The Asian Carp invasion is within six miles of the Great Lakes , putting the region “on the brink of a great ecological and economic disaster,” according to Ohio Gov. Ted Strickland. At least one carp somehow got past the electrical barriers that were supposed to keep the fish away; other schemes for stopping the invaders include fences , chemical odors , and deafening underwater sound guns . ” Ecological separation ” of the Mississippi Basin from the Great Lakes may be necessary, if it’s not already too late.
Is the Asian Carp invasion worth being terrified about? Or is it a weird projection of American insecurity and xenophobia onto fish? News reports warn, in nearly identical language, that, as Time magazine put it :
the carp can grow into 4-foot-long, 100-pound monsters who devour 40 percent of their body weight daily. They destroy ecosystems by gorging themselves, and starving out other species.
Planning to go fishing for the invaders? When startled, the Asian Carp hurl themselves out of the water and through the air, where they can ” deliver a knockout punch to an unsuspecting angler .”
That’s the bad news. The good news is, the “Asian carp” does not exist. There is no such species .
Instead, there are multiple different species of carp, of Asian origin, with different habits, physiology, and behavior. The two of greatest concern to the Great Lakes are the bighead carp , Hypophthalmichthys nobilis , and the silver carp , Hypophthalmichthys molitrix .* The bighead carp grows to immense size, though rarely to 100 pounds. The silver carp leaps violently through the air, but it is considerably smaller. The bighead carp eats zooplankton and algae; the silver carp eats phytoplankton and detritus.
Mash the two together, take the most alarming features of each, and you get the Asian carp: a 100-pound river monster that flies through the air and devours everything in the water, to the tune of 40 pounds of food per fish per day.
Is this fantasy xenophobic? Sure it is. Everyone does it. In Beijing, in the lobby of an office tower, I saw a sign warning inhabitants about an infestation of the “American cockroach.”
The carp scare makes nice counterpoint to the panic over the invasion of Chinese snakehead fish a few years ago. Then, the story was that the snakeheads were uniquely destructive because they were savage and insatiable predators at the top of the food chain. Now the story is that the Asian carp are uniquely destructive because they are voracious and insatiable browsers at the bottom of the food chain.
Are the silver and bighead carp going to be a problem in the Great Lakes if (or when) they get there? Maybe, but it’s not because they’re superfish. The carp have been domesticated for centuries. They originally got into the Mississippi via aquaculture ponds. What their success demonstrates is that America’s aquatic ecosystems have been already so abused and depleted that what’s left of nature can be conquered by escaped livestock.
* Typo corrected.