Charter boat captain Al Griffiths has been fishing the waters around Tampa Bay for more than a decade. He's seen fish-killing freezes before, but none quite as long or hard as the one happening now.
He wasn't surprised that victims of the frigid weather began appearing belly-up along riverbanks, the bay and gulf beaches.
"These Florida fish, they can't handle the cold," Griffiths said. "It just stuns them. Their bodies go comatose."
Thousands of catfish and mullet littered the Little Manatee River on Tuesday morning, and black and silver mullet, ladyfish, jack, spades and sea turtles were seen dead in Clearwater.
It's happening across Florida, said Ron Taylor, a Florida Fish and Wildlife Conservation Commission scientist. The casualty count is likely to multiply as the water continues to warm, allowing decomposing fish to float.
Taylor specializes in snook, which he said have taken a huge hit across the Gulf Coast in the recent cold snap. He said most tropical-weather fish can't survive water below about 45 to 50 degrees.
"Several thousand are reported dead, and hundreds of thousands are in some state of stupor," Taylor said. When the sun comes up today, those hanging on to life will likely be revived, he said.
But as the water warms, that's also when most of the dead ones show up, said Florida Fish and Wildlife spokesman Gary Morse.
Dead fish decompose at a slower rate when it's cold, Morse said. The lower temperatures preserve their bodies, and as it warms up they begin filling with gas that makes them float.
"It's chemistry," Morse said.
For some fish, such as non-native catfish or tilapia, large-scale kills can be a good thing, reducing competition with native fish, Morse said.
But for other fish, like snook, it causes serious problems.
Snook are notoriously sensitive to cold, and as a result fishing for them is prohibited until March.
The Tampa Bay area is on the northern end of the snooks' habitat, and thus often has the coldest temperatures, he said.
Rick Roberts, executive director of the Snook Foundation, said this could be the worst weather-related snook kill since 1977, the year it snowed in Florida and an estimated 1 million snook died.
A freeze in 1989 killed 60,000 snook in Tampa Bay alone. It took five years for that population to rebound.
"What we're looking at is a phenomenon that not many living people have seen," Roberts said. "We'll have at least as many dead fish that died in '77, if not twice as many. Every fish that swims has been affected."
It's happening everywhere north of Fort Myers, he said. In addition to snook, huge numbers of puffer fish, catfish, grouper, snapper, pompano and others have been reported "just littering the bottom."
"We're going to see an absolute decimation of our marine fish," he said.
Jim Huddleston, who charters fishing trips from Tampa, Palm Harbor and Clearwater, said it's the worst he has ever seen.
Huddleston said he saw hundreds of dead snook near Pop Stansell Park in Palm Harbor this week. One looked to weigh at least 50 pounds.
"I didn't even realize we had that big of snook over here," Huddleston said. "It was a sad sight to see."
On his boat in Sutherland Bayou last week, Huddleston said he measured the water temperature at 42 degrees. And it was probably warmer there than outside the bayou, he said.
Charter boat captain Griffiths, who runs his boat out of Tarpon Springs, said not only is cold weather bad for fish, but fishermen as well.
"It's going to be hard fishing for the next month or so," Griffiths said. "There's no point, when the fish aren't biting. I had a charter this Sunday — I told them I wasn't going out."
Griffiths said when fish get cold, they enter a sort of stasis mode, swimming just fast enough to keep water moving through their gills. And they don't eat — meaning they don't bite.
"In-shore, I'd say you're shut down for a little while," Griffiths said.
It's not always the cold alone that kills. Sometimes fish stressed by chilly water seek warmer spots, even where oxygen levels are not ideal.
Other times they become lethargic and are scooped up by predators.
"It's sort of like when people get hypothermia and become disoriented," Morse said.
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