TAMPA BAY – When the thick, slimy algae known as lyngbya gets into a boat motor, the fishing trip, dolphin tour, or sunset cruise is over.
A local tour boat operator fears it may not only stifle business but suffocate seagrass and even marine life if something isn’t done about it.
Captain Ben Webb, of AMI Dolphin Tours, helped coordinate a cleanup today of the Waterline Marina in Holmes Beach at the marina’s expense. High-pressure water from a hose pushed mats of algae against a seawall, where it was vacuumed into a tanker truck for disposal.
It’s not easy to talk about the smelly mess.
“It’s kind of a catch-22,” Webb said. “If we tell everybody about it, then our businesses drop, but if we don’t tell everybody about it, all of our seagrasses, everything’s gonna die.”
Growing mats of lyngbya can cover large areas and be several feet deep, impeding navigation and recreation, smothering submerged plants and clogging water intakes, according to the University of Florida Institute for Food and Agricultural Science.
“What a pain. It gets into my motor and if I’m not careful, I could overheat and burn up my motor,” said Capt. Kim Ibasfalean, of Capt. Kim’s Charters in Bradenton Beach, where the algae clogged canals last week.
It’s also a health threat. Lyngbya can emit cyanotoxins that can cause people hay fever-like symptoms, skin rashes, respiratory and gastrointestinal distress, and, if consumed, liver and kidney damage, according to the U.S. Environmental Protection Agency.
Some worry that the widespread bloom of lyngbya, a type of blue-green algae that appears brown, could be related to the April release of 215 million gallons of polluted water into Tampa Bay at Port Manatee from one of the closed Piney Point phosphate plant’s retention ponds. The emergency release prevented even more wastewater from being spilled from a pond built on top of a gypsum stack that had begun to crumble. The water contained the nutrients phosphorus and nitrogen. Lyngbya feeds on those nutrients.
Nutrients going into the water from various sources “are definitely the reason we have it,” Webb said.
Since the discharge, fewer dolphins are using the waters near Port Manatee and are congregating more than two miles away from the discharge site, according to the Sarasota Dolphin Research Program at Mote Marine. The program has been monitoring the dolphin community near Port Manatee for impacts from the discharge.
“In the dolphin business, we take people out every day to see these dolphins,” Webb said. “If all this seagrass goes away, what happens then is these dolphins that have been here for years and years and tens of hundreds of years are gonna move on to find better places to feed. We’re so fortunate to have what we do here but this grass is going to die.”
Scientists taking water samples to monitor the effects of the Piney Point discharge said today that there is no known connection between the nutrients in the release and any algae blooms.
Red tide is the more pressing threat, particularly in late summer and early fall, according to oceanographer Dr. Robert Weisberg, with the University of South Florida College of Marine Science in St. Petersburg.
“It’s a little too early now to prognosticate about what’s going to happen then,” he said.
Meanwhile, water monitoring continues.
No cyanotoxins – the neurotoxins that are produced by blue-green algae – were detected in the water samples taken in Tampa Bay on May 18, according to the Florida Department of Environmental Protection. Results taken from samples on May 20 are pending.
Large-scale removal of lyngbya is difficult, partly because of the potential for damage to seagrass and mangroves in some areas, and partly due to the volume of the algae and its mobility due to winds and tides, according to Damon Moore, with the Manatee County Parks and Natural Resources Department. The department is tracking a lyngbya bloom at Robinson Preserve in west Bradenton.
“It is not feasible to remove the extraordinary biomass of lyngbya during these bloom events on a bay-wide scale,” he wrote to county commissioners earlier this month.
“It is highly probable that even if extensive resources were expended on physical removal of algae mats… that would not be enough to prevent negative consequences like putrid smell and fish kills because most of the material cannot realistically be removed from the water,” he wrote. “The scale at which removal would have to occur in such a large and open system is not likely feasible and is cost-prohibitive. Focus should be placed on blocking floating mats entering areas where that is feasible and cleaning it from heavily used areas (i.e. beaches) where mechanical removal is feasible without causing additional natural resource damages.”
Captain Webb issued a dire assessment.
“Everything in this water is dying,” Webb said, following his day of cleaning algae-choked canals. “And we just can’t have that here. It’s just time for the business owners to step up and say this has to stop.”
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