Spearfishing the San Marcos River for Invasive Catfish

I’ve known this river for decades. I’ve fished in it, paddled it and coasted down it like an amusement park ride. It runs right through the middle of town, so it couldn’t be more convenient. The challenge has always been that I usually want to swim, so I don’t get much fishing done. Did this mean I didn’t have to choose?

On a weekday in late fall, my wife, Laura, and I decided to dive right in. We came equipped with wetsuits, photography gear and polespears, and were joined by photographer Scott Bauer and Dylan Depew, the local spearfishing champion. Our target was an invasive species known as the suckermouth armored catfish, aka Hypostamus plecostamus, aka “pleco.”

We were a spectacle in an empty river.

“What are you guys doing?” asked a long-haired young man sitting on the limestone blocks at the edge of the water below the old mill. A pair of goggles perched on his forehead. I explained our spearfishing mission. “No way,” he murmured, and then shouted over to his friend: “They’re hunting for catfish!”

In Spring Lake, the San Marcos River shoots up out of the Edwards Aquifer fully formed and fills a vast pond of crystal water. Giant fish and turtles cruise over springs that emerge from the lake bottom in spots that look like boiling sand. Visibility is so consistently clear, there is a small fleet of glass-bottom boats that allow tourists to watch fish and see an underwater archeological site where native tribes lived for at least 12,000 years. The place is in contention for being the longest continuously inhabited site in North America. Only scientists and divers are allowed in the water above the dam. I dream of swimming there like I dream of flying. I suspect it would make me young again.

A waterfall carries the river from Spring Lake past the old mill and drops into a pool under towering cypress trees before the river continues to Sewell Park. The old mill next to the falls, currently occupied by Kerby Lane Cafe, resides in what I consider to be the most beautiful location for a structure within a day’s driving distance. The first time I saw it, I assumed I would never be able to afford to eat there, but it was just another Joe’s Crab Shack. In the past 20 years, each restaurant on the site seemed like an unworthy boyfriend who had somehow landed the smartest and most beautiful woman in Hays County.

Spearfishing isn't really fishing. It’s hunting. Fishing is done by people who often cannot see their quarry — they stand in the everyday world with a thin filament connecting them to the hidden world, about which they must formulate and test theories.

Hunting underwater, you still must have theories about where to find prey, but the next step is to go there and look. And then strike.

The armored catfish we sought have been wreaking havoc on the San Marcos River since being introduced by people dumping their unwanted aquarium fish. They burrow into once-stable banks and disrupt the food web by eating algae and aquatic plants. They push out native species and take over important habitats. Spearfishing is one of the most effective ways of removing these invaders.

I tied my paddleboard to the arm of a fallen tree on the opposite side of the river and prepared to get in. There is so much stuff to keep track of: the board, the paddle, a dry bag full of clothes and snacks, a water bottle, sandals, thermos of hot tea, neoprene hat, goggles, snorkel and the spear itself.

While I was still fiddling with my stuff, Dylan emerged with his first kill, wriggling on the end of his spear.

I went down at the wall and worked my way toward the falls, looking in cracks between and below the stone blocks. I saw things looking back out at me. I launched my spear at one, and the spear came back missing a spine. I retrieved the spine and coaxed it back into its mount, noticing that my hands were already shaky from the cold. Not a good sign.

As I dove over and over, my body made invisible adjustments, lowering my heart rate and storing oxygen. I began to see the world underwater as my frame of reference, and surfaced only to breathe. Breathing became a kind of chore to be done as little as possible, and once I found the tempo of necessary breaths, the rest of my movements fell into place. I felt a sense of calm as I slowly explored the place.

The falls create an area of low visibility, not from silt but from the sharp, bright bubbles that danced against my goggles while the endless peal of the thunderous water pummeled my ears. I could see around this maelstrom from the edges of the river, as the contents of Spring Lake pounded down, disbursing a white column that split into curving hydraulics.

I settled into a pattern: clear goggles, grip spear, head down, swim, scan, dive. I held a diving flashlight in my left hand, but I had to drop it on its tether to hold onto a rock to resist the current. Now, without my light, I couldn’t see in the crevice. I tried to hook my feet around a log and find the flashlight again … was there something in there? I pointed the spear. I needed to breathe again, so I noted my location and resurfaced. I let off tension on the polespear’s rubber tube around my elbow, and blood flowed back into my forearm.

I went down again, saw something in a crevice and prepared to shoot. I opened my hand and my spear jumped out. The sound of steel tines digging into sand and rock carried through the water like it happened right next to my ear.

Dylan speared another pleco. It went into a red mesh bag, which closed on a metal hinge. He hung the bag on a piece of rebar that juts out of the old mill.

To the right of the falls, I searched through the bubbles. I edged around behind the falls, watching the cascade of bubbles pounding into the pit formed by the water. Behind me, obscured by the falls, a large rectangular chamber extended underneath the building. There is about a foot of clearance between the surface of the water and the concrete ceiling — enough room to allow a snorkel. When I panned with my flashlight, it was the aquatic version of walking into a bar in a western; the piano stopped and all eyes turned toward me. A couple of largemouth bass as big as my leg froze in place. It is illegal to spearfish bass here because they are a “game fish,” and spears are against the rules of the game. There were some sizable tilapia, which aren’t game fish, and are in fact invasive, but somehow, shooting into this scene felt uncouth.

A few feet above my head were the soles of the feet of patrons scanning the menu in Kerbey Lane.

Two bass sidled out of the chamber with one eye on me, and I turned to look back in the main pool. Scott was down there, moving across the bottom with his camera rig and scuba tank like a visiting alien. He was filming Dylan as he maneuvered in front of the crevice at the base of the falls. Dylan’s light was mounted on his head, which gave him a whole other arm. He got into the crack up to his shoulders and aimed his spear from the side.

I encountered Laura near the end of the wall. Like me, she had goggles on her face and a snorkel in her mouth. Humans can’t really communicate like this, so we regarded each other and went on with our respective quests. By the time I had an actual conversation with someone, it was difficult for me to talk.

“You look a little blue, you OK?” Dylan asked Laura. I looked at my wife — her lips were past blue, more of a purple. How long had we been in the water? I didn’t know what I was going to do next, other than somehow become warmer.

Back in the car we idled in the parking lot, cranked up the heater and drank hot tea out of a thermos. I was still too dizzy to drive, and Laura stared vacantly at the horizon. It was a pretty good feeling actually, like coming back from a long, beautiful vacation that had been compressed into a couple hours. We decided that spearfishing was a thing we did now, but we needed better wetsuits.