By Ed Killer for the TC Palm, view original story here.
There may be no oil on its way to Treasure Coast waters, but there is more cold water.
For the third time this year, unusually cold water temperatures are impacting the area’s marine environment. In January, frigid cold fronts generated chilling water temperatures experienced in South Florida only once per generation. But for a few weeks in May and June, and now again in August, upwellings of cold water from the depths of the Florida Straits have slid into the coastal shallows.
According to captains participating in the Stuart Sailfish Club’s Junior Angler Tournament on Saturday, water temperatures on the surface of the sea ranged from 82 degrees in 300 feet of water to 69 degrees in 70 feet of water.
“Out deep everything seemed fine on the surface,” explained Hotty Toddy Capt. James Ewing, “but several times I marked on the bottom what looked like bait (on the depth finder), but wasn’t able to get a bite.”
Like most anglers discovered, fishing activity was slow Saturday south of Fort Pierce to beyond Jupiter Inlet. Ewing figured it was probably cold on the bottom, but received confirmation of it when he heard two divers nearby talking to each other over the VHF radio.
“One diver south of Fort Pierce said it was 50 degrees in 80 feet of water,” he said. “As we trolled in closer to shore we started seeing the dead fish floating on the surface from about 200 feet of water into about 90 feet of water.”
Ewing said other than January’s fish kill in the Indian River Lagoon, he has never seen anything like it. Scattered in the currents were “every kind of snapper” including undersized mutton snapper, lane snapper, triggerfish and various reef fish like angelfish and parrot fish.
An upwelling is a meteorological phenomenon that takes place when surface waters are moved by winds and replaced by cooler water that arrives from the depths offshore. The challenge for anglers, scuba divers and snorkelers is to figure out when it will occur, how long it will last and what effects it will have on ocean activities and marine life.
Mitchell Roffer, a PhD. who founded Roffer’s Ocean Fishing Forecasting Service (ROFFS), said upwellings along Eastern Florida are created by persistent wind conditions from one of a few directions.
“Any kind of persistent winds that force surface waters farther offshore can generate an upwelling,” Roffer said. “As the surface water begins to move, other water will move in to replace it.”
Roffer noted that those winds can be southeast, southwest or even west winds. Sometimes the water that moves in comes from the north or south and in the summertime, it is common for that water to come from the depths of the Florida Straits.
“It is generally greener, more nutrient-rich water,” Roffer said. “Typically, although the temperatures will drop noticeably, it won’t hurt the fish species in a given area.”
But sometimes it does.
In 2008, Stuart diver Kerry Dillon recalled diving the Halsey wreck off St. Lucie County in 80 feet of water and seeing no fish whatsoever.
“I remember it being 47 degrees at another site and seeing gag grouper near the bottom completely motionless,” he said. That year, legal-sized grouper and snapper were found floating on the surface by fishermen.