Growth and survival of the bay scallop, Argopecten irradians, at various locations in the water column and at various densities

Abstract

Two experiments were carried out in 1971 using bay scallops spawned in Aug and Sept of 1970. 4 groups of 150 scallops were held at the surface, 1 m below the surface, 2 m off the bottom, and 1 m off the bottom, to find the effects of depth on growth and survival. Scallops were held in surface enclosures at 4 different densities (100, 75, 50 and 25/ft super(2)) to find out the effects of crowding. In the depth experiment growth was approx equal throughout the water column. Mortality decreased with increasing depth with the exception of those held at 1 m off the bottom. In the density experiment growth up to a height of 27.0-28.0 mm (1.1 in) was approx equal at all densities. Above this size, growth decreased with increasing density. Mortality was low and approx equal at all densities for the first 2 months but increased with increasing density during the last 2 months.