EFFECT OF RICE STRAW ON LIMONOLOGICAL PARAMETERS AND BACTERIOLOGICAL COMMUNITIES
IN EARTHEN FISH PONDS
Diaa A. Al-Kenawy and Taghred M. Ahmed
1Limnology department, Central Laboratory for Aquaculture Research, Agricultural Research Center, Egypt.
2Fish Disease department, Central Laboratory for Aquaculture Research, Agricultural
Research Center, Egypt.
| Received 25 /10 /2020 |
Accepted 8 /12 /2020 |
ABSTRACT
The present study carried out in the WorldFish center research station at Abbassa, Egypt, during the period from June to November 2017 to investigate the effect of applying rice straw as periphyton substrates in fertilized earthen fishponds on some water quality parameters and bacteriological communities. Six earthen ponds, of 1000 m3 average area each, divided into two groups, each of three replicates. Dry rice straw added to one of the two groups in a rate of 45 kg/pond to act as periphyton substrates (T2), while the other group left without applying rice straw to act as control group (T1). Some water quality parameters namely water temperature (ºC), dissolved oxygen (DO, mg/l), hydrogen ion concentration (pH), total ammonia nitrogen (TAN, mg/l), unionized ammonia (NH3, mg/l), total hardness (TH, mg/l as CaCO3), Calcium (Ca, mg/l), Magnesium, (Mg, mg/l), total dissolved solids (TDS, mg/l), total nitrogen (TN, mg/l), and total phosphorous (TP, mg/l) were measured fortnightly in source water, as well as in the two treatments’ ponds (T1 and T2). The bacterial communities also monitored and counted in water and fish samples. Most important results obtained summarized as follow: there were no significant (P < 0.05) differences in the mean average of water temperature among source water and the two treatments, while the values of dissolved oxygen, pH, TDS, TN, TP in the source water were significantly (P < 0.05) lower than those in both (T1) and (T2) treatments. Levels of TH and Ca were significantly (P < 0.05) higher than those in both (T1) and (T2) treatments. Mean values of most investigated parameters were significantly different between the two treatments in some months. However, all measured parameters and the bacteriological communities in the ponds of the two treatments were within the acceptable ranges recommended for successful aquaculture.
