◽  
Eunice Mutethya
Keyword(s):  
Lake Victoria ◽  
Nile Perch ◽  
Lake Naivasha ◽  
Population Parameters ◽  
Important Species ◽  
Fish Stocks ◽  
The Third ◽  
Common Carp Cyprinus Carpio ◽  
The Status ◽  
Commercially Important

This paper discusses the status of tilapiine species both native and those introduced into lakes Victoria and Naivasha. In Lake Victoria, four exotic tilapiine species (Oreochromis niloticus, O. leucosticus, Coptodon zillii and Coptodon rendalii) were reviewed, while in Lake Naivasha, three species were reviewed (O. niloticus, C. zillii and O. esculentus). The O. niloticus in Lake Victoria caused decline of the native O. variabilis and O. esculentus through competition and hybridization. Only O. niloticus has been able to establish in Lake Victoria, currently forming the third commercially important species after the introduced Nile perch, Lates niloticus and a native cyprinid Rastrineobola argentea, whereas other tilapias are extinct or are occasionally caught in the lake. Predation by Nile perch, overfishing, lake pollution and eutrophication are reported to have impacted negatively on the fish stocks in Lake Victoria. The introduced tilapiine species in Lake Naivasha have also declined in catches primarily attributed to the deteriorating lake conditions, competition and feeding behavior of the introduced Common carp, Cyprinus carpio. Only O. leucostictus and O. niloticus are presently recorded in catches in Lake Naivasha, whereas C. zillii is rarely caught in the lake. The biological and population parameters of the tilapiines have shown great variation over time. The O. niloticus and O. leucosticus in the lakes tend to mature early at smaller sizes. These changes are discussed as adaptive characteristics in response to intense fishing and changing ecological conditions. There is therefore need to improve on the measures used to manage the two lakes basing on evidence of the declining fish stocks.

Dietary shift in benthivorous cichlids after the ecological changes in Lake Victoria

2008 ◽  
Vol 58 (4) ◽  
pp. 401-417 ◽  
Author(s):  
Jan Wanink ◽  
Frans Witte ◽  
Mary Kishe-Machumu
Keyword(s):  
Lake Victoria ◽  
Stomach Contents ◽  
Water Clarity ◽  
Strong Increase ◽  
Nile Perch ◽  
Cichlid Species ◽  
Dietary Shift ◽  
Ecological Changes ◽  
Before And After ◽  
Intestine Length

AbstractCichlid fishes of Lake Victoria are well known for their trophic specializations. In our study area, the sub-littoral waters of the Mwanza Gulf (Tanzania), at least 12 trophic groups coexisted in the 1970s. After the Nile perch upsurge and eutrophication in the 1980s, most cichlids disappeared from the area. During the 1990s, heavy exploitation of Nile perch reduced the abundance of this predator. Subsequently, some cichlid species, mainly zooplanktivores and small benthivores, recovered. To establish their ecological role in the changed environment, among other factors we studied their diet. Stomach contents of fish caught before and after the ecological changes were compared. The small benthivores shifted from a diet dominated by detritus and phytoplankton, supplemented with small quantities of midge larvae and zooplankton, to a diet of invertebrate preys of larger sizes. Currently, the diet includes zooplankton, midge larvae, shrimps and molluscs, and a very small amount of detritus and phytoplankton. Apparently, the recovering benthivores have a more carnivorous than a herbivorous diet. Concomitantly, the ratio of intestine length to standard length of the benthivores decreased with 30% and the average stomach fullness decreased as well. The observed dietary shifts may be due to (1) the changed availability of food types and a decline of the nutritious quality of detritus and phytoplankton due to the strong increase of cyanobacteria in the lake, (2) the decline of the former trophic specialists, and (3) the reduced water clarity. The diet of the former detritivores is currently very similar to that of the zooplanktivores. Consequently, if diet plays a role in the relatively slow recovery of the small benthivores compared to the zooplanktivores, this would only hold if they are relatively poorly adapted to their new diet.

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