One important step in this process is the sorting or grading of live fish. Grading allows the producer to maximize profits when prices vary with fish size.
Large fish mixed with smaller ones can affect the appearance of a shipment of fish.
Smaller fish may appear less attractive, and the shipment may be considered of poor quality. Fish should be graded for economic reasons either to increase the value of the crop, to increase fish yields or both. In some markets and production systems, however, there are no advantages to grading fish. Many methods and types of equipment can be used successfully to grade fish. Sorting can be accomplished in ponds, holding vats, tanks and raceways.