It Had to Happen
By: Captain Ted Wilson
January 16, 2008

Winter time is upon us. Not a big deal really, it’s kind of a nice break from the autumn heat. It’s no wonder the snow birds flock here every year. Blue skies, mild temperatures and all of the trees still have their leaves. I’ve always maintained that barring a cold front, the winter weather is the nicest time of the year to be on the water. Now, you did hear me say, “barring a cold front” didn’t you?

Over the past year or so, it seems backcountry fishing has been better than ever. Days of 10 to 20 snook and/or redfish seemed almost commonplace. Granted, many of the fish were yearlings, often no bigger than an average sized seatrout, but the numbers were there. Fisheries management efforts seemed to be working well and the future looked promising for our beloved backcountry brawlers. Then Mother Nature threw a dirty curve ball right after the new year disguised as a cold front. The result was the most extreme drop in water temperatures in 18 years. The side effect was a massive fish kill due to the cold weather that affected not only the Keys and Florida Bay fish populations but fish stocks state wide as well. Snook, tarpon, grouper, snapper, grunts, parrot fish, barracudas and even catfish all succumbed to the fast-falling water temperatures. The Everglades National Park Service reportedly pulled over 500 snook and 50 goliath grouper out of Lake Ingram alone. I was in there a day or two later and witnessed dozens of dead fish they missed.

Weird things happen when sub-tropical ecosystems get blasted by unusually cold weather. Reports of permit and bonefish schooling in residential canals made for some fun dock fishing after the weather went back to normal. Dead crocodiles around Cape Sabal, iguanas free falling out of the trees. Cowfish and catfish swimming in circles near the surface in a daze. There were even quite a few reports of dead horseshoe crabs which is a species that has managed to survive for hundreds of millions of years with little or no evolution. It ain’t easy to kill a horseshoe crab. The guppies in my fish pond even died. I did manage to save some of them by dumping a few pots of well-timed boiling water into the waterfall. The neighborhood kids were pleased they still have a few left to overfeed when I go on vacations. But I digress.

The question is why did this happen? I spoke with Micah Bakenhaster from the Fish and Wildlife Research Association and asked him what it is about cold weather that kills fish. I’ll spare you the lesson in anatomy and physiology that he gave me (he’s pretty smart) and give you the meat and potatoes. Fish (and reptiles) are cold blooded. They depend on their environment to maintain internal temperature levels. Every species has a range of internal temperatures that they must maintain in order to survive. When levels go above, or in this case below, their specific range then the animal’s biochemistry begins to go a little haywire. Once this happens, things start to break down on a cellular level and if the animal does not find relief from the extremes it will perish.

The problem we had here in the Keys and Florida Bay was two fold. First of all it got very cold. Five-year lows were reported on the mainland. This in itself is not overly rare or necessarily a deadly problem. Fish can swim. If given time they will find deeper pockets of warmer water and grind it out. The second problem is what got ‘em. Not only did it get very cold, it got very cold, very fast. We were experiencing a mild winter up to the day of the cold front. Over a 24-hour period the air temperatures took a nose dive and the water temperatures followed. A fish kill double whammy. Florida Bay only averages around 38 inches deep. Water this shallow is the most vulnerable to huge temperature swings. There were reports of water temperatures dropping from roughly 75 degrees to the low 50s and in a few places high 40s. Too much, too fast. Nite, nite, termite.

So now what? I wondered what the long term effects are going to be on the fish populations due to the fish kill. The truth is, there really is no way to know. The oceanside fishing seemed less affected by the cold spell and is quite good. I’m assuming the insulating effects of the adjacent deeper, warmer water gave fish a cozy place to weather the storm. Up along the mainland, survivors have already moved into the holes made vacant by some of their unfortunate brethren. Despite the tremendous amount of fish that died back there, life still goes on. Mother Nature’s system of checks and balances is complex and at times hard to agree with but I’m sure She has a plan. For now, all we can do is scratch our heads and keep on fishin’.