Currents steering sea nettles our way
A sea nettle drifts through New Pass with the incoming tide on Tuesday morning. Luckily, the jellyfish with the long stinging tentacles seem to be staying away from Sarasota beaches.
By Kate Spinner
Tuesday, October 19, 2010 at 9:18 p.m.
SARASOTA COUNTY - In Sarasota Bay and some waters offshore, sea nettles are causing pain.
Driven by ocean currents, the jellyfish with the long stinging tentacles have been spotted from Fort Myers to St. Petersburg Beach. But luckily for swimmers in Sarasota, they seem to be staying away from the beach.
"I wouldn't say it's anything dangerous or severe, but there's a lot of them," said Gary Gilliland, an area charter fishing captain who has never seen so many nettles in his decades of fishing here.
During a kingfishing charter last weekend, he said, "there were jellyfish hanging off the line as the guy was reeling in."
Scientists do not keep track of sea nettle numbers here, making it difficult to say if there are more than normal, said Hayley Rutger, a spokeswoman for Mote Marine Laboratory in Sarasota.
But in an interesting abnormality, sea nettles were practically absent this summer in the northern Gulf of Mexico, where they are a near yearly nuisance for beachgoers.
"You guys got the sea nettles that we were supposed to get," said Monty Graham, a biological oceanographer who focuses his research on jellyfish at Dauphin Island Sea Lab in Louisiana. "What it looks like happened this year, for whatever reason the current went in an odd direction and moved the nettles south."
That could explain why fishermen are finding the nettles several miles offshore. They are usually a near-shore species.
Although sea nettles can propel themselves short distances to catch prey, they primarily move with ocean currents. Once the currents push them into bays and tidal estuaries, they tend to stay until cold weather takes its toll.
Sea nettles live only half their lives as floating jellyfish with tentacles. During the other half, they exist as polyps attached to reefs or hard surfaces on the sea floor.
When the water warms enough, the polyps transform and become free-floating. Nettles eat tiny fish, shrimp and other small sea creatures called zooplankton.
Because they can survive in low oxygen and other conditions inhospitable for other species, nettles tend to multiply into massive blooms when competing fish disappear.
For this reason, they are often associated with poor water quality.
Reports of sea nettles here are relatively scattered, with charter captains and divers in Sarasota seeing large numbers and others, in Englewood and Charlotte County, seeing what they consider normal for this time of year.
"After dragging in some lines and trolling, you get some hot jelly on the line," said Mark Leppa, an Englewood charter captain. "Whether there's an influx, I don't know."
At the Venice Fishing Pier, thick schools of threadfin herring commanded almost all the attention of tourists, fishermen and hungry flocks of pelicans and terns.
There were just enough nettles in the writhing mass of fish to give any swimmer pause, however. The nettles, and the fish, were at least 200 feet from high-tide line.
JR Ayers, lifeguard manager for Sarasota County, said the beaches are mostly clear of jellyfish. Sea nettle stings here are a rarity, he said.
If there is any known danger from marine life at guarded beaches, a purple flag goes up on the lifeguard stand. Last week, the flag was raised because a bullshark was feeding in the swim zone.
"Occasionally we do have folks that get stung, but we haven't had any reports out of the ordinary," Ayers said.
Sarasota Herald Tribune
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