Around the world, the carp is both a reviled and revered species.
Most anglers in Kentucky consider the common carp, introduced in the mid-1800s, to be a nuisance “trash” fish, a bottom feeder of poor quality flesh. In fact, all nine of the most prominent species of carp in family Cyprinidae, are considered globally invasive species.
Fishery biologist are alarmed at the feeding habits, rapid growth and enormous size of two invasive Asian carp species, the silver and bighead carp, that have literally taken over some waterways throughout the Mississippi River basin since their accidental introduction in the 1970s.
Non-native Exotic Species
Carp are not native to North America and pose a threat to native game fish populations. Various species of carp have been domesticated and reared for food across Europe and Asia for thousands of years. Aquaculture, fish production in ponds, of carp is still practiced in Central and Eastern Europe. In Asia, the farming of carp continues to surpass the total amount of sea-farmed salmon and tuna.
Goldfish and koi, popular ornamental fish were, were domesticated from carp.
Goldfish were first bred for color in China over a thousand years ago, and through selective breeding, have developed into many distinct breeds. Goldfish were introduced to Japan in 1603, and Europe in 1611.
Koi, a domesticated subspecies of the common carp, were selectively bred for color beginning in the 1820s by Japanese fish culturists. In Japan, raising koi is said to bring good luck.
Impact of Carp
The common carp spread quickly through North America’s waterways after its introduction. The negative impacts of the fish were soon realized.
A bottom-feeder, carp swim along uprooting vegetation, and sucking in mud and bottom debris, while feeding on aquatic insects, crustaceans, zooplankton and benthic worms.
The result is increased turbidity (muddiness) of the water, which in turn reduces the ability of predator fish to find prey, and decreases sunlight penetration, needed by rooted aquatic vegetation for growth.
With their high reproductive rate and few predators, carp numbers can quickly climb to a high percentage of the water body’s carrying capacity of fish.
The newest carp invaders, the bighead and silver carp, collectively known as “Asian carp,” are causing considerable damage to native fish populations.
Brought to the U.S. in the 1970s to reduce phytoplankton in aquaculture ponds, Asian carp escaped and have established breeding populations in open water habitats of large rivers and reservoirs in the Mississippi River basin.
Asian carp cause serious damage to the native fish populations because they out-compete other fish for food and living space. Unlike the common carp, Asian carp filter feeders in open water, consuming the zooplankton needed by young game fish to grow and survive when they are too small to eat forage fish.
Silver carp are a threat to boaters because they can jump out of the water at high speeds, causing injury to passengers and equipment. They are capable of jumping over barriers, too, including low dams, which aids in their population expansions.
The reproductive rate of the Asian carp is astounding.
Females lay hundreds of thousands of eggs at a time, multiple times per year, which means populations grow and spread quickly. It’s easy to see how they can quickly out-compete native species, and put ecosystems in danger.
Carp in Kentucky
There are four species of carp in Kentucky. The common carp and grass carp are found statewide, in all of Kentucky’s major river drainages.
So far, Asian carp are confined to the Mississippi, Ohio, lower Tennessee, lower Cumberland, lower Green, and lower Kentucky Rivers. Additionally, there are large populations of Asian carp in Kentucky Lake and Lake Barkley.
Here’s some details on the four species:
1) The common carp (Cyprinus carpio) is a deep-bodied fish with two short barbels on each side of the mouth, large scales, and long dorsal fin. Color is olive to brassy on the back and sides with a pale yellow belly, and orange tinted lower fins. Adults grow to about four feet and can reach 80 pounds, with individuals in the 30 inch size range weighing up to 20 pounds.
2) The grass carp (Ctenopharyngodon idella), often referred to as the white amur, has a wide head, robust body, and large, dark-edged scales. Color is dark olive above, becoming silvery or white on the sides and belly. Adults can grow to about 4 feet in length and weigh up to 100 pounds, although most fish reported from Kentucky are less than 50 pounds. The grass carp can eat up to 40 percent of its body weight in aquatic plants every day.
Triploid, non-reproducing, grass carp has been introduced statewide in private ponds and small public reservoirs as biological control for unwanted aquatic vegetation, but escapees from these stockings are taken regularly from larger streams and rivers, particularly in western Kentucky.
3) The silver carp (Hypophthalmichthys molitrix) has an eye below the midline of the head. Silver carp also have a keel that extends from its anus to the origin of the pectoral fins. They are silvery in color.
Silver carp are known for their jumping behavior, stimulated by noise and vibration from outboard motors. They can grow up to four feet in length, weighing over 75 pounds, but adults more commonly range from 10 to 20 pounds.
4) The bighead carp (Hypophthalmichthys nobilis ) has an eye below midline of the head, a keel that ends between the pelvic fins, and irregular gray-black blotches on the sides of the body. Bighead carp can grow up to for feet in length, weighing over 85 pounds, but adults more commonly range from 20 to 40 pounds.
Biology and Reproduction
The typical common carp female lays about 300,000 eggs when spawning, and fry can grow as much as eight inches in their first year.
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Although carp typically spawn in the spring, in response to rising water temperatures and rainfall, carp can spawn multiple times in a season under ideal water conditions.
Angling and Bowfishing
In Europe, especially England, carp are eagerly sought after by anglers, and are considered highly prized.
Few anglers in the U.S. pursue carp as sportfish. Dough balls, fished on bottom rigs, are used to catch carp on pole and line. Most carp are taken by commercial fishermen.
Kentucky’s state record carp weighed 54 pounds, 14 ounces and was caught by Ricky Vance, of Paris, Kentucky, from the South Fork of the Licking River on March 13, 1971.
Asian carp are a favorite target of bow fishermen, and the Kentucky state records reflect the enormous size these fish can reach. All three of the following bow fishing records exceed the hook and line records for the species:
— Grass carp (white amur), 72 pounds, arrowed by Jeff Moryl, of Mayfield, Kentucky, from Kentucky Lake on May 4, 2009.
— Bighead carp, 88 pounds, 8 ounces, arrowed by Sawyer York, of Benton, Kentucky, from the Tennessee River on May 3, 2016.
— Silver carp, 32 pounds, 2 ounces, arrowed by Jesse Raes, of Mount Vernon, Indiana, from the Tennessee River on April 16, 2016.
Asian carp are here to stay and in future years are likely to expand their range and further impact native fish populations. Unfortunately, state and federal fishery agencies can do little to curtail Asian carp numbers in Kentucky and throughout the Midwest, the epicenter of their infestation.
Art Lander Jr. is outdoors editor for KyForward. He is a native Kentuckian, a graduate of Western Kentucky University and a life-long hunter, angler, gardener and nature enthusiast. He has worked as a newspaper columnist, magazine journalist and author and is a former staff writer for Kentucky Afield Magazine, editor of the annual Kentucky Hunting & Trapping Guide and Kentucky Spring Hunting Guide, and co-writer of the Kentucky Afield Outdoors newspaper column.
