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  • 1
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    Lake Victoria Fisheries Research Project | Jinja, Uganda
    In:  http://aquaticcommons.org/id/eprint/4956 | 424 | 2011-09-29 15:39:53 | 4956 | Lake Victoria Fisheries Organization
    Publication Date: 2021-07-07
    Description: Four fleets of hanging coefficients 0.2, 0.4, 0.6 and 0.8 were used to determine size selectivity and selection factors of Nile perch populations. There was a linear relationship between mesh size and modal length of capture. Positively skewed length frequency distributions were found for smaller mesh sizes with entanglement becoming more prominent in mesh sizes above 101 mm. Nets of 114 to 141 mm stretched mesh yielded higher economic returns than small meshes, the catch consisting of few largefish.
    Description: Lake Victoria Fisheries Research Project Phase II
    Description: LVFRP/TECH/99/07
    Keywords: Biology ; Fisheries ; Information Management ; Africa ; Kenya ; stock assessment ; data collection ; data report ; Lates niloticus
    Repository Name: AquaDocs
    Type: book_section
    Format: application/pdf
    Format: application/pdf
    Format: 92-98
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  • 2
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    Lake Victoria Fisheries Research Project | Jinja, Uganda
    In:  http://aquaticcommons.org/id/eprint/5010 | 424 | 2011-03-25 06:43:37 | 5010 | Lake Victoria Fisheries Organization
    Publication Date: 2021-07-07
    Description: In a tagging experiment carried out in the Kenyan waters of Lake Victoria, an annual growth increment of 29 cm yr was obtained for Lates niloticus (L.). Growth parameters obtained using the von Bertalanffy model on the growth curve fitted by eye were L (inf.) = 122 cm yr and k = 0.26 yr. Data for other species tagged were inadequate to obtain meaningful results.
    Description: Lake Victoria Fisheries Research Project Phase II
    Description: LVFRP/TECH/99/07
    Keywords: Biology ; Fisheries ; Information Management ; Africa ; Lake Victoria ; Lates niloticus ; Bagrus docmak ; Oreochromis niloticus ; Clarius gariepinus ; data collection
    Repository Name: AquaDocs
    Type: book_section
    Format: application/pdf
    Format: application/pdf
    Format: 204-207
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  • 3
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    Lake Victoria Fisheries Research Project | Jinja, Uganda
    In:  http://aquaticcommons.org/id/eprint/4150 | 424 | 2011-09-29 16:25:28 | 4150 | Lake Victoria Fisheries Organization
    Publication Date: 2021-06-30
    Description: This document can be considered as the first step in the direction of a complete fish species catalogue for fisheries purposes of the Lake Victoria. (PDF contains 55 pages)
    Description: Republic of Kenya
    Description: Republic of Uganda
    Description: United Republic of Tanzania
    Description: European Development Fund (7 ACP-RPR-372)
    Description: Lake Victoria Fisheries Research Project Phase II
    Keywords: Biology ; Fisheries ; Africa ; Lake Victoria ; commercial species ; freshwater fish ; lake fisheries
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 1-39
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  • 4
    Publication Date: 2021-05-19
    Description: Trawling is carried out on Lake Victoria both for research and commercial purposes. Commercial trawling on the Kenyan side of the lake began in the 1960s, mainly to harvest haplochromines, but in the last two decades Nile perch has been the main species targeted. The trawlers are in business primarily to supply fish to the processing factories for export. They have cold storage facilities on board, thus ensuring high quality of fish. For this reason, there is strong linkage between trawling and the fish processing industry. Some factories own trawlers while others finance the operations of privately owned trawl boats, which supply them with fish. In Kenya 5-10% of the fish processed by factories is caught by trawlers. Of the fish landed by trawlers, it is mainly reject and undersize fish that is made available to the artisanal fish processors and traders. A trawler with engine capacity of about 300 HP and fitted with suitable gear can catch over 1 ton of fish in a day, earning the owner good profits. Such a trawler can employ about 10 crew. In comparison, about 8 artisanal boats employing over 30 crew can catch the same amount of fish. On a limited resource base such as Lake Victoria, therefore, one trawler can potentially displace many artisanal boats, resulting in a net loss of employment. At times though, trawlers assist in rescuing capsized boats or tow small vessels loaded with fish back to land. Trawling is regarded as the appropriate fishing method in deep parts of the lake where there are strong undercurrents. However, in practice, trawlers rarely restrict their activities to the open waters, preferring to operate in the shallower but richer fishing grounds traditionally occupied by artisanal fishermen. They destroy the set gillnets and long lines, leading to conflicts between the two groups. Trawlers can also have adverse biological implications. Bottom trawling disturbs the substrate, the water column and interferes with the breeding ground and the spawning process, especially for tilapines. It can also destroy larvae and eggs of fish, macro and micro-invertebrates at different strata of the lake. Thus, trawling using non-selective mesh nets, may cause overfishing by taking away both the adult and juvenile fish, reducing their potential yield. Trawlers and beach seines are officially banned in all parts of the lake. However, there is a big gap between fisheries policy statements and actual practice in all three countries. In Tanzania, for example, the enforcement of fisheries regulations is hindered by many factors. These include the lack of logistical support and inadequate remuneration to field staff, poor interpretation of the law by enforcement officers and mismatch between the fisheries policy goals and the interests of local communities. Although the ban on trawling in Tanzania when it was implemented, negatively affected business activities and employment, it also subsequently caused an increase in average catch to artisanal fishers. Before the ban, trawlers landed about 15 tons of fish daily in Tanzania. Trawlers do not in any way complement the activities in the artisanal fishery. Rather, increased trawling activities can have negative consequences on local employment, food security and resource sustainability. In conclusion, the negative socio-economic and biological effects of trawling on Lake Victoria clearly outweigh its advantages.
    Description: Published
    Keywords: Socioeconomic aspects ; Trawling ; Trawlers ; Fishing gear ; Fishing vessels
    Repository Name: AquaDocs
    Type: Report , Not Known
    Format: 33pp.
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  • 5
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    Lake Victoria Fisheries Project | Jinja, Uganda
    Publication Date: 2021-05-19
    Description: Four fleets of hanging coefficients 0.2, 0.4, 0.6 and 0.8 were used to determine size selectivity and selection factors of Nile perch populations. There was a linear relationship between mesh size and modal length of capture. Positively skewed length frequency distributions were found for smaller mesh sizes with entanglement becoming more prominent in mesh sizes above 101 mm. Nets of 114 to 141 mm stretched mesh yielded higher economic returns than small meshes, the catch consisting of few largefish.
    Description: Published
    Keywords: Gillnets ; Fishery management ; Stock assessment ; Artisanal fishing
    Repository Name: AquaDocs
    Type: Report Section , Not Known
    Format: pp.92-98
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  • 6
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    ICIPE SCIENCE
    Publication Date: 2021-05-19
    Description: Survival rates of Lates niloticus in Lake Victoria, Kenya were adduced from length derived age specific lifetables. Nature of the populations were inferred from calculated parameters. Unstable populations were observed between 1989 and 1992, which would subsequently lead to decreased catches between 1990 and 1994.
    Description: Kenya Marine and Fisheries Research Institute and European Economic Community
    Description: Published
    Keywords: Lates niloticus ; Kenya ; Lake Victoria ; Lake fisheries ; Stock assessment ; Population dynamics ; Survival ; Catch/effort ; Lake fisheries ; Population dynamics ; Stock assessment ; Survival
    Repository Name: AquaDocs
    Type: Proceedings Paper , Non-Refereed
    Format: 202099 bytes
    Format: application/pdf
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  • 7
    Publication Date: 2021-05-19
    Description: In a tagging experiment carried out in the Kenyan waters of Lake Victoria, an annual growth increment of 29 cm yr was obtained for Lates niloticus (L.). Growth parameters obtained using the von Bertalanffy model on the growth curve fitted by eye were L (inf.) = 122 cm yr and k = 0.26 yr. Data for other species tagged were inadequate to obtain meaningful results.
    Description: Published
    Keywords: Growth rate ; Tagging ; Artisanal fishing
    Repository Name: AquaDocs
    Type: Report Section , Not Known
    Format: pp.204-207
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