SIOUX FALLS, S.D. (KELO) — Some species of invasive carp found in South Dakota, which include Silver Carp, Grass Carp and Bighead Carp, can grow up to 90 lbs. While this is the maximum for Bighead Carp, S.D. GFP Aquatic Invasive Species Coordinator Tanner Davis says that you’re much more likely to find a carp between 10 and 25 lbs.
These fish are a problem, due to the impact they have on the ecosystem.
This is because these invasive carp consume the same food source as the gamefish (things such as bass, perch, walleye, salmon, trout, etc.) found in South Dakota waters. This food source is zooplankton and phytoplankton.
“They can actually consume up to 40% of their body-weight daily,” said Davis. “With Silver Carp getting up to 60 lbs, and Bighead Carp getting up to 90 lbs, those numbers add up really quickly.”
Davis says that the GFP has caught in the past a 62 lb Grass Carp. Based on average food intake, he says this fish alone could eat almost 2-tons of aquatic vegetation per year.
This appetite can very quickly become an issue, as in most cases, Davis says established carp populations will take up roughly 50% of the biomass in the water. Due to the speed and the size to which they grow, adult invasive carp have pretty much no natural predators.
Another point of concern? Concussions.
“Silver Carp — some people deem them the flying carp — they can actually jump up over 5-feet out of the water when scared by any loud noises,” said Davis. He pointed out that many areas with known Silver Carp populations also host ‘no-wake zones’ for boats.
Currently, invasive carp are primarily confined to southeast South Dakota, with one exception.
“Waters they are currently residing in would be the James River, Big Sioux River and the Vermillion River (east and west forks),” Davis said. These are in addition to the main repository for the carp, which is the Missouri.
Davis explains that in three of these waterways, barriers have stopped the carp from penetrating deeper into South Dakota. These are the Gavin’s Point Dam at Yankton, the falls at Sioux Falls, and the Lake Vermillion Spillway near Rumpus Ridge.
With no meaningful barriers however, the James River has been left open to the creatures, and invasive carp have made it all the way through the state and up into North Dakota along the James.
According to Davis, it’s not currently known exactly how many invasive carp there are in South Dakota, especially due to the transient nature of the fish, which swim in and out of river systems.
We do however know where they come from.
“They were first introduced into the United States down in Arkansas, into agriculture ponds to help with algae masses in those waters,” Davis said. “Just like here in South Dakota, they experience floods and they were able to escape in the early 80s — we actually saw them below Gavin’s Point Dam in the mid-90s.”
Carp have long been considered undesirable fish for anglers due to their bottom feeding nature, which can result in an unpleasant taste. However, South Dakota’s invasive carp actually feed on plankton, resulting in a much more pleasant tasting fish.
Davis cautions that these carp are rather boney, and can take some extra effort to fillet, however he does advocate catching them for consumption. Asked about taste, he says they are a very mild white meat fish.
“A lot of times people will deep-fat fry them,” Davis said, claiming that under this condition, most would be unable to tell it from walleye. “It’s very mild favoring, and whatever you like to season your fish with is the flavor it will take on.”
Carp is also surprisingly healthy it turns out, high in omega-3.
If you do find yourself attempting to fish for carp, you must take care with how you handle your catches. In order to prevent the further spread of the invasive species, Davis says fish intended to be eaten should be killed on location and taken home, never transported alive.
If you accidentally catch one and do not wish to keep it, don’t kill it. Davis clarified that killing and leaving the fish lie on the ground can do little but worsen the experience for fellow fishers, and attempting to move the fish could result in unintentional spread of the species. “Release it back to the same water body,” Davis said.