COLLIER COUNTY — Monitors are stepping up their efforts to track an algae bloom that has been fouling parts of Collier County’s shoreline for the past two weeks and has been blamed for periodic fish kills on the beach.
The state’s Fish and Wildlife Research Institute, based in St. Petersburg, sampled offshore Thursday, and Mote Marine Laboratory in Sarasota plans to launch a robotic glider into the same area next week.
Scientists with FWRI, an arm of the Florida Fish and Wildlife Conservation Commission, collected samples from the surface and from the bottom at seven spots between two and 10 miles offshore Collier County, marine research assistant Matt Garrett said. Results could be available today. Scientists also measured levels of dissolved oxygen, salinity, pH and chlorophyll.
Garrett said the water offshore Thursday looked darker than it should be this time of year and had higher chlorophyll levels than would otherwise be expected.
Thursday’s sampling will help prove or disprove original theories that an algae bloom came ashore from offshore rather than starting inshore, but it won’t pinpoint what triggered the bloom, FWRI research scientist Alina Corcoran said.
“I don’t know we can identify an actual cause,” she said.
Algae blooms can be triggered by nutrients, such as from fertilizer or animal waste, that run off land and into canals and rivers that empty into the Gulf of Mexico.
But some algae species don’t always require new nutrients to bloom, Corcoran said. She said they also can use recycled nutrients or feed on byproducts of other algae.
An algae bloom first appeared along northern Collier County’s shoreline July 18 along with an unusual mix of offshore marine creatures, from lobsters to reef fish, some of them dead. The algae was not toxic but monitors said it robbed the water of oxygen.
The fish kill peaked the next day, eventually killing hundreds of fish between Doctors Pass and Wiggins Pass. Another smaller fish kill was reported last weekend between Third and Seventh Avenues South in Old Naples.
Reports of dead fish have since waned, but the algae bloom has not gone away.
Water samples collected Monday along the beach showed a bloom of Takayama tuberculata and other types of algae at Barefoot Beach, Vanderbilt Beach, Seagate and the Naples Pier.
The hunt for algae will continue next week when Mote launches a torpedo-shaped robotic glider nicknamed Nemo.
Scientists will program the glider, about six feet long and 110 pounds, to follow a predetermined course for a week or less between six and 20 miles offshore of Collier County, according to Mote.
The glider will send data continuously via satellite back to Mote for analysis. If all goes well, scientists will be able to use the glider’s data to retrieve it from the water when its mission is completed.
Connect with Eric Staats at www.naplesnews.com/staff/eric_staats