Environmental conditions and natural food resources for commercial fish production in the valley dams of Mbarara District, Uganda

To chci

The Mabira, Kyenshama and Rushozi valley dam reservoirs in the Mbarara District, Uganda, provide suitable environmental conditions for fishery exploitation and controlled fish farming and/or ranching management. Physico-chemical parameters were correlated to primary production in Rushozi and Kyenshama and to altitude and geology in Mabira. All dams were eutrophic with nitrogen likely to be limiting in Mabira and Rushozi and phosphorus in Kyenshama. Phytoplankton abundance (with Chlorophyceae and Cyanobacteria dominance) was significantly higher in Rushozi. Abundance of zooplankton and benthic macroinvertebrates was similar across dams. Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) were the dominant and available culture species. Their condition based was highest in Rushozi dam (1.86 ± 0.18 and 0.63 ± 0.07 for tilapia and catfish, respectively) and coincided with the highest oxygen, temperature, food uptake and phytoplankton abundance and biomass (according to chlorophyll-a concentration). Detritus, plant material, and phytoplankton were the most important diet items for both tilapia and catfish however the level of justifiable food coincidence (~ competition) was very low amounting to 2.9% in phytoplankton. The majority of food coincidence concerned low valued food items - detritus (12.7%) and plant material (14.7%). … celý popis

Podrobná bibliografie

Hlavní autor

C. Kemigabo

Další autoři

Zdeněk Adámek, 1949-

Typ dokumentu

Články

Fyzický popis

17 il., 1 mapa

Publikováno v

Agricultura tropica et subtropica. -- ISSN 0231-5742. -- Roč. 43, č. 4 (2010), s. 248-260

Témata

méně…

přehrady

vodní nádrže

chov ryb

environmentální činitelé

faktory prostředí

zdroje krmiv

přírodní zdroje

kvalita vody

fyzikálně-chemické vlastnosti

vodní organismy

plankton

fytoplankton

zooplankton

bentos

Oreochromis niloticus

sumeček africký

AFRICA

UGANDA

DAMS

WATER RESERVOIRS

FISH CULTURE

ENVIRONMENTAL FACTORS

SITE FACTORS

FEED RESOURCES

NATURAL RESOURCES

WATER QUALITY

CHEMICOPHYSICAL PROPERTIES

AQUATIC ORGANISMS

PLANKTON

PHYTOPLANKTON

ZOOPLANKTON

BENTHOS

OREOCHROMIS NILOTICUS

CLARIAS GARIEPINUS

Afrika

Uganda

více… méně…

Popis jednotky

7 grafů, 10 tabulek

Bibliografie

Literatura na s. 259-260