TIME-TEMPERATURE EFFECTS ON BACTERIOLOGICAL QUALITY OF STORED SHELLFISH .I. BACTERIOLOGICAL CHANGES IN LIVE SHELL FISH - PACIFIC OYSTERS (CRASSOSTREA GIGAS) OLYMPIA OYSTERS (OSTREA LURIDA) NATIVE LITTLENECK CLAMS (PROTOTHACA STAMINEA) AND MANILA CLAMS (VENERUPIS JAPONICA)