The Massachusetts-based Woods Hole Oceanographic Institution (WHOI) has introduced a new device for monitoring and predicting “red tide events” in New England.
Red tide is a harmful algal bloom which can color ocean water red. Toxins released by the blooms may be ingested by shellfish and cause humans who eat toxic shellfish to develop paralytic shellfish poisoning (PSP) which can be fatal.
Darcie Couture, lead scientist at Resource Access International LLC (a Brunswick company which provides laboratory testing for shellfish), said shellfish are high-risk foods because as filter-feeders, the organisms ingest what’s in the surrounding environment. And since shellfish aren’t usually cooked at temperatures high enough to destroy all bacteria or toxins, she said, this contributes to their risk as a food.
%uFFFC”Cooking them at temperatures that high would make them rubbery,” said Couture. Monitoring is critical to protect public health, she said.
Because the Gulf of Maine and the Bay of Fundy are environments in which the harmful algae species Alexandrium thrives, Maine, other New England states and the Canadian Maritimes are required by FDA to monitor shellfish for safety. When shellfish approach the regulatory limits for PSP, states must close the affected harvest areas.
WHOI recently deployed a robotic device known as an “environmental sample processor” (ESP) in the Gulf of Maine to monitor red tide toxins. The ESP has been described as “a laboratory in a can.” WHOI’s senior scientist and director of the Cooperative Institute for the North Atlantic Region Don Anderson explained that the new pint-sized device, housed in a large metal canister about the size of a kitchen garbage can, samples ocean water for red tide toxins and transmits data to shore via a cell%uFFFC phone.
%uFFFCAnderson said that while the new ESP is expensive, with a base cost of around $200,000, he hopes that future refinements in the technology will make it possible to deploy multiple robotic devices in strategic locations along the coast to monitor red tide.
%uFFFCThe original robotic device was developed by Chris Scholin, one of Anderson’s former students. Scholin, now president and CEO of the Monterey Bay Aquarium Research Institute in California, coined the phrase “laboratory in a can” after developing the first ESP.
The new device has a filter containing RNA (similar to DNA) particles from red tide toxins that attract other RNA particles from red tide toxins in ocean water.
“It’s similar to how Velcro works,” said Anderson. After the particles bind together, a chemical process inside the computer then makes the particles luminescent so those can be viewed and counted. That data is then transmitted back to shore by a cell phone.
%uFFFCESP video demonstrations and an animated drawing can be viewed at http://www.mbari.org/esp/
Anderson said the robotic method won’t replace the Maine’s onshore monitoring but instead will complement it. Knowledge of what’s taking place offshore should enable state officials to mandate earlier closures of affected harvesting areas and better manage red tide events.
Couture, who directed the Maine DMR’s red tide monitoring program for seven years, said a remote sensing buoy would never fully replace a traditional shore side sampling program, but if the buoy suddenly detects a sharp increase in cell concentrations, “then managers have a full day or more to prepare for a potential spike in inshore toxicity, and can plan for additional site sampling locations or more frequent testing.”
A 2009 red tide event spelled disaster for many Maine fishermen when a
%uFFFClarge section of Maine’s coastline remained closed much of that fishing season due to very high levels of red tide toxins in the water.
DMR scientist Alison Sirois reported that “four regional mussel, carnivorous snail and European oyster closures were implemented on May 15.”
NOAA scientists predicted in March that New England would experience a moderate red tide this spring and summer based upon red tide data collected during the past year.