A new study on perceptions of coastal water quality shows users may have more difficulty interpreting warning signs than previously thought.

The University of Rhode Island study, recently published in the Marine Pollution Bulletin, surveyed more than 600 recreational users around Narragansett Bay regarding their understanding of water quality to find that water quality had “multiple meanings.” A complicated conceptualization of water quality could have big implications for water policy and management.

“Water quality is pretty complex for people,” said Tracey Dalton, a URI marine affairs professor and Rhode Island Sea Grant director, who co-authored the study. “It’s not as simple as the chemical components that we tend to manage for.”

Water quality managers typically look at a variety of biochemical and physical indicators, including nutrients, temperature, acidity, oxygen levels, phytoplankton, fecal coliform and enterococci, to see if a site meets surface water quality guidelines set by the Environmental Protection Agency and outlined in the Clean Water Act.

But, according to the recent study led by URI marine affairs doctoral candidate Ken Hamel, these indicators can be difficult to understand for beachgoers, who more commonly tote sunscreen and beach towels than sterile sample bottles, plankton nets or conductivity, temperature and depth (CTD) sensors.

With help from his research team, Hamel conducted hundreds of in-person surveys at 19 sites along the Rhode Island shoreline. They asked recreational users to grade water quality in the area on a scale from 1 to 10, and then explain the reasons for their score.

Users generally perceived water quality in upper Narragansett Bay to be worse than in the lower bay. This assessment aligned fairly well with biochemical reports in the area, Hamel said, generally cleaner on the southern, open end of the bay than in the more urban, post-industrial north.

“You’ve got to wonder … how do people make that judgment,” he said. “Because they don’t necessarily know how much sewage effluence is in the water. They can’t see E. coli or enterococcus. They can’t smell it. Nutrients are also invisible.”

After a statistical analysis of the responses, the survey showed nearly 23 percent of users based water quality determinations on the presence of macroalgae or seaweed.

“Seaweed, which is a perfectly ecologically healthy organism for the most part — people perceive that as a water quality problem,” Hamel said. “From a Clean Water Act perspective, [seaweed in] the north is a water quality problem, the south is not.”

In the northern reaches of Narragansett Bay, macroalgal concentrations are often the result of nutrient overload, especially nitrogen and phosphorous borne of fertilizers and road runoff. It can indicate a problem with marine water quality.

But further south, macroalgae are less associated with pollution and are not necessarily an indicator of nutrient enrichment or water degradation, according to Hamel. Seaweed grows in reefs off the coast, breaks up due to wave action and can be blown on shore, especially on south-facing sands.

With no simple association between water degradation and seaweed, Hamel was surprised to see so many people use it as a basis for water quality determinations.

“There is very little research on perceptions of algae or seaweed period,” Hamel said. “It’s just a very understudied subject.”

Shoreline trash, “broadly defined” pollution, strong odor, water clarity, swimming prohibitions and nearby sewage treatment plants were also cited by beachgoers as indicators of poor water quality.

“People figured if there was a sewage plant nearby the water must be dirty,” Hamel said. “Although if you think about it, it’s slightly backward right. That should make the water a little bit cleaner.”

Another 9 percent of respondents also indicated that firmly held place beliefs played a role in water quality grades. These place beliefs, Hamel said, were “hard to pin down,” but were based primarily on the reputation of a place, whether linked to former industry or long-embedded regional knowledge of Narragansett Bay.

“One person even said, ‘This place is too upper bay.’ Like it was just common sense for them that water in the upper bay must be bad,” Hamel said.

Narragansett Bay visitors with water quality questions can find detailed reports for sites through the Rhode Island Department of Environmental Management and through the Narragansett Bay Commission. But, according to Hamel, the survey shows a need and opportunity to better engage beachgoers in water quality education, so the average recreation user can more accurately read the warnings presented in an environment.

“As a group of social scientists, we’re really interested in understanding how people are connected to their environment,” Dalton said. “From a policy perspective, it’s really important to understand what the general public thinks since they’re the ones who are going to coastal sites, they’re the ones affected by policies.”

The Clean Water Act, Hamel said, has gaps in the way it was written and interpreted by water managers. As set out in 1972, the federal law mandated that states reduce and eliminate pollutants primarily to protect wildlife and recreation. Nicknamed the “fishable/swimmable goal,” the law gives priority to recreational users.

The law is enforced at the state level, with slight variations in procedure, though it typically takes the form of measuring and monitoring biochemical and physical variables. But, according to Hamel, that strategy can leave out certain stakeholders and minimize non-user concerns.

“There’s a lot of other people that use the water that aren’t necessarily in it or on it,” he said. “And their … perspectives aren’t really considered by the way the Clean Water Act is implemented.”

There isn’t necessarily anything wrong with the law, Hamel said, and it has been instrumental in improving water quality. But policymakers and managers could better address all stakeholders and “more explicitly consider” the needs of non-users, he said, including those who may work or live nearby.

“In terms of how we direct our investments and direct our funds, we want to make sure that we’re also addressing what people care about,” Dalton said. “It’s really important to ground that in what the understanding is of the concept of water quality.”