A federal investment in two monitoring projects in the Gulf of Maine will help keep shellfish managers and harvesters prepared for seasonal blooms of toxic algae.Shellfish beds in the Gulf are threatened each summer by red tide, or blooms of the dinoflagellate Alexandrium fundyense. The algae produce toxins that can accumulate in filter-feeding shellfish and cause illnesses like paralytic shellfish poisoning in people who eat them.
State shellfish managers test mussels, clams and other species throughout the bloom season and often have to close areas to harvesting to protect human health. As recently as 2009, 97 percent of the state’s coastline was closed during the peak harvesting season
The shellfish industry has a $60 million economic impact in Maine, said Darcie Couture, director of biotoxin monitoring for the Maine Department of Marine Resources. So the more data managers have when considering closures, the better.
To help keep the data coming, the National Oceanic and Atmospheric Administration Center for Sponsored Coastal Ocean Research recently granted $1.6 million to projects underway at Woods Hole Oceanographic Institution in Massachusetts. The money will fund the operation of a bloom forecast model and and the deployment of advanced sensors in the Gulf.
The model is a sophisticated computer program that forecasts the timing of the bloom and where it will hit the hardest. The sensors, which will be moored offshore, carry cutting-edge cell-detecting technology that robotically measures concentrations of the toxic algae and sends the data back to shore.
“It’s the first level of triage for us to understand what’s going on in the offshore environment with models and with the sensors,” said Couture. “That will be our first line of defense against what’s coming in from offshore.”
The model has been under development at Woods Hole, and its forecasts have already already helped shellfish managers in Maine, Massachusetts and New Hampshire, said Dennis McGillicuddy, senior scientist in applied ocean physics and engineering at Woods Hole.
Collaboration with local managers is an important part of the model’s success, McGillicuddy said.
“We stay in very close contact with them, sharing our model results with them, and then they share with us what they’re seeing in terms of toxicity in the shellfish,” he said. “I think that’s ultimately why NOAA decided they wanted to proceed with taking this model operational. They saw that it was being actually used by shellfish managers up and down the coast.”
The model depends on a stage of the algae’s life cycle in which the species lies dormant as cysts resting in coastal sediments. In 2005, particularly large cyst deposits were followed by one of the worst blooms in 30 years, McGillicuddy said. Further monitoring showed that the number of cysts and the size of the bloom were strongly correlated.
Scientists now sample the cyst beds in October and November and plug those numbers into a model that simulates ocean currents and cell division. The results, McGillicuddy said, are “pretty specific predictions about where and when the blooms are likely to occur.”
Funding from NOAA will also help deploy and operate state-of-the-art sensors in Gulf of Maine waters. The sensors, called Environmental Sample Processors, robotically sample water and test for genetic material of harmful algae cells and toxins. The instruments will eventually send managers near real-time data on bloom concentrations and toxicity.
The Environmental Sample Processor, or ESP, was developed by Chris Scholin, president and CEO of the Monterey Bay Aquarium Research Institute in California. This will be the first deployment of commercially available ESP technology, said Don Anderson, senior scientist in biology at Woods Hole.
“This type of sensor has never been deployed for an extended interval in the Gulf of Maine or the East Coast before, nor has any ESP data been directly used to augment state monitoring programs for shellfish toxicity,” Anderson said.
Anderson’s laboratory received a $2 million grant from the National Science foundation to purchase five ESPs and the associated mooring hardware, and an additional ESP was purchased with funds from the Environmental Protection Agency.
Couture, of Maine’s Department of Marine Resources ,doubts that forecasting and remote monitoring will ever replace the need to physically test shellfish for toxins. But these research programs help to better allocate the program’s small budget and focus testing to the places that really need it.
“It just helps everybody plan ahead,” she said. “The managers and the shellfish industry.”
Image credit: Coastal Care