Written by Amber Skinner | 03 May 2010

With summer close at hand, the annual threat of red tide is on the minds of many local shellfish harvesters, especially because this year's outbreak is predicted to rival the devastation experienced in 2005.
The Maine Department of Marine Resources (DMR) issued its first red tide warning of 2010 in March, a month earlier than usual. At that time, the harvesting of mussels and surf clams was banned from Harpswell south to the Maine/New Hampshire border.
As of April 15, no one was allowed to "dig, take or possess" carnivorous snails or mussels, because of red tide, according to the DMR's website (www.maine.gov/dmr).
In mid-April, Harpswell Shellfish Warden George Lee Bradbury was asked by the DMR to procure 12 clams from five Harpswell coves for red tide testing. Those results were unavailable at the time of printing.
According to the Woods Hole Oceanographic Institution (WHOI), an "abundant seed population in bottom sediments" has laid the groundwork for a substantial bloom of the toxic alga Alexandrium fundyense. The algae rise to the water's surface in February and March and, depending on a combination of sunlight, nutrients in the water and water temperature, "divide again and again to form a ‘bloom' or red tide." The algae also produce dormant cells, often called cysts, that drift to the ocean floor as these blooms wane.
A survey conducted late last year reveals the greatest number of cysts the WHOI team has ever measured, "more than 60 percent higher than what was observed prior to the historic red tide of 2005." In that year, nearly the entire coast of New England was closed to shellfish harvesting for weeks and weeks on end.
The number of cysts, combined with a winter and spring of unusually warm weather and heavy rainfall, which renders nutrient-rich, freshwater runoff, is predicted to again produce a significant outbreak of red tide in New England.
The Alexandrium fundyense alga poses no direct threat to humans, although the toxins it makes accumulate in filter-feeding shellfish, such as mussels and clams, which can cause paralytic shellfish poisoning (PSP) in humans who eat them.
Red tide "works its way up" the coves "slowly," Bradbury said. "When it gets close to harvesting areas, the coves are shut down for public health."
The shellfish industry generates an estimated $50 million in Maine, with the highest revenues from May to August. Approximately 3,000 harvesters and dealers in the state rely on shellfish for the bulk of their income, with "30 to 40 (of those) families" living in Harpswell, Bradbury explained.
With major outbreaks in three of the past five years, and another on its way, Congresswoman Cherie Pingree has sponsored a bill calling for continued funding of monitoring buoys and development of "‘next generation' buoys to measure nutrients in the water and allow for even better monitoring of red tide.
"Currently, four critical buoys have been taken out of the water because of a lack of funding," Pingree said.
We've already seen "the first shellfish closures and I'm worried it's going to be another very bad season for red tide," she continued. "If we can monitor red tide with new buoys we will have a better understanding of how it spreads and be able to reopen shellfish beds more quickly."
Better predictions also allow for shellfish dealers and restaurants to find alternative supply sources and help "stage (the state's) limited resources during an otherwise overwhelming environmental and economic crisis," Darcie Couture, DMR's director of Biotoxin Monitoring, explained.
In February, the WHOI received approximately $500,000 in federal funding to help forecast future red tide outbreaks. And, despite significant cuts in most areas of Maine's 2009-2011 budget, Governor John Baldacci has maintained funding for the state's red tide monitoring program.
With 70 residential commercial harvesters in Harpswell, the "loss of income" from red tide closures can be crushing, Bradbury said. "It's extremely hard for those who need to work every day."
For closure updates and any other related information, call 1-800-232-4733 or visit www.maine.gov/dmr.