Invasive Mussels May Help Fight Invasive Asian Carp

Here's one from the "Invasive Species Poetic Justice" file. Asian carp are knocking on the door of the Great Lakes, but at least one researcher believes the plankton-eating fish might have trouble establishing itself, due in large part to...wait for it...invasive zebra and quagga mussels!

From this story in the Milwaukee Journal-Sentinel:
Bighead carp can grow to more than 100 pounds by feasting on plankton - food upon which every other fish in a body of water directly or indirectly depends. Silver carp are slightly smaller, but they can be more disruptive to anglers - and boaters in general - because of their habit of jumping out of the water when disturbed by the whir of a boat motor. _These two types of Asian carp grow fast. If conditions are right they can consume up to 20% of their weight in plankton per day. "They are aquatic vacuum cleaners," says Charlie Wooley, deputy regional director of the U.S. Fish and Wildlife Service. "They will come in and clean out our native fish and sport fish."

But will plankton conditions be right in the Great Lakes? Gary Fahnenstiel, a researcher with the National Oceanic and Atmospheric Administration, thinks the invasive quagga and zebra mussels likely beat the carp to the Great Lakes buffet. The fingernail-sized mollusks have devastated plankton populations in the past decade, and Fahnenstiel says that means he doesn't think the carp will find enough to eat. Indeed, few believe the fish would thrive in the cold and relatively sterile open waters of the big lakes, but many biologists think they might flourish in the warmer bays and harbors - places where people tend to use the water.

Duane Chapman, a U.S. Geological Survey biologist and Asian carp expert, says the fish are remarkably resourceful at scrounging up meals. He says they likely could feast on the fields of cladophora covering the lake bottom, and they may even be able to sustain themselves on mussel excrement. At this point at least a small number of carp likely already have made their way into Lake Michigan, given the recent find of an adult bighead six miles south of the shoreline and multiple water samples in recent months showing the presence of Asian carp DNA in the Chicago area, including in Lake Michigan itself. But this doesn't mean a self-sustaining Great Lakes population is inevitable. The fish not only have to find enough to eat, they also have to find each other, and then they have to find an appropriate place to spawn. That means long free-flowing rivers that feed into the lakes._

Now if we could just find an invasive species to deal with the mussels, and then another species to deal with the species dealing with the mussels...