As the sea warms up at this time each year, the seeds of a plant buried just offshore in the sediment of the Gulf of Maine germinate into cells that swim to the surface — and there are more of those seeds this year than scientists have ever seen before.
Typically, the algae — known to science as Alexandrium fundense — concentrate into blooms so dense they turn the surface of the ocean crimson.
If conditions are just so, these blooms of red tide will be pushed in-shore by northeast winds and carried south by the prevailing currents, and it is here in the protected, shallow waters of Maine, New Hampshire and Massachusetts that the red tide wreaks its havoc on coastal economies committed to shellfishing since Native Americans were digging by themselves.
The algae are gathered in the flesh of the filter-feeding bivalves — soft-shelled clams and their immediate cousins, but not lobsters, crabs or scallops — in concentrations that render the healthy shellfish toxic to humans, and can induce paralytic shellfish poisoning.
Traditionally, even before concentrations rise to dangerous levels, the harvesting and sale of affected shellfish are halted. In 2005, the bloom and distribution of the toxin were pandemic along the northern New England coast, and shellfishermen, their buyers, distributors and restaurants from the Bay of Fundy to Martha's Vineyard suffered losses estimated at more than $50 million.
The National Oceanic and Atmospheric Administration declared the Maine shellfish fishery that year to have been brought into "commercial failure." In Massachusetts, more than 1 million acres of beds, most of them in Essex County, were closed from May 19 through July 19.
It was the greatest red tide since 1972. So extensive were the losses that the Woods Hole Oceanographic Institution was granted $540,000 by the federal government to survey the floor of the Gulf of Maine for the distribution of the cysts or seeds which settle to the bottom each fall and produce modeling for future outbreaks.
The grant to scientists at Woods Hole allowed mapping of the footprint of the 2005 outbreak, which allowed overlaying the footprints from subsequent years. What the team from Woods Hole found last fall in the Gulf of Maine — now coming back to life — are more seeds by far than were transformed into the great red tide bloom of three years ago.
"It's watch and wait time," Don Anderson, the senior scientist, director of the Coastal Ocean Institute and recognized red tide expert, told the Times yesterday.
The regional observation and modeling program known as the Gulf of Maine Toxicity study organized from Woods Hole has found a worrisome concentration of the red tide algae seed. The seafood study by Anderson's team found "the number of cysts is more than 30 percent higher than what was observed in the sediments prior to the historic (2005) bloom," the institution reports.
Already, there have been isolated closures in Cape Cod and Maine.
The closure on Cape Cod by the state Division of Marine Fisheries is almost certainly an isolated local event, Anderson said. The bloom in Maine between Harpswell and Phillsburg is of uncertain genesis, he said.
"Nobody can say what's going on in Harpswell," Anderson said.
The area between Bath and Brunswick is close to the highest concentration of red tide seeds found during last fall's survey by the team from Woods Hole.
Anderson explained that the super size of the seed bed was not by itself certain to produce widespread red tide harvesting closures later this spring.
But the other natural conditions are in place. These include the necessity of unusual amounts of snowfall and winter rain. The coast received record amounts of both.
In years of extreme outbreaks, the extra strong pulses of fresh water carry nutrients into the coastal waters. As they warm, the nutrient-rich waters become ideal for the multiplication of the red tide algae.
What else is required to bring red tide to civilization? Winds.
Northeast winds, a fairly typical pattern for spring, will push the blooms into estuaries such as those along the coast of Essex County. Southwest winds, which are not atypical, can keep huge blooms out at sea, where they can remain for months, harmless to coastal economies.
"Our hypothesis is that cyst abundance is an indicator of the magnitude of the bloom," said Woods Hole oceanographer Dennis McGillicuddy in a report on the institute's Web site. He and his team were at sea this week on the research vessel Oceanus.
"If there is a large bloom offshore," he wrote, "the wind patterns and ocean currents in the next few weeks will determine whether it will be transported onshore and have an effect on coastal shellfish resources."
The Gulf of Maine Toxicity Study programmed the weather and ocean conditions observed in four consecutive years — from 2004 through 2007, including the crisis year of 2005 — into a computer simulation of the cell concentrations found on the bottom last fall.
What the computer runs produced were four very different outcomes suggesting the range of possibilities for this year's red tide — from "major" to "very weak."
The senior scientist and director of the Woods Hole Coastal Ocean Institute, Anderson reduced the morale of the story found in the multiple modeling to a simple point.
"Hope and pray for southwesterly winds in the next month," he recommended.
Richard Gaines can be reached at rgaines@gloucestertimes.com
