However, the introduction of a non-native species, like the Japanese oyster, requires serious consideration. The potential consequences are unknown. Please follow the student lesson prior to your students so that you can learn more about the incredible, edible oyster. Fresh, unshucked oysters are available at most seafood markets and grocery stores. You may also want to have several shucked oysters available so that students can see the critter out of its shell.
Raw shellfish can carry bacteria.
An even better suggestion is to conduct the following experiment so that students can actually see the filtering capacity of the oyster. As they filter the water for food, the clarity improves steadily. If you use two aquariums, one will serve as a control for the demonstration. Obtain live oysters from a local seafood market or grocer. If you do not have access to a body of water that supports oysters, you may use stream or dechlorinated tap water mixed with sea salt to the correct salinity for oysters.