Placing the North American invasion of Asian carp in a spatially explicit context

Abstract

The bighead (Hypothalmichthys nobilis) and silver carp (H. molitrix) have invaded much of the Mississippi River. It is unclear how reproduction in northern impounded pools of the Upper Mississippi River System (UMRS) compares to unimpounded (open) southern reaches. During spring through summer 2005 and 2006 and once in spring 2007, we quantified larval and juvenile production in the pooled and open UMRS. We then simulated population dynamics in pools as a function of apparent reproductive success. Larvae occurred during about 2 weeks each spring. Peak density and apparent spawn duration were greater in the open reach. Larval production peaked when discharge was high plus rising and water temperatures reached 18°C. Most juveniles ([97%) occurred in the open reach. Low flow during drought years in the pools may limit reproductive success. The simulation demonstrated that, by treating dams as barriers to invasion from the lower open river (i.e., a source), climatic conditions may interact with flow in pools to limit populations by creating an isolated sink.

Recruitment sources of invasive Bighead carp (Hypopthalmichthys nobilis) and Silver carp (H. molitrix) inhabiting the Illinois River

“…However, the relative importance of the Illinois, Mississippi, and Missouri rivers as natal environments and recruitment sources for Illinois River bigheaded carp stocks is unknown. As of 2013, bigheaded carps were known to be reproducing in the middle and lower sections of the Illinois River, the Mississippi River downstream from the mouth of the Missouri River, the lower Missouri River (unimpounded section), and pools 22, 24, and 26 of the upper Mississippi River (impounded section of the river upstream from the Missouri River confluence) (Schrank et al 2001;DeGrandchamp et al 2007;Lohmeyer and Garvey 2009;Baerwaldt et al 2013;Deters et al 2013). In the Mississippi River, larval bigheaded carp densities were substantially higher in pool 26 and the open river downstream from the Missouri River confluence compared to pools 22 and 24 (Lohmeyer and Garvey 2009).…”

“…As of 2013, bigheaded carps were known to be reproducing in the middle and lower sections of the Illinois River, the Mississippi River downstream from the mouth of the Missouri River, the lower Missouri River (unimpounded section), and pools 22, 24, and 26 of the upper Mississippi River (impounded section of the river upstream from the Missouri River confluence) (Schrank et al 2001;DeGrandchamp et al 2007;Lohmeyer and Garvey 2009;Baerwaldt et al 2013;Deters et al 2013). In the Mississippi River, larval bigheaded carp densities were substantially higher in pool 26 and the open river downstream from the Missouri River confluence compared to pools 22 and 24 (Lohmeyer and Garvey 2009). Age-0 bigheaded carps have also been collected from connected floodplain lakes along the Illinois River (Pegg et al 2002;DeGrandchamp et al 2007); however, the relative importance of these floodplain lakes and low-velocity river channel margin habitats as nursery areas for Bighead and Silver carps is also unknown.…”

Geology, hydrology, water quality, and potential for interbasin invasive-species spread by way of the groundwater pathway near Lemont, Illinois

“…For example, Asian carp in the upper Mississippi River system spawned between June 4 and 10, 2005, and then again between August 19 and 22, 2005. Spawning coincided with rising discharge in both time periods (Lohmeyer and Garvey, 2008).…”

“…Both bighead and silver carp are now found in most of the Mississippi River system (Lohmeyer and Garvey, 2008).…”

“…Larvae (Lohmeyer and Garvey, 2008). In 2005 and 2006, which are considered to have been dry years, water-level management of the Upper Mississippi River limited the production of larvae of both bighead and silver carps.…”