Alaska Department of Fish and Game FAQs: Oysters can grow very well in cold water if there is abundant, high-quality plankton. Many estuaries in Alaska produce so much high-quality plankton during certain times of the year that Alaska shellfish can match growth achieved by shellfish raised in warmer waters of the Pacific Northwest. Cold, clean water also reduces bacterial contamination, extending shelf life and assuring safety when eating cultured oysters, especially when consumed raw.