Regulatory control of toxicity among hemolytic, neurotoxic, fish-killing species of phytoplankton under current and future ocean conditions

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Human activities are affecting all coastal oceans. At the forefront are changes in the form and rate of supply of nitrogen-containing compounds (eutrophication), increased levels of dissolved organic carbon (brownification), lowered pH (ocean acidification), and enhanced mixing with freshwaters. Added to these factors are the global changes in temperature and wind stress that alter the physical structure of mixing and transport. Within these changes is the rise in frequency and duration of events of harmful algal bloom (HAB) species. My research program will proactively consider the effect of the future oceans on HAB events as part of a knowledge-based marine forecast. We are a long way from ascertaining with confidence how HABs will respond to climate change forcing. My research team is dealing with present conditions to answer questions that are critical to scientific advancement and address society concerns about the future of the oceans. My research program will generate world leaders in understanding the interactions between several of these drivers (temperature, salinity, and pH) on three fish killing HAB species, Heterosigma akashiwo, Karenia mikimotoi and Prymnesium parvum. While taxonomically disparate, the three HAB species share common physiological traits in the action of toxicity leading to a unified research program relevant to both coastal marine and freshwater systems. To rigorously address this research program, my research team will: (1) Create an eco-toxicological approach to evaluate the assessment of the levels of toxicity in cells grown under controlled conditions; (2) Establish, using biochemical methods, an inter-species comparison of key toxicological attributes (e.g., hemolysins, neurotoxins, membrane penetrating fatty acids); and (3) Evaluate the growth success and toxin content of each species under single (salinity, pH, temperature, and stability) and combinatorial (salinity x pH x temperature x stability) conditions. My research team will develop a deeper discussion on the consequences of HABs that are likely to occur under future ocean conditions. This research program is important to the general Canadian population that depends on fresh fish, particularly west coast salmon where outbreaks of Heterosigma sp. have caused great losses in the natural salmon run, and to Canadians that depend on the aquaculture industry. Our anticipated outcomes are to reduce the frequency of HAB outbreaks or to mitigate toxic consequences of the natural blooms of H. akashiwo and the two potentially invasive species, K. mikimotoi and P. parvum, provide coastal environments with great benefits to the natural and commercial fisheries, and provide Canadians with esthetically improved water and air quality.