Blooms of the picoplanktonic cyanobacterium Synechococcus in Florida Bay, a subtropical inner‐shelf lagoon

Abstract

Seventeen sites in Florida Bay were sampled on a monthly basis for 51 months to describe the spatial and temporal patterns of phytoplankton blooms. The study focused on the picoplanktonic cyanobacterium Synechococcus. The greatest frequency and intensity of blooms was observed in the north‐central region of Florida Bay, where cellular biovolumes of this species regularly exceeded 10 × 106μm3 ml−1 and chlorophyll a concentrations were frequently >20 mg m−3. Synechococcus blooms were often restricted to this region of the bay, in part because of the network of shallow mudbanks and islands that restrict water exchange with other regions and outlying waters of the Atlantic Ocean and Gulf of Mexico. The most severe blooms occurred in the summer and fall (May–December). High concentrations of Synechococcus also appeared during the fall in the south‐central region of the bay. The appearance of blooms in this region coincided with the onset of seasonal cold fronts, whose strong northerly and northwesterly winds appear to drive bloom‐laden water from the north‐central region into adjacent parts of the bay. A number of physical and chemical factors appear to contribute to the remarkably high phytoplankton biovolumes observed in the north‐central region of Florida Bay. Physical factors include the shallowness and hydrological isolation of the region. The dominance of Synechococcus in the center of the bay may be attributable to several of the unique physicochemical characteristics of this species, including its small size, cyanobacterial metabolism, euryhaline character, buoyancy, and tolerance to high light intensity.

Evidence for dissolved organic nitrogen and phosphorus uptake during a cyanobacterial bloom in Florida Bay

“…blooms in Florida Bay in the fall in the north central region (e.g. Phlips et al 1999). Such blooms have been hypothesized to be related to the hydrography of the area, its shallow depth and enhanced internal nutrient cycling, as well as to seasonal winds.…”

“…The central region of Florida Bay has experienced frequent microalgal blooms in the past decade (Phlips & Babylak 1996, Hitchcock et al 1998, Phlips et al 1999, typically dominated by the cyanobacterium genus Synechococcus (Phlips & Babylak 1996, Phlips et al 1999. The relationship between such blooms and potential eutrophication originating from the Everglades watershed has been the topic of much debate (e.g.…”

“…Longterm management plans for the Southern Florida area call for restoration of the natural flow conditions within the Everglades. Thus the key questions of concern to both scientists and ecosystem managers are to what extent do nutrients originating from the Everglades contribute to eutrophication in Florida Bay, and what are the greatest impacts of these nutrients?The central region of Florida Bay has experienced frequent microalgal blooms in the past decade (Phlips & Babylak 1996, Hitchcock et al 1998, Phlips et al 1999, typically dominated by the cyanobacterium genus Synechococcus (Phlips & Babylak 1996, Phlips et al 1999. The relationship between such blooms and potential eutrophication originating from the Everglades watershed has been the topic of much debate (e.g.…”

“…Such blooms have been hypothesized to be related to the hydrography of the area, its shallow depth and enhanced internal nutrient cycling, as well as to seasonal winds. In particular, fall cold-fronts may be responsible for shifting the prevailing wind direction from east/southeast to northeast (Phlips et al 1999), which may bring water from the north into the more central region, in turn leading to increased resuspension and nutrient flux. Other environmental characteristics of this sampling period are also consistent with long-term data sets The data reported here add to the growing body of evidence that algae can and do take up DON and DOP, and that uptake of these organic fractions contributes disproportionately to different algae groups.…”

Regional characterisation of hard‐bottom nursery habitat for juvenile Caribbean spiny lobster(Panulirus argus)using rapid assessment techniques

“…Impacts on the abundance of lobster have been documented on hard-bottom areas in Florida affected by siltation (Herrnkind et al 1988). Declining water quality and harmful algal blooms are the suspected culprits that have triggered massive die-offs of sponges in the Florida Keys and the wholesale reconfiguration of impacted hard-bottom areas (Butler et al 1995;Phlips et al 1999). Commercial fishing of sponges removes approximately 7 million sponges from shallow hard-bottom habitat in the Florida Keys each year (Witzel 1999) with unknown consequences, but the indirect effects of other fishing activities may be more severe.…”