ST. PETERSBURG — The city finally stopped pumping millions of gallons of sewage into Tampa Bay early Friday.

But now the region must grapple with the aftermath: What public health and environmental risks do 10 straight days of sewage spills pose to those who boat, kayak, fish and enjoy the bay?

A University of South Florida researcher said her initial findings are troubling.

Early but strong indications of an antibiotic-resistant bacteria were found in water* samples taken near the shoreline along Lassing Park and Harborage Marina, said researcher Suzanne Young. More tests will be needed.

Young and her fellow researcher have experience uncovering the hidden dangers of sewage. In July, they published a scientific study detailing the presence of vancomycin-resistant enterococci (VRE) in a 2014 sewage spill in Joe's Creek in Pinellas County.

That strain of dangerous bacteria found in untreated sewage hasn't been seen outside of hospital waste before, Young said.

She said her recent samples from St. Petersburg's shoreline provide another warning of the hidden dangers of sewage discharges. Young said climate change and rising sea levels makes the spread of such bacteria more likely.

"I don't see how it gets better," she said.

The Tampa Bay Times shared the USF researcher's results with the mayor's office, but an official said St. Petersburg Mayor Rick Kriseman would not comment until the final test results are available.

It's not just human life at risk. Kent Bailey, chairman of the Tampa Bay group of the Sierra Club, said the recent dumps endanger nearly every type of marine life.

Commercial fishermen like Steve Maisel, who has fished for grouper and snapper since 1984, worry that the sewage spills will lead to algae blooms like red tide.

"These red tides kill our fish," he said. "The ones that live near shore are devastated."

The ecological recovery of Tampa Bay has been a feel-good story for the region as the waters returned to a healthy state. A recent study showed that a healthy bay brings $22 billion in annual value to the region.

"Tampa Bay has been recovering extremely well from a low point back in the 1970s," Bailey said. "We're seeing scallops return. The water quality had been doing much better."

But now all of that could be undone. Tourism could be affected as prospective visitors see images of swirling sewage plumes and decide to vacation somewhere else.

St. Petersburg City Council member Charlie Gerdes is more concerned about the residents whose lifestyle is often centered around the water and use the bay for boating, kayaking, swimming or walking along the beach.

One of those people is Tom Lep, 47, who was fishing Friday at Vinoy Park.

"I fish every week, and I eat the fish I catch," Lep said. "But this makes me not want to. People use this water to swim and refresh themselves. Feces shouldn't be a part of that."

Meanwhile, residents fret about safety. The city removed warning signs from Spa and North Shore beaches after testing showed bacteria at safe levels. Warning signs remain posted at Lassing Park because of high counts of other bacteria.

The city tests for bacterial indicators, such as fecal coliform. But officials said they don't test for the antibiotic-resistant strains sought by the USF team.

The city is confident that its testing is accurate, said John Palenchar, St. Petersburg's environmental compliance manager. The city posted test results on its website Friday.

The city needs to communicate better and faster to residents, said City Council member Steve Kornell. Many of his constituents contacted him, worried whether they should be in or around the water after Hermine overwhelmed and damaged the city's sewer system.

"We need to do a little better job of getting (information) out quickly and more clearly," he said.

The dumping began Aug. 31, and the city reported to the state on Sept. 5 that an estimated 20 million gallons had been released. But the sewage discharge continued. At Thursday's City Council meeting, officials said a stuck flow meter may make it impossible to determine exactly how many millions of gallons of waste were released into the bay.

Harborage Marina managers say tenants have been upset that the smell of sewage fills the air around the docks.

"I find it difficult to understand how in 2016 this is happening," said marina manager Brian Sweeney. "We have people asking questions that we can't answer."

"There is no sense of urgency. This is about more than business, this is about destroying a natural resource that a lot of people in this county depend on."

The good news, Kornell said, is the city has allocated $58 million in the coming year's budget for sewer fixes.

But how dirty is the sewage that was dumped?

When the city starting dumping, officials estimated its composition would be similar to prior discharges. In June, the city's dump was between 30 and 50 percent untreated sewage.

Public works officials told council members that sewage flowing into the Southwest plant had been diverted from initial screening and filtering to accommodate more flow. Much of that sewage was pumped north to Albert Whitted, then into the bay.

Kriseman's office declined Friday to comment on the composition of the sewage.

The Pinellas County legislative delegation is now set to discuss the county's recent sewage woes. State Sen. Jack Latvala, R-Clearwater, has scheduled a meeting of the delegation on Sept. 20. The meeting was requested by state Rep. Kathleen Peters, a South Pasadena Republican, to address the problem.

Latvala said he will ask Kriseman for a tour of the Albert Whitted sewer plant. It was closed in 2015, removing nearly 20 percent of the city's sewage capacity. Until June's sewage crisis, Kriseman sought to repurpose the facility as a fish farm.

"We cannot go backward on our protection of the environment," Latvala said.

Update: USF researcher Suzanne Young collected water samples for testing. A previous version of this story contained incorrect information about what substance Young tested.

Contact Charlie Frago at cfrago@tampabay.com or (727)893-8459. Follow@CharlieFrago.