Silver carp : invasive species

Abstract

"Reasons for Invasive Status: Silver Carp are native to eastern Asia, but were imported to the United States in 1973, primarily as a biological water quality control mechanism in fish hatcheries to clean up excess plankton in the water. The fish were also stocked in various other locations, such as sewage treatment facilities, for the same reasons. The fish escaped these impoundments during flood events, and were introduced into the free-flowing rivers, such as the Missouri River, where they flourished and spread. These fish are so successful because they eat a lot of plankton, competing directly with native planktivores, such as Paddlefish and Gizzard Shad. Since plankton form the base of any aquatic food chain, they can also affect an entire ecosystem, therefore food can run out or be reduced for all animals and the whole ecosystem suffers as a result. Their presence is often linked to the decline of native species with similar feeding habits and with fish with early life stages that compete with adult Silver Carp. In addition, the sounds of boat motors or paddles slapping water can disturb Silver Carp and cause them to leap from the water as high as ten feet into the air."--Page 1-2.