Ecosystem management is an integrated approach to managing Florida's biological and physical environments designed to maintain, protect, and improve the state's natural, managed, and human communities. This document contains activities designed for 4th-5th grade students that meet the guidelines of Florida's K-12 Science Framework to better acquaint students with Florida's natural systems and the wildlife that are dependent on these systems. The activities are based on Strand 7 of the Science Curriculum Framework "How Living Things Interact with the Environment." Activities are presented according to the following areas of focus: (1) individuals, populations, communities, and ecosystems are interrelated and interdependent; (2) the flow of energy and cycling of matter through biological systems links organisms to one another and to their physical setting; (3) limited resources create competition among organisms in ecosystems; (4) the environment plays a key role in selecting adaptations that ensure species variability and viability; and (5) human interaction may result in accelerated change in the environment leading to habitat loss or the creation of new habitats. Activities on the development of Bay Island and setting up and maintaining a marine aquarium are also included. (JRH)