@article{liénart_cirtwill_hedgespeth_bradshaw_2022, title={A sprinkling of gold dust: Pine pollen as a carbon source in Baltic Sea coastal food webs}, volume={11}, url={https://doi.org/10.1002/lno.11974}, DOI={10.1002/lno.11974}, abstractNote={AbstractAllochthonous subsidies to marine ecosystems have mainly focused on biogeochemical cycles, but there has also been recent interest in how terrestrial carbon (C) influences marine food webs. In the Baltic Sea, pine (Pinus sylvestris) pollen is found in large amounts in shallow bays in early summer. Pollen is a significant C‐source in freshwater ecosystems and may also be important in coastal food webs. We examined the consumption of pollen and autochthonous resources by benthic invertebrates in shallow bays of the Baltic Sea. We used stable isotopes to estimate diets and reconstructed consumer‐resource networks (food webs) for grazers and particulate organic matter (POM)‐feeders to compare how these different guilds used pollen. We found thatP. sylvestrispollen was consumed in small amounts by a variety of animals and in some cases made up a sizeable proportion of invertebrates' diets. However, invertebrates generally depended less on pollen than other resources. The degree of pollen consumption was related to feeding traits, with generalist invertebrate grazers consuming more pollen (> 10% of diet) than the more specialist POM‐feeders (< 5% of diet contributed by pollen). POM‐feeders may consume additional microbially‐degraded pollen which was not identifiable in our model. We suggest that pollen is a small but substantial allochthonous C‐source in shallow bay food webs of the Baltic Sea, with the potential to affect the dynamics of these ecosystems.}, journal={Limnology and Oceanography}, publisher={Wiley}, author={Liénart, Camilla and Cirtwill, Alyssa R. and Hedgespeth, Melanie L. and Bradshaw, Clare}, year={2022}, month={Jan} }
 @article{hedgespeth_mccord_phillips_strynar_shea_nichols_2021, title={Suspect-screening analysis of a coastal watershed before and after Hurricane Florence using high-resolution mass spectrometry}, volume={782}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2021.146862}, abstractNote={On September 14, 2018, Hurricane Florence delivered ~686 mm rainfall to a 106 km2 watershed in coastal North Carolina, USA. A forested land treatment site comprises one third of the watershed wherein municipal wastewater effluent is spray-irrigated onto 8.9 km2 of forest. This communication provides insight for land treatment function under excess water duress as well as changes in organic chemical composition in on- and off-site waters before (June 2018) and after (September & December 2018) Hurricane Florence's landfall. We compare the numbers and relative abundances of chemical features detected using suspect screening high resolution mass spectrometry in waste-, ground-, and surface water samples. Values for upstream and receiving waters in September were lower than for sampling events in June and December, indicating an expected dilution effect across the watershed. Chemical diversity was greatest for all surface water samples in December, but only upstream surface water showed a dramatic five-fold increase in relative chemical abundance. Chemical abundance in on-site water and downstream surface water was equal to or lower than the September storm dilution effect. These data suggest that the land treatment system is functionally and hydrologically robust to extreme storm events and contributed to dilution of upstream chemical reservoirs for downstream receiving waters for months after the storm. Similar systems may embody one water reuse strategy robust to the increasing occurrence of extreme precipitation events.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Hedgespeth, Melanie L. and McCord, James P. and Phillips, Katherine A. and Strynar, Mark J. and Shea, Damian and Nichols, Elizabeth Guthrie}, year={2021}, month={Aug} }
 @article{hedgespeth_nichols_2019, title={Expanding phytoremediation to the realms of known and unknown organic chemicals of concern}, volume={21}, ISSN={1522-6514 1549-7879}, url={http://dx.doi.org/10.1080/15226514.2019.1633265}, DOI={10.1080/15226514.2019.1633265}, abstractNote={Abstract Recent advancements in analytical chemistry and data analyses via high-resolution mass spectrometry (HRMS) are evolving scientific understanding of the potential totality of organic chemical exposure and pollutant risk. This review addresses the importance of HRMS approaches, namely suspect screening and nontarget chemical analyses, to the realm of phytoremediation. These analytical approaches are not without caveats and constraints, but they provide an opportunity to understand in greater totality how plant-based technologies contribute, mitigate, and reduce organic chemical exposure across scales of experimental and system-level studies. These analytical tools can enlighten the complexity and efficacy of plant-contaminant system design and expand our understanding of biogenic and anthropogenic chemicals at work in phytoremediation systems. Advances in data analytics from biological sciences, such as metabolomics, are crucial to HRMS analysis. This review provides an overview of targeted, suspect screening, and nontarget HRMS approaches, summarizes the expanding knowledge of regulated and unregulated organic chemicals in the environment, addresses requisite HRMS instrumentation, analysis cost, uncertainty, and data processing techniques, and offers potential bridges of HRMS analyses to phytoremediation research and application.}, number={14}, journal={International Journal of Phytoremediation}, publisher={Informa UK Limited}, author={Hedgespeth, Melanie L. and Nichols, Elizabeth Guthrie}, year={2019}, month={Jul}, pages={1385–1396} }
 @article{hedgespeth_gibson_mccord_strynar_shea_nichols_2019, title={Suspect screening and prioritization of chemicals of concern (COCs) in a forest-water reuse system watershed}, volume={694}, ISSN={0048-9697}, url={http://dx.doi.org/10.1016/j.scitotenv.2019.07.184}, DOI={10.1016/j.scitotenv.2019.07.184}, abstractNote={Much research has assessed organic chemicals of concern (COCs) in municipal wastewater and receiving waters, but few studies have examined COCs in land treatment systems. Many prior studies have implemented targeted methods that quantify a relatively small fraction of COCs present in wastewater and receiving waters. This study used suspect screening to assess chemical features in ground- and surface waters from a watershed where secondary-treated wastewater is irrigated onto 900 ha of temperate forest, offering a more holistic view of chemicals that contribute to the exposome. Chemical features were prioritized by abundance and ToxPi scoring across seasonal sampling events to determine if the forest-water reuse system contributed to the chemical exposome of ground- and surface waters. The number of chemical features detected in wastewater was usually higher than on- and off-site ground- and surface waters; in wastewater, chemical features trended with precipitation in which greater numbers of features were detected in months with low precipitation. The number of chemical features detected in off- and on-site waters was similar. The lower overlap between chemical features found in wastewater and downstream surface waters, along with the similar numbers of features being detected in upstream and downstream surface waters, suggests that though wastewater may be a source of chemicals to ground and surface waters on-site, dissipation of wastewater-derived features (in number and peak area abundance) likely occurs with limited off-site surface water export by the forested land treatment system. Further, the numbers of features detected on site and the overlap between wastewater and surface waters did not increase during periods of low rainfall, counter to our initial expectations. The chemical features tentatively identified in this watershed appear common to features identified in other studies, warranting further examination on the potential for resulting impacts of these on humans and the environment.}, journal={Science of The Total Environment}, publisher={Elsevier BV}, author={Hedgespeth, Melanie L. and Gibson, Nancy and McCord, James and Strynar, Mark and Shea, Damian and Nichols, Elizabeth Guthrie}, year={2019}, month={Dec}, pages={133378} }
 @article{hedgespeth_karasek_ahlgren_berglund_brönmark_2018, title={Behaviour of freshwater snails (Radix balthica) exposed to the pharmaceutical sertraline under simulated predation risk}, url={https://doi.org/10.1007/s10646-017-1880-6}, DOI={10.1007/s10646-017-1880-6}, abstractNote={AbstractDue to their potential for affecting the modulation of behaviour, effects of selective serotonin reuptake inhibitors (SSRIs) in the environment are particularly interesting regarding interspecies interactions and non-consumptive effects (NCEs) induced by predator cues in prey organisms. We evaluated the effects of sertraline (0.4, 40 ng/L, 40 µg/L) over 8 days on activity and habitat choice in the freshwater snailRadix balthica, on snails’ boldness in response to mechanical stimulation (simulating predator attack), and their activity/habitat choice in response to chemical cues from predatory fish. We hypothesised that sertraline exposure would detrimentally impact NCEs elicited by predator cues, increasing predation risk. Although there were no effects of sertraline on NCEs, there were observed effects of chemical cue from predatory fish on snail behaviour independent of sertraline exposure. Snails reduced their activity in which the percentage of active snails decreased by almost 50% after exposure to fish cue. Additionally, snails changed their habitat use by moving away from open (exposed) areas. The general lack of effects of sertraline on snails’ activity and other behaviours in this study is interesting considering that other SSRIs have been shown to induce changes in gastropod behaviour. This raises questions on the modes of action of various SSRIs in gastropods, as well as the potential for a trophic “mismatch” of effects between fish predators and snail prey in aquatic systems.}, journal={Ecotoxicology}, author={Hedgespeth, Melanie Lea and Karasek, Tomasz and Ahlgren, Johan and Berglund, Olof and Brönmark, Christer}, year={2018}, month={Mar} }
 @article{mceachran_hedgespeth_newton_mcmahen_strynar_shea_nichols_2018, title={Comparison of emerging contaminants in receiving waters downstream of a conventional wastewater treatment plant and a forest-water reuse system}, volume={25}, ISSN={0944-1344 1614-7499}, url={http://dx.doi.org/10.1007/s11356-018-1505-5}, DOI={10.1007/s11356-018-1505-5}, abstractNote={Forest-water reuse (FWR) systems treat municipal, industrial, and agricultural wastewaters via land application to forest soils. Previous studies have shown that both large-scale conventional wastewater treatment plants (WWTPs) and FWR systems do not completely remove many contaminants of emerging concern (CECs) before release of treated wastewater. To better characterize CECs and potential for increased implementation of FWR systems, FWR systems need to be directly compared to conventional WWTPs. In this study, both a quantitative, targeted analysis and a nontargeted analysis were utilized to better understand how CECs release to waterways from an FWR system compared to a conventional treatment system. Quantitatively, greater concentrations and total mass load of CECs was exhibited downstream of the conventional WWTP compared to the FWR. Average summed concentrations of 33 targeted CECs downstream of the conventional system were ~ 1000 ng/L and downstream of the FWR were ~ 30 ng/L. From a nontargeted chemical standpoint, more tentatively identified chemicals were present, and at a greater relative abundance, downstream of the conventional system as well. Frequently occurring contaminants included phthalates, pharmaceuticals, and industrial chemicals. These data indicate that FWR systems represent a sustainable wastewater treatment alternative and that emerging contaminant release to waterways was lower at a FWR system than a conventional WWTP.}, number={13}, journal={Environmental Science and Pollution Research}, publisher={Springer Science and Business Media LLC}, author={McEachran, Andrew D. and Hedgespeth, Melanie L. and Newton, Seth R. and McMahen, Rebecca and Strynar, Mark and Shea, Damian and Nichols, Elizabeth Guthrie}, year={2018}, month={Feb}, pages={12451–12463} }
 @article{assessing potential vulnerability and response of fish to simulated avian predation after exposure to psychotropic pharmaceuticals_2016, url={http://www.mdpi.com/2305-6304/4/2/9}, DOI={10.3390/toxics4020009}, abstractNote={Psychotropic pharmaceuticals present in the environment may impact organisms both directly and via interaction strengths with other organisms, including predators; therefore, this study examined the potential effects of pharmaceuticals on behavioral responses of fish to avian predators. Wild-caught juvenile perch (Perca fluviatilis) were assayed using a striking bird model after a seven-day exposure to psychotropic pharmaceuticals (the antidepressants fluoxetine or sertraline, or the β-blocker propranolol) under the hypotheses that exposure would increase vulnerability to avian predation via increasing the probability of predator encounter as well as degrading evasive behaviors upon encounter. None of the substances significantly affected swimming activity of the fish, nor did they increase vulnerability by affecting encounter probability or evasive endpoints compared to control treatments. Counter to our expectations, fish exposed to 100 μg/L fluoxetine (but no other concentrations or pharmaceuticals) were less likely to enter the open area of the arena, i.e., less likely to engage in risky behavior that could lead to predator encounters. Additionally, all fish exposed to environmentally relevant, low concentrations of sertraline (0.12 μg/L) and propranolol (0.1 μg/L) sought refuge after the simulated attack. Our unexpected results warrant further research as they have interesting implications on how these psychotropic pharmaceuticals may affect predator-prey interactions spanning the terrestrial-aquatic interface.}, journal={Toxics}, year={2016}, month={Apr} }
 @article{hedgespeth_nilsson_berglund_2014, title={Ecological implications of altered fish foraging after exposure to an antidepressant pharmaceutical}, volume={151}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84899485526&partnerID=MN8TOARS}, DOI={10.1016/j.aquatox.2013.12.011}, abstractNote={Pharmaceutical residues are increasingly detected in environmental and biological samples, some at levels known to adversely affect non-target organisms; however, less is known of how these organism-level effects relate to the ecology of aquatic systems. Foraging processes may be used as behavioral endpoints that link effects on individuals to the population and community levels, enabling risk assessment of environmental contaminants at larger ecological scales. In this study, we performed feeding trials using juvenile Eurasian perch (Perca fluviatilis) exposed to the selective serotonin reuptake inhibitor (SSRI) sertraline to test the hypothesis that sertraline alters foraging ecology of the fish in terms of their functional response. We found an exposure-dependent decrease in feeding with increasing sertraline concentrations. Further experiments revealed that feeding rates decrease at both low and high prey densities, indicating effects on both attack rate and handling time, respectively. Because the functional response can shape consumer-resource dynamics, such effects may alter the stability of predator-prey systems and consequently, community structure.}, journal={Aquatic Toxicology}, author={Hedgespeth, M.L. and Nilsson, P.A. and Berglund, O.}, year={2014}, pages={84–87} }
 @article{hedgespeth_sapozhnikova_pennington_clum_fairey_wirth_2012, title={Pharmaceuticals and personal care products (PPCPs) in treated wastewater discharges into Charleston Harbor, South Carolina}, volume={437}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84867593767&partnerID=MN8TOARS}, DOI={10.1016/j.scitotenv.2012.07.076}, abstractNote={This study assessed seasonal and regional trends of pharmaceuticals and personal care products (PPCPs) detected in monthly samples from two local wastewater treatment plants (WWTPs) in Charleston, South Carolina, USA, over the period of one year. Surface water of Charleston Harbor was also analyzed to examine environmental distribution in an estuarine ecosystem. Of the 19 compounds examined, 11 were quantified in wastewater influent, 9 in effluent, and 7 in surface water. Aqueous concentrations of many PPCPs were reduced by > 86% in wastewater effluent compared with influent, though some compounds showed low removal and greater effluent concentrations compared with influent (e.g. estrone and fluoxetine). Differences in effluent concentrations and estimated removal between facilities were likely related to variations in the facilities' operating procedures. Surface water concentrations were generally reduced by > 90% for those chemicals found in effluent. Additionally, there were seasonal trends that indicate reduced degradation in colder months in wastewater and surface water. To our knowledge, this is the first study examining PPCPs in the South Atlantic Bight.}, journal={Science of the Total Environment}, author={Hedgespeth, M.L. and Sapozhnikova, Y. and Pennington, P. and Clum, A. and Fairey, A. and Wirth, E.}, year={2012}, pages={1–9} }
 @article{sapozhnikova_hedgespeth_wirth_fulton_2011, title={Analysis of selected natural and synthetic hormones by LC-MS-MS using the US EPA method 1694}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79959754853&partnerID=MN8TOARS}, DOI={10.1039/c0ay00748j}, abstractNote={The US EPA Method 1694 (which is specific to the analysis of pharmaceuticals and personal care products) was evaluated for analysis of selected hormones: 17α- and 17β-estradiol, estriol, estrone, 17α-ethynylestradiol, diethylstilbestrol, equilin, equilenin, testosterone, progesterone and norgestrel in filtered sewage influent/effluent and seawater. The extraction of hormones from fortified water matrices with HLB Oasis solid phase extraction cartridges resulted in good recovery efficiencies: 86–113% for seawater and 80–114% for sewage samples with a relative standard deviation of 6–16% (seawater) and 7–14% (wastewater). Natural and synthetic estrogens (17α- and 17β-estradiol, estriol, estrone, 17α-ethynylestradiol, diethylstilbestrol, equilin, equilenin) were separated with a Gemini-NX C18 (Phenomenex, Inc.) column and detected by Liquid Chromatography Tandem Mass Spectrometry (LC-MS-MS) in negative ElectroSpray Ionization (ESI) multiple reaction monitoring (MRM) mode. Three other hormones (testosterone, progesterone and norgestrel) were separated using an Xterra MS C18 (Waters Corp.) column along with the Group I compounds of the EPA Method 1694 and detected by MS–MS in ESI positive mode. Most compounds were quantified by isotope dilution with matched labeled internal standards. The method was applied to the analysis of effluent and influent from wastewater treatment facilities in South Carolina, USA, and surface seawater samples from Charleston Harbor, South Carolina. Only estrone was detected in surface seawater at a concentration of 0.5 ng L−1, which was below the method reporting limit of 1 ng L−1. Estriol, estrone and testosterone were found in influent samples at 155–179 ng L−1, 27–28 ng L−1 and 41–49 ng L−1, respectively. The estrone concentration was 24 ng L−1 in an effluent sample from one of the treatment plants. This study demonstrates that the US EPA Method 1694 can be successfully used for the analysis of natural and synthetic hormones along with the pharmaceuticals and personal care products (PPCPs) currently listed in the method.}, number={5}, journal={Analytical Methods}, author={Sapozhnikova, Y. and Hedgespeth, M. and Wirth, E. and Fulton, M.}, year={2011}, pages={1079–1086} }