Jon M Vallazza (Former Employee)

Silver carp (Hypophthalmichthys molitrix) are a nonnative, planktivorous, and highly invasive species of cyprinid located throughout the Mississippi River Basin. Although they co-occur with largemouth bass (Micropterus nigricans), an abundant native predatory fish, their predator–prey relationship is poorly understood. This potential relationship warrants investigation as largemouth bass...

Invasive carp (Hypophthalmichthys nobilis [Richardson, 1845; Bighead Carp], H. molitrix [Valenciennes in Cuvier and Valenciennes, 1844; Silver Carp], Ctenopharyngodon idella [Valenciennes in Cuvier and Valenciennes, 1844; Grass Carp], and Mylopharyngodon piceus [Richardson, 1846; Black Carp]) expansion threatens the Laurentian Great Lakes and other major waterways. Numerous tools and...

Invasive carp (Hypophthalmichthys nobilis [Bighead Carp], Mylopharyngodon piceus [Black Carp], Ctenopharyngodon idella [Grass Carp], and H. molitrix [Silver Carp]) continue to spread in the United States and deterrents at river navigation locks are one emerging control strategy for slowing the spread. High-head navigation dams on large rivers serve as impediments to the upstream spread...

Movement and dispersal of migratory fish species is an important life-history characteristics that can be impeded by navigation dams. Although habitat fragmentation may be detrimental to native fish species, it might act as an effective and economical barrier for controlling the spread of invasive species in riverine systems. Various technologies have been proposed as potential fish...

No abstract available.

As the range of non-native bigheaded carps (Hypophthalmichthys spp.) continues to expand throughout river systems of the United States, managers are tasked with preventing or slowing the spread of these invasive species. Main stem navigation dams on the upper Mississippi River, long considered a deterrent to fish migration, may slow or prevent the spread of invasive fish species. As...

Asian carps continue to expand their range in North America, necessitating efforts to limit the spread and establishment of reproducing populations. Mississippi River Lock and Dam 19 is a high-head dam that represents a population ‘pinch-point’ as passage through the lock chamber is the only means by which fishes can complete upstream movement. As such, this location could be a pivotal...

No abstract available.

Similarity in community composition declines as distance between locations increases, a phenomenon that has been observed in a wide variety of freshwater, marine and terrestrial ecosystems. One driver of the distance-similarity relationship is the presence of environmental gradients that alter the suitability of sites for particular species. Although some environmental gradients, such as...

In river systems, high‐head dams may increase the distance‐decay of fish community similarity by creating nearly impermeable dispersal barriers to certain species from upstream reaches. Substantial evidence suggests that migratory species are impacted by dams, and most previous studies in stream/river networks have focused on small streams and headwaters. Here, we assess whether a high...

No abstract available.

Recent work indicates that the establishment of bigheaded carps (Hypophthalmichthys spp.) in the United States has led to a reduction in condition of native planktivores and may detrimentally affect other trophic levels by altering the base of aquatic food webs. We used fatty acids to evaluate potential effects of bigheaded carps on taxa from multiple trophic levels in the Upper...