Portsmouth pond chosen for algae study
PORTSMOUTH — Danny Charles laughed when asked whether he eats the fish he catches in the upper pond at Melville Park.
“Oh, no,” said Mr. Charles while watching the line he had cast from a wooden platform on the east side of the pond Friday.
For the retired Navy man, the pond is simply a peaceful oasis where fishing is done for sport — not for dinner. He’ll hook a couple of bass or a few catfish — “They’ve got some big cats in here,” he said — and then release them.
“I’ve been fishing this pond for years,” said Mr. Charles. “This is just a nice place to come and relax.”
While Mr. Charles was searching for a bite from one side of the pond, Thurston Gray was in his 16-foot steel canoe, conducting one of the Melville Park Committee’s weekly water quality tests.
“We come here every week from the middle of May to the middle of October. We work with a program called Watershed Watch in conjunction with Linda Green at URI,” said Mr. Gray, adding that the pond has been monitored for about 15 years.
Watershed Watch is a volunteer water quality monitoring program that works with local communities to assess water quality, identify sources of pollution in water and provide information about water leading to more effective management of critical water resources.
“The first goal is to monitor nutrients, bacteria — things like that. If there are issues, hopefully the right person involved would take steps to improve it,” said Ms. Green, director of Watershed Watch, adding that the R.I. Department of Environmental Management (DEM) keeps a list of impaired waters with the hopes that its municipality will take steps to correct the issues.
Mr. Gray usually goes out with Edward Rizy, chairman of the Melville Park Committee. They use a Secchi disk — a plain circular disk about 12 inches in diameter — to measure water transparency. “We lower it down to a point where it just disappears. The string is calibrated in tenths of meters and we go down to the bottom. We do four readings,” he said, adding they also measure water surface temperatures.
Around every other week, they also take water samples which are run through a filter that is brought to URI for monitoring.
Although there’s nothing currently stopping anyone from eating fish caught from the upper pond, Mr. Gray, like Mr. Charles, advises against it. He was surprised to hear that stone flies, which are used by scientists as a sign of good water quality, were found recently in the pond by students from nearby Melville Elementary School.
“Look at it,” he says, motioning to the cloudy, greenish water. “I wouldn’t want to drink it or swim in it and I’m not so sure about eating fish that comes out of it. I think some of the fishermen save the fish and eat them, but a lot of them just throw the fish back. I wouldn’t eat it.”
Blue-green algae blooms
The pond, however, is in better shape that it was last September, when blue-green algae blooms prompted The R.I. Department of Health and the R.I. Department of Environmental Management — the latter stocks the pond with fish — to put up notices advising people not to swim, boat, fish, eat caught fish or allow pets to enter into or drink from the water.
“At least one year, Portsmouth DPW put up signs saying the pond’s closed,” said Mr. Gray.
The algae blooms have taken place three out of the past four years, said Mr. Gray. Because of that, the upper pond has been selected for a blue-green (cynobacteria) algae study that URI Watershed Watch began this week.
“Besides the fact that it makes a pond very green and slimy and uninviting, those algae can, under certain conditions, produce toxins that can make dogs other animals or even other people sick from going into the water,” said Ms. Green.
The Melville pond was one of only nine or 10 chosen in Rhode Island for the study. “I looked for locations where we had good volunteers, some locations where we’ve had those blooms before and others just because they fit some other criteria,” said Ms. Green. “Thurston and Ed are really dedicated, great guys and I really appreciate their help.”
The new study involves lowering a tube down slowly to sample the entire water column down to the depth, Mr. Gray said.
He’s not sure what much can be done about the pond’s water quality. The Melville Park Committee has been using a company called Aquatic Technology to treat the pond annually for a number of years, he said.
“I’m not exactly sure what they treat it for, but I noticed that the weed growth disappeared after they treated and I haven’t seen much of that weed growth since then,” he said.
The committee doesn’t monitor Melville’s lower pond, which is also stocked with fish, but he said judging by an eye test it seems to be a little cleaner.
Mr. Charles agreed, but says he doesn’t trek to the lower pond because it’s difficult to access. As for the upper pond, he has his theories about its water quality.
“This pond is getting worse each year,” he said. “I just don’t think there’s enough circulation for this pond; it’s gotten stagnant.”
Mr. Charles, who’s originally from Virginia, added as he baited a hook, “The ponds up here aren’t as good as those down south.”