Black sea bass fisheries in the Middle Atlantic have traditionally used fish traps without escape vents that required sorting the catch by size after hauling the trap. The need to reduce discard mortality and increase the yield per recruit in sea bass fisheries prompted an investigation into the effectiveness of escape vents in the traps. An array of experimental traps using one of four escape vents openings (sizes of 2.86 cm×14.6 cm, 3.18 cm×14.6 cm, 3.49 cm×14.6 cm, or 3.81 cm×14.6 cm) was fished from May to November 1994. Use of escape vents significantly (p