The Mashpee Environmental Coalition is grateful for the generous permission granted by the Mashpee Enterprise for the reprint here of this excellent article from their 9/15/06 Edition.
Once
‘Beautiful,’ Santuit Pond Now Degraded, Unswimmable
BRIAN
H. KEHRL
On
a bright and breezy early fall afternoon this week, looking out over Santuit
Pond from the town landing off Timberlane Drive, the water glowed a deep
yellowish green color that looked like cold, thick pea soup.
Upon
closer inspection, peering down at the water from the shoreline, it is murky,
brimming with a dense layer of particles suspended in the top few inches of the
water. A layer so dense that one’s feet disappear behind it at a depth of less
than 12 inches.
A
few yards away, tacked to a tree, a Mashpee Board of Health sign posted two
weeks ago warns that, if visibility is less than 18 inches, swimming in the
water may cause illness or skin irritation.
“If
it’s so thick that you can’t see your feet when you are knee deep, it’s
probably prudent when it’s like that to avoid swimming,” said George
Heufelder, director of the Barnstable County Department of Health and
Environment.
The local board of
health and county health department have in the past few weeks found two
different forms of bacteria, both known as blue-green algae because like plants
they use sunlight to create energy, plus another common bacteria, E. coli, that
indicates fecal contamination in freshwater ponds, according to officials at the
town and county departments. Blue-green algae, despite its name, can range in
color from red to black to green, according to Richard H. York Jr., Mashpee’s
shellfish constable and a former algae specialist at a marine biology program in
Hawaii.
The
local health board in the end of August discovered traces of anabaena, which is
potentially toxic, according to Glen E. Harrington, the Mashpee health agent.
Anabaena
(pronounced anna-beana) can be partially or completely toxic, according to Mr.
York. The current crop of anabaena in Santuit Pond is not necessarily toxic. It
was not tested to determine whether it is or not, Mr. Harrington said.
Within
a single bloom, different sections can have varying levels of toxicity and can
even switch from being toxic to nontoxic, Mr. York said. The toxicity depends on
environmental factors, he said.
The
board of health warnings were posted to be on the cautious side, Mr. Harrington
said. Even if not fully toxic, anabaena can cause significant digestive and
liver illnesses if it is ingested with water in heavy concentrations.
“It’s
something to watch out for. Is it a huge risk? No. It’s a matter of education
and information. That’s why we posted the notices,” Mr. Harrington said.
Visibility
in the water is the best way to look out for high levels of blue-green algae,
Mr. Harrington said.
Edward
A. Baker, an active environmentalist and president of the Mashpee Environmental
Coalition, takes regular visibility measurements of the pond. On Wednesday, Mr.
Baker found the visibility to be 22 inches. On August 16 it was 13 inches. Both
measurements are considerably less than the average visibility measured in
Santuit Pond from May to October, from 2003-2005.
The
state sanitary code for swimming beaches sets 4 feet as the recommended
visibility, according to Mr. Baker.
The
dissolved oxygen level, the amount of oxygen available to plants and aquatic
species in the water, has picked up in August, from around 7.5 milligrams per
liter in July to about 9.2 in August, according to data from the MEC. Oxygen is
needed both for aquatic species to survive and for dead algae and plant matter
to decompose.
Anabaena
can pull nitrogen out of the air, adding to the excess nutrient levels in the
pond.
Anabaena
was also discovered in Ashumet Pond in July 2002 and was closely followed by a
mass death of freshwater mussels. Mr. York said he was unable to prove that the
anabaena was directly responsible for the dead mussels, so it may have been a
result of low oxygen levels.
Mr.
Heufelder tested samples of pond water on Wednesday and found them “totally
blown out with microcystis,” he said.
Like
anabaena and other forms of blue-green algae, if it is ingested, microcystis
will impair liver functions, he said, comparing it to drinking “a six-pack of
beer.”
“It’s
not particularly dangerous unless you’re going to go down there and take that
stuff through a straw,” he said.
Combined
with the warm water temperatures in late August, an injection of phosphorous, a
type of nutrient with effects on freshwater similar to nitrogen’s effects on
saltwater, probably caused the blue-green algal bloom, officials said.
The
phosphorous may have come from septic system runoff from nearby houses, which
were likely running at high levels in August because of seasonal residents, Mr.
Harrington said.
Septic
runoff also may have caused the high E. coli levels at Bryant’s Neck, a small
public beach off Santuit Lane, Mr. Harrington said. The beach failed county E.
coli testing on at least six occasions in August, including three tests in a row
toward the end of the month.
Both
the blue-green algae and E. coli concentrations can be blown around the pond by
changes in wind direction, several officials said.
“We’re
hoping that the wind pushes it away from the swimming areas and that it cools
down a little more so that the algae dies,” Mr. Harrington said.
Residents
who live near the pond and environmental advocates in town have long spoken out
about the pond’s condition.
“This
has been going on for years. Back in the eighties, I went to the selectmen and
brought in a bottle of the water and told them it was degrading,” said Evelyn
L. Buschenfeldt, of Timberlane Drive, who serves on the Nitrogen Management Plan
Community Advisory Committee and volunteers for the Mashpee Environmental
Coalition. “No one ever did anything about it. Nothing has been done since.
It’s in sad shape.”
Ms.
Buschenfeldt said she has seen the pond make a turn for the worse since she
moved nearby in 1979. “The pond was beautiful, clear, just beautiful,” she
said.
“Every
year it gets worse. This year, right now, it’s terrible,” she said. “I
won’t even let my grandkids swim in it any more, even if they wanted to. I
just worry about it, you know?”
Members
of the Popponesset Bay Pilot Program, a joint effort between Mashpee and
Barnstable sponsored by the state and federal environmental departments, has
been looking into possible solutions to the water quality issues in Santuit
Pond. One solution discussed has been dredging to clear away the dense plant
matter smothering the sandy bottom, according to a draft report on nitrogen
mitigation in the pond prepared Mr. Baker, Mr. York, and James P. Hanks,
chairman of the waterways commission.
The
report, which Mr. York emphasized is preliminary and will require substantial
further research, primarily considers enhancing inoperative cranberry bogs
around the pond to help attenuate nitrogen.