THE BIOLOGICAL LOAD OF SILVER CARP CAGES IN THE RIVER NILE AND THEIR EFFECTS ON WATER QUALITY AND GROWTH PERFORMANCE | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 7, Volume 11, Issue 2, April 2007, Pages 119-143 PDF (2.2 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2007.1938 | ||
| Authors | ||
| Ibrahim Shaker1; Ahmed Mahmoud2 | ||
| 1Limnology Department and 2- Aquaculture Department Central | ||
| 2Laboratory for Aquaculture Research,(CLAR) Abbassa, Sharkia, Egypt. | ||
| Abstract | ||
| Silver carp fmgerlings were stocked in cages at three different densities. Four replicates cages 6x9x4m were cultured for 150 days during two seasons from February to December 2004. These stocking densities of silver carp (initial weight 5-10g) were tested in three locations; El-Mahmoudia (8, 10 and 12 fish/m); Fazara (6, 8 and 10 fish/m3) and Edfina (4, 6 and 8 fish/m3) in cages suspended in the River Nile at each location in two seasons. The impacts of cages on water quality were investigated. Results obtained are summarized as follows: 1- Water temperature ranged from 26.5 to 27.4°C in all cages at all locations. 2- Values of pH, DO, NH4, NH3, N02, TP, OP and chlorophyll a increased significantly down stream after passing the cages. 3- SD decreased sharply after the site of cages at all locations. 4- Survival rate was affected by location 5- Location released affects on cage production. The maximum production rate achieved was 19.87 kg/m3 in first season with initial weight of lOg fish/m3 at EI-Mahmoudia. The results of this study suggest that cages in the River Nile and stocking density are more than load on water. We can suggest that necessary codification the use of water in the River Nile in cages culture, also, transferring these cages in lakes. | ||
| Keywords | ||
| cages; intensive; River Nile; Growth performance; water quality; biological load; Silver carp | ||
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