The Maryland Marine Science Education Project has produced a series of mini-units in marine science education for the junior high/middle school classroom. This unit focuses on the American oyster. Although the unit specifically treats the Chesapeake Bay, it may be adapted for use with similar estuarine systems. In addition, the unit may be incorporated into existing life science courses using the Chesapeake Bay as a concrete example of working biological principles. The unit consists of sections devoted to content/background reading for the teacher, student activities, and resource materials. Topics in the teacher's narrative include background information on the Chesapeake Bay, nature/anatomy of oysters, oyster life cycle, oyster predators/parasites, oyster distribution and possible reasons for their decline, methods of oyster harvest in the Chesapeake, state oyster repletion program, and comments on oyster processing. Eight activities/games are included in the student activities section. These activities include graph interpretation, map reading, oyster classification, making oyster stew, and three vocabulary games (bingo, rummy, and a word search). An annotated list of resources for additional activities (including field trips), student/teacher references, and list of junior high/middle school science texts where the mini-unit may be incorporated are provided in the resource materials section. (Author/JN)