Habitat Use By Age-0 Silver Carp in the Mississippi River Basin

The expansion of silver carp Hypophthlamichthys nobilis, has been documented by the long-term resource monitoring program and can provide insight into life history attributes of this nonnative species. Since 2007, catches of silver carp have increased and evidence of successful spawning and recruitment has been evident. However, early life history of silver carp has not been fully evaluated within the Mississippi River Basin. A thorough understanding of early-life history may be imperative to facilitate control or manage silver carp populations. Furthermore, age-0 silver carp survival and eventual recruitment may be regulated by habitat availability during this critical life stage. Thus, the objective of this study was to evaluate age-0 silver carp mesohabitat (i.e., depth, velocity, and substrate) use in the Mississippi River Basin. Using LTRMP data collected from the three lower most reaches of the Mississippi River Basin, we investigated age-0 silver carp detections from 2007 to 2012. Overall, 79,410 age-0 silver carp were collected during this long-term effort. Generally, silver carp were collected most frequently in shallow low velocity off channel locations.  This extensive data set has provided needed information about the early life history of silver carps and has identified potential areas or “hot spots” for control.