Title: Cross-regional comparison of Dinophysis bloom dynamics, drivers, and toxicity
Virginia Institute of Marine Science: Juliette Smith, Lead
Texas A&M University: Lisa Campbell
Stony Brook University: Christopher Gobler
NOAA/NMFS/NWFSC Vera Trainer
US FDA, College Park: Jonathan Deeds
Funding Source: NOAA-NOS-NCCOS ECOHAB Program
Introduction: Species of Dinophysis, known to produce toxins that cause diarrhetic shellfish poisoning (DSP), have threatened the safety of shellfish consumers in Asia and Europe for decades. Recently, harmful algal blooms (HAB) caused by Dinophysis spp. have emerged as a human health threat in the US. Since first detected on the coast of Texas in 2008, D. ovum has been detected in six of the last eight years and has resulted in the closures of shellfish harvesting to prevent DSP. Since 2011, closures due to DSP from D. acuminata and D. fortii have also been enforced annually at multiple sites throughout Puget Sound, WA, and toxin levels in shellfish exceeding FDA regulatory limits have been reported in New York, Maine, and Massachusetts due to blooms of D. cf. acuminata and most recently D. norvegica (ME). Chesapeake Bay and the larger DELMARVA region (Delaware, Maryland, and Virginia) harbor toxin-producing species of Dinophysis. The region, however, provides contrast as a relatively new area of concern, with evidence of an approaching tipping point.
Rationale: Given the rapid increase in frequency of Dinophysis blooms on nearly every US coast, with clear regional variability in timing and species, it is essential that the drivers of Dinophysis success in coastal ecosystems be identified using a coordinated, nationwide effort. Such a cross-regional comparative study will identify not only potential drivers, but create a baseline for understanding how future climate and eutrophication scenarios will influence intensity, frequency, and toxicity of blooms.
Objective: The goal of this project is to identify and quantify environmental factors controlling Dinophysis blooms and DSP across the US as a means of developing optimized regional early warning systems and management plans. A carefully coordinated and collaborative study including high-resolution phytoplankton time series by Imaging FlowCytobots (IFCBs), field collections, and culturing experiments will be undertaken to address the following research objectives in the Gulf of Mexico, Long Island Sound, Puget Sound, and Chesapeake Bay: 1) Identify the environmental factors (e.g., temperature, ammonium) that control Dinophysis blooms and toxicity within and across regions; 2) Use isolates to characterize genetic variability and potential toxicity, under a variety of conditions; and 3) Develop an early warning system for Dinophysis blooms and DTXs using IFCBs in Long Island Sound and Chesapeake Bay.