JACKSONVILLE, Fla. -

Despite a recent case of flesh-eating bacteria in the St. Johns River, the seventh annual State of the River report shows reason for optimism.

According to the report, the levels of nutrients and metals have continued to decline, something researchers have been working for.

This comes just one day after a case of flesh-eating bacteria was found in a 7-year-old girl that officials believe had been swimming in the river. Experts caution that the bacteria occurs naturally in warm saltwater and brackish water and isn't something of major concern.

Overall, they say the health of the St. Johns River is improving.

"I think there are a lot of reasons to be optimistic about the health of the river now and in the future," said Lucy Sonnenberg, of Jacksonville University. "Twenty, 30, 40 years from now, there is no doubt that the river is in better shape than it has been."

The news isn't all good. Researchers found higher salinity levels in the river this year, which they said could cause a problem to some of the underwater plant life, especially between the Fuller Warren and Buckman bridges. That could lead to more algal blooms as the summer goes on.

"Those grasses and wetlands service filters to help the river deal with pollution going into it," St. Johns Riverkeeper Lisa Rinaman said. "So as you get more more salinity and you lose the grass -- we've already lost so many, and so the pollution problems are only greater."

While nonnative species like lionfish and muscovy ducks are a growing concern, researchers say that something that is naturally found in the river but wasn't included in this report -- vibrio vulnificus, a form of flesh-eating bacteria -- isn't cause for major concern.

"It is present, but we do expect to see growth in summer months, just like we do in shellfish," Sonnenberg said. "We see growth of bacteria in shellfish increasing in summer months."

While the St. Johns Riverkeeper said this latest report is another positive sign that the river is a great place for everyone to enjoy, she said there are ways for everyone to help make it better.

"The bottom line is we need to use less fertilizer and really focus on being river-friendly and protecting our river any way we can," Rinaman said.

Experts said that as the summer goes on and the weather stays warm, be on the lookout for algal blooms. They said if you do see any of them, report them to river authorities so they can try to find out exactly what is causing them.