Narragansett Bay is Cleaner Than it’s Been in 150 years

Earlier in June, the “World Oceans Day Summit: Lessons from Narragansett Bay to the Global Ocean,” sponsored by the Newport-based nonprofit Sailors of the Sea and the the Bigelow Laboratory for Ocean Sciences, located on the Gulf of Maine, highlighted Narragansett Bay’s long journey to restoration from its history as a dumping ground for toxic metals, sewage, and other pollutants since the Industrial Revolution. With the advent of the Clean Water Act and the enforcement of upgrades for wastewater treatment facilities, Narragansett Bay is now cleaner than it has been in 150 years, says Dr. Candace Oviatt from the University of Rhode Island Graduate School of Oceanography, who led a decade-long study that found nutrient levels in the Bay down and the water clearer.

Scientists have collected three sets of long-term temperature data from Rhode Island’s Narragansett Bay; all of them show that it’s getting warmer. Photo by Doc Searls

“About 15 years ago, [the Rhode Island Department of Environmental Management] proposed regulations on wastewater management facilities emptying directly into Narragansett Bay. They had a goal of reducing the nitrogen input by 50 percent by 2014,” she said. “And I’m here to tell you they succeeded.”

To be more specific, nitrogen input into Narragansett Bay from Rhode Island wastewater facilities have been reduced by 65 percent in the upper to mid Bay to date, said Janet Coit, director of RI DEM.

“Every wastewater treatment upgrade has had dramatic reductions in nitrogen,” said Coit, noting that DEM is continuing to work with communities that don’t have plans in place to comply with the Clean Water Act by upgrading sewage and stormwater treatment technology through state and federal funding resources.

Nitrogen reduction has been such a steadfast focus for the state in cleaning up the Bay to reduce harmful algal blooms that lead to low dissolved oxygen levels, which can lead to fish kills, such as occurred in 2003 in Greenwich Bay. And while there are many sources of nitrogen, wastewater facilities have been identified as the primary source in Narragansett Bay.

Although the Bay is cleaner, in general, one area that isn’t is Mount Hope Bay, a tidal estuary that is an arm of Narragansett Bay. This may because of urban sprawl into the Tauton watershed that feeds into Mount Hope.

“The challenges are daunting because [Narragansett Bay’s] watershed spans 1,600 square miles across two states,” said Jon Stone, Director of Save The Bay, explaining that advocating for and managing water quality in two different management systems is difficult. “Water knows no political boundaries.”

And neither do fish.

“Our assemblage of fish through our trawl surveys looks more like the mid-Atlantic,” said Coit, noting the impacts of warming waters and increased acidification of Bay waters as a result of increasing levels of carbon dioxide in the atmosphere. “That’s changing, and we don’t understand all that’s going on.”

Regardless of the type of fish, one assumption was that cleaner waters would mean more fish, but scientists have yet to see that result.

“Since nitrogen reduction goals have been met, fish biomass is down,” said Oviatt, explaining that how the Bay will fully respond to reduced levels of nitrogen, in addition to warming waters and acidification, is still unknown. “We need to watch trends of [secondary impacts].”

Amidst the many unknowns, it is clear that the Bay is cleaner. “The turn around we’ve seen in Narragansett has been without question, dramatic,” said Dennis Nixon, director of Rhode Island Sea Grant, adding that “it’s a remarkable story of a coordinated effort,” between marine scientists, state agencies, local municipalities and nonprofits.

 

The World Oceans Day is celebrated on June 8 every year to honor the vast resources and intrinsic values of the ocean. This year, Rhode Island Sea Grant, Save The Bay, and the Rhode Island Department of Environmental Management joined Sailors of the Sea and the Bigelow Laboratory for Ocean Sciences to discuss the state of our global ocean, focusing on the success story of Narragansett Bay’s improved water quality.