Retention and Escapement Characteristics of Pound Nets as a Function of Pound-Head Mesh Size

Abstract

Pound nets have frequently been blamed for the destruction of large quantities of undersized and immature fishes termed “scrap-fish,” which include commercially and recreationally important species. Capture of these small fishes is facilitated by the 51-mm stretched mesh size commonly used in the entrapment portion, or pound-head, of the net. Series of five major fish species in the scrap landings of the lower Chesapeake Bay were used to derive theoretical and experimental 50% retention lengths, plus gilling frequencies in experimental pound-heads with stretched mesh sizes ranging from 38 mm to 76 mm in 6.4-mm increments. Significant gilling in stretched mesh sizes of 57 mm and larger lead to the conclusion that 51-mm stretched mesh in pound-heads is a necessary though wasteful compromise. However, an escape panel of larger mesh size, located in the pound-head, would allow escapement of small sciaenids while retaining clupeids which are utilized as bait in the blue crab fishery. In situ mesh size measurements are necessary when determining selectivity characteristics of a particular pound-head.