A few concerned local citizens are taking the health of the Long Island Sound into their own hands.

From May through October, nonprofit Save the Sound, an organization dedicated to the health of the body of water, will continue its Unified Water Study: Long Island Sound Embayment Research program for a second year, testing the water conditions in the Sound’s bays and harbors. The program operates through a grant from the Environmental Protection Agency and using a corps of trained testers, called Sound Sleuths, who volunteered to measure dissolved oxygen, chlorophyll, temperature, salinity and water clarity out on the water at dawn twice monthly during the six-month period. Port Jefferson Harbor will be tested by members of Setauket Harbor Task Force, a nonprofit group founded in 2014 to monitor and advocate for the health of the harbor, who volunteered to serve as Sound Sleuths. Setauket Harbor lies within the greater Port Jefferson Harbor Complex.

Task force members George and Maria Hoffman, Laurie Vetere and volunteer Tom Lyon set out in a roughly 15-foot-long motorboat May 25 at 6:30 a.m. to test 10 randomly preselected specific locations in Port Jeff Harbor, with testing equipment provided by Save the Sound, for the second round of research set to take place this spring and summer. The testing needs to be completed within three hours of sunrise in order to ascertain the most valid data possible, according to George Hoffman.

“I know a lot of people are familiar with water testing, but it’s usually about pathogens,” Hoffman said, which often is examined to determine the safety of swimming or eating shellfish. Testing for water chemistry will reveal more about the health of marine life in the harbor. Hoffman discussed the task force’s plans for testing during a May 6 meeting of the Port Jefferson Harbor advisory commission, a group overseen by the Town of Brookhaven that includes representation from all nearby municipalities and also takes up the responsibility of monitoring harbor health.

“We’re not testing for pathogens,” he said. “This is really about harbor health and chemistry.”

Hoffman said while out on the boat May 25 the group tested each of the 10 sites twice — once about a half a meter off the bottom of the harbor and once a half a meter from the surface of the water, using an instrument called a sonde, which is attached to a long cable and submerged in the water. Hoffman said the instrument costs about $30,000.

“That gives us a pretty good idea of what’s happening in the water column,” he said.

Save the Sound explained the importance of testing the chemistry of bays and harbors within the Sound in a May 16 press release announcing the year 2 testing kickoff.

“More than a decade of federally funded monitoring of the open Sound has documented the destructive impact of nitrogen pollution — including algae blooms, red tides, loss of tidal marshes and fish die-offs — and the incremental improvements brought about by wastewater treatment plant upgrades,” the release said. “Conditions in the bays and harbors — where much of the public comes into contact with the Sound — can be different from conditions in the open waters. More testing on bays and harbors is needed to judge the effect of nitrogen on these waterways and what action is needed to restore them to vibrant life.”

Suffolk County Legislator Kara Hahn (D-Setauket), who also chairs the county’s Environment, Planning and Agriculture committee, said while the county has taken up the fight in finding ways to reduce the amount of nitrogen in Long Island’s waters, having dedicated citizens also keeping an eye is an asset.

“That’s critical, these kind of community efforts to protect water bodies,” she said. “It’s special.”

Results of the study will be published in future editions of Save the Sound’s Long Island Sound Report Card.