Posted on 07/07/2022 6:20:00 PM PDT by nickcarraway
There are efforts to reduce invasive fish populations on Twin Cities lakes by a process called "electro-shock."
"We were catching them by the buckets. Five-gallon buckets. We couldn't even count them there were so many," said Jordan Wein of WSB.
Last year, it was open season on goldfish at lakes in Chaska and Robbinsdale. The former pets had been released into the water, where they multiplied and squeezed out native fish.
This summer WSB is going after another invasive species -- carp. The engineering company is trolling across Normandale Lake in Bloomington, using their electro-fishing boat to stun the fish below.
"It sends electricity in front of the boat by connecting an anode and a cathode just like a battery," Wein said.
While Wein drives, environmental scientist Kyle Blazek uses a net to bring in the catch.
"You have a second, maybe half a second to really grab at them," Blazek said.
It's not just carp they're hauling in. Catching other fish species gives them a better understanding of how healthy the lake is.
But it's the invasive carp they're targeting. Many are disposed of while others are tagged for tracking purposes.
"They are RFID tags, which are pretty similar to what you put into your home pet," Wein said.
So far, the electro shock efforts used to study and reduce goldfish have worked well. Catch rates are much smaller this summer, meaning the population has declined. Wein and his crew are now hoping for similar success with carp.
"I think knocking those carp and holding them back and really keeping them from rebounding will really solidify that those water qualities are here to stay for the long term," Wein said.
Wein said the concern with carp and goldfish is that they uproot vegetation at the bottom of lakes, which hurts native fish species.
Fish that can be turned into fertilizer.
And there are so many they literally just jump into your boat!
Electroshocking fish to remove invasive species and count desirable species is routine. Done properly, the electroshock does not kill the fish.
I have seen it done by the DNRs of several states.
Goldfish are a type of carp.
I have driven by the lake in Robbinsdale (I live nearby) there are some GIANT goldfish in that lake. You can see them from the street as you pass by.
They go airborne?
You can see them from the street as you pass by...35 years ago.
I would rather carp was crap and the word lake was not in the title. The invasive crap are the Somalis infesting the Twin Cities.
I’ve seen videos of them jumping out of the water and knocking boaters out as they drive by.
Rotenone works better. Just kill them all and restock.
The gov boys live area spraying!
Yep. I’ve seen rotenone used. And also plain old mullein, which does not kill the fish like rotenone. (Mullein is illegal for catching fish everywhere in the US, AFAIK)
Wow, incredible. Are they checking to see if there’s anything good to eat in the boat?
Yup!
Take a sustainable population of the native fish, wipe out any others, and re-introduce the farmed natives. Of course you'll have to factor in habitat/pH/spawning grounds, prey, etc.
Blaze the lake/river, and get the trash out.
“I have seen it done by the DNRs of several states.”
The company I worked for back in the 80s/90s built some electro-shock gear for the Oklahoma Department of Wildlife for population studies. The fisheries biologists would come by to pick up the orders and share stories with us.
“They go airborne?”
Go to YouTube and look them up. Insane.
1) they’re friggin’ HUGE.
2) The boat driver suggested a shotgun. I concur.
I watched the YT vid that “Airborne” provided in #11. Just incredible.
The ones I’ve seen were big metal hoops with generators/batteries providing electricity. Dropped into areas with large fish populations found with what looked like ordinary fish finders.
Very large (20+ lbs.) carp and 10+ lbs. northern pike were notable.
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