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Entries in Mississippi River (42)

Friday
Oct172014

Ground Zero for Asian Carp Invasion

Havana, Ill., is Ground Zero for the Asian carp invasion, according to the Illinois Department of Natural Resources. On the Illinois River, it’s about 200 miles south of Lake Michigan and 120 miles north of the Mississippi.

“You find more carp per acre, per mile of river, tan nearly anyplace else in the world,” says Kevin Irons, DNR’s Asian carp program director.

If you doubt that, check out this video.

Based on electrofishing surveys, bighead and silver carp now account for about 60 percent of the fish biomass in that stretch of the river. That means native species have declined dramatically because the exotics outcompete them for food and habitat.

And peaceful boat rides are a thing of the past because of silver carp, which go airborne when startled.

“People have been hit and seriously injured,” says DNR’s Matt O’Hara. “I know there have been some cases of broken noses and jaws.

“Pretty distressing when you come out here and you’re looking for native fish, and all you see is invasive Asian carp,” he adds.

Friday
Oct102014

Bass Assist With Native Mussel Restoration

Photo courtesy of Nathan Eckert, USFWS

Smallmouth and largemouth bass assisted recently with an innovative program to boost sagging mussel populations in Wisconsin.

Carrying shellfish larvae in their gills, they were released into the Chippewa River by the U.S. Fish and Wildlife Service (FWS).

“The fish will swim around like normal and, after a week or two, the mussel larvae will mature and drop from the fish gills down into the substrate,” explained biologist Nathan Eckert. “In doing a free release of fish with mussels, our hope is that the fish drop off more mussels than would occur naturally, thus bolstering the native population.”

For the project, 2,500 bass were released with larval mucket, 1,050 walleye with larval black sandshell , and 800 lake sturgeon with larval hickorynut.

“Mussels are nature’s water filter,” the biologist said. “They leave the water cleaner than they found it. This is a benefit that the public will receive, even if they do not notice it.”

Additionally, cleaner water allows for more robust phytoplankton and zooplankton populations, which provide the base of the food chain for bass and other game fish.

Biologists “equip” the fish by placing them in tubs of water and then pouring in the larvae. “We let them swim around in the mussel glochidia soup for about a half hour and, during that time, the mussels grab ahold of the fish’s gills,” Eckert said.

With preliminary findings encouraging, FWS also has used this method to assist with recovery of the endangered Higgins eye pearlymussel in tributaries of the Upper Mississippi River.

“We haven't found many, but we have recovered individuals from multiple age classes in two of those streams and the individuals have reached maturity,” the biologist explained.

“Now we are watching and waiting to see if those individuals will start reproducing on their own. Once we have documented that the animals we released are reproducing, we can declare the effort a success and the population has been re-established in these streams where that mussel hasn't been seen in the last 100 years.”

Thursday
Aug212014

Sky Isn't Falling, But Dead Zones Are Real

The Mississippi River dead zone is overloaded with nutrients from upstream sources. This photo shows the color change between the hypoxic (brown) and oxygen-rich (blue) waters. Photo courtesy of NOAA.

Climate change occurs naturally. It always has, and it always will vary from day to day, week to week, season to season, year to year, decade to decade, and century to century. Possibly humans play a role in that change in some way, but no verifiable evidence supports that. Even if it did, we, as one nation, could do little to nothing about it because our contribution is miniscule compared to what’s happening in China, India, and the rest of the world.

The billions of dollars wasted on this sky-is-falling hysteria could be far better spent on providing food and clean water to the millions who need it.

By contrast, dead zones pose legitimate threats to our fisheries and oceans and could be minimized if we changed our ways.

LiveScience.com reports the following:

“Agricultural practices are the biggest culprit for dead zones in the United States and Europe. Rains wash excess fertilizer from farms into interior waterways, which eventually empty into the ocean. At the mouths of rivers, such as the Mississippi, the glut of phosphorous and nitrogen intended for human crops instead feeds marine phytoplankton.

“A phytoplanktonic surge leads to a boom in bacteria, which feed on the plankton and consume oxygen as part of their respiration. That leaves very little dissolved oxygen in the subsurface waters. Without oxygen, most marine life cannot survive.”

In the United States, the most notorious dead zone occurs each summer in the Gulf of Mexico, spreading out from the mouth of the Mississippi River. This year, it consumes more than 5,000 square miles, slightly smaller than last year. On average, it is estimated to cost $82 million annually in diminished tourism and fishing yield.

More than 150 dead zones have been identified in this country, most of them along the coasts. A few occur inland, notably the Great Lakes.

Some of them have been cleaned up through improved management of agricultural runoff and sewage. But as fertilizer and factory farming both increase, LiveScience.com warns, “the United States is creating dead zones faster than nature can recover.”

More than 400 dead zones have been identified worldwide, covering about 1 percent of the area along continental shelves.  But likely many more than that exist, since portions of Africa, South America, and Asia have yet to be studied.

Wednesday
Mar122014

Asian Carp Eggs Found in Upper Mississippi River

 

Just when we think that we know what is going on with Asian carp . . . 

The U.S. Geological Survey (USGS) says that researchers found eggs, including late-stage embryos, in samples collected last summer from the Upper Mississippi River, as far north as Lynxville, Wisc. 

Here's more from the USGS:

"This discovery means that Asian carp spawned much farther north in the Mississippi than previously recorded," said Leon Carl, USGS Midwest Regional Director. "The presence of eggs in the samples indicates that spawning occurred, but we do not know if eggs hatched and survived or whether future spawning events would result in live fish."

The Asian carp eggs and late-stage embryos were discovered two weeks ago while processing samples that were collected in mid-May and mid-June, 2013. The samples were taken as part of a larger research project designed to identify Asian carp spawning habitats. The eggs and late-stage embryos were 250 river miles upstream of previously known reproductive populations in the river. Spawning would have occurred upstream from this site.

Once the scientists visually identified the eggs, they examined other samples taken from the Mississippi River and found Asian carp eggs at seven locations between Pool 19 near Keokuk, Iowa, and Pool 9 of the main channel of the Upper Mississippi River near Lynxville. Iowa, Missouri, Illinois, Minnesota and Wisconsin border the navigation pools where these samples were collected.

The eggs and late-stage embryos were identified as bigheaded carps — either bighead carp or silver carp — through visual analyses of specific features of the eggs and embryos. It is also possible that some eggs could be from grass carp, although no eggs were visually identified as such. The USGS attempted genetic analyses to definitively determine which species of Asian carp the eggs belong to, but the results were inconclusive. Additional steps are being completed to attempt genetic confirmation, and those results are expected in one to two weeks.

The research project that collected these eggs is being coordinated by the USGS in collaboration with Western Illinois University. Scientists plan to collect additional samples from the Mississippi River in 2014 as part of their on-going research project.

"Invasive Asian carp could pose substantial environmental risks and economic impacts to the Upper Mississippi River if they become established," Carl said. "Further research will help us to better understand their habitat requirements and inform integrated control efforts."  

Friday
Feb142014

Electric Barrier Is NOT Stopping Fish

Oh, yeah! That electric barrier is going to keep Asian carp from entering Lake Michigan via a manmade connection to the Mississippi River basin.

Or maybe not.

A video obtained by the Milwaukee Journal Sentinel shows small fish swimming through the electrified water, just 35 miles downstream from Chicago’s lakeshore.

And no one said that the invaders must be adult fish.

“The only thing holding back the Asian carp at the moment is the electric barrier, but few people beyond Illinois politicians, the canal-dependent barge industry, and the Army Corps are buying the idea that the barrier is doing its job. Many worry the agency's continued confidence in this leaky, last line of defense will take a tragic toll on the Great Lakes, the world's largest freshwater system,” said the newspaper.