Geology topics

Lisa V. Kennedy

Publications and source records attributed to Lisa V. Kennedy.

6 recordsLinked to original sources

USGS2024

Structurally selective ozonolysis of p-phenylenediamines and toxicity in coho salmon and rainbow trout

The tire-rubber-derived ozonation product of N -(1,3-dimethylbutyl)- N ′-phenyl- p -phenylenediamine (6PPD), N -(1,3-dimethylbutyl)- N ′-phenyl- p -phenylenediamine-quinone (6PPD-Q), was recently discovered to cause acute mortality in coho salmon ( Oncorhynchus kisutch ). para -Phenylenediamines (PPDs) with variable side chains distinct from 6PPD have been identified as potential replacement antioxidants, but their toxicities remain unclear under environmentally relevant ozone conditions. We herein tested the multiphase gas-surface ozone reactivity of four select PPDs [6PPD, N -isopropyl- N ′-phenyl- p -phenylenediamine (IPPD), N , N ′-diphenyl- p -phenylenediamine (DPPD), and N -phenyl- N ′-cyclohexyl- p -phenylenediamine (CPPD)] and evaluated the toxicity of their reaction mixtures in coho salmon, rainbow trout ( Oncorhynchus mykiss ), and fathead minnow ( Pimephales promelas ). 6PPD and IPPD were found to rapidly react with ozone, while no significant multiphase ozone reactivity was observed for DPPD or CPPD. The viability of coho salmon CSE-119 cells was strongly affected by the ozonolysis products of 6PPD but not by those of the other three PPDs. Acute mortality was only observed in juvenile rainbow trout that were exposed to oxidized 6PPD, suggesting a common mechanism of toxic action in the two salmonid fish species. This study reports the structurally selective ozone reactivity of PPDs and the unique toxicity of 6PPD ozonolysis mixtures, which demonstrates that other PPDs are potential alternative antioxidants.

Environmental Science and Technology↗

USGS2024

Structurally selective ozonolysis of p-phenylenediamines and toxicity in coho salmon and rainbow trout

The tire rubber-derived ozonation product of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q), was recently discovered to cause acute mortality in Coho Salmon (Oncorhynchus kisutch). para-Phenylenediamines (PPDs) with variable side chains distinct from 6PPD have been identified as potential replacement commercial antioxidants, but their structure-related ozone reactivities and toxicities remain unexplored. We herein tested the multiphase gas-surface ozone reactivity of four select PPDs and evaluated the toxicity of their reaction mixtures in Coho Salmon and Rainbow Trout (Oncorhynchus mykiss). 6PPD and N-Isopropyl-N'-phenyl-p-phenylenediamine (IPPD) were found to rapidly react with ozone to form 22 and 16 transformation products, respectively, including PPD-Qs. No significant multiphase ozone reactivity was observed for N,N'-Diphenyl-p-phenylenediamine (DPPD) or N-Cyclohexyl-N'-phenyl-p-phenylenediamine (CPPD) despite their structural similarity to 6PPD. The viability of Coho Salmon CSE-119 cells was strongly affected by the ozonolysis products of 6PPD, but not by those of the other three PPDs. The cytotoxicity of the 6PPD reaction mixture increased with ozonolysis time, with the strongest toxicity being observed after 7 days of oxidation by 100 ppb of ozone. As with Coho Salmon cells, acute mortality was only observed in juvenile Rainbow Trout that were exposed to the oxidized 6PPD reaction mixture, suggesting a common mechanism of toxic action in the two salmonid fish species. Compound- and regio-selective formation of hydroxylated metabolites of 6PPD-Q were detected in Rainbow Trout exposed to the 6PPD reaction mixture, which may be related to its selective toxicity. This study reports the structurally selective ozone reactivity of PPDs, and the unique toxicity of 6PPD ozonolysis mixtures, which demonstrates that other PPDs are potential alternative antioxidants.

ChemRxiv↗

USGS2020

Annual adult survival drives trends in Arctic-breeding shorebirds but knowledge gaps in other vital rates remain

Conservation status and management priorities are often informed by population trends. Trend estimates can be derived from population surveys or models, but both methods are associated with sources of uncertainty. Many Arctic-breeding shorebirds are thought to be declining based on migration and/or overwintering population surveys, but data are lacking to estimate the trends of some shorebird species. In addition, for most species, little is known about the stage(s) at which population bottlenecks occur, such as breeding vs. nonbreeding periods. We used previously published and unpublished estimates of vital rates to develop the first large-scale population models for 6 species of Arctic-breeding shorebirds in North America, including separate estimates for 3 subspecies of Dunlin. We used the models to estimate population trends and identify life stages at which population growth may be limited. Our model for the arcticola subspecies of Dunlin agreed with previously published information that the subspecies is severely declining. Our results also linked the decline to the subspecies’ low annual survival rate, thus potentially implicating factors during the nonbreeding period in the East Asian-Australasian Flyway. However, our trend estimates for all species showed high uncertainty, highlighting the need for more accurate and precise estimates of vital rates. Of the vital rates, annual survival had the strongest influence on population trend in all taxa. Improving the accuracy, precision, and spatial and temporal coverage of estimates of vital rates, especially annual survival, would improve demographic model-based estimates of population trends and help direct management to regions or seasons where birds are subject to higher mortality.

The Condor↗

USGS2018

Life‐history tradeoffs revealed by seasonal declines in reproductive traits of Arctic‐breeding shorebirds

Seasonal declines in breeding performance are widespread in wild animals, resulting from temporal changes in environmental conditions or from individual variation. Seasonal declines might drive selection for early breeding, with implications for other stages of the annual cycle. Alternatively, selection on the phenology of nonbreeding stages could constrain timing of the breeding season and lead to seasonal changes in reproductive performance. We studied 25 taxa of migratory shorebirds (including five subspecies) at 16 arctic sites in Russia, Alaska, and Canada. We investigated seasonal changes in four reproductive traits, and developed a novel Bayesian risk‐partitioning model of daily nest survival to examine seasonal trends in two causes of nest failure. We found strong seasonal declines in reproductive traits for a subset of species. The probability of laying a full four‐egg clutch declined by 8–78% in 12 of 25 taxa tested, daily nest survival rates declined by 1–12% in eight of 22 taxa, incubation duration declined by 2.0–2.5% in two of seven taxa, and mean egg volume declined by 5% in one of 15 taxa. Temporal changes were not fully explained by individual variation. Across all species, the proportion of failed nests that were depredated declined over the season from 0.98 to 0.60, while the proportion abandoned increased from 0.01 to 0.35 and drove the seasonal declines in nest survival. An increase in abandonment of late nests is consistent with a life‐history tradeoff whereby either adult mortality increased or adults deserted the breeding attempt to maximize adult survival. In turn, seasonal declines in clutch size and incubation duration might be adaptive to hasten hatching of later nests. In other species of shorebirds, we found no seasonal patterns in breeding performance, suggesting that some species are not subject to selective pressure for early breeding.

Journal of Avian Biology↗

USGS2018

Effects of environmental conditions on reproductive effort and nest success of Arctic‐breeding shorebirds

The Arctic is experiencing rapidly warming conditions, increasing predator abundance, and diminishing population cycles of keystone species such as lemmings. However, it is still not known how many Arctic animals will respond to a changing climate with altered trophic interactions. We studied clutch size, incubation duration and nest survival of 17 taxa of Arctic‐breeding shorebirds at 16 field sites over 7 years. We predicted that physiological benefits of higher temperatures and earlier snowmelt would increase reproductive effort and nest survival, and we expected increasing predator abundance and decreasing abundance of alternative prey (arvicoline rodents) to have a negative effect on reproduction. Although we observed wide ranges of conditions during our study, we found no effects of covariates on reproductive traits in 12 of 17 taxa. In the remaining taxa, most relationships agreed with our predictions. Earlier snowmelt increased the probability of laying a full clutch from 0.61 to 0.91 for Western Sandpipers, and shortened incubation by 1.42 days for arcticola Dunlin and 0.77 days for Red Phalaropes. Higher temperatures increased the probability of a full clutch from 0.60 to 0.93 for Western Sandpipers and from 0.76 to 0.97 for Red‐necked Phalaropes, and increased daily nest survival rates from 0.9634 to 0.9890 for Semipalmated Sandpipers and 0.9546 to 0.9880 for Western Sandpipers. Higher abundance of predators (foxes) reduced daily nest survival rates only in Western Sandpipers (0.9821–0.9031). In contrast to our predictions, the probability of a full clutch was lowest (0.83) for Semipalmated Sandpipers at moderate abundance of alternative prey, rather than low abundance (0.90). Our findings suggest that in the short‐term, climate warming may have neutral or positive effects on the nesting cycle of most Arctic‐breeding shorebirds.

Ibis↗

USGS2017

Overview of avian toxicity studies for the Deepwater Horizon Natural Resource Damage Assessment

The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries in terms of effects on bird viability. As a result, the US Fish and Wildlife Service proposed various assessment activities to inform NRDA injury determination and quantification analyses associated with the Deepwater Horizon oil spill, including avian toxicity studies. The goal of these studies was to evaluate the effects of oral exposure to 1–20 ml of artificially weathered Mississippi Canyon 252 oil kg bw -1 day -1 from one to 28 days or one to five applications of oil to 20% of the bird's surface area. It was thought that these exposure levels would not result in immediate or short-term mortality but might result in physiological effects that ultimately could affect avian survival, reproduction and health. These studies included oral dosing studies, an external dosing study, metabolic and flight performance studies and field-based flight studies. Results of these studies indicated changes in hematologic endpoints including formation of Heinz bodies and changes in cell counts. There were also effects on multiple organ systems, cardiac function and oxidative status. External oiling affected flight patterns and time spent during flight tasks indicating that migration may be affected by short-term repeated exposure to oil. Feather damage also resulted in increased heat loss and energetic demands. The papers in this special issue indicate that the combined effects of oil toxicity and feather effects in avian species, even in the case of relatively light oiling, can significantly affect the overall health of birds.

Ecotoxicology and Environmental Safety↗