Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Standard station CTD profiles measurements (down casts) with water sampling (up casts);

Calculations of the concentration (cells/Liter) of Alexandrium catenella, formerly A. fundyense, were completed using MS Excel. The spreadsheet used inputs of the original volume sieved at sea (usually 2 Liters), the volume re-suspended into formalin and then methanol (usually 14ml), and the volume of the plankton concentrate filtered for the molecular probe assay (usually 7ml,  or less volume if during a significant bloom), and the number of labeled cells observed on that filter.

"Whole Cell" preserved samples. For the “Whole Cell” A. catenella water samples collected during the surveys, 2 Liters of seawater were drained from Niskin bottles into pre-rinsed bottles and sieved thru 20µm Nitex. The concentrated particulate material retained on the sieve was backwashed with filtered seawater (<15µm) into 15ml centrifuge tubes to a final volume of 14ml and preserved with formalin to a final concentration of 5%. After storage at 4oC for no longer than 36 hours, the tubes were centrifuged for 5 min (5000 x g), formalin was removed by aspiration leaving the pellet, replaced with 100% cold methanol, and stored at -20C for later analysis.

Enumeratio"n of the WC samples followed the methods developed by Anderson et al (2005a) using a species-specific oligonucleotide probe (NA-1) conjugated to a Cy3 fluorochrome and visualized with epi-fluorescence microscopy.

“Live" Count samples. To obtain quick estimates of Alexandrium sp. concentrations while at sea, 10 L of seawater from a surface 10L Niskin bottle was sieved and concentrated to 14ml.   A 1ml aliquot of the concentrate was loaded into a Sedgewick- Rafter counting chamber and enumerated using standard light microscopy.

The goal of this project is to identify commonalities and differences in regional bloom dynamics for two key harmful algal bloom (HAB) taxa, Alexandrium fundyense and Pseudo-nitzschia spp. The project’s central hypothesis is that HAB global biogeography and variable bloom and toxin dynamics are determined by a common repertoire of physiological and behavioral responses to environmental forcings and that the ability to understand, forecast, and mitigate HAB events requires a deep understanding of the plasticity of these repertoires within species and between populations. Novel, targeted, efficient, and data-rich in situ sampling paradigms developed with previous WHCOHH funding have revealed numerous unforeseen aspects of A. fundyense dynamics in the Nauset Marsh (NM), a long-studied inshore “model” bloom habitat. It is now clear that accurate rate estimates and behavioral patterns are needed for modeling and forecasting, and that these need to be generated as much as possible through in situ observation, a recognized strength of the WHCOHH.  In this project, the approach includes deployments of a portable, solar-powered observatory platform supporting remotely controlled instruments and profiling capabilities, the centerpiece being the IFCB, a unique autonomous underwater microscope for the in situ detection of rates of growth, accumulation, mortality, and life cycle stage conversions.  Variability in environmental forcing across years and among habitats provides a proxy for future climate scenarios, revealing the responses of these key HAB organisms under natural conditions. These novel observational and analytical approaches will be used to characterize the behaviors and responses of A. fundyense across a range of other habitats and environmental regimes.  They will also be directed towards Pseudo-nitzschia spp., a group that presents a growing public health threat to the northeast U.S. Improved understanding of critical physiological and behavioral features of both taxa are essential for accurate predictions of their climate responses and assessment of short- and long-term human health impacts.

NSF Award Abstract

The mission of the Woods Hole Center for Oceans and Human Health is to protect the public health through enhanced understanding of how oceanic and environmental processes including climatic variation affect the population dynamics of toxin producing organisms, and the risks from exposure to their potent neurotoxins. Factors affecting the distribution, survival, proliferation, and toxicity of harmful algal bloom (HAB) species still are poorly known, despite their enormous consequences for human health. Three research projects and two cores comprise the Center. The Center structure will facilitate the integration among projects, and the integration of research with education and community engagement activities. The Center will engage stakeholders, facilitate education on HAB science at many academic levels, and strengthen public knowledge about HAB blooms and their impacts. The Center is jointly supported by NSF and by the National Institute for Environmental Health Sciences (NIEHS).

The research activities of the Center will focus on two key HAB taxa: Alexandrium fundyense that produces the saxitoxins responsible for paralytic shellfish poisoning (PSP), and Pseudo-nitzschia spp. that produce domoic acid responsible for the amnesic shellfish poisoning (ASP) syndrome. Novel, targeted, efficient, and data-rich sampling approaches developed by the applicants and applied in situ have revealed that critical aspects of A. fundyense dynamics in natural settings differ dramatically from those inferred from laboratory studies, indicating plasticity in response to climate. The research proposed will build on these new and fundamental insights into what regulates blooms, and on the Center's established strengths in ocean observation technologies and modeling, to predict how environmental variables may influence population dynamics of known and emerging HAB threats. Hindcast simulations compared with climate data records in the Gulf of Maine will assess model performance and uncertainty. Forecasts run for a range of potential climate scenarios can help quantify future public health risks. Similarly, specific cells have been identified in the developing brain that are targets of HAB toxins, findings giving insights into developmental toxicological mechanisms. These will guide studies to address the scope of toxin effect in the developing central nervous system, potentially linking developmental exposures to adult consequences. Studies of new mechanisms of toxin action will include determination of the effects of combined or repeated exposure to sub-lethal levels of saxitoxin and domoic acid, and possible silent neurotoxicity, at different life stages in the zebrafish model.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

The data management plan for the program can be found here.