Virginia Institute of Marine Science
Marine Advisory Program (MAP)
Fishery Resource Grant FRG 2012- 01
Setting for spat on shell typically beings when water temperatures reach about 20° C. This optimal temperature is normally reached in Virginia's climate by May. Setting spat on shell is completed by September; this gives the spat just enough time to grow before the cold of winter puts them in hibernation. Hatcheries start spawning oysters as early as February. By heating the water and adding food they can successfully produce millions of larvae during the cold winter months. When the ambient water temperature rises it brings more food but in many cases poor water conditions. Unfortunately, in the heat of summer such as August, sometimes hatcheries are unable to produce masses of larvae. If the setting season and availability of oysters from hatcheries time frame can coincide there would be more larvae to set. This would also extend the Growth season for spat by at least a month.
Ruark, R. H. (2012) Early Spat on Shell Setting. Fishery Resource Grant FRG 2012- 01. Virginia Institute of Marine Science, William & Mary. https://scholarworks.wm.edu/reports/2185