Export to

Contact Us

Abstract of Applied Sciences and Engineering

July 2015, Volume 3, 3, pp 07-08

Tilapia Fish Production in Cage Culture by Using Local Feeds and Temporal Dynamics of Physical, Chemical and Biological Parameters in Lake Babogay, Oromia Region, Ethiopia

Zelalem Dessalegn

Zelalem Dessalegn 1

  1. Adama Science Technology University,School of Applied Natural Science,Department of Applied Biology, Ethiopia 1

on Google Scholar
on PubMed

Abstract:

Ethiopia is well known for its richness in water potential. Lake Babogaya is one of the Crater Lake. From the biological view and utilization the lake is not this much utilized and fish production in cage culture has not been studied. So, the research work has explored the means of enhancing Tilapia fish production in Cage Culture by using local feeds and also temporal dynamics of   physical, chemical and biological aspects in Lake Babogay from April 7,2013 to October 14,2013.The sampling station of the present study was selected from the near shore  of Lake Babogaya for physic-chemicals and phytoplankton species composition. Water samples were collected twice a month from the stations with a bottle sampler. Tilapia fish species was grown in the cage with the stocking of up to 180 fingerlings at near shore of 2m. At the study period, the weight, length relationship, daily growth rate, feed conversion ratio and Fulton’s Conditioned Factor were measured.Major species of phytoplankton preserved with Lugol’s iodine found in samples collected on each sampling date were identified.Phytoplankton biomass was estimated as chlorophyll a concentration spectrophotometrically from water samples filtered through glass filters (GF/C). Composition of dry feed was given two times a day(early morning at 8:00 am and late afternoon at 4:00 pm).Feeding rate tables were adjusted every two weeks based on the average weight of fish. The daily growth rate of   Oreochromius niloticus  species at study period were ranges from 0.86 g in April  and maximum 1.23 g in the month of  July. Feed added to the cage was 3% of the body weight of fishes for a given date. Fingerlings of 180 with a weight of 10-18 gm weight (mean weight of 13g) or total weight of 2.288 kg and 4-6.5(mean length of 5.02 cm) cm length were collected and introduced to the lake. The initial mean weight of recruited fish was 13 g while the final mean weight of one fish was 194.6 g within the incubation period of 186 days.The daily mean weight gain was 1.05 g.The feed conversion ratio of the cultured fishes ranged from 0.86 in April  2013 to 6.23 in October 2013.The phytoplankton community of Lake Babogaya was dominated by Bacillariophyceae (Diatoms) and Chlorophyceae (Green algae). Phytoplankton biomass of Lake Babogaya was found to vary from 5 to 13  mgChl a m-3 during the study period.A positive but fairy strong correlation between phytoplankton biomass in the composite samples and nitrate-nitrogen (r=0.45) and silica (r=0.53) was found while its correlation with phosphate was positive, but weak (r=0.37). The surface water temperature of lakeBabogaya ranged from a low value of 22 °c at the shore station at the end of August, 2013 to a high value of 28.3 °c in May, 2013 and varied directly with air temperature. The pH of the surface water ranged from 8.76 to 9.05 in April and September 2013 respectively. Dissolved oxygen (DO) concentration at the surface of Lake Babogaya  ranged from a minimum of 5.77  to maximum of 9.34 mg l-l  in September and October 2013.Carbonate-bicarbonate alkalinity determined over the study period ranged from 8.4 to 11.15 meq l-1 .Nitrate-N varied from near the lower limit of its minimum of 3 µg l-1  to 30 µg l-1.Soluble reactive phosphate (SRP) of Lake Babogaya varied from below 0.5 µg L-1 to about 15µg L-1.In opposite  to nitrate and phosphate, molybdate reactive silica was found at concentration 11 mg l-1 to 54 mg l-1  in October 2013 to August 2013 respectively.

Keywords:

Cage culture, Tilapia, phytoplankton

Statistics:

Google Scholor ideas Microsoft Academic Search bing Google Scholor

Funding:

Competing Interests:

Acknowledgement: