Seagrasses increase sediment complexity by trapping particulates and influencing biogeochemical cycles via root oxygen loss and organic matter exudation. However, their impact on trace metal sequestration is poorly studied. We found significantly higher trace metal concentrations in seagrass sediments compared to adjacent bare sediments, correlating with total organic carbon, iron, and fine sediments.
View Article and Find Full Text PDFRecent revelations have brought to light the misconduct of high performers across various fields and occupations who were promoted up the organizational ladder rather than punished for their unethical behavior. Drawing on principles of motivated moral reasoning, we investigate how employee performance biases supervisors' moral judgment of employee unethical behavior and how supervisors' performance-focus shapes how they account for moral judgments in promotion recommendations. We test our model in three studies: a field study of 587 employees and their 124 supervisors at a Fortune 500 telecom company, an experiment with two samples of working adults, and an experiment that directly varied explanatory mechanisms.
View Article and Find Full Text PDFThis study establishes baseline water quality characteristics for the Gold Coast Broadwater, southern Moreton Bay (Australia) utilising routinely monitored parameters between 2016 and 2021, across 18 sites. Combined site mean concentrations of NO-N, NH-N and total nitrogen were 11.4 ± 33.
View Article and Find Full Text PDFEstuarine ecosystems have very high ecological and economic value, and also act as a buffer for coastal oceans by processing nutrient inputs from terrestrial sources. However, ongoing pressures from increased urbanisation and agriculture, overlaid by climate change, has reduced inflows and increased nutrient loads that challenge the health and buffering capacity of these ecosystems. This study aimed to investigate whether restoring the bioturbating activity of Simplisetia aequisetis (Polychaeta: Nereididae) and other macrofauna could improve biogeochemical conditions in 'hostile' (i.
View Article and Find Full Text PDFEstuarine ecosystems are considered hotspots for productivity, biogeochemical cycling and biodiversity, however, their functions and services are threatened by several anthropogenic pressures. We investigated how abundance and diversity of benthic macrofauna, and their functional traits, correlate to sediment biogeochemistry and nutrient concentrations throughout an estuarine-to-hypersaline lagoon. Benthic communities and functional traits were significantly different across the sites analysed, with higher abundance and more traits expressed in the estuarine region.
View Article and Find Full Text PDFModels of trust have focused on the notion that an employee's trust in a coworker is based on that coworker's trustworthiness and the employee's trust propensity-a generalized tendency to believe others are trustworthy. Although these models capture the general of risk associated with trusting a particular coworker, they provide insufficient insight into why an employee might the risk associated with trust on a particular day. Bringing the concept of -the tendency to accept or avoid risk-from the decision-making literature into the trust literature, we build a model of trust that suggests employees' trusting behaviors stem from both their calculated assessment of risk (encapsulated in trustworthiness and trust propensity) and their tendency to take those risks.
View Article and Find Full Text PDFConcepts in microplastics studies are not well established due to the emerging nature of microplastic research, especially in jellyfish. We conducted experiments to test whether ephyrae would ingest more microbeads via trophic transfer than direct ingestion and whether medusae would ingest more aged microbeads than virgin microbeads. We exposed ephyrae of Aurelia coerulea to two treatments, aged microbeads and Artemia nauplii that had ingested microbeads.
View Article and Find Full Text PDFThe surge of opportunities available through the gig economy has increased the sizeable population of people who hold multiple jobs. Many of these multiple jobholders are full-time employees who have adopted side-hustles-income-generating work performed alongside full-time work. A core and ubiquitous feature of both full-time work and side-hustles is status, or membership in a social hierarchy.
View Article and Find Full Text PDFMicroplastics are ubiquitous pollutants in aquatic environments globally. Wastewater treatment plants are considered to be a major source of microplastics and jellyfish have been proposed as potential bioindicators of microplastic pollution. We tested whether treated wastewater influenced the concentration and/or composition of microplastics in the receiving water by comparing the concentration and composition of microplastics in seawater collected in the wastewater plume and at sites distant from treated wastewater releases in the Gold Coast Broadwater, Australia, and at sites within the nearby Tweed River estuaries, which receives >10 times less wastewater discharge.
View Article and Find Full Text PDFThis study describes the validation of a diffusive gradients in thin film (DGT) technique for determining lanthanide rare earth elements (REEs) and in situ measurements of REEs in sediment pore waters. Laboratory experiments demonstrated that Chelex-100 binding layers had uptake efficiencies ranging from 78.0% to 92.
View Article and Find Full Text PDFJellyfish are voracious planktonic predators that may be susceptible to ingesting microplastics. We measured rates of ingestion and egestion of microbeads by Aurelia aurita (Scyphozoa) and evaluated whether ingesting microbeads affected metabolism or gut epithelia. Ingestion rates were measured by exposing medusae to microbeads and randomly sampling them 6 times over a 32 h period to determine the number of microbeads in their tissues.
View Article and Find Full Text PDFMeasurement of sulfide in pore waters is critical for understanding biogeochemical processes, especially within coastal sediments. Here we report the development of a new colorimetric DET (diffusive equilibration in thin films) technique for determining mm-resolution, two-dimensional sulfide distributions in sediment pore waters. This colorimetric sulfide DET method was based on the standard spectrophotometric methylene blue assay, but modified to allow quantitation of sulfide by computer imaging densitometry.
View Article and Find Full Text PDFOver recent decades, a great number of pit lakes have been formed, as a result of sand and gravel quarrying in river floodplains that are often also heavily exploited for agriculture. These lakes can act as nutrient filters and regulate the nitrogen pollution resulting from agricultural fertiliser use. In this paper we report the main outcomes of a study of the major nitrogen pathways in five pit lakes of differing trophic status, located along a lowland stretch of the Po river (Northern Italy).
View Article and Find Full Text PDFDetermining inorganic nutrient profiles to support understanding of nitrogen transformations in stream sediments is challenging, due to nitrification and denitrification being confined to particular conditions in potentially heterogeneous sediment influenced by benthic microalgae, rooted aquatic plants and/or diel light cycles. The diffusive gradients in thin films (DGT) and diffusive equilibration in thin films (DET) techniques allow in situ determination of porewater concentration profiles, and distributions for some solutes. In this study, DGT, DET and conventional porewater extraction (sectioning and centrifugation) methods were compared for ammonium and nitrate in stream sediments under light and dark conditions.
View Article and Find Full Text PDFAn unintended side effect of the goal-setting literature's focus on cognitive dynamics has been an insufficient acknowledgment of how employees affectively experience high-performance goals. This is potentially a crucial oversight, considering the substantial body of research that has demonstrated the impact of employees' affective states on organizationally relevant attitudes and behaviors. Drawing on cognitive-motivational-relational theory (Lazarus, 1991), we explore the discrete affective states elicited by high-performance goals.
View Article and Find Full Text PDFIn undisturbed, metal-contaminated marine sediments, porewater metal concentrations are generally low due to their associations with strong binding phases such as organic matter, Fe/Mn (oxy)hydroxides and sulfides. Bioturbating fauna can alter redox conditions and, therefore, metal binding, potentially leading to increased metal bioavailability and subsequent toxicity to inhabiting organisms. Here we assessed the impacts of bioturbation (by bivalves and large amphipod species) on sediment biogeochemistry, metal bioaccumulation and toxicity to a smaller amphipod species in a metal contaminated sediment with low and high acid volatile sulfide (AVS) concentrations.
View Article and Find Full Text PDFHypersaline sediments derived from poor land management or the decommissioning of large-scale salt production contribute to the long-term degradation of aquatic environments. Obstacles impeding remediation of these environments include salt crusts restricting benthic recolonisation, hypersalinity-induced toxicity to organisms, and disruption of biogeochemical cycles. Remediation often focuses on engineered solutions, despite sediment-biota interactions often playing a crucial role in improving long-term remediation and restoration of contaminated areas.
View Article and Find Full Text PDFThere has been growing interest in ethical leadership from both scholars and practitioners because of the positive effects that ethical leaders can have on their subordinates. These benefits come not only from ethical leaders acting as moral exemplars, but also from the tendency for ethical leaders to forge high-quality social exchange relationships with subordinates that help to establish expectations for appropriate conduct and ensure accountability through reciprocal obligation. However, the act of developing and maintaining strong social exchange relationships is resource intensive and requires considerable personal investment from ethical leaders.
View Article and Find Full Text PDFAmmonium is an important nutrient in primary production; however, high ammonium loads can cause eutrophication of natural waterways, contributing to undesirable changes in water quality and ecosystem structure. While ammonium pollution comes from diffuse agricultural sources, making control difficult, industrial or municipal point sources such as wastewater treatment plants also contribute significantly to overall ammonium pollution. These latter sources can be targeted more readily to control ammonium release into water systems.
View Article and Find Full Text PDFAntimony (Sb) and arsenic (As) are priority environmental contaminants that often co-occur at mining-impacted sites. Despite their chemical similarities, Sb mobility in waterlogged sediments is poorly understood in comparison to As, particularly across the sediment-water interface (SWI) where changes can occur at the millimeter scale. Combined diffusive gradients in thin films (DGT) and diffusive equilibration in thin films (DET) techniques provided a high resolution, in situ comparison between Sb, As, and iron (Fe) speciation and mobility across the SWI in contaminated freshwater wetland sediment mesocosms under an oxic-anoxic-oxic transition.
View Article and Find Full Text PDFA modified diffusive gradients in thin films (DGT) technique uses both a mixed binding layer (PrCH and A520E resins for NH-N and NO-N, respectively) and multiple binding layers (Metsorb binding layer for PO-P overlying the mixed binding layer) for the simultaneous measurement of dissolved inorganic nitrogen (nitrate and ammonium) and phosphate in freshwater (INP-DGT). High uptake and elution efficiencies were determined for a mixed (PrCH/A520E) binding gel for dissolved inorganic nitrogen and an agarose-based Metsorb binding layer for PO-P. Diffusion coefficients (D) obtained from DGT time-series experiments (conductivity 180 μS cm) for NH-N, NO-N and PO-P agreed well with those measured using individual DGT techniques in previous studies, but were characterised over a wider range of ionic strengths here.
View Article and Find Full Text PDFIn productive coastal sediments the separation between different biogeochemical zones (e.g. oxic, iron(III)-reducing and sulfate-reducing) may be on the scale of millimetres.
View Article and Find Full Text PDFThe performance of DGT-Chelex, DGT-Metsorb and DGT-MBL (Chelex-Metsorb mixed binding layer) with open and restricted diffusive layers for trace metal (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) and oxyanion (As, Mo, Sb, V) measurements, was evaluated in four natural waters with different pH (range 3.29-7.81).
View Article and Find Full Text PDFAntimony is a priority environmental contaminant that is relatively poorly studied compared to other trace metal(loid)s. In particular, the behaviour of antimony in wetland sediments, where anaerobic conditions often dominate, has received considerably less attention compared to well-drained terrestrial soil environments. Here we report the results of a spatial assessment of antimony in the sediments and vegetation of a freshwater wetland exposed to stibnite tailings for the past forty years.
View Article and Find Full Text PDFAnthropogenic nutrient inputs enhance microbial respiration within many coastal ecosystems, driving concurrent hypoxia and acidification. During photosynthesis, Symbiodinium spp., the microalgal endosymbionts of cnidarians and other marine phyla, produce O and assimilate CO and thus potentially mitigate the exposure of the host to these stresses.
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