Geology topics

Hilary B. Treanor

Publications and source records attributed to Hilary B. Treanor.

5 recordsLinked to original sources

USGS2024

Survival and growth of larval Pallid Sturgeon are improved by a live diet

Objective Conservation propagation facilities in the upper basin of the Missouri River are currently experiencing inconsistent survival of first-feeding larval Pallid Sturgeon Scaphirhynchus albus among genetic families (i.e., distinct male–female pairings). The inconsistent survival can have unintended negative consequences for genetic representation of Pallid Sturgeon that are returned to the Missouri and Yellowstone rivers. We conducted a laboratory study designed to determine whether a live diet improves survival and growth of first-feeding larval Pallid Sturgeon. Methods First-feeding larval Pallid Sturgeon from three distinct genetic families were assigned to one of the following diets: live first instar brine shrimp ( Artemia franciscana ) nauplii, an Otohime dry diet, a 50–50% combination of Otohime and live first instar brine shrimp nauplii, or food restricted (no food). Mortality was evaluated at the end of each day and at the end of the trial (21 days after the onset of exogenous feeding), and individual weight (g) was measured at the end of the trial. Result Pallid Sturgeon larvae that received a live diet (either solely live first instar brine shrimp nauplii or the combined diet) experienced higher survival than larvae that were fed solely Otohime. Furthermore, there was statistical evidence that larvae receiving solely live first instar brine shrimp nauplii were heavier at 21 days postexogenous feeding than larvae that were fed either solely Otohime or the combined diet. Conclusion Our results suggest that a live diet can improve survival and growth of first-feeding larval Pallid Sturgeon at conservation propagation facilities.

North American Journal of Aquaculture↗

USGS2024

Prioritizing imperiled native aquatic species for conservation propagation

Native aquatic species are in decline, and hatcheries can play an important role in stemming these losses until larger ecological issues are addressed. However, as more federal and state agencies face budget uncertainty and the number of imperiled species increases, it is necessary to develop a tool to prioritize species for conservation propagation. Our objective was to create prioritized lists of aquatic species that may benefit from conservation propagation for five states in the United States. Biologists developed an influence diagram and provided information for multiple attributes affecting prevalence of species. The influence diagram and information for each species was used in a Bayesian belief network to generate a score to prioritize propagation of a species and the feasibility of propagation. When all taxa were ranked together within a state, mussels, amphibians, and a crustacean were included among fishes in the top species that may benefit from propagation. We recognize that propagation is one tool for conservation of imperiled species and that additional factors will need to be addressed to ensure species persistence. Nevertheless, we contend our quantitative approach provides a useful framework for prioritizing conservation propagation.

Colorado, Kansas, North Dakota, South Dakota, Utah↗

USGS2020

Carbon dioxide-induced mortality of four species of North American fishes

Fisheries managers have a growing interest in the use of carbon dioxide (CO 2 ) as a tool for controlling invasive fishes. However, limited published data exist on susceptibility of many commonly encountered species to elevated CO 2 concentrations. Our objective was to estimate the 24-h 50% lethal concentration (LC 50 ) and 95% lethal concentration (LC 95 ) of CO 2 for four fishes (Rainbow Trout Oncorhynchus mykiss , Common Carp Cyprinus carpio , Channel Catfish Ictalurus punctatus , and Westslope Cutthroat Trout Oncorhynchus clarkii lewisi ). In the laboratory, we exposed juvenile fish to a range of CO 2 concentrations for 24 h in unpressurized, flow-through tanks. We developed a Bayesian hierarchical model to estimate the dose-response relationship for each fish species with associated uncertainty, and estimated 24-h LC 50 and LC 95 values based on laboratory trials for each species. The minimum concentration inducing mortality differed among cold water–adapted species and warm water–adapted species groups: 150 mg CO 2 /L for Westslope Cutthroat Trout and Rainbow Trout and 225 mg CO 2 /L for Common Carp and Channel Catfish. We observed complete mortality at 275 mg CO 2 /L (38,672 microatmospheres [μatm]), 225 mg CO 2 /L (30,711 μatm), and 495 mg CO 2 /L (65,708 μatm [Common Carp]; 77,213 μatm [Channel Catfish]) for Westslope Cutthroat Trout, Rainbow Trout, and both Common Carp and Channel Catfish, respectively. There was evidence of a statistical difference between the 24-h LC 95 values of Westslope Cutthroat Trout and Rainbow Trout (245.0 [222.2–272.2] and 190.6 [177.2–207.8] mg CO 2 /L, respectively). Additionally, these values were almost half the estimated 24-h LC 95 values for Common Carp and Channel Catfish (422.5 [374.7–474.5] and 434.2 [377.2–492.2] mg CO 2 /L, respectively). Although the experimental findings show strong relationships between increased CO 2 concentration and higher mortality, additional work is required to assess the efficacy and feasibility of a CO 2 application in a field setting.

Journal of Fish and Wildlife Management↗

USGS2017

Using carbon dioxide in fisheries and aquatic invasive species management

To restore native fish populations, fisheries programs often depend on active removal of aquatic invasive species. Chemical removal can be an effective method of eliminating aquatic invasive species, but chemicals can induce mortality in nontarget organisms and persist in the environment. Carbon dioxide (CO 2 ) is an emerging alternative to traditional chemical control agents because it has been demonstrated to be toxic to fish, but is naturally occurring and readily neutralized. In addition, CO 2 is a commercially available gas, is highly soluble, and has high absorption efficiency. When these characteristics are paired with advances in modern, large-scale gas delivery technologies, opportunities to use CO 2 in natural or artificial (e.g., canals) waters to manage fish become increasingly feasible. Our objective is to describe the history of CO 2 use in fisheries and outline potential future applications of CO 2 to suppress and manipulate aquatic species in field and aquaculture settings.

Fisheries↗

USGS2015

Broadening the regulated-river management paradigm: A case study of the forgotten dead zone hindering Pallid Sturgeon recovery

The global proliferation of dams within the last half century has prompted ecologists to understand the effects of regulated rivers on large-river fishes. Currently, much of the effort to mitigate the influence of dams on large-river fishes has been focused on downriver effects, and little attention has been given to upriver effects. Through a combination of field observations and laboratory experiments, we tested the hypothesis that abiotic conditions upriver of the dam are the mechanism for the lack of recruitment in Pallid Sturgeon ( Scaphirhynchus albus ), an iconic large-river endangered species. Here we show for the first time that anoxic upriver habitat in reservoirs (i.e., the transition zone between the river and reservoir) is responsible for the lack of recruitment in Pallid Sturgeon. The anoxic condition in the transition zone is a function of reduced river velocities and the concentration of fine particulate organic material with high microbial respiration. As predicted, the river upstream of the transition zone was oxic at all sampling locations. Our results indicate that transition zones are an ecological sink for Pallid Sturgeon. We argue that ecologists, engineers, and policy makers need to broaden the regulated-river paradigm to consider upriver and downriver effects of dams equally to comprehensively mitigate altered ecosystems for the benefit of large-river fishes, especially for the Pallid Sturgeon.

Fisheries↗