Box 5: Understanding the origins of profound biological changes at one site will require understanding similar or related changes at the regional level.


In what may be a system that mirrors the broad range of human alterations to estuaries, there is disturbing evidence that the Florida Bay ecosystem is collapsing. Florida Bay (2,200 km2), and the adjacent Florida Keys, is the only tropical marine ecosystem in the continental United States, with a vast economic value for the state of Florida. Florida Bay and the coral reef tracts of the Keys are connected by coastal currents, and thus the Bay may have a critical influence on the reefs. Likewise, alterations to land runoff and freshwater systems can affect Bay waters.

  • In 1987, seagrasses began to die and this has affected over 18 percent of the Bay as of 1993.
  • Because algal blooms have increased, large areas of the Bay are now subjected to bloom conditions, and these have spread to the coral reefs of the Keys.
  • Populations of water birds, forage fish, and juvenile gamefish are significantly reduced in eastern Florida Bay where freshwater inflow from the Everglades has been reduced and hypersalinity results.
  • Catches in the Dry Tortugas of commercially valuable pink shrimp, which spend their juvenile stages in Florida Bay, have declined considerably. Large sponges, important for spiny lobster habitat, have also declined.

There is considerable scientific debate over the causes of collapse, and thus of the potential for recovery, or the steps that are necessary to implement and facilitate recovery. Whereas some of these changes could be considered as only "local" effects, it is important to view this ecosystem collapse in terms of broader changes in the Caribbean marine and terrestrial ecosystems. A more narrow focus on only Florida Bay may be doomed to failure. An important further lesson of the Florida Bay situation is that the water systems on land that impact the Bay, and in turn the Keys offshore, also must be understood and managed.


Key References: Robblee et al., (1991); Porter and Meier (1992); Boesch et al., (1993); Ogden et al., (1994).

is designed to accommodate studies at all scales relevant to a specified biodiversity research project.

A Rationale for Studying Several Types of Regional Model Systems

Three biological rationales suggest the need to use a regional-scale approach to study, concurrently, a variety of different types of marine ecosystems.

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