Off-flavor in pond-cultured marine shrimp

Off-flavor is common in fish, but also occurs in penaeid shrimp. Off-flavor compounds are soluble in lipid and tend to concentrate in shrimp heads. Thus, off-flavor usually is not a major concern unless shrimp enter the "heads-on" market. As in fish, the main cause of off-flavor in shrimp is compounds produced by blue-green algae (cyanobacteria). Blue-green algae can be expected in shrimp ponds when salinity of water is below 5 or 10 parts per thousand (ppt). Shrimp fanning has extended into low-satinity areas and into inland areas where salinities of 2 to 5 ppt are achieved by mixing saline well water or brine solution with freshwater. Blue-green algae can be as troublesome in inland shrimp ponds as in freshwater fishponds. Where salinity is higher, filamentous blue-green algae may be a major component of benthic algal communities ("lab-lab") which may occur on bottoms of ponds with shallow or clear water. Procedures for controlling off-flavor in shrimp have not been developed. The usual response is to flush water through ponds in an attempt to remove blue-green algae.