Condition of the Natural Resources of Biscayne National Park; A State of the Parks Technical Report

Robles; Armentano, T; DiResta, D; Lara, M.R.; Jones, D.L.; Butler, M.J.; NatureServe

Biscayne National Park (N.P.), located in the heart of a shallow sub-tropical lagoon in south Florida known as Biscayne Bay, embodies the greatest aspirations and deepest challenges faced by the National Park Service. On the one band, the 173,000-acre park- the largest marine park in the United States-represents a bold attempt to preserve an ecosystem that is unique in America. Biscayne N.P. protects the northernmost extent of the third-longest chain of coral reefs in the world, contains the longest patch of coastal mangroves left in eastern Florida, and harbors a diverse array of marine and tropical fauna and flora, including commercially and recreationally important fish, crustaceans and shellfish, and many rare and endemic species. On the other band, Biscayne N.P. is bordered by Miami, a rapidly-growing city that anchors the sixth-largest metropolitan area in the United States, with more than five million people. Urban, industrial, and agricultural land uses in south Florida have given rise to a wide array of threats to the park's natural resources. Because the ecological health of the park-95% of which is water-depends upon the natural flow of freshwater into Biscayne Bay, the chief threats to these resources are: I) drainage, dredging, and water diversion projects that have altered the timing, distribution and quantity of freshwater inputs into the bay, and 2) habitat loss and disturbance to the coastal wetlands that these waters once flowed through. These changes have transformed the estuary from a system characterized by periodic and pulsed inputs of freshwater from surface waters, overland sheet flow, and more gradual, diffuse groundwater flows, into an artificially pulsed system that is driven by freshwater inputs from man-made canals. In this report, we assess the condition of Biscayne Bay's natural resources using the methodology developed by the National Parks Conservation Association (NPCA) for its State of the Parks Program. This technical report will inform NPCA's State of the Park Report for Biscayne N.P. It should be read together with NatureServe's related report on Florida Bay, an adjacent body of water. Our assessment consists primarily of a thorough review and summary of existing published scienti fie research, supplemented by expert input from natural resource professionals and scientists familiar with the issues affecting Biscayne Bay. For each of several key natural resources, we review its current condition within a historic context, describe its role and importance within the bay ecosystem, summarize the threats to the resource, and consider opportunities for restoration and management. In this report, we document the extent to which the natural resources of Biscayne N.P. are showing signs of ecological stress and the degree to which this stress is caused by natural versus anthropogenic (i.e. human-caused) forces. Below we highlight key findings related to water resources, terrestrial ecosystems, marine ecosystems, and marine species.