We don’t see beneath the surface very well, so our view of the underwater world is pretty limited. As a result, we can never really be certain about exactly what’s swimming around down there.
This creates all sorts of challenges for fishery scientists who are tasked with keeping tabs on our aquatic ecosystems. If someone pointed at a lake and told you that your job was to figure out exactly what fish were in it — which species, what sizes and how many — what would you do?
If it was a small enough body of water, there might be a way to net it out. Or maybe you could electroshock the fish or use some other method of collecting them. But what if your task was to do this for a miles-long stream, or a river, or an entire ocean? For bigger bodies of water, it’s pretty tough to know what’s down there.
As you can probably imagine, scientists spend a lot of time figuring out which fish live where. Some of this is done by going fishing. Yes, biologists go fishing to sample fish, and sometimes it’s done with rods, reels, hooks and bait in a manner very similar to the way recreational anglers do their fishing. In other situations, nets or traps are employed. Some of this sampling gear is similar to the equipment used by commercial fishermen.
But there are other ways to get an idea about which fish might live in a bit of water. If you are looking at water that is not at all familiar to you, would it make sense to ask around to find out what fish have been caught there in the past?
Scientists do this in different ways. One method is to hang around boat ramps, marinas and bait shops and question anglers about their catches. After all, in a lot of places there are far more people fishing for far more hours over a much longer period of time than is ever likely to be accomplished by scientists, who always seem to be constrained by time, budget or both.
Talking to recreational anglers about their catches is called a creel survey. Creel surveys have been used for centuries by people studying fish, and this is a very valuable way to collect fish data.
Of course, there are problems with creel surveys. If the person asking the questions doesn’t actually see all the fish that were caught, then it’s possible that they will not be getting absolutely accurate information.
Anglers might not remember exactly how many or what species of fish they released earlier that day or last week. Some anglers might fib about what they caught, too, if you can imagine such a thing. A few might inflate their catches to feed their ego. Others might under-report their catches out of fear for spilling the beans about their secret hotspot, or out of a general distrust for government types who ask a lot of questions about anything.
And a surprisingly large number of anglers don’t really know what species they are catching to begin with. Have you ever misidentified a fish? I have, more than once.
To help keep track of which fish live where, fish scientists maintain lists of the fish that have been “officially” documented as having been caught in certain areas. For example, you might want to know what species of fish live in the Peace River watershed. This is a huge area which includes thousands of ponds, lakes, streams, creeks, canals and other waters. It would take several lifetimes to sample all of that water, and you’d never get it all anyway.
But you could look up the fish that have been documented in the watershed over the years and get at least a good starting point. The Florida Museum of Natural History at the University of Florida maintains data about the locations where fish species have been documented throughout the state. If a fish is included, it is known for sure that the fish came from the location listed.
It takes some doing to make this documented species list. If you catch a fish which has never been seen in your area before, you can contact UF with your information. But to make the “official” list, your catch will need to be verified by more than just a phone call. Crisp, clear photos are nice, but they really want a specimen of the fish which can be examined to confirm the precise species.
There are lots of fish, especially small fish, which look very similar to other fish. Often a careful exam of an actual specimen is required to positively ID them. The scientists keep those specimens stored in jars of preservative, and the jars are organized kind of like a huge dead fish reference library.
How huge? The collection at UF includes more than two million specimens. Well-preserved specimens can be viable hundreds of years after they were collected. It’s still possible to look at preserved fish that were collected by Charles Darwin in the first half of the 1800s. That’s pretty cool.
Florida has been undergoing something of a fish invasion for the last 100 years or so, especially in fresh waters of the southern part of the state. More and more non-native species are being discovered in more and more places as the populations of these creatures expand over time. Oftentimes the first indication that the scientists get that a new species has showed up in an area is when anglers start catching them.
For example, UF has gotten a few reports of a small (less than 4 inches) freshwater cichlid called an acara being caught in Charlotte County, where no official record of this fish exists. There is a species known as the black acara which is well established in Collier County, and another called the green acara which has been documented in the Tampa Bay area. It’s a guessing game as to which might be found here.
So here’s a question for our local freshwater anglers: Have you seen this fish? If you have a specimen, you could end up with your name on a jar in Gainesville.
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.