Aquaculture has becoming one of the fastest industries in the world as it provides high quality animal protein food. To cope the increasing of the progressive demand of all aquaculture products, aquacultural academics and experts must develop new schemes with low environmental impact. Moreover, the scarcity of good quality water and the land, represent a complicated challenges for improving this industry. Consequently, a symbiotic experiment between fish and plants was conducted, in a private fish hatchery in Kafr ElSheikh , to investigate the effect of both organisms on each other. The aim of this work is to achieve dual use of the water and remediate the environment in fishpond during 72 days of fish nursing.The hydroponic system was designed as Deep Flow Technique (DFT) in its simplest type. Foam panels are used to fix the plants on water pond surface. Four panels were supplied to each pond (3*8*0.8). each panel contained 10 plants (fig.1) covering about (%) of water pond surface area. The plants used in this experiment were Mentha spicata L. (mint) 46cm TL, Ocimum basilicum L. (basil) 43.5cm TL, Origanum majorana (Marjoram) 37cm TL, Salvia Rosmarinus (rosemary) TL 33cm and Origanum syriacum (thyme) 34.7 cm TL, obtained from a commercial plantation for 60 days. 4800 tilapia fingerlings ( Oreochromis niloticus L.) were stocked at density of 400 fish/ pond (1.3 g wet weight). Diet used in this experiment was a commercial feed for specific species (crude protein 32) which was supplied at satiation and divided in two doses during the day (9:00 h and 14:00 h). Five treatments were conducted (4 plants and control treatment) with three replicates each. The results indicated that aromatic plants use led to water quality enhancement specially in un-ionized ammonia values. When the NH3 in control ponds was 0.12 mg/l, this value decreased to 0.02 mg/l in Basil and Marjoram with highly significant differences. In the same context, the physical parameters of water; pH, temperature, dissolved oxygen, were enhanced in all symbiotic ponds. Fish performance showed best values in case of basil followed by mint ponds, while survival rate was the best in rosemary ponds, 96.25%, without any significant differences. Significancy absence maybe due to the culture system which is extensive in this case. The best performance was achieved by mint as it grows about 200% in length. Possibly it is due to that some aromatic plants needs additional fertilizer together with ammonia. moreover, it is noteworthy that the roots of Marjoram attain noticeable growth in length which indicating that the plant produce new roots. This observation explains the remarkably low NH3 in Marjoram ponds.
Symbiotic relationship with both fish and plants has a positive influence on water quality and some aromatic plants performance. Furthermore, additional research must be taken place to evaluate the effect intensive culture on the performance of this scheme.