IS THERE A DIFFERENCE GROWING LETTUCE WITH TILAPIA  Oreochromis niloticus OR BLUEGILL Lepomis macrochirus

C. Bauer Duke III
 Aquaculture and Fisheries Center
 University of Arkansas at Pine Bluff
 1200 North University Drive
 Pine Bluff, AR 71601
 dukeb@uapb.edu

Two identical aquaponics systems were designed to grow buttercrunch lettuce in a nutrient film technique (NFT) format placed in a greenhouse. Fish portions of the systems were stocked with equal biomass of either tilapia or bluegill. NFT portions of the design were constructed of plastic rain gutters with foam board covers. Holes were drilled in the covers sufficient to hold 5 cm diameter net pots in place. Rockwool was placed in the net pots and seeded with 1-2 lettuce seeds per pot. The plant portion of each system was composed of 6 gutter lines with 19 holes per line for a total of 114 net pots per system. Plant height was measured every 7 days and all heights summed for comparison between the two units. At the end of a trial, fish and plant total weights were recorded.

Three trials were completed. In one of the trials, fish species were switched between NFT systems. From trial to trial fish results were variable, but in each case, the Bluegill NFT system created taller lettuce, although in Trial 2 case the overall mass was greater with Tilapia.

These trials suggest bluegill are as productive as tilapia in aquaponics systems and may reduce problems with thermal requirements and non-native species aspects of raising tilapia.