There is a lot that we don’t know, but there is some stuff about which we’re pretty confident — such basic facts as water is wet, the sky is blue, the sun sets to the west, and my fish will always be bigger than yours.
But wait — did you notice that none of those four “facts” is always true? Water’s not wet. It’s a liquid that gets things wet. Blue skies? Sure — or gray when there’s an overcast, or black at night, or tangerine orange as the sun is setting.
Even the sun doesn’t truly always set to the west, even though we think it does because we’ve heard that factoid countless times during our lives and have come to believe it. It’s sort of true, but not completely. The sun does set in a generally westerly direction, but the compass heading to the setting sun varies greatly with the time of year. In Punta Gorda, the direction varies from about 245 degrees to around 300 degrees, a variation of approximately 55 degrees.
This means that if you set sail from Boca Grande Pass and steer across the Gulf of Mexico towards the setting sun, you could come ashore anywhere from New Orleans to Veracruz, Mexico depending on the time of year. That difference is bigger than the state of Texas.
There are other things that fishermen “know” that turn out to not be accurate. Some are little things, such as the names of fish. A good example of this is the slender fish with the suction disc on its head that hitches a ride on sharks and other creatures including sea turtles, manatees and scuba divers. Pretty much everybody in Southwest Florida knows that these fish are called remoras.
But that’s usually not true. Most of these fish that we encounter in local waters are actually sharksuckers, not remoras. Remoras are generally associated with whales and big pelagic fish. Both fish are similar overall, but ours are sharksuckers.
And speaking of sharks, have you ever heard a Southwest Florida angler confidently proclaim that the shark that’s just been landed is a “sand shark?” This happens a lot, but it’s almost guaranteed to be wrong. Sand sharks, more frequently called sand tiger sharks, are very rare on this coast. But we think that sand sharks are common because we’ve heard that misidentification so many times.
Here’s another fact: If you need to bolster a fish stock that’s too low, one way to do it is to reduce the harvest of that fish. In recreational fisheries, one of the tools used by managers is the daily bag limit, a restriction on the number of fish that each angler can retain in a day’s fishing. Reducing the bag limit on a fish species can reduce the annual harvest of that fish.
That’s an easy concept to understand, and it’s definitely true. But things get hazy quickly when you dig a little deeper. If you want to reduce harvest by half, you’d cut the bag limit in half, right? That also seems pretty obvious and many fishermen assume that it’s true.
But it’s not. In fact, it’s not even close to being true. In most recreational fisheries, few anglers catch their bag limit every time they go fishing.
For example, the FWC is currently looking at reducing the harvest of flounder. One of the proposals being considered is to reduce the bag limit from the current 10 fish per person per day to only five fish per day. But this will not reduce the harvest of flounder by half. In fact, a more accurate estimate of the impact on the harvest of flounder in Southwest Florida would be that it will have essentially no effect at all.
How can this be? Well, here’s a question: Have you ever caught 10 flounder in a day’s fishing on local waters? Not many people can answer yes to that question. How many times have you caught even five flounder in a day? For most area anglers, the answer to that question is probably also zero.
Of course, somebody at some time has harvested more than five flounder in a day — or more likely, in a night, since the only way you’re likely to catch that many flounder here is by gigging them after dark. Point is, there are so few times that anglers take more than five flounder a day in our waters that reducing the bag limit from 10 to five will save hardly any fish at all from the fillet knife.
In fact, because it’s so rare for anglers here to catch multiple flounder in a day, it’s likely that even reducing the bag limit from 10 per day to only one still wouldn’t reduce the actual annual harvest by half.
Here’s another undisputed fact: When fish are scarce, we don’t catch as many as when there are lots of them around. But here’s a related “fact” that most anglers think is true, but is not: The best way to ensure that lots of fish are caught is to manage the fishery so that there are as many fish in the water as possible. This might sound like a scam being pushed by inept fishery managers or by greedy fishermen, but the truth is that most fisheries produce more fish for harvest when there aren’t as many fish as there could be.
Say what? Here’s how it works: If you eliminate all harvest of a species of fish and let the stock grow to its maximum potential as determined by the carrying capacity of the habitat, the stock of fish will naturally slow its reproduction rate so as to not overpopulate.
But if you harvest enough fish to drive down the overall population, that population responds by reproducing at a more rapid rate. The maximum annual long-term harvest of that fish stock occurs if you harvest enough of them to keep the population below the maximum carrying capacity of the habitat — but not so low that there aren’t enough fish left to reproduce successfully or to be found and harvested by anglers.
This theoretical sweet spot for the population of a stock of fish produces what’s called “maximum sustainable yield,” and it occurs when the population is substantially lower than the highest possible level. This seems counter-intuitive, but it’s true.
There are plenty of other non-facts floating around out there, too, but I fibbed about all of the first four being untrue — because my fish will always be bigger than yours.
Let’s go fishing!
Capt. Ralph Allen runs the King Fisher Fleet of sightseeing and fishing charter boats located at Fishermen’s Village in Punta Gorda. He is an award-winning outdoor writer and photographer, and is a past president of the Florida Outdoor Writers Association. Contact him at 941-639-2628 or Captain@KingFisherFleet.com.