"Man and the Gulf of Mexico (MGM)" is a marine science curriculum developed to meet the marine science needs of tenth through twelfth grade students in Mississippi and Alabama schools. This MGM unit, which focuses on marine and estuarine ecology, is divided into six sections. The first section contains unit objectives, discussions of the estuarine ecosystem and reasons for classifying organisms, and an activity on using a taxonomic key. The next five sections focus on: (1) plankton; (2) nekton; (3) intertidal organisms and their environment; (4) coastal habitats; and (5) coastal ecology. Each section includes a statement of concept(s) to be learned, objectives, vocabulary activities, vocabulary lists, and (with the exception of the section on nekton) one or more science activities. Objectives, procedures, and list of materials needed are provided for these activities which investigate: plankton bodies; osmosis; snails; population pressures and succession in a laboratory community; relationship of habitat to survival of an organism; diversity of organisms in an aquatic habitat; and the best use for a marsh beach. Activities involving the construction of a plankton net and an artificial ecological system are also included. (JN)