Document Type



Virginia Institute of Marine Science

Publication Date



Marine Resources Special Report


The Virginia Institute of Marine Science (VIMS) conducts annual surveys of oyster spatfall ( or "") in Virginia waters. This survey provides an estimate of the potential of a particular area for receiving a "striken or set of oysters and helps define the timiug of setting events. In 1988 spatfall was monitored from June 6 to October 16 at a total of forty-two stations (Figure 1). · During this period shellstrings were deployed at each station (0.5m off the bottom) on a weekly basis. A shellstring consists of 12 oyster shells drilled through the center and strung on a piece of wire. The number of spat that settle on the smooth surface (underside) of the center 10 shells was counted with the aid of a dissecting microscope. This number was then divided by 10 to get the number of spat per shell for that time interval. A computer program was used to calculate the number of spat per shell per week. These values were evaluated as follows: 0, none; 0.1-1.0, fair; 1.1 - 10.0, moderate; 10.1 - 100, heavy. Frequent sampling allowed setting trends to be compared over the course of the summer between the various locations. By adding the weekly values of spat per shell for the entire setting season, comparisons were made between years.



Oyster fisheries--Chesapeake Bay (Va.), Oyster--Monitoring, Oyster fisheries--Virginia, Oysters--Chesapeake Bay (Va.)