Funding Program: Invasive Species
Statement of Problem:
Bighead carp (Hypophthalmichthys nobilis) and the closely related silver carp (Hypophthalmichthys molitrix) are rapidly expanding in numbers and distribution in the Mississippi and Missouri River basins. Like the paddlefish (Polyodon spathula) and bigmouth buffalo (Ictiobus cyprinellis), which are native to the Missouri River, bighead and silver carp are primarily filter feeders. These Asian carps are capable of filtering particles of a much smaller size from the water than native filter feeders and therefore may have the capability to out compete native fishes in the filter-feeding niche.
A. Determine habitats used by bighead and silver carp in the Missouri River
B. Characterize the habitats in terms of depth, velocity, and temperature, water quality, and presence of hard structures like wing dikes and large woody debris. Provide ongoing locations of bighead carp to another USGS researcher for use in in-depth characterization of bighead carp habitat including substrate types, bedform hydraulic modeling, mapping, and habitat fragmentation, and
C. Develop better methods for aging Asian carps. This is necessary for determining the age structure of the population, which in turn is necessary to understand the effects of environmental variables on recruitment. This understanding is required for control and management.
D. Determine trophic overlap between Asian carps, their hybrids, and native filter feeders.
E. Determine contaminant concentrations in Asian carp tissues, a pre-requisite for control of Asian carps through market development.