Fishing for Science! How Scientists Use Fishing as a Tool for Understanding Nature.
Fishing, by hook-and-line or other means, is perhaps one of the most valuable methods available to fish scientists. After all, fish often need to be caught before they can be studied. When one of my labmates at Wake Forest University, MC Regen, needed measurements of lots of sharks for her research, we went fishing. I called up my friend Capt. Joel Brandenburg, drove to Ruskin, Florida, met up with Ronnie Green, and caught and measured a bunch of sharks (inadvertently winning a fishing tournament in the process).
A lot of fish research in the US is performed on fish that people catch while fishing because they are easy to get a large sample size of, but also because there is a lot more public interest here in knowing about the life history and ecology of largemouth bass or snook than a small minnow in Gabon or a cichlid in war-torn Cameroon. However, these little-known fishes are perhaps the most important to study because so little is known about them and they may soon face extinction as a result of human activities. Joe Cutler, a National Geographic’s Explorer and PhD Candidate at UC Santa Cruz, has made it his mission to describe these fish before they are gone. To do this, he goes fishing.
The best thing to do when nobody knows about the biodiversity of fish in a stream or lake is just to go and catch everything you can to see what’s there. That’s what Joe does; he uses a variety of fishing methods (hook-and-line, dip nets, gillnets, electrofishing, fish traps, cast nets, seines, etc.) to catch a wide range of sizes and species throughout Gabon and Cameroon. This allows him to get the best idea of the biodiversity in those waters, as well as describe new species by catching them and realizing that they are not in any books or museum collections.
In Gabon, Joe uses this information to describe biodiversity hotspots and determine locations that may be most at risk due to human activities like mining, deforestation, and pollution. Next year, he will drift 750 miles down the Ogooue River, catching as many fish as possible. By determining the number and distribution of species in the river, he can inform the government of Gabon on where the biodiversity is greatest in the river. Since there are currently 14 proposed hydroelectric dam sites along the Ogooue River, the government can use this information to avoid dam sites that would cause the most ecological harm. While his main goal on this trip will be conservation, Joe assures me that he will bring his fly rod and plenty of flies with him this time
However, fly fishing may not work in many places off the beaten path, particularly in west Africa, where the water is so murky that you’d wonder if it also tastes like chocolate milk (although you may have some luck with dark dry flies and poppers). If you plan on fishing somewhere where there isn’t much information on how to fish, Joe recommends trying a variety of hook sizes and natural baits to get the best idea of what’s biting in these waters. In murky waters, natural baits work great because fish can follow the scent to your hook. However, if you insist on using artificial lures, crankbaits will also work well because they make a lot of noise and vibration that well get the attention of fish, even if they can’t see it.
If you don’t care about using a fishing rod and just want to add a ton of new species to your list (not to brag, but I’m currently at 321 species), try using a cast net or dip net in an exotic place. According to Joe, if you dig around in the reeds with a dip net in west Africa, you can easily catch 50 different species in an hour! Personally, when I travel to a new place, be it Scotland, Belize, or the Yadkin River in North Carolina, I make sure to bring a handful of spoons. When the water has at least a few inches of visibility, something will always hit a spoon (Scotland – salmon; Belize – jacks; Yadkin River – bass, sunfish, and a 40 lb flathead catfish that got away and still haunts me to this day)! It may not always be big, but something will strike and that’ll at least give you a sense of what’s in the water.
Noah Bressman is a PhD candidate studying fish biology, behavior, and biomechanics at Wake Forest University. Below is Noah and MC Regen with Bonnethead Sharks (Sphyrna tiburo), caught on live threadfin shad with 30 lb monofilament leader on the flats near Ruskin, Florida.
Follow Noah on social media: @noahwithfish