Report: L.I. Sound water quality mixed

Connecticut Post eEdition

Progress cited in individual bays and near open Atlantic Ocean, overall trend indicates plateau or decline in water quality

By Vincent Gabrielle

BRIDGEPORT — Regional nonprofit environmental organization Save the Sound released its biennial Long Island Sound Report Card this week at Captain’s Cove Marina. The report combines 14 years of water testing results in Long Island Sound and four years of testing in more than 50 bays.

“There’s millions of people that live along the Sound and up in the watershed,” said Bill Lucey, Long Island Soundkeeper. “It is incredibly integral to the ecology, the economy and our wellbeing.”

The report synthesizes several metrics of water quality including dissolved carbon, nitrogen, chlorophyll levels and water clarity. High levels of carbon, nitrogen and chlorophyll indicate the water quality is declining. Low water clarity indicates lower water quality. In bays the team also looked for seaweeds and oxygen saturation, marks of high quality. An interactive version is available on the organizations’ website.

While some progress has been made in individual bays, the overall trend of water quality indicates a plateau or decline in many regions of Long Island Sound. The open water portions of the report maintain the trend identified in earlier reports. The less developed regions of the Sound, closer to the Atlantic Ocean, have overall higher water quality than the narrower portions of the sound near New York City.

However, even though the overall grades and trends are stable there are signs of overall improvement in the water of the Sound. The Western Narrows, which have the worst water quality, have shown dramatic improvements in dissolved organic carbon, a marker of human impacts. Dissolved nitrogen, a marker of dangerously high nutrient levels, saw substantial improvements Sound-wide following decades of work to reduce the impact of sewage treatment plants.

Individual bays show similar trends to the open waters: bays closer to the cleanest water seem to be doing better. However, bay health is more dependent on local conditions. Over half of the bays, or bay segments got lower than a grade of a C for water quality. The five worst bays in Connecticut were Wequetequock Cove in Stonington, Inner Norwalk Harbor, Black Rock Harbor in Bridgeport, the Farm River near East Haven and Mystic River. Two of those bays are close to the mouth of the sound.

The healthiest bays in Connecticut were Outer Stonington Harbor, Mystic Harbor, Outer Housatonic Harbor, Inner Stonington Harbor and Scott Cove near Darien. The discrepancy between Mystic Harbor and Mystic River is likely due to the narrow mouth between the river and the harbor, which prevents nutrients from flushing.

While shouting over the wind and cries of seagulls state Rep.Jose Gresko of Stratford put a positive spin on Black Rock Harbor’s grade of D-plus.

“I don’t know how much worse you can get than an F minus,” said Gresko, referring to a previous grade. “But now we’re a D.”

State Rep. Steve Strafstorm of Bridgeport said that he was proud of the work Bridgeport was doing to reduce sewage overflows into the harbor and pointed to the state’s recent appropriation of money for Clean Water Act projects.

“The sound is the lifeblood of the Connecticut economy,” said Strafstorm. “Particularly here in Bridgeport.”

Jason Krumholtz, a scientist for Save the Sound cautioned that with climate change everyone has to be vigilant and keep working to improve water quality in the sound. Increasing temperatures, Krumholtz warned, would probably have widespread impacts to reduce water quality.

“Put simply, the warmer the water is, the less oxygen it holds,” said Krumholtz. Lack of dissolved oxygen is very dangerous for fish. “Well-coordinated efforts are necessary to protect water quality in Long Island Sound. Local action is necessary to protect base water quality.”

Krumholtz said that these shallow bays once supported vibrant eel grass meadows, oyster beds and fisheries and could do so again with our collective help.

“We’ve seen positive results from investments such as sewage treatment upgrades and green infrastructure,” said Krumholtz. “If we continue to commit the necessary resources, we will continue to make progress towards healthy conditions throughout the sound.”