Reversing the Tide of Habitat Loss

Charting

Reversing the Tide of Habitat Loss

As a clear water subtropical estuary, the bay supports rich ecological communities and a diverse variety of fish and wildlife. Specific habitat is provided for each species that lives in the bay, including species that migrate in and out of the bay daily or seasonally. If habitat for these communities becomes unsuitable or disappears, the animals lose their home and humans lose the benefits of their presence. Coastal wetland habitat and benthic habitat, including seagrasses, are of the greatest importance to aquatic life. Intertidal habitat and adjacent upland habitat, including coastal scrub and coastal tropical hardwood hammock, are critical to the entire bay ecosystem and are impacted by changes to watershed hydrology and development.

The benthic communities of the bay act to maintain water clarity, stabilize sediments, and provide food and shelter for fish, shrimp, lobster, crab, and many 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 from their absence can prevent their reestablishment. Over 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. Bulkheaded shorelines, which deflect waves and boat wakes and cause resuspension 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, but 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 impacted by the construction of 19 water management canals throughout the region 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 fluctuat-ing salinity regimes adjacent to canals, and loss of estuarine habitat elsewhere. Diversion of freshwater flow away from coastal wetlands degrades their ability to support wildlife, fish communities, and the bay ecosystem by preventing the establishment of 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 would prevent restoration of more natural timing and distribution of freshwater flow to the bay. Restoration of coastal wetlands is key to restoring estuarine habitat and estuarine fish commu-nities and wildlife in Biscayne Bay.

Key actions

? The Florida Legislature should provide funding to support the continuation of major habitat restoration projects and the 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, particu-larly 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 accelerate identification of any additional lands needed to provide these functions.

? 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.