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

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

Report to the York River Oyster Research Corporation on the physiological response of oysters to several polymeric materials and their derivatives

The physiological responses of several polymeric materials and their derivatives, associated with the manufacturing process of pulp, were tested on oysters. It was thought that, when fed in small quantities, these substances might increase shell or meat size or be of value as possible nutritive supplements . The substances tested were divided into two classes. The first, consisting of basic polymeric materials, may occur in natural water s as the result of chemical changes. Representatives of these were indulin C and dextrose. The second class is composed of chemically pure derivatives of the preceding substances. These may appear in trace amounts in natural waters and represent breakdown products of the lignin and carbohydrate substances similar to indulin C and to dextrose. Representatives of this group tested in the following study were glycolic acid, lactic acid, vanillin and catechol

Survey of cultchless spat planted by the VMRC in Nomini and lower Machodoc Creek

As part of a major repletion activity by the VMRC, cultchless spat were planted in Lower Machodoc Creek and Nomini Creek in October and November 1973. The Virginia Institute of Marine Science surveyed these plantings on 10 and 11 December, 1973. The areas planted and surveyed are shown in figures 1 and 2. In Lower Machodoc Creek, 5.35 acres were planted with 240.5 bushels of cultchless spat during October, 1973. Within this area, five sub-areas were seeded, each with about one million spat. In Nomini Creek there were two planting areas. The largest was located in Nomini Cut, and seven one acre sub-areas were delimited here; each receiving about one million spat. One area (15) was planted up-river from Nomini Cut

Weekly Oyster Spatfall Reports 1969

Data sheets for stations monitored weekly in the Great Wicomico, James, York, Rappahannock, Nansemond and Piankatank Rivers. Monitoring starting and end dates vary at the river sites