Asian Carp Could Threaten Brackish Water Fisheries Too

Asian carp caught in Kentucky Lake. Photo by Steve McCadams

As Activist Angler has reported, the Great Lakes aren’t the only fisheries at risk because of bighead and silver carp.  The invaders threaten riverine impoundments in the Dakotas and natural lakes in Minnesota, as well as reservoirs along the Tennessee, Cumberland, and Ohio River systems.

And now it appears that brackish water fisheries, especially in Louisiana, are endangered as well, according to an article in Houmatoday.com. If that’s the case, we now should worry about shrimp, oysters, crabs, redfish, trout and many other saltwater species.

Here’s an excerpt from the article:

Evidence of bighead and silver carp living in the salty, brackish waters of coastal Louisiana is worrisome because the fish family they belong to is typically restricted to fresh water, U.S. Geological Survey biologist Duane Chapman said.

“Asian carp appear to be the exception, which was a complete shock to us,” Chapman said. “We don’t have any real data yet on the effects of the fish on brackish water populations of other species. We don’t know what will happen, but we are very concerned.”

 Also in Louisiana, chef Philippe Parola, an angler himself, has been leading the way in encouraging fishermen to catch, keep, and eat Asian carp. Check out his website.

For a little light entertainment, check out the silver carp explosion during rowing practice on a lake off the Missouri River, near St. Louis.

Help Prevent Spread of Asian Carp

Here are a couple of good sources for more information about Asian carp:

Mississippi Interstate Cooperative Resource Association (MICRA) and Asian Carp Regional Coordinating Committee.

Most importantly, check out the fliers at the MICRA website and be an Activist Angler in preventing the spread of these invaders that are outcompeting native species for food and habitat in many of the major riiver systems in the eastern half of the country.

More Carp DNA Found in Lake Erie

Silver carp.

From Lake Erie’s Sandusky Bay and Sandusky River comes bad news about Asian carp.  Twenty of 150 water samples tested positive for the presence of silver carp environmental DNA.

DNA was collected as part of extensive sampling effort conducted earlier this summer for Asian carp in Sandusky Bay and Maumee Bay in western Lake Erie. Maumee Bay DNA results are being analyzed.

On the positive side, no Asian carp were found through intensive electrofishing and test netting.

These areas are among the most productive in Lake Erie, the warmest and shallowest of the Great Lakes. As a consequence, Asian carp invasion could be catastrophic for bass, walleye, and yellow perch fisheries. Through their filter feeding, the exotics eliminate food needed for forage species, collapsing the food chain.

Read the full story here about the DNA discoveries.

Go here to see a video about how to identify bighead and silver carp. If they don’t recognize them, anglers who seine their own bait could accidentally transport these invaders from one fishery to another.

Carp Are Doing Damage Even When You Don't See Them

These bighead carp were damaging a Missouri pond without the owner even knowing they were there. USGS photo.

The Journal Sentinel offers an in-depth look about the search for techniques to track Asian carp. But first, it presents this anecdote that typifies damage that invasive species can cause with little or no realization of what’s going on:

A fish pond in Missouri reveals just how stealthy Asian carp can be.

Maybe an acre in size, the pond had been stocked with catfish, bass and bluegills. The owner was pumping it full of fish food, yet the fish appeared to be starving. So in early 2010 the owner called in a consultant. 

"They came out with electrofishing gear, caught some fish and looked at them," said Duane Chapman, one of the country's leading Asian carp experts and a biologist with the U.S. Geological Survey. "The fish were emaciated and he didn't know why. He said, 'There's something wrong here. We need to start over again.' They brought in rotenone and completely killed the pond."

Over the next week, the rotting carcasses of about 300 bighead carp surfaced. The smallest were 20 pounds. The big ones were a border collie-sized 35 pounds. Poisoned Asian carp, Chapman explained, are different from many fish species in that they typically don't surface unless the water is warm enough for gases to build up in their bellies, a process that can take a week.

"It was quite amazing there could be that much poundage in one small pond," Chapman said.

It turned out that a decade earlier the previous property owner had stocked the pond with bighead. They had flourished right under the nose of the new owner, who had smelled trouble - but couldn't see a thing.

I found the story especially interesting because grass carp --- illegally introduced by lakefront property owners who should be arrested --- have done the same thing to the small lake behind my house. Those carp, most of them 20 pounds and more, make up the majority of the biomass.

And just as an acre of land can grow only so many bushels of corn, a lake can sustain only so many pounds of fish. As a result, the bass and catfish in my little lake grow slowly, if at all, with the bulk of the bass being 12 inches or less.

Will what has happened in that pond and my lake also occur if/when Asian carp move into the Great Lakes?

Do we really want to wait and see what happens, endangering a billion-dollar sport fishery? The time is long past due to close the manmade connection between the Great Lakes and the Mississippi River basin. Right now, it provides an open door for invasive species to migrate from one system to another.

Invasive Species Concerns Force Access Restrictions on Anglers

The failure of elected officials to protect our waters from aquatic invasive species is becoming more and more evident, not only in the damage done by these exotics but in restricted access for anglers and other boaters.

Here’s an example: Earlier this summer, the Minneapolis Park and Recreation Board unanimously approved an emergency order requiring all boats using its three public boat ramps to be inspected.

That in itself doesn’t restrict access. But the limited hours that inspectors will be at the launch sites does. For example, if you want to go fishing mid-day Monday through Thursday, you can’t. Or, if you do, you will get a ticket for violating the order.

See the full story here.

It’s certainly understandable that the city wants to prevent the spread of invasives such as mussels and Eurasian watermilfoil by hitchhiking on and in boats.

 But in bowing to special interests for decades, our state and federal governments unquestionably have caused this crisis. For example, they’ve allowed commercial shipping to introduce zebra and quagga mussels --- along with dozens of other species --- into the Great Lakes via ballast water from ocean-going ships.

They’ve allowed the exotic pet industry and plant nursery businesses to sell problematic species that now degrade our waters, including milfoil, hydrilla, water hyacinth, parrot feather, giant salvinia, and Brazilian elodea, among others.

And they’ve permitted fish farmers to bring in silver, bighead, black, and grass carp, which now infest the nation’s rivers and threaten sport fisheries.

Of course, that wasn’t the intent of any of these special interests. But shipping has opposed stricter standards for ballast water, while the others have insisted that they would be damaged economically if not allowed to import with few restrictions.

And officials have allowed these lobbies to mostly get what they want without consequences. Now, this irresponsible behavior is causing billions of dollars in damage to our country economically and environmentally, as well as forcing access restrictions on anglers and boaters to prevent further spread of this invasives.

Certainly, responsible fishermen and the fishing industry should help contain these invasions. Wisconsin provides an example of that, where bait shop owners are helping educate anglers about how to prevent the spread of aquatic invasives.

See the full story here.

Meanwhile, anglers and the industry also must be vigilant and active against those who will use concerns about invasives to advance an anti-fishing agenda.  Hints of that agenda show clearly in a recent article in the Pioner Press.

Check out these excerpts about how to keep Asian carp from spreading up the Mississippi River:

"Another option? Eliminate recreational boating from the lock and dams."

"Another suggestion is to limit fishing in Pool 2, to give native fish a chance to flourish before the carp arrive."