Theft, vandalism, and fouling of cages can be serious problems. Outdoor raceway systems either require a constant flow of good quality water or, if water is recirculated, some sort of treatment process is required. Water may need to be circulated through acres of ponds before entering the raceway system again. Harvesting is facilitated in raceways, but skilled management is required for successful operation of a raceway system. Existing raceways operate only half the year due to low water temperatures during the winter months.
Proponents are quick to point out advantages but slow to mention the large number of failures.
While certain designs of recirculating systems are technically feasible and can produce fish, production costs generally are much higher in these systems than for pond culture. Presently, these systems are best suited for research purposes or for the production of certain high value crops, such as aquatic organisms for toxicity studies. Recirculating systems are a complex mix of biological and mechanical components and require highly skilled management. While recirculating systems may hold much promise for the future, additional research is required before these systems can compete economically with pond culture. They can also assist you with pond design and construction costs.