Update from Miami-Dade County regarding its response to recent events in Biscayne Bay

Miami-Dade County staff scientists continue to investigate the recent algal bloom event in Biscayne Bay and are conducting inspections, as well as obtaining water quality samples. An evaluation of the main drivers of this event is based on an analysis of recent water quality results, historical water quality data and other potential contributors, such as inputs from canals.

For over the past two weeks, County staff have been in the field conducting a comprehensive water quality investigation to identify the factors that may have led to both the fish kill primarily within the Julia Tuttle basin as well as the algal bloom that is occurring mostly north of the 79th Street Causeway. Staff scientists will continue to collect water quality data going forward, weather permitting with Tropical Storm Laura. And while the County is committed to fully investigating the main drivers of both the fish kill and algal bloom specifically, including whether the two events are linked, the County remains focused on understanding the many variables that impact the health of the bay and identifying and working to eliminate the sources of those impacts. Staff scientists will continue to collaborate with agency and academic partners to evaluate the data.

It is important to note that based upon present conditions in this portion of the bay, particularly during the warm and rainy summer months, further events such as these may continue to occur in the near term, and that it will likely take some time for this portion of the bay and its complex ecology to stabilize and return to more favorable conditions. 

Biscayne Bay is a complex ecosystem that has experienced a decline in seagrasses in north Biscayne Bay linked to chronic as well as short-term pulses of water that can carry an excess of nutrients and other pollutants that can impact water quality. These pressures on the ecosystem, combined with recent ambient conditions such as high water temperatures, lower tides, and lower dissolved oxygen available in the water column, contribute to the conditions that can lead to both fish kills and algal blooms.

Identifying the specific sources of water quality impacts that lead to these events and implementing the changes that are needed to address them will also take some time. However, the County believes this can be achieved through working with municipal and state partners and with the cooperation of the community as a whole, and together, do all that can be done to protect our bay.

The public is asked to report any environmental concerns or complaints to the Division of Environmental Resources Management's (DERM) hotline at 305-372-6955 or [email protected].