If it's green, blue and looks like goo, don't swim in it or near it, DES officials warn

One in four cyanobacteria blooms in Maine or N.H. may carry dangerous toxins, a DES official says. (Courtesy photos)

When you and your family take off this weekend to enjoy a refreshing swim in a Maine or New Hampshire lake keep in mind that cyanobacteria can occur in pretty much any inland body of water and needs to be respected for the health hazard it can be.

"If there is something gross looking in a pond I would steer clear of it," says Sonya Carlson, beach program coordinator for the New Hampshire Department of Environmental Services. "If you can visually see it, even if it's a ways away, better safe than sorry. Find another place to swim."

Cyanobacteria was spotted at Milton Town Beach last week and an advisory against swimming or wading was issued, but the algal bloom was gone by last Friday.

Blooms typically last four or five days, but cyanobacteria can pretty much reoccur at any time, Carlson added.

Swimming in, ingesting or showering in water drawn from a cyanobacteria bloom can cause a wide spectrum of symptoms ranging from skin irritation to nausea and vomiting to nerve damage including numbness, even paralysis, according to the DES.

A cyanobacteria bloom at Bow Lake in Northwood, N.H., 2006

In one study cyanobacteria was even linked to potentially fatal Arterial lateral sclerosis, commonly referred to as Lou Gehrig's disease.

One of the frustrating things about cyanobacteria is the level of toxicity of an algal bloom is impossible to detect at this point, though Carlson is hopeful testing equipment will soon be available in her office.

So the cyanobacteria that led to Milton's advisory may have had toxins in it, or not.

Carlson said earlier this week even she has to look at cyanobacteria under a microscope to positively identify its presence, but she did give a few clues that will identify it 90 percent of the time.

"It could be anything from speckles in the water to big globs colored greenish-blue," she said.

She said it could appear green or blue depending on how the sun is hitting it or whether it's under trees.

The chief culprits that cause cyanobacteria blooms are nutrients such as phosphorous and nitrogen, Carlson explained, adding that a human element is most often at the root of the problem.

She said warm weather, dog poop, fertilizers and faulty septic systems and leach fields are often to blame.

"It's hard to pinpoint any one thing," she said, adding it could be a combination of factors.

She said an entire community has to take action in order to be proactive against cyanobacteria.

She said DES has watershed assistance programs to help a community implement a proactive plan.

"It would take people around the lake to study the lake and look at some of the sources of nutrients that are causing this and make up a comprehensive plan," Carlson added.

A bloom in Webster Lake in Franklin, N.H., in 2005

Homeowners can help by testing their soils before applying fertilizers and, if they must apply a fertilizer, making sure that they apply only what they need, according to the DES website. The NH Shoreland Protection Act prohibits use of fertilizer closer than 25 feet from shore. Also, between 25 and 250 feet from shore, only low phosphate, slow release nitrogen fertilizer may be used. Keeping septic systems maintained will also help keep nutrients from leaching through the soil into nearby streams or lakes.

The DES also advises that if you suspect a cyanobacteria bloom is occurring at your lake or pond, to call DES immediately at (603) 271-2457 or email beaches@des.nh.gov and they will conduct a site visit. People may also collect a sample in a clean container (plastic or glass jar) and bring it to DES to identify, however, if collecting a potentially toxic algal sample, avoid contact with skin. They also advise that you wear waterproof gloves when sampling and/or immediately wash all areas of the body where water contact has occurred.

Linda Bacon, a lake assessment section leader for Maine DES, said on Thursday cyanobacteria is very widespread, calling it "ubiquitous" in Maine lakes, however, Maine does not currently have any criterion for posting and does not post individual lakes.

Bacon said eventually they expect to have a statewide advisory, but added those advisories would be worked out with the Center for Disease Control.

She noted that many cyanobacteria algal blooms do not have toxins and to test every bloom would likely be prohibitively expensive. One machine that can test for toxins costs about $10,000, and each test also carries additional costs.

In Maine, she said the biggest concern is when the bloom produces a thick scum which is a risk to pets and livestock that may drink lake water or for children who might play in it.

She said the heaviest concentrations of cyanobacteria blooms are in Central Maine.

Lastly, both Carlson and Bacon advise swimmers to err on the side of caution. "If you see something green, blue and gross in the water, stay away," Carlson said.