In the past decade seagrass die-offs, algal blooms, and declining numbers of shellfish and sponges have occurred in Florida Bay. These changes have been attributed to human activities; however, neither the natural patterns of change, nor the pre-human baseline for the environment have been determined. Currently, efforts are underway to restore the Everglades ecosystem to a more natural state, but the restoration should be guided by a clear understanding of the natural range of variability that exists within the ecosystem.