The most popular fish grown in aquaponic systems are tilapia. Tilapias are a robust fish that do extremely well in recirculating systems. Many states have restrictions on the culture of tilapia as they are non-native fish and resource agencies do not want the fish established in natural waters if they were to escape aquaculture systems. California, for example, has restrictions on where tilapia may be cultured in the state, and most tilapia culture is restricted to southern California in counties located south of the Tehachapi mountain range that separates southern California from the Great Central Valley. The State’s resource agency originally stocked tilapia in southern California as they once believed that the fish could not reproduce, or even survive the cool winter temperatures. Tilapia not only survived, but successfully reproduced, even in the high salinity inland Salton Sea. The restrictions are in place now to prevent tilapia from being introduced in the watersheds north of the Tehachapi mountain range. Source: California Aquaculture
Currently, tilapia zilli, tilapia hornorum, and mossambica are the only species of tilapia allowed to be cultured in California and they are allowed only in the following counties: Riverside, Los Angeles, Orange, San Bernardino, San Diego, and Imperial. Please note that you must first obtain a Restricted Species Permit to possess, import, and transport tilapia zilli. Please contact the DFG License and Revenue Branch at (916) 928-5845 for more information on obtaining a Restricted Species Permit.
If you live in one of the counties listed above and plan to raise tilapia in an aquaculture or aquaponics system for commercial purposes then you must register as an aquaculturist with the Department of Fish and Game. Please see the Aquaculture Registration Application Form. Also attached is DFG Informational Leaflet No. 35 – Aquaculture in Inland Waters of California, which contains the existing laws and regulations governing aquaculture in California. You can find these documents and more information on aquaculture in California on the DFG Aquaculture webpage at: http://www.dfg.ca.gov/Aquaculture/