by Valerie Verkamp
Kansas City's hot weather trend has many people turning to the water for recreation, but anglers and boaters on the Missouri River may not hook the fish they’re pursuing.
A large herbivorous freshwater fish, known as Asian carp, is rapidly depleting native fish from the environment and altering the existing food web.
Asian carp are notorious for heavily filtering precious plankton from the water.
“Plankton is the first food for every fish,” said Jake Allman, a fisheries management biologist with the Missouri Department of Conservation. “Regardless of species, every fish in its larva stage eats plankton. In addition, the largest fish in Missouri, the paddle fish, also exclusively eats plankton. “
With Asian carp now wiping out vast areas of plankton, native fish species that spawn and nurse young fish in highly dense areas of aquatic plants are threatened.
In addition to threatening the native fish population, Asian carp are dangerous to boaters and anglers. Asian carp have also been known to jump 10 feet out of the water, sometimes surprising and injuring unsuspecting boaters.
Allman said he has been injured by Asian carp leaping out of the water and striking him on the head and shoulder.
Allman, who has dedicated the past 32 years of his life to protecting fish and aquatic habitats, said Asian carp are a problem in the waterway systems of Mississippi, Ohio, Illinois and Missouri.
“Like many exotics, when they get into a system with no natural predators they tend to have very high numbers,” said Allman.
To combat the growing number of these heavily-bodied fishes, he said the U.S. Fish and Wildlife Service and the United States Geological Survey are monitoring and preventing their advancement upstream.
“Federal agencies are taking the lead on this because it is a multi-state problem,” said Allman. “Once they're in a system as big as the Missouri and Mississippi, physically removing them is very difficult.”
There is growing concern Asian carp will eventually make their way to the Great Lakes. Experts warn if Asian carp take up residence in the Great Lakes it would negatively impact the growth rate of native fish and reduce their numbers. This would be detrimental to the fishing industry of the Great Lakes.
But eradicating them altogether may not be completely feasible.
Experts say there are two ways to eradicate a species from an aquatic
system. The first technique typically deployed is to alter their habitat. Allman says with the channelization project on the Missouri River, we have already done all the habitat destruction we can do. Altering it any further is simply not an option.
The second technique is over fishing. The problem with that method is that there are already more fish than the market demands.
Some towns have taken an ancillary approach. In Cape Girardeau, for example, experts are rearing alligator gar to feed upon Asian carp. Experts say it will take a lot of these ancient, toothy creatures to wipe out Asian carp from the Mississippi River.
Threats to fish species
Minimizing the spread of this invasive species is just one obstacle experts are struggling with.
The Missouri River is clearer today than nearly anytime in the past. Upstream dams and erosion control practices used by many farmers have significantly minimized the amount of sediment coming into the river.
But experts have discovered that a lack of sediment in the water can be a detriment to some fish species.
“There are fish in the water that have evolved with that sediment load coming down the river,” said Allman. “Pallid sturgeons have used sediment to build sandbars and create the habitat they need to reproduce. Without that sediment load coming down the river, pallid sturgeons have a hard time reproducing.”
Pallid sturgeons are distinctively known for their large head and elongated nose that resembles a shovel. Their body armor is made up of large bony scales. Although long and slender, they can get up to 100 pounds.
Crews with the MDC have been monitoring and restocking rivers with pallid sturgeons for more than a decade. Unfortunately, the ones they sample have been no bigger than 30 pounds.
“Pallid sturgeons are a very long-lived fish,” said Allman. “They can live for 100 years.”
But pallid sturgeon are not as prolific as other aquatic species.
“Unlike other native species, pallid sturgeons don't become sexually mature until they are almost 20 years of age,” he said. “Once they become mature, they don't expel hundreds of eggs or reproduce every year, which is also distinct from other fish species.”
To protect the existing pallid sturgeon population, anglers are required to return pallid sturgeons back to the water. But sometimes anglers will incorrectly identify the fish as a shovelnose sturgeon and take it home if it exceeds the 30-pound requirement.
Despite the problems posed against native fish species, anglers do hook monster sized fish in the depths of the Missouri River.
Allman certified the current state record for a flathead catfish.
“It was caught from the Missouri River, near Riverside. It was 100 pounds on the nose.”
Allman suspects the catfish was about 25 years old.
In Missouri, the population of flathead and blue catfish are flourishing. Today, there are more blue catfish than there were in the early 1990's.
“I attribute that to the 1993 flood,” said Allman. “Prior to 1993, I would rarely see a blue catfish through Kansas City reach the Missouri River. In 1996, I started catching a lot of 13-inch blue cats. All the same size and three years old.”
Allman went on to say the flood occurred during the catfish spawn. Elevated water levels reconnected the river to flood plains. This presumably allowed cat fish to breed in their preferred aquatic habitat.
Health of the river
From our drinking water to recreation, rivers play a pivotal role in communities throughout Missouri.
“Over the past three decades, the river's overall health has been improving,” said Allman.
This is attributed to habitat restoration projects and less pollution making its way into the water system. Today, more state agencies are also putting forth more effort in managing aquatic habitats and aquatic fish populations.
Although the river is healthier today, some people remain hesitant to engage in recreational activities on the river.
“Twenty-five years ago I could barely get people on the river to kayak,” said Allman.
Many were concerned about superstitious gossip about whirlpools that would pull people under. But truth be told the Missouri River does not have whirlpools that will suck people under, said Allman. The whirlpools are just not that powerful.
Allman also wants to dispel the belief that people need a big boat. A little 14-foot John boat with a 25-horse-power motor will suffice just fine.
To increase awareness about recreational activities on the river, county recreational officials are organizing more events on the river, especially group kayak trips.
Today, hundreds of kayakers make their way along the river between Kansas City and St. Louis.
“That popularity tends to lead to understanding and appreciation,” said Allman. "Those are both good things.”