State of the river report gives mixed review

Jesse Hollett
Posted 10/18/17

GREEN COVE SPRINGS – An annual report shows the health of the St. Johns River and its tributaries has improved while other aspects continue to worsen.

The 10th annual State of the River Report …

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State of the river report gives mixed review

Posted

GREEN COVE SPRINGS – An annual report shows the health of the St. Johns River and its tributaries has improved while other aspects continue to worsen.

The 10th annual State of the River Report published in September by researchers from the University of North Florida, Jacksonville University, Florida Southern College and Valdosta State University shows mixed results regarding the health of the St. Johns River and its tributaries that show the need for continued testing.

Trends from the latest report show lower nitrogen and phosphorus levels from years prior. High nutrient levels in waterbodies can contribute to the growth of toxic algae blooms, which harm marine wildlife.

“Our summary of 10-year findings shows long-term drops in both nitrogen and phosphorus, which is good news about an important indicator that regional organizations have worked to improve. But algal blooms, which come from high nitrogen and phosphorus, haven’t decreased yet,” said Radha Pyati, chair and professor of chemistry at the University of North Florida.

Chlorophyll-a levels in the river, however, have remained largely unchanged over a 10-year timeframe and show no indication of decreasing soon, according to the report. Chlorophyll a is the type of chlorophyll found in cyanobacteria – the bacteria that causes toxic algae blooms. Researchers monitor the density of chlorophyll-a in a waterbody to gauge the likelihood that toxic algae blooms will grow there.

Dissolved oxygen levels within the St. Johns River has improved overall. However, researchers said, oxygen levels in most tributaries remain unsatisfactory and worsening. Researchers said the lowest oxygen levels recorded occur in the summer months.

Many tributaries continue to sustain unhealthy levels of fecal coliform bacteria. Researchers often use the bacteria, which is ubiquitous in mammal feces, as an indicator of the presence of dangerous pathogens in the water.

Fecal coliform levels in St. Johns River tributaries have been rated unsatisfactory for all 10 years of the report series due to levels persistently higher than water quality criteria. Despite concerted efforts to identify remedies to these contaminations, sometimes referred to as Basin Management Action Plans, “this stubborn problem of fecal coliform bacteria persists in some tributaries,” Pyati said. “It’s getting better, although it’s not below water quality standards, in some tributaries, but in some tributaries – it’s not getting better, and it’s actually getting worse…it’s been a very stubborn problem.”

Other indicators have worsened as well. River salinity has risen gradually over the last two decades, threatening native marine species and vegetation.

“There are a lot of different activities in the Lower St. Johns River Basin that are going to affect salinity,” Pyati said. “I think the region has to balance all of the important concerns and get the very best information that it can.”

Of concern among environmental groups is a $704.5 million project to dredge the St. Johns River to enable the newest class of large cargo ships to travel to Jacksonville’s port. The Army Corps of Engineers expects the first phase of the project to begin in December, despite a federal lawsuit filed by the St. Johns Riverkeeper.

The Riverkeeper maintains the dredging project would harm the health of the river and increase salinity.

According to the river report, improvement has been made in conditions for the bald eagle, wood stork and the Florida manatee. Manatees, in particular, are susceptible to major salinity increases, which can kill off waterbed grasses – therefore, the report maintains that while conditions for these animals are improving, it is important to continue to monitor water conditions.

“Salinity continues to increase from a variety of factors, some of which are natural and some caused by human actions. Ever since the river has been modified by humans, particularly by digging it deeper and removing fresh water, the increase in salinity has been exacerbated,” said Gerry Pinto, associate research scientist at the Jacksonville University Marine Science Research Institute.

“The cumulative effects of increasing salinity stress the system, creating unfavorable conditions for habitat and what it supports. Of particular concern in this regard are the grass beds that prefer to grow in fresher conditions and provide food for manatees and shelter for juvenile fish,” Pinto said.

Among other development in the river is that nonnative species infiltration rose from 56 total in 2008 to 80 this year, according to the report. The lionfish continues to hold the limelight in dangerous nonnative species for their threat to the native ecosystem.

The State of the River Report doesn’t attempt to draw causal links from one piece of data to another, but rather draws from collected data by local and state agencies as well as researchers to form an easily accessible report for the public.

To read the report, visit sjrreport.com.

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