Could the Tampa Bay red tide be linked to the Piney Point disaster?

Red Tide has arrived in Tampa Bay.

A patchy bloom suspected to be the cause of fish kills on the Pinellas Coast and around Port Manatee emerged two months after 215 million gallons of sewage was pumped into the estuary from the site of a former fertilizer factory.

People already have suspicions. But can we know for sure if harmful algae are feasting on the pollution at Piney Point?

“Nutrient chemistry in seawater is a complex issue, and that’s certainly true for Tampa Bay,” said University of South Florida chemical oceanography professor Kristen Buck, who took samples. after the liberation of Piney Point. “Red tides are also a complex phenomenon. At this point, we simply don’t have data to support a direct cause and effect relationship.

While there may not be hard evidence, said Tampa Bay Estuary Program Executive Director Ed Sherwood, “it doesn’t take much to put two and two together.”

“We haven’t seen this level of algae production at this time last year,” he said in an interview. And 2021 brought unusually dry weather, meaning heavy rains didn’t wash excess nutrients, namely nitrogen, into Tampa Bay. This runoff would provide an obvious alternative source of fuel for the algae.

Related: Red Tide reported off Pinellas Beaches; shellfish farming closed again

The state wildlife agency said the release would not cause Red Tide organisms to appear in Tampa Bay, but nutrients in the sewage could feed them once they arrive.

Scientists, including Buck, want to understand whether the specific nutrients found in Piney Point’s sewage match those taken up by organisms growing around the bay. They plan to use a sort of signature within different molecules – which can act as a natural tracer – allowing researchers to track where nitrogen goes and how it is used in the environment.

Sherwood described the process as similar to matching a fingerprint. It will take time to get results.

In April, shorebirds congregate on a fallen tree branch in the coastal mangrove estuaries near Port Manatee. [ DOUGLAS R. CLIFFORD | Tampa Bay Times ]

Thick mats of an algae called Lyngbya have blanketed waterways around Anna Maria Island in recent weeks, and Red Tide has been found at bloom levels near Port Manatee – where sewage from Piney Point were rejected – and off Pinellas beaches around Pass-a-Grille, Redington Shores, Indian Shores and Sand Key.

Dead fish were reportedly scattered at Sunset Beach, Madeira Beach and Indian Rocks Beach, among other places, according to the Florida Fish and Wildlife Conservation Commission, as well as near the Sunshine Skyway Bridge.

Hillsborough and Pinellas health officials have issued advisories warning visitors they may experience mild, cold-like breathing problems when around a bloom.

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Algae use nitrogen to grow. Polluted water at Piney Point has put high levels of nitrogen in the bay. It was released with the approval of the Florida Department of Environmental Protection, which said it feared a leaking tank on the property could collapse. The state has pledged to hold the private landowner, HRK Holdings, liable for damages.

Related: Failure at Piney Point: Florida lets environmental risk escalate despite warnings

Red Tide is not well understood. Algae produce toxins that harm marine life and can cause coughing, itchy throat, and eye and nose irritation. The flowers are generally more troublesome for people with chronic respiratory problems like asthma.

Several research projects are underway to better understand the causes of blooms and ways to potentially mitigate their effects. Carly Jones, spokeswoman for the state’s Fish and Wildlife Research Institute, said “there is no direct link between nutrient pollution and the frequency or triggering of red tides caused by Karenia brevis– the scientific name of the organism that has been found at high levels here.

“Piney Point did not cause the red tide in Tampa Bay,” Jones wrote in an email to Tampa Bay Weather“but whether or not this may be a contributing factor is a possibility we are exploring with a number of other collaborators.”

“We also just transitioned from drought conditions into Florida’s rainy season and started seeing rain for the first time. Drought and now rain may also play a role in some of the patterns we observed, in addition to some complex ocean currents.

Effluent flows from a pipe into a drainage ditch at Port Manatee South Gate April 6, opposite the former site of the Piney Point phosphate mill.
Effluent flows from a pipe into a drainage ditch at Port Manatee South Gate April 6, opposite the former site of the Piney Point phosphate mill. [ DOUGLAS R. CLIFFORD | Tampa Bay Times ]

Excess nitrogen spilled in lower Tampa Bay from Piney Point, according to an estimate shared by Sherwood, is equivalent to pouring about 100,000 bags of fertilizer into the water over several days.

He said he didn’t expect all the consequences to be immediately obvious. Sewage contaminants, he said, were pushed by winds, tides and currents through parts of the bay and along the coast. They may have been used first by other organisms, but when those die, the nitrogen is recycled back into the ecosystem.

Related: Piney Point contamination diluted in Tampa Bay, researchers say

Captain Todd Romine, who fishes at Holmes Beach, said there had been dead fish, particularly pinfish and grunts, found around Port Manatee. He said these species are “very typical of a fish killed by the red tide”.

The red tide is not everywhere, according to the latest update from the conservation commission. Clean samples were taken south of Tampa Bay, including Sarasota Bay.

Romine thinks the Piney Point landfill has something to do with the overgrowth.

“Typically that would be late August or September during the rainy season when runoff is at its peak,” he said. “It’s tough enough without having an additional man-made problem like Piney Point spilling 215 million gallons…into the bay.”

At a Thursday meeting of the Bay Stewardship Agency, a community organization that aims to protect Tampa Bay, Sherwood told scientists and government workers that the Piney Point situation had diverted attention from major restoration work.

A 2020 seagrass monitoring report found declining area in Tampa Bay, which could be a warning sign for the overall health of parts of the estuary. The heaviest losses were in Old Tampa Bay, near Feather Sound, researchers said. Bay managers who might be dealing with the algae problems there are rather engrossed in the response at Piney Point.

Related: Tampa Bay lost 13% of its seagrass beds in two years, study finds

Seagrasses are a fundamental part of the ecosystem as they provide food for animals such as manatees, habitat for nursing fish, and natural water filtration. The Estuary program monitors the seagrass beds near Port Manatee to determine how they are responding to the release and any potential algal blooms.

The area is years away from a devastating red tide that hit the southern Gulf Coast, shaking up a tourism industry now trying to recover from the economic drag of the local peak of the coronavirus pandemic.

“We are now in 2021 and we are preparing to potentially repeat these kinds of events,” Sherwood said in his presentation Thursday. The 2017-2019 bloom washed up tons of dead marine life on Florida’s west coast. Pinellas has spent at least $7 million cleaning up its shores.

People are enjoying the water on the beach, with most not paying attention to the occasional dead fish washed up after reports of red tide found in water samples along the Pinellas County coast.
People are enjoying the water on the beach, with most not paying attention to the occasional dead fish washed up after reports of red tide found in water samples along the Pinellas County coast. [ MARTHA ASENCIO-RHINE | Times ]

Visit St. Pete/Clearwater, Pinellas’ public tourism agency, said it was following up on new reports of Red Tide.

Tampa Bay’s restoration is seen as an environmental success that could recede unchecked. Defenders for decades have restored seagrass beds and improved water quality by pushing to reduce nutrients dumped into the estuary by people, including in sewage.

Nature relies on balance, they say, and a man-made crisis like Piney Point threatens to upend the system.

“It’s something that ripples through the environment in the weeks and months to come,” Sherwood told those gathered Thursday. “We are still in the throes of the response.”

Thursday, dead fish lie on the sand in Indian Shores.
Thursday, dead fish lie on the sand in Indian Shores. [ ARIELLE BADER | Times ]
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