PRELIMINARY RECRUITMENT STUDIES OF THE EASTERN OYSTER, CRASSOSTREA-VIRGINICA, AND THEIR POTENTIAL APPLICATIONS, IN COASTAL GEORGIA

Oyster recruitment was monitored in Wassaw Sound, Georgia from April t hrough October, 1991. The study was initiated to determine precise rec ruitment patterns of oysters over the 7 month spawning season. One of the goals was to determine the most suitable time for the collection o f natural spat for maricultural, fisheries and recreational purposes. Three sites of varying hydrographic characteristics were chosen in Was saw Sound, The sites varied in terms of temperature and salinity regim es and in their exposure to wind and wave action. Within each site, oy ster recruitment was estimated at three tidal heights; subtidally, at mean low water and intertidally, approximately 2 h above the mean low water mark. Sampling took place so as to measure net recruitment over biweekly (BW), monthly (M) and seasonal (S) periods. The results indic ated that the recruitment of oysters in this region of coastal Georgia is protracted, lasting 6 months (May through October). The levels of recruitment were very high relative to other regions on the east coast of the USA, with peak recruitment for the entire study area ((x) over bar = 2800 spat m(-2) for BW and (x) over bar = 3020 spat m(-2) for M ) occurring between July and September. The intensity of recruitment v aried significantly among the three sites. The most sheltered site in terms of wave exposure experienced the highest recruitment ((x) over b ar = 4380 spat m(-2) BW; (x) over bar = 6260 spat m(-2) M). This site also had higher overall water temperatures as well as greater daily te mperature fluctuations. The least sheltered site had the lowest number s of young oysters ((x) over bar = 1000 spat m(-2) BW; (x) over bar = 686 spat m(-2) M), as well as having the most stable temperature regim e. The biweekly samples generally experienced higher recruitment subti dally at the three sites. The monthly samples had higher numbers of oy ster spat at the mean low water mark while the seasonal samples showed significantly higher recruitment intertidally (up to (x) over bar = 7 353 spat m(-2)). The shift in recruitment patterns over time is partia lly attributed to increased subtidal predation pressure on the recruit s. The collection of natural spat in relation to the natural fishery, potential maricultural activity and the recreational fishery is discus sed.