January 24, 2010

As most have probably heard by now, the recent extended stay of abnormally cold weather in Florida has made its mark on many of the fish populations of the state. The winter here had already been cool. By December, many of the snook had already moved up into their backcountry winter hideouts that they hadn’t ventured into until mid-January or later in the previous few years.  When the first punch of extra cold weather reached in early January, it was like bad cold fronts of previous years – the snook found a deep spot to hide in, became lethargic, and waited it out. But the cool weather continued, and then it became colder. There were even reports of snow flurries as far south as Tampa. The Southwest Florida coast had frost for at least five nights in a row. The water temperature was stuck in the 40s, and fish started to die.

Although we certainly don’t fish for them, it was sad and amazing to see tens of thousands of catfish dead and floating. Mixed in with the catfish were spadefish, striped mojarra, mullet, jacks, pompano, and needlefish.  One day I helped a friend dipnet a mass of floating fish that had log-jammed at the end of his canal. We netted the fish with long-handled nets, dropped the fish into the bucket of his front-end loader, and he dumped the fish in an out-of-the-way location. Under normal circumstances this would have been illegal, but the state of Florida put out an Executive Order allowing the collection and disposal of dead fish.  We filled the bucket of that front end loader to overflowing five times before calling it quits. We got rid of most of the floaters on that day, but over the next week they kept coming.

When they died, some of the fish, like the ones I helped my friend dispose, floated right away. In shallow areas, or where the water was clear, the dead fish on the bottom could be seen, their white bellies glowing on the darker bottom. The extra low tides gave brief daily glimpses into the graveyard building in deeper waters. This is when the first counts of dead fish started, and when the media coverage came and went.

In deeper areas where the bottom wasn’t visible, most of the fish didn’t show themselves until they started bobbing to the surface a few days to a week after they died. The smaller, lighter fish floated first. Then the bigger fish started to show themselves – a lot of snook, a few tarpon.

Let me give you an idea of how the dead fish appeared over time, from what happened at one of our sample locations.  The first couple of nights when the temperature dipped into the low 30s, a lot of snook were belly up, but the gills were still pumping slowly. We sampled 30 dead snook – measured them and checked to see if they held tags from one of our studies. A handful of fish were struggling to swim at the water surface, where they could get the most from the bright sunshine.

In years past, this would have been the end of it. But this time the cold continued, and there was even a reinforcing front. A few days later another 35 dead snook were sampled. And then another 30 snook a day later.  

By the time the temperature started to warm, we had experienced extreme cold for almost two weeks, and the fish suffered.

A week later, the snook started to float. They were coated with mud from the bottom that had been their once and future grave.  On Saturday, we pulled 30 dead snook from the water. On Monday we counted 204. By Tuesday the count was up to 1,131. They mixed with dead catfish to form rafts that floated in and out with the tide, and around with the wind. I’m not aware of any other single spot with that many dead snook, but there are a lot of reports of 100 here, 100 there.
The sample of snook measured ranged from about 15” to 38”, with in the slot (in season, snook can be kept if between 28 and 32”) and above.

The impact of this cold kill on the snook populations won’t really be known for quite some time. It seems that some areas were harder hit than others. It will take a while for the state fisheries biologists to assemble, sort through, verify, and tally all of the reports they received. Believe it or not, it’s actually not easy to count fish accurately, and this is exacerbated by the shock of so many dead floating fish. It’s easy to get caught up in the moment, and overestimates are common.

In addition to the normal seasonal temperature patterns in Florida, events like this are why we are at the northern end of the geographic range of snook and numerous other fish species. The fish populations have been through these severe events before, most recently in 1989 and 1977. Natural disturbances like hurricanes and cold fronts are part of the world we live in, and are events the fish populations have been through many times before. They are going to continue to impact gamefish and their habitats. But two things are different now – there are more fishermen and less habitat – so it may be tougher for the fish to recover.

As if one should be needed, this should really be a wakeup call for recreational anglers. Get involved. Push for habitat protections and for habitat restoration. Commit to being a responsible, conservation-minded angler, and work on getting your fellow anglers involved. There is no quick fix for this.  IT will take diligence on the part of the recreational fishing community to make sure we have gamefish populations and habitats that are healthy enough to bounce back from these types of disturbances. If not out of a sense of responsibility, anglers should get involved in their own self-interest.

I’ve posted a few photos below. Snook are the fish with the flared gills, the others are catfish.

All material copyright Aaron Adams 2010 and beyond, unless noted.