TAMPA BAY – The Sarasota Dolphin Research Program at Mote Marine is monitoring the dolphin community near Port Manatee for impacts from the April discharge of 215 million gallons of polluted water from the Piney Point phosphate plant into Tampa Bay last month.
The water was released from one of the closed plant’s gyp stack retention ponds to take pressure off the compromised stack, avoiding its collapse and a potentially worse spill of its contents. It is an acidic blend of saltwater and debris from a Port Manatee dredge project, stormwater runoff, rainfall and “legacy process water” – wastewater from phosphate processing that contains nutrients such as phosphorus and nitrogen, which feed toxic algae blooms.
The plant is in an environmentally sensitive area, near aquatic preserves at Bishop Harbor and Terra Ceia Bay.
Since April 5, four days before the discharge ended, scientists have conducted photographic identification surveys to determine which resident dolphins are being exposed to the highest concentrations of discharged waters, whether they are moving away from the discharges and whether they are having respiratory issues, exhibiting abnormal behavior or developing unusual skin conditions.
Preliminary indications are that fewer dolphins are using the waters near Port Manatee and are mostly congregating more than two miles away from the discharge site. Scientists have identified two dolphins known to the program since 1990, and another first identified in 2009.
The program, which works with the Chicago Zoological Society, has been studying the dolphin communities along Florida’s central and southwest coast since 1970.