'Frankenfish', Killer of Bass, or Misunderstood Transplant? The Truth about Snakeheads
Please leave some snakeheads for me!” shouted a local fisherman at my colleagues and I while we were collecting northern snakeheads (Channa argus) from Bumpy Oak Pond, Maryland, for my research. Like many other fishermen in the area, this guy wanted the thrill of catching these aggressive, tenacious fish. Despite initial fear of this invasive, Asian fish after they first appeared in a pond in Maryland in 2002, which inspired the 2004 horror movie Snakehead Terror, some people welcome their presence.
Are they an ecological nightmare that will eat everything in the water and then come onto land to eat your children? Or have their harmful effects been over-exaggerated? After learning more than I could possibly ever want to know about snakeheads at the 1st International Snakehead Symposium in July, I’m here to separate fact from fiction, weigh the pros and cons of snakeheads, and let you decide if they are good or bad for yourself.
Let’s start with the pros about snakeheads in the US. According to Dr. Annette Tagawa of Hawaii’s Division of Aquatic Resources, the only problem with non-native snakeheads in Hawaii is that there is not enough of them! Hawaii only has 5 native freshwater fishes, most of which do not get bigger than your finger, due to its isolation in the middle of the Pacific Ocean. The introduction of snakeheads (and other larger fishes from around the world) give Hawaiian anglers a great fish to catch; they strike and fight aggressively (they can’t resist hitting topwater), grow larger than bass (up to 20-40 lbs, depending on the species), and they taste really good.
Seriously, they may look ugly on the outside, but that shouldn’t matter because they are so delicious on the inside (tastes similar to walleye and snapper – I personally recommend blackened Cajun snakehead, but you can’t go wrong in how you prepare it). In Maryland, there is even a commercial fishery for snakeheads, which primarily involves bowfishing.
While many bass fishermen enjoy catching them throughout Florida, Arkansas, Hawaii, and the eastern states because they crush topwater baits like no other, many also see them as a nuisance. Whereas it is easy to lip a 4 lb bass, take the hook out, and quickly release it, a toothy, slippery, 15 lb snakehead can be more dangerous to unhook. According to Dr. Joseph Love of the Maryland Department of Natural Resources, a fisherman in the US lost a finger while unhooking a snakehead. He advises fishermen to avoid lipping snakeheads, instead using pliers to remove the hook. They also produce a lot more mucus than bass, making them very difficult to hold onto. Now, aside from their direct impacts on people, how do they affect the ecosystem?
Snakeheads are top freshwater predators in Maryland, Virginia, and most of their invasive range, says Dr. Love, consuming a wide variety of native species, particularly sunfish, shad, killifish, and frogs. Does that diet sound familiar? While snakeheads don’t eat many bass, they do eat the same things as bass, potentially competing with them for resources (Saylor et al., 2012). In some habitats, snakeheads outnumber bass, while in other habitats, bass do just fine with snakeheads around. Resource availability is the likely explanation for this.
“Snakeheads seem to occupy a much wider breadth of habitats than largemouth bass, which means they’d co-occur with bass in good habitats and possibly go it alone in habitats [poorly] suitable for bass,” says Dr. Love. So, snakeheads do have at least some negative impacts on bass and other native fishes (Love and Newhard, 2012; Love et al., 2014), but the extent to their ecological harm is still largely unknown.
Now, for the final snakehead mystery: can they walk on land? That’s actually the focus of my current research! Because of this, I can’t divulge all the details until this research is published (that’ll be for a future blog post), but let’s just say you don’t have to worry about snakeheads out running your children on land and eating them. Terrestrial behaviors aside, whether these fish are good, evil, or just misunderstood is for you to decide. If you catch a snakehead in the US, I encourage you to keep it instead of letting it go, to help mitigate any harmful ecological effects they may have (and have some delicious fish tacos), before the science regarding them is conclusive. If you don’t want to kill the fish, that’s your decision, but know that it is illegal in most places to transport live snakeheads in the US, and there are harsh penalties for spreading them to new bodies of water.
Noah Bressman is a PhD candidate studying fish biology, behavior, and biomechanics at Wake Forest University. Below is Noah (wearing his back-up fishing sunglasses) struggling to hold onto a very slippery Northern Snakehead (Channa argus), caught while electrofishing in the Nanjemoy Creek, Maryland.