Executive Director and Waterkeeper, Rachel Silverstein, provided a keynote address for Sierra Club Miami at their "Saving Seagrass" event at the Sacred Space Miami. Rachel discussed the state of seagrass in Miami as well as the Miami-Dade County Report on the ongoing seagrass die-off in Biscayne Bay.
Biscayne Bay is home to many ecologically important habitats, including seagrass. Seagrasses provide a host of benefits to the ecosystem, both directly and indirectly benefitting humans. They provide habitat and shelter for juvenile species of recreationally and commercially important fish. Both recreational and commercial fishers make their living on Biscayne Bay collecting species such as baitfish, stone crab, blue crab, shrimp, and lobster. Seagrasses support the diving industry in South Florida by providing habitat to juvenile fish that colonize reefs later in their development. Seagrasses enhance shoreline protection and prevent erosion by stabilizing sediments with their roots. In addition to this, they absorb nutrients. They attenuate wave energy from storms as well. Seagrasses help maintain water quality and clarity and are also a food source to several different species.
The bay has been experiencing seagrass die-offs, several of which have occurred in the last decade. Miami-Dade County has monitoring programs for bay water quality and bay habitat. The seagrass losses that occurred in the last decade are associated with three regions in the bay. These regions include: the Barnes Sound and Manatee Bay regions experienced a 93% decrease in seagrass; the central portion of the bay near Coral Gables saw a decrease in seagrass of approximately 85%; and the basins north of the Rickenbacker Causeway saw a decrease in seagrass of approximately 66% - 89%.
A study of the County's water quality and seagrass survey data indicates that chronic, nutrient loading is likely linked to seagrass loss in Biscayne Bay. Excess nutrients can lead to a shift from a seagrass-dominated habitat with clear water, low turbidity, and low levels of algae in the water column, to an algae-based ecosystem that is turbid and contains reduced fisheries habitat.
The County's recommendations to combat this issue include: maintaining and improving the county's water quality and habitat monitoring programs; maintaining and improving the county's bay habitat restoration program activities; maintaining the county's support for state and federal regional restoration programs; ensuring the county's coastal construction and regulatory program adequately protects existing bay resources; and improving public awareness through outreach.
Read the full report here!