Predicting red tide blooms with ESP
Red tide poisoning is an aquatic phenomenon caused by a rapid increase/accumulation in the water column of reddish colored algal bloom (large concentrations of aquatic microorganisms) comprising a few species of toxic dinoflagellates. Forecasting the phenomenon has been critical for coastal communities. This year though, WHOI is introducing a new tool called Environmental Sample Processors (ESP) to measure bloom concentration and associative toxins for real-time reporting to land based researchers.
Red tide is caused by the incubation of dormant cysts of alga called Alexandrium fundyense. These toxic cysts produce can cause paralytic shellfish poisoning (PSP). They accumulate in "seedbeds" found in bottom sediments and near-bottom waters where they provide the optimal conditions for cells to rapidly divide to form blooms each spring. Red tides events have historically greatly affected the local ecology and fishing commerce.
Researchers typically base the annual red tide forecast on the abundance of cysts in bottom sediments combined with a computer model that simulates a range of bloom scenarios based on previous years' conditions. While this approach provided useful forecasts for most of the years since 2006, the bloom potential for both 2010 and 2013 was not realized. In those years warmer, fresher (less salty), low-nutrient waters in the Gulf of Maine were present, which likely suppressed the blooms.
"We are seeing oceanographic conditions that are different from those used to make our past forecasts, and thus and we are adapting our modeling and observational efforts to meet this challenge," said WHOI biologist Don Anderson.
Environmental Sample Processors (ESP) will measure bloom concentration and toxins at multiple locations along the Gulf of Maine providing near real-time data to land-based personnel. Developed by the Monterey Bay Aquarium Research Institute, the ESPs are molecular biology labs packed inside canisters the size of kitchen garbage cans. They automatically collect a sample of water and then rapidly test for DNA.
The ESPs were tested off the coast of Portsmouth, NH, during 2011 and 2012, and then two of the instruments were deployed in 2013. NOAA's Integrated Ocean Observing System (IOOS) provided funding to double the number of ESPs deployed in the Gulf of Maine in 2014, as part of the WHOI-led pilot project funded by NOAA's Monitoring and Event Response for Harmful Algal Bloom (MERHAB) program that is demonstrating how to integrate these sensors into HAB observing and forecasting systems. Three ESPs were successfully deployed on May 3-4 and are already transmitting data to shore, indicating that low cell concentrations of the toxic Alexandrium are present in the nearshore waters of western Maine. A fourth will be deployed later in the season.
Read more at Woods Hole Oceanographic Institution.
Red tide sign image via Shutterstock.