Geology topics

Kendell Ray Bennett

Publications and source records attributed to Kendell Ray Bennett.

3 recordsLinked to original sources

USGS2026

Chronic exposure to waterborne nickel significantly reduced growth of juvenile crayfish (Faxonius virilis)

Crayfish are critical functional components of aquatic ecosystems. Previous research has documented adverse effects of mineral extraction on crayfish. Here, we characterize potential risks of mining-derived waterborne nickel (Ni) to crayfish by documenting the effects of dissolved Ni on growth and food consumption of juvenile virile crayfish ( Faxonius virilis) in a 28-day chronic laboratory exposure. Nominal Ni concentrations ranged from 31.25 to 500 micrograms per liter (µg/L; pH = 7.96 ± 0.20, hardness = 150 ± 1 milligrams per liter as calcium carbonate). Crayfish survival, carapace length, and wet weight were measured. After 28 days of exposure, a 24-h feeding trial was performed to determine differences in food consumption. During the growth trial, 99% of crayfish survived. Change in wet weight and final wet weight were the most sensitive endpoints, with 20% effect concentrations of 24.8 and 22.6 µg/L Ni, respectively. Crayfish exposed to an average of 438 µg/L Ni consumed 41% less, and weighed 65.1% less, than control crayfish. These results suggest chronic, sublethal exposure to waterborne Ni may have negative effects on crayfish growth. Reduced growth and consumption rates in crayfish could have wide-ranging consequences throughout aquatic ecosystems since crayfish are consumers, prey, keystone trophic regulators, and ecosystem engineers. Finally, these results could inform bioenergetics and may be coupled with population models to predict potential changes in population sizes of native and invasive crayfishes.

Ecotoxicology↗

USGS2025

Combined effectiveness of light and bait to enhance trapping for monitoring and removal of invasive crayfish: Virile crayfish example

Invasive populations of crayfish are a major threat to native aquatic ecosystems around the world. The virile crayfish ( Faxonius virilis ) has become problematic outside of its native range in North America. Use of minnow traps is a common method used to detect the presence of and reduce invasive crayfish numbers. The primary goal of this study was to determine if the effectiveness and practicality of control through trapping for invasive crayfish could be significantly improved with the addition of lights. From this study, we found virile crayfish were attracted to white light and avoided blue light in the laboratory. In pond trials, traps with white or blue lights had catch per unit effort (CPUE) greater than traps without light, and traps with white lights had a CPUE nearly twice that of traps with blue lights. The addition of white lights to traps with food led to a nearly three-fold increase in CPUE than white light alone or two-fold for food bait alone. We found a continued decline in capture rates from the same pond over 3 days of trapping where captured crayfish were not returned to the pond. The continued decline in catch rate of new individuals suggests that our trapping may have been having a significant effect on the density of crayfish remaining in the pond. In addition, the size distribution of the crayfish collected during these trapping studies showed that the effort appears to be effective at collecting both juvenile and adult crayfish across almost all sizes. This would suggest that the combination of white light and bait is effective in the management of invasive crayfish populations.

Management of Biological Invasions↗

USGS2024

Sicklefin Chub (Macrhybopsis meeki) and Sturgeon Chub (M. gelida) temporal and spatial patterns from extant population monitoring and habitat data spanning 23 Years

Sicklefin ( Macrhybopsis meeki ) and sturgeon chub ( M. gelida ) historically occurred throughout the Missouri River (MR), in some tributaries, and Mississippi River downstream of the MR. They have been species of U.S. state-level conservation concern and U.S. Endangered Species Act listing candidates since the 1990s. We applied analytical approaches from occupancy modeling to correlation to monitoring data spanning 23 years to assess relationships between occupancy and time, space, environmental factors, habitat, and other species. Sicklefin chub occupancy appeared higher in the early to mid-2000s and mid-to-late 2010s. A potential decline in occupancy occurred for sturgeon chub in the mid-to-late 2010s. Spatially, chub occupancy was depressed for 159 to 438 km downstream of MR dams. Among macrohabitats, inside bends had relatively high occupancy for both species; secondary connected channels had relatively high values for sturgeon chub. Co-occurrence was likely between sicklefin and sturgeon chub and between chubs and shovelnose sturgeon ( Scaphirhybchus platorybchus ) and channel catfish ( Ictalurus punctatus ). The observed co-occurrence of chubs and pallid sturgeon ( Scaphirhynchus albus ; PS) was potentially higher than expected for adult PS. For juvenile PS, co-occurrence was lower than expected in the Lower MR and potentially higher than expected in the Upper MR, warranting future research. Results from this research suggest management for the improvement of sicklefin and sturgeon chub populations may benefit other MR fish populations.

Fishes↗