Two major microalgal blooms have occurred in Biscayne Bay in recent years (2005-2008 and 2013) and although the first was well noted, the considerable ad hoc observations about the second bloom have not been compiled or integrated with information from the first. Neither of these blooms been examined in relation to each other or the historical record. In fact, little has been recorded about the usual microalgal flora of Biscayne Bay, the bloom participants, and the ecological implications of the population explosions. Chlorophyll a measured during the first observed event, which occurred in the southernmost part of the bay, was contrasted with chlorophyll a reported from Florida Bay at about the same time. Especially in its southern part, Biscayne Bay is a classic shallow, seagrass dominated, oligotrophic bay, despite the fact that canals draining agricultural areas in both the upper and lower parts of its watershed empty into it. That excessive nutrients can stimulate blooms was noted when maximum nitrate and phosphate concentrations increased 7 to 10 fold respectively at the mouth of the Mowry Canal in association with the passage of Hurricane Katrina. Nutrient levels increased baywide after Katrina, but decreased to normal within three months; suggesting processes were operating to prevent eutrophy. We propose to combine available information about the two recent events, available historical data, and new data to be obtained from opportunistic sampling to provide an overview of the microalgal communities in Biscayne Bay, their dynamics, and their ecological implications. Community descriptions will emphasize the western nearshore bay, site of a long-term monitoring project by Browder and others that includes salinity, submerged aquatic vegetation, the epifauna, and reeffish sheltering in mangroves. Planned microalgal work will help to build a view of the foodweb base. This nearshore study area will be one of the first areas affected by structural and operational modifications to the massive regional water management system under the Comprehensive Everglades Restoration Plan (CERP). Proposed work will support and complement ongoing monitoring to assess the effects of CERP as it is implemented.

References

Zhang JZ, Kelble CR, Fischer CJ, Moore L: Coastal and Shelf Science 84: 209, 2009

Boyer JN, Kelble CR, Ortner PB, Rudnick DT: Ecological Indicators 9: 556, 2009