PALMA SOLA BAY – With red tide fresh in local memory and blue-green algae hanging around since May, everything that produces nutrients that feed harmful algae blooms is under the microscope.
That includes the horse waste floating in Palma Sola Bay.
The Tampa Bay Regional Planning Council asked the Florida Department of Environmental Protection and the Pinellas County Commission in June to ban recreational horseback riding in Tampa Bay along the Sunshine Skyway Bridge causeway to reduce nitrogen and phosphorus from animal waste and to protect seagrass.
Some of the same horses that are rented at the Skyway also carry tourists up and down beaches on the Palma Sola Bay causeway and swim in the bay.
“We need cooperation from the public who bring horses and dogs to the bay,” said Darcy Young, director of planning and communications for the Sarasota Bay Estuary Program.
Palma Sola Bay has seagrass beds on both sides of the causeway as of last year’s survey, Young said, including in the northeastern section where most commercial horseback rentals occur.
“It’s possible, even likely, that the horses are walking on it,” she said, adding that people trample seagrass too.
“Bacteria, parasites and viruses can lead to poor water quality,” Young said. “If the situation gets bad enough in a concentrated area, you do start to worry.”
Horses are vegetarians, and don’t produce the same bacteria that carnivores – like dogs – do, said Charlie Hunsicker, director of the Manatee County Parks and Natural Resources Department.
“But horse poop is horse poop,” he said. “Whether or not it’s generating harmful levels, we don’t know.”
Jennifer Hoffman, executive director of Keep Manatee Beautiful, said the organization’s members are concerned about the impact the horses may be having on water quality in Palma Sola Bay, and rely on the Manatee County Healthy Beaches Program to advise of any issues.
The Florida Healthy Beaches Program lists good water quality in Manatee County except for Palma Sola Bay on May 13 and June 11, due to enterococcus bacteria from fecal matter. Enterococcus also can be a result of runoff or sewage spills in the bay.
Other bacteria like leptospirosis, which can be carried by horses and dogs – also allowed on the causeway – can be spread to people through contact with water, especially cuts in the skin, and from soil containing urine from an infected animal, according to the Florida Department of Health.
The Palma Sola Scenic Highway Corridor Management Entity also has discussed the horses at the causeway.
Horses and dogs historically used the causeway beaches long before companies began using it for commercial purposes, Co-chair Ingrid McClellan said.
While there have been issues with the companies that rent horses on the causeway leaving waste on the shoreline, companies now scoop it from the shore, McClellan said.
“We have signs saying, ‘leave only hoofprints behind,’ ” she said, adding that representatives from one of the horse rental companies told the group that horses do not defecate in the water.
Manatee cause of death uncertain
Waste in the bay was blamed on social media on July 5 for the death of a juvenile manatee photographed at the boat ramp at Palma Sola Bay with the title, “Palma Sewar at its finest.”
The Manatee County Utilities Department confirmed no spills of untreated sewage in Palma Sola Bay in the 48 hours following the appearance of the manatee carcass, Hunsicker said.
The carcass was retrieved by the Florida Fish and Wildlife Marine Patrol and transported to the boat ramp, but it is not known if the manatee died in the bay or was retrieved from elsewhere, he said.
