Carp: Shunned in Great Lakes, welcome in Texas
In fact, just last week city officials dumped 3,000 of the fish into Lake Austin, according to the Austin-American Statesman. That’s on top of 10,000 they already put in the lake to control hydrilla, an aggressive plant that clogs the lake, fouls propellers and overtakes native plants.
The grass carp is one of the species of Asian carp that wildlife experts fear could bypass an electric barrier at the Chicago River and eventually get into Lake Michigan. The concern is that the voracious eaters will thrive, disrupt the ecosystem and threaten the survival of native species.
The ancestors of the potential Great Lakes invaders also had been imported to crop down unwanted plant growth in commercial fish ponds. But when ponds overflowed during storms, the fish escaped into the Mississippi River where they’ve become prolific and spread to the point that they’re knocking on the Great Lakes door.
So what’s up with Texas?
Well, the grass carp in question are sterile – the city pays $6.90 a fish to an Arkansas fishery to get them that way, the newspaper reports. And local officials want up to 12,200 more in coming months. I guess the idea is that they grow fat by cleaning up the lake but leave no progeny behind that pose a longterm threat.
The Texans are not alone: A South Carolina town is stocking more than 100,000 of the fish for the same hydrilla-munching chore.
Again, all these fish are sterile. Or supposed to be.
I’m not sure how they make sure that’s the case – are there individual inspections? But with those kind of numbers you’ve got a wonder if a fertile Myrtle or two might slip through.
Regardless, there is a real cost-benefit weighing going on here with using one invasive species to control one already well-established.
What do you think of that kind of trade-off?