Pat Glibert - SMSP Fall Seminar Series 2025

"Red tides in Florida: Climate shifts, anthropogenic effects, and previously unexplored nutrient sources"

Pat Glibert
University of Maryland Center for Environmental Science - Horn Point
November 7, 2025, at 12:00 PM
Cannon 202 + via Zoom in Robinson 202
Hosted by Nicholas Ray

Abstract: Blooms of the toxigenic dinoflagellate Karenia brevis are an almost annual occurrence in the eastern Gulf of Mexico, typically initiating in late summer and early fall months and terminating in late spring or earlier. The question of whether blooms have been expanding in frequency or duration has long been debated. Reliable, long-term data on bloom severity and duration have been recorded since at least the 1970s, and these decades have seen major climatic shifts as well as increasing anthropogenic pressures. Annual bloom severity has indeed increased with increasing temperatures, and blooms have also become longer in duration in relation to increased temperatures and river flows as well as increasing population since the mid 1990s. Even though nutrient loads have been inferred from such relationships, the questions of nutrient sources supporting these blooms are not fully answered. Blooms typically initiate with the wet season, bringing inorganic nutrients, but they may be sustained by a diversity of sources. In addition to mixotrophy, inorganic nutrients are retained in the coastal waters and recycled via various pathways, keeping the bloom nourished for months. Submarine groundwater sources, including blue holes which are underwater sink holes, have recently been identified as another important mechanism by which nutrients may be made available. Stable isotope data as well as molecular data support that these features may be hot spots for nutrients and for a diversity of Karenia species. 

Zoom Recording ID: 95312472245 UUID: +ZS6QDA8RdilZn8/fqpgtw== Meeting Time: 2025-11-07 04:44:42pmGMT