The prevailing hypothesis for karenia brevis bloom initiation and development focuses on initiation in offshore oligotrophic shelf waters, followed by transport shoreward to nutrientenriched,…

The National Oceanic and Atmospheric Administration awarded Mote Marine Laboratory, Inc. a $1,371,372 cooperative agreement on June 1, 2026, under the Center for Sponsored Coastal Ocean Research Competitive Research Program (CFDA 11.478) to identify and characterize Karenia brevis source and seed populations in coastal waters.

The project applies molecular techniques including fluorescent in-situ hybridization using novel molecular probes to identify low-abundance cyst and vegetative cell populations, single-cell polymerase chain reaction to validate individual cyst identity, and quantitative PCR to estimate abundances of K. brevis cysts or vegetative cells in sediment and water column samples. The work addresses unresolved aspects of harmful algal bloom dynamics, specifically the location and nature of source populations that initiate and fuel K. brevis blooms, the environmental triggers that activate seed populations, and replenishment mechanisms when blooms terminate in nearshore regions.

Work is performed in Sarasota, Florida, with a period of performance from June 1, 2026 through May 31, 2029. The award represents peer-reviewed, competitive funding from NOAA's National Center for Coastal Ocean Science to produce actionable science supporting management and policy decisions on harmful algal blooms and coastal ecosystem protection.

The prevailing hypothesis for karenia brevis bloom initiation and development focuses on initiation in offshore oligotrophic shelf waters, followed by transport shoreward to nutrientenriched, coastal waters during development and maintenance stages, and ending with termination and/or dissipation nearshore. However, many unresolved questions remain and key aspects of bloom dynamics are poorly understood. One of the primary unresolved aspects of k. Brevis bloom dynamics is the location and nature of a source population. The current paradigm of offshore initiation does not adequately address the origin/location of the source population (inoculum) that might fuel a developing bloom, the potential environmental triggers that activate a source/seed population, or how the population becomes replenished when blooms terminate in the nearshore region. Further, the presence of multiple types of k. Brevis source populations at multiple locations could indicate more than one initiation scenario, possibly explaining the occasional DE-coupling of bloom events from WFS circulation patterns. Source populations for dinoflagellate blooms can take several potential forms, including; vegetative cells in or near the bottom sediment layers, as diffuse populations in the water column, or as aggregations in thin layers of the water column, or populations could consist of benthic cysts. The overall objective of this proposed ecohab project is to identify and characterize the form and possible locations of k. Brevis source, or seed, populations. To achieve this goal, the project team will utilize multiple cutting edge molecular approaches including; fluorescent in-situ hybridization (fish) using novel molecular probes for identification of low abundance populations (cysts or vegetative cells), single cell polymerase chain reaction (PCR) to validate the identity of individual isolated cysts, and quantitative (qpcr) to estimate abundances of k. Brevis cysts or vegetative cells in sediment and in water column. To identify potential locations of seed populations, how emerging (awakening) seed populations might be transported, and where developing seed population derived from bloom termination sites might be deposited, we will use existing and modified wfcom models developed and operationalized by the USF ocean circulation laboratory. Laboratory studies will evaluate the triggers and conditions that could lead to the development of cysts. The lack of knowledge concerning k. Brevis source populations obfuscates our thorough understanding of where and when blooms may occur. Identifying and characterizing these populations could provide a paradigm shift in our understanding of bloom dynamics of this species.