Relation of Catches of Postlarval Pink Shrimp in Everglades National Park, Florida, to the Commercial Catches on the Tortugas Grounds

Postlarval pink shrimp (Penaeus duorarum) were sampled at Buttonwood Canal and Little Shark River, Everglades National Park, Florida, from July 1965 to December 1967. These samples were used to measure the effects of environmental factors on the catches of postlarvae, and to compare catches of immigrating postlarvae with commercial catches of pink shrimp on the Tortugas Grounds.

Postlarvae were more numerous in night samples than in daylight samples. More were caught during flood tides than during ebb tides. Bottom samples produced more shrimp than surface samples. In Little Shark River a lunar periodicity was indicated by larger catches during new and first quarter lunar periods. Summer catches were highest.

The catch of postlarvae per cubic meter of water filtered during the night flood tide on new and full moons was chosen as an index of abundance, to predict the catches of 68-and-over-count (smallest sizes) shrimp landed per boat-night from the Tortugas Grounds in water less than 15 fathoms deep. With the catches of postlarvae from Buttonwood Canal and Little Shark River we could predict 61 per cent of the monthly variation in commercial catches for the 17 months examined.