Toxic algae levels feared in lower Charles River
- Toxic algae levels feared in lower Charles River
Officials warn against contact
By Beth Daley, Globe Staff | August 16, 2006
Explosive growth of algae that can be highly toxic to humans and animals has streaked the Charles River with fluorescent green filaments, prompting state health and environmental officials to warn boaters and dog owners to avoid any water contact from the Massachusetts Avenue Bridge to the Museum of Science.The organism, known as microcystis, can secrete toxins that irritate the skin, eyes, and ears of people who come in contact with contaminated water. A person would have to drink an enormous amount of water to become seriously ill, but ingesting even a small quantity may cause diarrhea. Dogs and wildlife, which are smaller and therefore more susceptible, can become sick or die from drinking the water.Community Boating Inc., located on the Charles River near the Hatch Shell, has temporarily suspended all kayaking, windsurfing, and some sailing classes using boats that can more easily capsize. Rowing teams are steering clear of the lower Charles River.``We've never seen an algae bloom like this before" on the Charles, said Anna Eleria, a water-quality scientist with the Charles River Watershed Association, an environmental advocacy group that is working to warn the public. ``It's not safe for people to let their dogs in, and we want to warn people to avoid contact."No one is known to have become sick from the water since testing first indicated a problem Friday, state health officials said, although they received several calls from people wondering what the streaks of green slime were in the water. No animal or fish deaths have been reported. State Department of Conservation and Recreation officials said they put up 50 warning signs over the weekend on the banks of the 1.7-mile contaminated stretch, although none were visible yesterday on the Boston shore.Though final testing is still needed to confirm that the algae is secreting toxins, state environmental officials said yesterday that the density and type of bloom convinced them it probably poses a danger to humans and animals.Concentrations of microcystis are extraordinarily high in the river. World Health Organization guidelines say health threats can occur in recreational waters once a threshold of 100,000 cells per milliliter of water is reached. On Friday, state Department of Environmental Protection officials recorded more than a million cells per milliliter in a sample taken two days earlier near the Museum of Science. Subsequent tests Saturday yielded results of 600,000, 300,000, and 200,000 cells per milliliter closer to the Massachusetts Avenue Bridge, and more testing was taking place yesterday in the area and further upstream.Yesterday's wind and early rain broke up the mats of the organism so that only pea- and dime-sized flecks floated on the water, making them no less toxic but harder to see. Experts say the sun and warm temperatures predicted for the next few days will probably allow the organisms to regroup into what can look like green cottage cheese or streaks of antifreeze. The microcystis is most apparent in lagoons, but it is also in the main river and tends to clump near the banks.Microcystis is a type of blue-green algae, also known as cyanobacteria, found in fresh water. The organisms are usually present in amounts so small they are harmless, but can have rapid growth spurts when exposed to nutrients. Scientists say large amounts of nutrients, from lawn fertilizer and road runoff, probably washed into the Charles River during the spring's heavy rains. Then hot temperatures allowed microcystis colonies to glom together to grow their telltale long filaments.Such outbreaks occur with some regularity in New England. New Hampshire has temporarily closed several freshwater beaches this year because of microcystis. In the summers of 1999 and 2000, two dogs died after drinking contaminated water from Lake Champlain on the New York-Vermont border.``It's a global problem," said Bob Howarth, a professor of ecology at Cornell University who studies cyanobacteria. Howarth said the bloom might not dissipate in the Charles until the cool days of autumn. And since the Charles now has a serious outbreak, he said, it's more likely that another bloom will happen in the future. The bacteria form cysts that sink to the river 's bottom, waiting to start another growth spurt, helped by another nutrient infusion.The outbreak was first spotted by employees of the Charles River Watershed Association 2 1/2 weeks ago, but they didn't know what it was or think it was serious. Then, the US Environmental Protection Agency scooped up a sample last Wednesday during monthly monitoring of the Charles River. The state Department of Environmental Protection tested the sample by Friday. Soon after, the Charles River Watershed Association began calling boathouses, sending e-mail alerts, and posting red flags that signal poor water quality in the Charles River.Boaters and rowing enthusiasts seemed largely unperturbed by the bloom yesterday, saying they would simply practice upstream or take care not to be splashed or fall in the water.The same type of algae has been detected in the Charles River before, but never in the concentrations recorded over the last week.An official with the EPA said the outbreak shows how much still needs to be done to clean up the Charles. While it's come a long way from being the inspiration for The Standells' song ``Dirty Water" in the 1960s, it still has problems.``This is a system that's been overloaded for a long time" with nutrients, said Mark Voorhees, an environmental engineer for the EPA.His agency plans to issue new limits on nutrients in the Charles this fall. ``It's going to take time to fix," he said.
Beth Daley can be reached at bdaley@....
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