(1) Determine infective /total particle ratio in fresh human stool for G1. 1 and GII.4 stool samples using the PGM-MB/RT-PCR. Determine infective /total norovirus particles in wastewater treatment (WWT) and lagoon influent and effluent. Evaluate the effect of chlorination, and UV as used in WWT. (2) Evaluate impact of bio accumulation on infective/total particle ratio in oyster as compared to harvest water. Evaluate the effect of sunlight and other environmental conditions on viability of norovirus. (3) In conjunction with objectives 1 and 2, the effect of WWT/oyster bioaccumulation and environmental conditions will be evaluated on male-specific coliphage. Quantitative measures of the number of male-specific MS2 (phage MS2) particles by qRT-PCR and conventional culture techniques. Phage MS2 is an enteric viral surrogate for human norovirus.