Asian carp, an invasive and destructive fish, have spread through the Mississippi, Ohio, Illinois and Missouri rivers. In total, the fish are affecting more than 20 states from Louisiana to South Dakota.
Under the right conditions, it could take as few as a dozen Asian carp to establish a population in the Great Lakes. That’s according to a report published this month by scientists in Ontario.
If they’re correct, the risk of even just a handful of Asian carp escaping into the Great Lakes could be more significant than officials had planned.
SACHA PFEIFFER, HOST:
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The invasive and destructive fish called the Asian carp has spread through the Mississippi, Ohio, Illinois and Missouri Rivers. Overall it's affecting more than 20 states from Louisiana to South Dakota. And under the right conditions, it could take as few as a dozen Asian carp to establish a population in the Great Lakes. That's according to a report published this month by scientists in Ontario.
If they're correct, the risk of even just a handful of Asian carp escaping into the Great Lakes could be bigger than officials have planned for. So Michigan is getting ready to face off with this invader. From the HERE AND NOW Contributors Network, Michigan Radio's Lindsey Smith reports.
LINDSEY SMITH, BYLINE: Michigan's Department of Natural Resources considers Asian carp an imminent threat to at least some of the state's rivers. Tammy Newcomb is a senior water policy advisor with the DNR.
TAMMY NEWCOMB: All of the states that are facing invasion of Asian carp right now are having to adjust and learn. These fish are different than what we - the fish that we normally would catch like walleye.
SMITH: Adult Asian carp - we're talking specifically big head and silver carp - are a lot bigger than, say, a full grown walleye. They have huge appetites that can wipe out food for other native fish, and they can spawn more than once a year, outcompeting native fish that typically only reproduce once a year or less. Michigan's DNR sees prevention as key to saving a multibillion dollar fishing and recreation industry.
So this month they gathered the entire fisheries division on St. Joseph River. It's near the Michigan-Indiana border. There are no Asian carp here in St. Jo River, yet. There are electric barriers in the shipping canals near Chicago. Experts hope that'll keep the carp at bay. But...
TOM GONIEA: If they get into Lake Michigan, they have two choices. They can go left or they can go right.
SMITH: Tom Goniea is a senior fish biologist with the DNR.
GONIEA: If they go right, they're going to go up the Michigan coastline. The very first major river they're going to encounter would be the St. Jo.
SMITH: This drill is a test of that scenario. If Asian carp escaped, would the DNR's first responders, the fisheries team, would they be able to catch them? To find out, the Department of Natural Resources uses regular old carp, already living in the St. Jo, as target practice.
GONIEA: What they're going to do here is they're going to set nets perpendicular to the shoreline here so that they can electrofish into these as a wall.
SMITH: A dozen boats stamped with the DNR logo zigzag down a two-mile stretch of the St. Joseph river. But a few have these metal poles sticking out about three feet in front of the boat. At the end of each pole are these long pieces of metal cable that hang down in the water. The DNR's Todd Somers is the foreman of one of these homemade boats. He points out a 240-volt generator near the back of the boat. It can deliver up to 16 amps through the metal poles, sending electric shocks through the cables into the river. That'll stun any fish nearby.
TODD SOMERS: It's a lot of electricity. Yeah, it's very dangerous.
SMITH: So dangerous they didn't let reporters like me climb aboard to watch the drill. Somers says electrofishing isn't as easy as you think.
SOMERS: When the fish gets shocked, he doesn't actually gets stunned completely. He's still wiggling a little bit. Lot of times they'll come up to the top, but most of the time you got to go after him down on the bottom.
SMITH: Common carp are rounded up, zapped, netted, tagged and released. Then they try again using a different technique. Tom Goniea watches his team do this over and over again from shore.
GONIEA: Primary objective of this is to see how efficient we are at recapturing those fish. So we caught them once. Was it dumb luck? Can we do it again?
SMITH: Goniea says they hope such an effort would stop or at least slow Asian carp down if they got into Michigan rivers like the St. Jo, a river that researchers say would be good spawning habitat for the invasive fish. Researchers will analyze data from the drill. They expect to have results later this month.
For HERE AND NOW, I'm Lindsey Smith in Berrien Springs, Michigan.
PFEIFFER: You're listening to HERE AND NOW. Transcript provided by NPR, Copyright NPR.