The Invasive Trifecta
By Jeff Little
Anglers tend to personify fish. Maybe it's to protect one's ego when being duped by an animal who's brain is less than pea sized. "She knew right where that log was, bulldogged 'til she was past it and wrapped me around it!" Uh-huh. That animal is on the same cerebral tier as you, right? Well if we are going to personify fish, let's get into some character development on three fish I caught from the Potomac River recently. None are native to the watershed.
The Villian: Northern Snakehead (est. early 2000's)
This newcomer has drawn the ire of the media, been fingered as an impending ecological disaster and been portrayed as a fish that Darwin would have pointed to and said, "See! I told you!" The beast does inhabit shallow water, and lives for a long time when high and dry. But it's not going to crawl out the water, come to your house and eat your wife's Shih Tzu.
The stomach contents of the 30 incher I caught recently included predominately banded killifish, a plentiful mud minnow the length of your pinky. The snakehead’s long body and shovel-nosed face is perfectly designed to rocket forward onto the skinny mud flat shoreline and slurp down a mouth full of these morsels. I believe that the overwhelming fear from the angling community in this region was that the snakehead would replace the largemouth bass as top predator on the Potomac. It hasn't. It's just found it's niche and it's way into the hearts of many anglers.
I posted a photo of the beast to my Facebook account within minutes of catching it. By the time I car-topped my kayak, I had 16 comments, bipolar in nature. "Kill it now!" and "They are here to stay, I hope you released it!" are two that stood out showing how the initial Department of Natural Resources inspired lynching party has turned as many anglers have found the species to be a hard fighter and even better table fare.
The Hero: Largemouth Bass (est. late 1800's)
Bass Anglers from all over know what a terrific largemouth fishery the tidal Potomac is. What they may not know is that it wasn't always there. When George Washington made his home at Mount Vernon, overlooking the tidal Potomac, there were no largemouth bass in those waters. Now, you look in any direction and you're likely to see several bass boats zooming from grass bed to grass bed. I'm glad that they are here now, and I'm really glad that the northern snakehead has not pushed them out of existence.
The Biggest Threat: Blue Catfish (est. mid 1990's)
The first blue catfish I caught, I probably mistook for a channel cat. The gray to silvery blue coloration is similar to the gray to olive coloration of the native channel cat. The anal fin is the easiest way to discern if you're holding a blue or a channel. The channel cat has a rounded anal fin, whereas the blue cat anal fin has a flat edge. You can also count the number of rays in the fin, but who has time for that?
Just as stomach contents of northern snakehead are examined, fisheries biologists will slice open a blue catfish and take a look. What they often find is Maryland's most famous catch: the Chesapeake Bay blue crab. They also consume the same foods that our beloved striped bass eat: American shad, river herring and menhaden. Two of the three of these baitfish species are protected fisheries in Maryland. We can't catch and live-line an American shad or herring, but the exploding blue catfish population in our tidal rivers is gobbling them up by the truck load.
Jeff Little covers fishing options for times the water is muddy.
The fact that blue catfish has an economic impact on recreational and commercial fisheries is exactly what makes it invasive. If it had no economic impact, it would be deemed exotic or non-native. The invasive flathead catfish has established a population in the lower Susquehanna. It is an equally aggressive consumer of native fishes.
Maryland Natural Resources replied to an angler’s inquiry on their fishing reports page with the following strongly worded suggestion: "We ask anglers to remove and kill any blue and flathead catfish they catch. Catch and release of blue and flathead catfish is discouraged, as they are invasive top predators and pose a serious long-term threat to our native species." My strongly worded recommendation: catch them and release them into some hot peanut oil. Just like the northern snakehead, they are delicious!