A subtropical estuary* of clear waters, the bay supports rich ecological communities and a diverse variety of fish and wildlife. Specific habitat is provided for each species living in the bay, including species that migrate in and out of the bay daily or seasonally. If their habitat becomes unsuitable or disappears, animals and plants lose their home and people lose the benefits of their presence.
Coastal wetland habitat and benthic** habitat, including seagrasses, are most important to aquatic life. Intertidal habitat and adjacent upland areas, including coastal scrub and tropical hardwood hammock, are also critical to the bay ecosystem and are affected by changes to watershed hydrology and development.
The benthic communities of the bay help maintain water clarity, stabilize sediments, and provide food and shelter for fish, shrimp, lobster, crab and other species — especially in sensitive early juvenile stages. When these communities are damaged or eliminated, they cannot serve these vital roles and the increased turbidity that results can prevent their return. More than 40 percent of the bottom area in north Biscayne Bay has been altered by spoil displacement and dredging; turbidity problems persist in the northern part of the bay partly as a result. Shoreline bulkheads, which deflect waves and boat wakes and cause re-suspension of bottom sediments, also contribute to turbidity problems in the northern bay, as does increasingly heavy boat traffic. Protection and restoration of vital benthic communities are needed.
In the past, freshwater and brackish marsh habitats bordered the bay’s western shoreline and barrier islands. Over the last century, the bay’s western shorelines and eastern barrier islands have undergone extensive loss of marsh and mangroves. The western bay was heavily affected by the construction of 19 water management canals that drained wetlands and now release water in pulses to prevent intermittent coastal flooding and facilitate agriculture. The result is a highly modified delivery of freshwater to the bay, rapidly fluctuating salinity regimes adjacent to canals, and loss of estuarine habitat.
Diversion of freshwater flow away from coastal wetlands degrades their ability to support wildlife and the bay ecosystem by preventing a natural estuarine salinity gradient from wetlands to the bay. Development of coastal wetlands and inappropriate development of adjacent uplands are other major threats to coastal wetlands that prevent restoration of more natural timing and distribution of freshwater flow to the bay. Restoration of coastal wetlands is key to restoring natural habitat and estuarine fish communities and wildlife in Biscayne Bay.
* An estuary is the wide part of a waterway where fresh water and salt water mix.
**Benthic refers to habitat on the bottom of a sea, lake or bay.
To help preserve and restore bay habitats, the Biscayne Bay Partnership Initiative has recommended these actions:
* The Florida legislature should provide funding to support continuation of major habitat restoration projects and development and implementation of a process for comprehensive planning and oversight of bay habitat restoration.
* Management of Biscayne Bay must focus on protecting and enhancing natural areas and open land, particularly in south Miami-Dade, as well as on restoring and improving environmental value and infrastructure in the built areas.
* The Florida legislature should provide adequate funding for acquisition of lands currently identified as important in providing protective buffer or water redistribution functions and should accelerate identification of additional lands needed for these functions. More about land acquisition.
* The Florida legislature should provide funding to mark channels, seagrass beds and coral areas and provide maintenance for markers and signage.
* The Biscayne Bay Aquatic Preserve Act is inviolate and should never be weakened.