Tomales Bay oysters infected with a norovirus prompted the California Department of Public Health to intervene early this month. On Jan. 4, the public health department shut down oyster harvesting and recalled a batch of oysters sold by Hog Island Oyster Company to a host of West Marin and Bay Area restaurants. The closure remains in effect, though the farm is open and selling product from other regions. Dr. Matt Willis, Marin County’s public health officer, said the virus…