Cold Water Permit

An article by Ben Ianotta in the Keys News raises some interesting questions about how permit behave in response to cold water temps. As the article notes, a lower Florida Keys guide, Darren Doop, found permit in a surprising place during the recent cold weather: “After the last front, Doop went into the backcountry and couldn’t believe what he found. Permit. Not a lot of them, but big ones. They were swimming near the mangroves in the rising tide, at a place where a creek enters a backcountry island. The water temperature was 66 degrees.”
For those who wonder, 81 seems to be the ideal water temperature for getting permit up onto the flats, and if there are gobs of them around, that will continue until the water starts warming to 87 or so. The “slot”, if you will seems to be 78-88. Obviously wind direction and cloud cover will make a 2-3 degree difference to the equation: I’d much rather fish for permit in 79-degree water with a SE wind than 82 degree water with a north wind. The strength and timing of the tides also makes an enormous difference. Here’s an example: the air temperature could be 74, the rising water in the morning could be 70 degrees, but later in the afternoon, large sheets of water heating up over a dark grass flat might rise 5-6 degrees in temperature, so permit may begin feeding near the end of the outgoing on the edges of that flat, drawn up in to water that is now in the mid-70s.
As for whether big fish are more resistant, my guess would be yes. It seems that if the weather turns colder, the big fish leave the flats last. As to whether they come up first, I kind of doubt it, though if you see really big permit on the gulf side of the keys it is typically in cooler months, probably because they are stimulated by the same events that make early spring permit fishing so good.
(Thanks to reader David Dalu for the link to the Cold Water Permit article.)