Da. Moroney et Rl. Walker, The effects of tidal and bottom placement on the growth, survival and fouling of the eastern oyster Crassostrea virginica, J WORLD A C, 30(4), 1999, pp. 433-442
Oysters Crassostrea virginica in Georgia are naturally small and grow in cl
usters; however, it is more profitable to harvest large, single oysters. Th
is study attempts to identify favorable tidal and bottom placements for the
grow-out of large, single oysters in Georgia. Three bags, each containing
50 single oysters, were placed in four different tidal positions (subtidal
on-bottom, subtidal off-bottom, intertidal on-bottom and intertidal off-bot
tom) at five sites in House Creek, Georgia. Measurements of oyster growth,
survival and degree of oyster spat fouling were taken seasonally (every 3 m
o). Oysters from on-bottom treatments exhibited significantly lower growth
(P = 0.0364 intertidal only), survival (P = 0.0044) and degree of fouling (
P = 0.0154) than oysters from the intertidal off-bottom treatment. However,
the oysters placed intertidally off-bottom were heavily fouled during the
recruitment period. It may be necessary to sacrifice some growth and surviv
al by culturing oysters intertidally on-bottom during the recruitment perio
d in order to reduce the degree of fouling. During the non-recruitment peri
od, placing oyster culture bags intertidally off-bottom maximizes growth an
d survival.