Weekly Oyster Spatfall Reports 1971

Data sheets for stations monitored weekly in the following locations: Dyer Creek East River Great Wicomico Horn Harbor James River Nansemond North River Pepper Creek Piankatank River Potomac Rappahannock Stutts Creek Winter Harbor York River Monitoring starting and end dates vary at the river sites in the June - September period

Levels of the herbicide Diquat in two estuarine molluscs and in the water and mud

Soft clams Mya arenaria and oysters Crassostrea virginica were exposed to 0.35 ppm of the herbicide Diquat during June and July 1967 in Nomini Creek Virginia, a tributary of the Potomac. No detectable residue was found in oyster meats or in the water. Meats of soft clams minus the rough integument surrounding the neck, showed no Diquat. The integument, however, contained from 0.00 to 0.05 ppm. Mud samples contained from 1.17 to 7 .14 ppm. It was assumed that Diquat was strongly sorbed on clay particles in sediments; residues in clam integuments were due to trapped clay particles

A study of the hard and soft clam resources of Virginia : annual contract report for the period 1 July 1969 through 30 June 1970, Contract no. 3-77-R-1

The fallowing report contains results of our studies from 1 July 1969 through 30 June-1970. Included in this report is a complete summary of all studies related to soft clams. This includes growth rates, recruitment studies, distribution of juveniles, and effects of the dredge on the substrate and on adjacent bottoms. Hard clam studies reported in this report include studies on growth, recruitment, distribution of young, and effects of .the escalator on the bottom

The Impact of Low Salinities on James River Oyster Populations 1979-1980

During the fall, winter and spring of 1979-1980 there was an extensive and prolonged mortality of the 1979 se•t of oysters in the James River, Virginia. Yearling oysters died at lesser rates, with mortalities starting in mid-winter. Small oysters showed moderate to 100% mortalities at two locations. Market-sized oysters showed the lowest mortality. Deaths were associated with prolonged periods of low salinity