Stories tagged carp


Yesterday, I had the pleasure of attending Environmental Initiative's 2012 Legislative Preview, part of their Policy Forum series.

Basically, a bipartisan group of legislators discussed their environmental priorities with a diverse audience of public, private and nonprofit representatives for the purpose of providing

"a valuable first look at the most pressing environmental issues facing the state in anticipation of the upcoming legislative session."

MN Most Wanted: Asian carp, aquatic invasive species
MN Most Wanted: Asian carp, aquatic invasive speciesCourtesy State of Michigan

The biggest surprise to yours truly was the prevalence of carp among the discussion. Asian carp, AIS (aquatic invasive species), etc., etc.. Everyone appeared in agreement regarding the threat posed by carp, so the real question is what do we do about their impending invasion?

One repeated suggestion was to fund more research, specifically at the University of Minnesota. This is probably an important step towards defending our state waterways, and I think this story helps illustrate why:

"As yet, no technology can stop these downstream migrations; neither grates nor dangerous, expensive electrical barriers do the job.

But a wall of cheap, harmless bubbles just might—at least well enough to have a significant benefit."

Researchers at the U of MN have discovered that bubble barriers may deter 70-80% of carp migration. It's not the visual affect of the bubbles that prevents all but the most daring carp from penetrating the barrier, rather the noise -- equivalent to what you or I would experience standing about three feet from a jackhammer.

The bubble barrier has currently only been tested on common carp, but researchers involved in the experiment want to test the technology on Asian carp next.

In addition to the bubble barrier, U of M researchers are investigating whether Asian carp pheromones can be used to lure them into traps.


Great Lakes fishing industry endangered

Asian carp
Asian carpCourtesy kate.gardiner
The commercial fishing industry in the Great Lakes, worth more than $7 billion a year, is threatened by Asian carp. Asian bighead (Hypophthalmichthys nobilis) and silver (H. molitrix) carp imported in 1970 to remove algae from catfish farms escaped into the Mississippi River during a flood. Since then they have outcompeted other fish. Along some stretches of the Illinois River, the carp make up 95 percent of the biomass. In December, the State of Michigan filed a lawsuit against the State of Illinois to close of locks between Chicago-area waterways and Lake Michigan.

"We cannot allow carp into the Great Lakes. It will destroy our Great Lakes fisheries, the economy," Michigan Gov. Jennifer Granholm said in a prepared statement." New York Times

Supreme Court denies appeal to protect Great Lakes ecosystem

On Jan 19, 2010, the U.S. Supreme Court turned down Michigan's request to block Asian carp invasion of Great Lakes (Scientific American). The Supreme Court didn't reveal any of the reasoning behind its ruling, which simply read: "The motion for preliminary injunction is denied."

White House appeal

Governor of Michigan, Jennifer Granholm, is "asking for an immediate summit at the White House with the administration to shut down these locks, at least temporarily, until a permanent solution can be found.”

The AP reported the White House response to be:

“The Obama administration clearly understands the urgency of this critical issue, and we look forward to meeting with them on the threat the Asian carp poses to the Great Lakes.” Dayton Daily News


Dude just took a huge carp: out of the lake. The carp referenced in the article, however, was found in a cave near a lake.
Dude just took a huge carp: out of the lake. The carp referenced in the article, however, was found in a cave near a lake.Courtesy redcarper
Did I write “carp” in the title of this post? That’s not at all what I meant to write. I guess it’s just one of those things spell check isn’t going to catch, you know, because “carp” is a real word. It’s a fish, but I wasn’t talking about fish.

No, I meant to point out that scientists have added another nail to the already pretty well sealed coffin of the Clovis-first hypothesis for the population of the new world. And exactly what is this nail? This crusty, brown nail? Why, it’s an ancient piece of dried human excrement. That’s right, a 14,300-year-old piece of carp.

The carp in question was found in Oregon’s Paisley Caves, a series of eight westward facing, wave-cut caves overlooking Lake Chewaucan. Not a bad place for a carp, I imagine. Apparently ancient Americans thought so too.

The Clovis first/pre-Clovis debate has been mentioned on the site before, but, briefly, here it is: For decades it was generally believed that the Clovis people (named so for the distinct style of stone tools they used) were the very first humans to inhabit the Americas. Clovis people are thought to have arrived in North America about 13,000 years ago at the earliest, and that there could have been people here before then was not seriously considered by most archaeologists. In the last thirty or so years, however, an increasing number of archaeological sites have been excavated that demonstrate very compelling evidence for pre-Clovis cultures in the Americas, people who arrived here thousands of years before Clovis. Clovis-first proponents still argue against the validity of some of these sites, which seem to indicate—stratigraphically and through carbon dating—occupation significantly earlier than 13,000 BP, but the presence of pre-Clovis peoples in the Americas is now more or less agreed upon.

This carppy new find, however, is the first actual example of pre-Clovis human DNA that has been found; it is the oldest human DNA obtained from the Americas. The team’s lucky geneticists were able to extract and analyze mitochondrial DNA, which is passed down the maternal line, from the dried carp. The carp itself was radiocarbon dated to be about 14,300 years old, and the DNA found was matched to haplogroups A2 and B2, genetic groups common to Siberia and east Asia. Interestingly enough, three of the six pieces of carp also tested positive for DNA similar to red fox, coyote, or wolf. My money’s on the theory that the carpers of Paisley Cave were some kind of wolf-people, although the University if Oregon team working at the site thinks it’s more likely that the people had simply eaten some foxes, or that one of these animals had urinated on the carp later.

Although the Paisley Cave site has generally been very productive in terms of yielding artifacts—archaeologists have found exceptionally fine threads of sinew and plant fibers, hide, basketry, cordage, rope, wooden pegs, animal bones, projectile point fragments, and “diverse kinds of feces”—exactly who its former occupants were is still unknown. The site lacks a broad assemblage of stone tools, something often used to define Paleo-Indian cultures. So we don’t really know how these people relate to the Clovis culture, only that they were definitely present in North America at a much earlier time.

Still, not a bad discovery at all. I mean, who would have thought that the oldest human remains discovered (so far) would turn out to be carp? There’s something like irony here.

A couple other pretty well established pre-Clovis sites:
Monte Verde in Chile
The Meadowcroft Rockshelter in Pennsylvania


Driving on ice: Swirling pools of carp on Lake Elysian have caused two trucks to break through thin ice, even though air temperatures were well below zero.Courtesy lisaschaos.
Driving on ice: Swirling pools of carp on Lake Elysian have caused two trucks to break through thin ice, even though air temperatures were well below zero.
Courtesy lisaschaos.

Just when you thought it might be save to drive on lake ice, watch out for the carp!

That's what happened to a couple of pick-up truck drivers in southern Minnesota this winter. After the temperatures finally went low enough last week to make ice thick enough to drive on Lake Elysian, they were thrown a curveball by those ugly creatures of the deep.

They cracked though the ice while driving about (one truck actually had to be towed out from the hole that it fell in) due to ice being abnormally thin for sub-zero weather. The cause? Swirling pools of carp in the shallow waters of that portion of the lake.

Earlier in the winter when the ice was clear visitors on Lake Elysian and other area lakes could see pools of carp churning up the waters under the surface. A Minnesota DNR official likened the carps’ swimming action as an agitator, which keeps the water moving and ice from forming.

Carp are also a fresh water fish species that will spend more time near the ice surface rather than staying near lake bottoms, helping continue the ice-thinning action.

The situation on Lake Elysian was kind of a perfect storm of conditions. The area where the trucks went through the ice is extremely shallow as well, helping add to the effect carp can have on thinning the ice. Local authorities are discouraging people from driving on the ice of Lake Elysian, which is located just west of Waterville, Minn., in Waseca County.

Now I have one more reason to detest carp!


Grass Carp: Grass Carp (White Amur) - Ctenopharyngodon idella Courtesy USGS

Grass carp, which sound like the kind of fish you would find in Cheech and Chong’s aquarium, have been turning up in the rivers around Minnesota. And authorities aren’t excited by the possibilities of this invasive species making a home in northern waters.

In early April, a commercial fisherman caught a 45- to 50-pound grass carp in the St. Croix River near Prescott, Wisc. While it was a thrilling fish to pull in for the angler, it does raise concerns about the changing dynamics of the fish population in the Mississippi River and its tributaries.

The grass carp is one of three reported catches in the Minnesota/Wisconsin river in the past two years. The others came in the past two falls, with one being caught in Lake Pepin on the Mississippi River and the other caught further downstream near the southern Minnesota border. While the Minnesota Department of Natural Resources is concerned about these intruders, it hasn’t found any evidence that they’re breeding yet in northern waters which would accelerate their numbers.


Natural resource officials in Minnesota and Iowa are advocating for the construction of two fish barriers on the Mississippi River that they hope willl stop the upstream migration of Asian carp.

These barriers, which would be placed below lock and dam 14 or 15 (just north of Davenport, Iowa) and lock and dam 11 (just north of Dubuque, Iowa), might use bubbles and sounds to stop the fish from entering the open locks. The fish could be directed into pools where commercial fishermen could harvest them. (Similar barriers are already used on a smaller scale to keep fish away from water intake pipes at power plants.) Minnesota Department of Natural Resources employees are looking at a variety of different technologies, trying to find one that's as selective as possible. The idea is to find something that will deter the carp, but not the paddlefish and other species that ecologists want migrating up the river, many of which are threatened or endangered.

How big is the invasive carp problem? That's a little unclear. So far, two species of the fish--bighead and silver carp--have escaped from southern fish farms and moved north along the Mississippi and its tributaries. A third species, black carp, has been caught in several areas, but scientists don't know if it's reproducing. One bighead carp was caught in Lake Pepin (south of the Twin Cities) in the fall of 2003, but no others have since been reported.

But the Upper Mississippi is one of the most pristine of American rivers, and officials are anxious to keep it that way.

Silver and bighead carp can reach more than 50 pounds, and out-compete native species for food such as plankton. Silver carp are also dangerous to recreational boaters and water-skiers, as they jump out of the water when disturbed; they've injured people and damaged equipment.

The University of Minnesota's Bell Museum of Natural History has an invasive carp feature on their "Hot Topic" website.

The Star Tribune has a special feature on invasive species in the Great Lakes.