Local marine scientist predicts toxic algae bloom in river this summer
Conditions are ripe for a “toxic” algae bloom to crop up in the St. Johns River this summer, warned Dr. Quinton White, executive director of the Marine Science Institute at Jacksonville University during a meeting of the City’s Waterways Commission April 12.
“The river is warming up rapidly after what was a very mild winter. I’m very concerned that because the water is so warm, and we have so many nutrients in the river, there is a good chance a toxic algae bloom may occur sometime this summer,” White reported.
In his report to the Waterways Management Commissioners, White also said he was concerned about “high salinity” in the river due to warmer water temperatures, a lack of rainfall, and an especially “bad drought” in Central Florida.
“Right now, salinity is running high – 20 to 23 parts per thousand at JU while at the mouth of the river at Mayport, it’s running almost full strength sea water at 35 parts per thousand. The situation at JU is a little bit higher than normal,” White said, adding the water temperature was 75 degrees at the university, and at the mouth of the river, 72 degrees.
In short, the current situation is “very stressful for marine organisms,” he said, noting when a “deluge” of rain comes, it drives the salinity down temporarily causing a yo-yo effect with the river’s salinity, forcing many marine species to shift to different parts of the river.
“We’ve been watching all the submerged vegetation in the river in Duval County go away because of the high salinity. This will cause a problem in the foreseeable future, especially when we see potential dredging without active mitigation,” he said.
However, the State of the River report was not all bad news. White’s JU colleague, Dr. Gerard Pinto, reported recently the manatee had been “delisted” from the endangered species list and placed on the “threatened” list.
“We have 6,200 manatees, which is a lot higher than in the 1980s when the number was around 1,200,” said Pinto, noting in 2017 there have been only two manatee deaths, one due to watercraft and the other due to stress from the cold. “The population is really coming back and growing,” Pinto said. “In the last 10 years, it has increased significantly.”
River problems: salinity and nutrients
In an interview at the Marine Science Institute April 17, White said the two main problems facing the river today are the increase in salinity and nutrients, which are the cause of algae blooms. While salinity, caused by a lack of rainfall and water-use patterns in Central Florida, is beyond an individual’s control, White said there is much individual residents can do to assist in limiting the amount of nutrients that flow into the river.
“People don’t fully appreciate that what they do impacts the river,” White said. “People think, ‘what I do doesn’t really matter,’ yet if we could get more people to reduce the amount of fertilizer they use and not to blow leaves and grass clippings into the street, it would make a difference.
“Also, it is important to be very strategic in watering. I don’t water my grass. I only water my fruit trees and my garden. My grass stays fairly green, though it’s mostly weeds,” he chuckled. “It’s wasteful to water your lawn all the time.”
Although the upcoming Jaxport dredging project will most likely cause damage to the river, dredging smaller tributaries such as Millers Creek can be “beneficial” to the health of the St. Johns, White said. “It increases the river’s flushing capacity,” he said. “Tributaries are like our kidneys. We have silted them in through construction and road debris and by blowing clippings into the street,” he said. Having street sweepers routinely clean the streets would help in cleaning up debris, and it is important after a tributary is dredged to have a campaign against throwing debris down storm drains. “Until you stop the source of the sediment, you will have to keep up with the dredging because silt will flow right back in,” he said.
White said he is optimistic about the river’s future due to the increased awareness of the St. Johns by City Council President Lori Boyer’s Waterways Initiative, the city Waterways Commission, and other entities such as TruJAX, which has discovered that water has much to do with Jacksonville’s identity.
The Marine Science Institute has worked hard to educate the public and bring an increased awareness of the river, he said. Through its research, it is encouraging the city to add more artificial reefs in the St. Johns. The two manmade reefs, which lie 1,200 feet off Riverfront Park in San Marco, are already drawing fish and more fishermen to that section of the river, he said.
JU’s recent cooperative partnership with Ocearch, a nonprofit organization that does research and tracking on great white sharks and other large apex predators, will also help draw attention to Jacksonville and subsequently the river, he said. Ocearch has recently made its home base at JU, and Chris Fischer, the founder of Ocearch, is now the university’s “Explorer in Residence,” he said, adding that the Ocearch research vessel was docked at JU in April.
“Jacksonville may be the key to what Chris says is the “North Atlantic Great Shark Puzzle,” he said. “They (the sharks) all come through here, and what is starting to emerge from the data is that the female animals give birth every two years and their migratory patterns reflect that. The males, on the other hand, try to mate with every female they can find and tend to go back to the calving areas on an annual basis.”
The folks at Ocearch are also looking at the impact of plastics and currents and other ocean phenomena, he continued, noting that although Ocearch concentrates on the sea, its research will still raise awareness of the St. Johns and its problems. “Anytime you raise awareness of the environment, the rising tide floats all boats,” White said. “Ocearch at Jacksonville University will bring attention to Jacksonville, and Chris Fischer is pumped about having some sort of center here where we can have displays and tours and all that. All we need is money, and a little time,” he said.
“I think it’s fascinating that all this interest in the river is coming to a point,” he said. “As somebody who has worked on the river for 40 years, it’s kind of fun to see this kind of grassroots support. It’s what we only dreamed of 30 years ago.”
By Marcia Hodgson
Resident Community News
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