Asian Carp in the Mississippi River
Asian carp are in the Mississippi river, on their way to the great lakes.
They don’t worry me.
The story goes that state agencies and fish farmers, looking for a biological solution to weed control, imported silver, bighead, and black carp, collectively known as Asian carp, to the United States. They escaped to the Mississippi River and bred. They crowd native fish out of preferred habitat, compete with young game fish for food, and most annoying of all, jump out of the water, which poses a hazard to boats traveling a high speed. The big worry is they’ll get into the great lakes. Fisheries managers have identified and blocked a potential point of entry in Illinois.
That’s not good, or so they tell me.
But some of the worries are exaggerated.
Asian carp pose no existential threat to native fish, with the possible exception of paddlefish. Bass aren’t going to disappear, for example.
Non-native species are not bad by definition. We stock and manage populations of non-native fish in many places.
Asian carp have good qualities. They’re tasty, make good fertilizer, and provide a recreational opportunity for people.
We’ll habituate to Asian carp with time, as we’ve done with other introduced species. Asian carp will become naturalized.
Asian carp won’t cause other fish to go extinct
It’s hard to make fish go extinct.
The Devils Hole pupfish, a fish that lives in only one body of water, could disappear if the water dried up, or the wrong predator got in there.
But fish with a wider range, like bass, are much less vulnerable. Fish are resilient to population disturbance. Fish lay a lot of eggs.
When times are good for bass, predators key in on the numerous bass fry. When times are bad, predators move away from bass fry, for the same reason bears don’t beat the bushes after berries in bad years. A high percentage of bass fry survive to adulthood in lean years.
Asian carp might reduce the numbers of native fish, but as native fish and Asian carp adapt to each other, the numbers will come into balance, as they did with native fish and common carp.
Fish are not threatened in the same way tigers are, for example. Tigers breed more slowly than fish, and disappear more easily.
An outlier fish that might be threatened is the unique and interesting paddlefish, a filter-feeding, direct competitor of Asian carp. The Mississippi River, however, is an over-productive system. Fertilizer runoff from the midwest grows plankton, just as it grows corn on land. Plankton cycles through the water column, feeds bacteria, and leads to oxygen loss in the water. Removing plankton from the river, which Asian carp do, is not necessarily bad. Paddlefish will still have food. Paddlefish are common enough that snagging them is legal in some states.
Black carp, which feed on molluscs, threaten endangered snails and mussels. However, black carp are the least successful of the three Asian carp species in America. That may change, but it’s true now.
Food, fertilizer, and for sport.
Asian carp are one of the the safest fish to eat from the Mississippi River. They eat plankton. You can’t get lower on the food chain than that. Fish low on the food chain have the fewer toxins than fish higher up.
Asian carp make good fertilizer. Some fertilizer plants already process Asian carp on an industrial scale. It should happen more. Removing Asian carp from the Mississippi River removes nitrogen and phosphorus, which helps solve a longstanding environmental problem. Excess nitrogen and phosphorus from the Mississippi create dead zones in the Gulf of Mexico.
Asian carp provide sport now, and will provide more sport in the future, as people learn to fish for them. People take them a fair amount with a bow and arrow already. Some people snag them, which is jerking a hook into their flanks. They can also be taken with exotic hook-and-line techniques not yet common in the United States. Asian carp have the potential to entertain outdoors-oriented people in a variety of ways.
We’ll get used to Asian carp
We habituate to all things.
Common carp, also from Asia, were introduced in the United States in the late 1800s. They colonized the Mississippi River from top to bottom. A commercial fishery exists for them. Fifty years ago, when I developed an interest in fishing, hand-wringing over common carp was common. Magazine articles described common carp in terms usually reserved for human villains. Common carp ruthlessly shoved innocent bass away from their nests to eat eggs, thoughtlessly muddied the water, and so on.
I don’t hear narratives like that anymore. In the past 50 years, carp-fishing fever has crossed the pond from England. Americans like carp now. It’s a thing. People hire carp-fishing guides. Cool kids fly fish for them.
I used to live in Phoenix, Arizona. The cement-lined city canals held common carp and grass carp. In a traditional, native-fish centered view of the world, I lived surrounded by trash fish in an artificial environment. It looked like paradise to me. I caught twenty-pound carp with bread balls and a Zebco 202 just down the block. It’s all in how you look at things.
Even if we don’t learn to love Asian carp, with enough time we won’t hate them. They’ll just be there. But I think we’ll like them.
Non-native fish are OK
Great lakes fisheries professionals manage non-native Pacific salmon.
In other words, Asian carp may be bad, but give me a better reason than non-native status. We value other non-native species.
The whole concept of native and non-native species is dubious. Animals have always moved around, and always will.
We’re hypocritical about species movements, depending on when they happened. If species moved in the distant past, if iguanas made it to the Galapagos islands, if people made it out of Africa, we see a miracle to be celebrated, wondrous life adapting to ever-changing circumstances, and so on. But let Asian carp get in the Mississippi River, and we’re appalled. “It’s a curse, a calamity, and a catastrophe.”
Well, Asian carp are here now. We might as well get used to them.
The idea that things are fixed in place is false. Our short lives are the only reason we see things as relatively stable.
Yes, people helped Asian carp, but fish eggs travel on bird feet too. Animals have always helped spread other animals around.
There’s little chance Asian carp damage the great lakes as much as introduced lampreys did. We’ve controlled lampreys, hard as that was. If we were a little less squeamish, we might eat them into submission.
Asian carp might pose a big threat to the great lakes, but not an unprecedented threat. We’ve been here before. We’ll adapt.
Fish of the future
As time passes, water quality will degrade further in North America. This is inevitable, unless human population stops growing.
Fish assemblages will include more rough fish like Asian carp.
There will be little victories for game fish here and there, rivers restored to a pristine state, that kind of thing.
But rough fish will have their day.
We should be thankful for Asian carp, not upset.
They thrive in a degraded Mississippi river, and in what numbers!
Most of the great assemblages of wildlife in North American, the passenger pigeons, the buffalo, are gone.
The fantastic numbers of Asian carp are heartening as much as they are discouraging. They’re a fantastic show.
Now, despite the arguments I make here, I wouldn’t have introduced Asian carp to the United States. I’m an old school, brook-trout kind of guy.
But I’m learning. I’m adapting.
Let’s live with Asian carp, instead of pretending they’ll go away.