Seed size at planting is the dominant factor affecting hard clam survival to marketable size when field grow-out techniques are used. The use of plastic mesh nets, crab traps, and wire mesh bags (filled with oyster shells) alone or in combination can be used to increase survival of hard clams of ~ 6 to 8-mm shell height. These techniques do not provide sufficient protection for 2-mm seed. The combination of net + crab trap + shell bag was nearly twice as effective as the net alone when 10 to 14-mm seed was used and over five times as effective as the net alone when 6 to 8-mm seed were planted. Survival in excess of 50% slows the growth rate and yields higher percentages of submarketable, \u3c 25-mm thick (New York legal limit) clams. Local markets and dealers would accept all clams \u3e22 mm
