ALBERT

Description: The objective of this study was to assess experimentally the potential impact of anthropogenic pH perturbation (ApHP) on concentrations of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP), as well as processes governing the microbial cycling of sulfur compounds. A summer planktonic community from surface waters of the Lower St. Lawrence Estuary was monitored in microcosms over 12 days under three pCO2 targets: 1 × pCO2 (775 µatm), 2 × pCO2 (1,850 µatm), and 3 × pCO2 (2,700 µatm). A mixed phytoplankton bloom comprised of diatoms and unidentified flagellates developed over the course of the experiment. The magnitude and timing of biomass buildup, measured by chlorophyll a concentration, changed in the 3 × pCO2 treatment, reaching about half the peak chlorophyll a concentration measured in the 1 × pCO2 treatment, with a 2-day lag. Doubling and tripling the pCO2 resulted in a 15% and 40% decline in average concentrations of DMS compared to the control. Results from 35S-DMSPd uptake assays indicated that neither concentrations nor microbial scavenging efficiency of dissolved DMSP was affected by increased pCO2. However, our results show a reduction of the mean microbial yield of DMS by 34% and 61% in the 2 × pCO2 and 3 × pCO2 treatments, respectively. DMS concentrations correlated positively with microbial yields of DMS (Spearman’s ρ = 0.65; P 〈 0.001), suggesting that the impact of ApHP on concentrations of DMS in diatom-dominated systems may be strongly linked with alterations of the microbial breakdown of dissolved DMSP. Findings from this study provide further empirical evidence of the sensitivity of the microbial DMSP switch under ApHP. Because even small modifications in microbial regulatory mechanisms of DMSP can elicit changes in atmospheric chemistry via dampened efflux of DMS, results from this study may contribute to a better comprehension of Earth’s future climate.

Description: Gaseous elemental mercury observations were conducted at Churchill, Victoria, in Australia from April to July, 2013, using a Tekran 2537 analyzer. A strong diurnal variation with daytime average values of 1.2–1.3 ng m–3 and nighttime average values of 1.6–1.8 ng m–3 was observed. These values are significantly higher than the Southern Hemisphere average of 0.85–1.05 ng m–3. Churchill is in the Latrobe Valley, approximately 150 km East of Melbourne, where approximately 80% of Victoria’s electricity is generated from low-rank brown coal from four major power stations: Loy Yang A, Loy Yang B, Hazelwood, and Yallourn. These aging generators do not have any sulfur, nitrogen oxide, or mercury air pollution controls. Mercury emitted in the 2015–2016 year in the Latrobe Valley is estimated to have had an externalized health cost of $AUD88 million. Air pollution mercury simulations were conducted using the Weather Research and Forecast model with Chemistry at 3 × 3 km resolution. Electrical power generation emissions were added using mercury emissions created from the National Energy Market’s 5-min energy distribution data. The strong diurnal cycle in the observed mercury was well simulated (R2 = .49 and P value = 0.00) when soil mercury emissions arising from several years of wet and dry deposition in a radius around the power generators was included in the model, as has been observed around aging lignite coal power generators elsewhere. These results indicate that long-term air and soil sampling in power generation regions, even after the closure of coal fired power stations, will have important implications to understanding the airborne mercury emissions sources.

Description: Methane leakage from point sources in the oil and gas industry is a major contributor to global greenhouse gas emissions. The majority of such emissions come from a small fraction of “super-emitting” sources. We evaluate the emission detection and quantification capabilities of Kairos Aerospace’s airplane-based hyperspectral imaging methane emission detection system for methane fluxes of 18–1,025 kg per hour of methane (kgh(CH4)). In blinded controlled releases of methane conducted over 4 days in San Joaquin County, CA, Kairos detected 182 of 200 valid nonzero releases, including all 173 over 15 kgh(CH4) per meter per second (mps) of wind and none of the 12 nonzero releases below 8.3 kgh(CH4)/mps. Nine of the 26 releases in the partial detection range of 5–15 kgh(CH4)/mps were detected. There were no false positives: Kairos did not detect methane during any of the 21 negative controls. Plume quantification accuracy depends on the wind measurement technique, with a parity slope of 1.15 (σ = 0.037, R2 = 0.84, N = 185) using a cup-based wind meter and 1.45 (σ = 0.059, R2 = 0.80, N = 157) using an ultrasonic anemometer. Performance is comparable even with only modeled wind data. For emissions above 15 kgh/mps, quantification error scales as roughly 30%–40% of emission size, even when using wind reanalysis data instead of ground-based measurements. This reflects both uncertainty in wind measurements and in Kairos’ estimates. These findings suggest that at 2 mps winds under favorable environmental conditions in the United States, Kairos could detect and quantify over 50% of total emissions by identifying super-emitting sources.

Description: Across Canada and the United States, public universities were founded with a mission to contribute to broad societal well-being. Yet, the capacity of public research institutions to develop and disseminate flexible and accessible tools for resilient agriculture has been challenged in recent decades. The role of universities in advancing extractive, rather than regenerative, economies has been amplified by the privatization of public agricultural research and extension of knowledge to farmers, particularly in plant breeding and plant genetics. In this article, we examine the history of public research for seed systems in North America through a “seed regimes” framework, arguing that a narrow focus on commercialization of public research has exacerbated inequalities inherent in the founding structure of public agricultural research, including the displacement of Indigenous land and seed relations. We then discuss how community organizations are challenging the enclosure of seed through seed sovereignty organizing and freelance plant breeding, in some cases through the development of community–university partnerships based on the principles of the cocreation of knowledge. We conclude by offering a reimagined public seed research agenda that focuses on strengthening links between public research and grassroots seed movements, as an opportunity to build more resilient seed and food systems.

Description: The estimation of important carbon fluxes in a changing Arctic environment remains a challenge, one that could benefit from the development of biomarkers that distinguish between sympagic (ice-associated) and pelagic organic material. Products of 10S-DOX-like lipoxygenase and fatty acid cis-trans isomerase (CTI) activity of bacteria attached to sympagic particulate organic matter (POM) were proposed previously as potential biomarkers of the contribution of sympagic biota to carbon fluxes to the seafloor. To date, neither the bacteria involved in such enzymatic activities nor the detection of these potential biomarkers at their presumed source (i.e., sea ice) has been investigated. Here, we determined and compared the diversity of prokaryotic communities (based on operational taxonomic units) attached to sea ice POM and under-ice sinking particles during an early stage of ice melt (brine drainage) in Baffin Bay (Canadian Arctic). Based on a time series of biodiversity analyses and the quantification of lipid tracers of these two bacterial enzymatic activities, we suggest that CTI-active bacteria, exposed to hypersaline stress, are attached to algal POM just above bottom sea ice and released into the water column following brine drainage. In contrast, bacteria attached to sinking particles and exhibiting 10S-DOX-like lipoxygenase activity are suggested to come from the bottommost layer of sea ice, where they may play a role in the detoxification of algae-produce free fatty acids. These results provide a refined view of the potential use of products of CTI activity as specific biomarkers of sympagic organic matter.

Description: A scientific scenario paper was prepared ahead of the Gulf of Maine (GOM) 2050 International Symposium to review and summarize possible weather-related and sea-level changes within the GOM as a result of climate change. It is projected that the GOM will experience warming temperatures, continued sea-level rise, and changes to storm characteristics and related elements such as precipitation and waves in the intermediate term, by approximately 2050. Coastal communities within the GOM region are particularly vulnerable to the anticipated impacts of climate change. This article aims to provide context on some of the consequential impacts that may occur from the changes projected within the area.

Description: Biotechnology describes a range of human activities in medicine, agriculture, and environmental management. One biotechnology in particular, gene technology, continues to evolve both in capacity and potential to benefit and harm society. The purpose of this article is to offer a policy bridge from unproductive descriptions of gene technology to useful methods for identifying sources of significant biological and socioeconomic risk in complex food systems. Farmers and the public could be voluntarily and involuntarily interacting with new techniques of genome editing and gene silencing in entirely new ways, limiting the usefulness of previous gene technology histories to predict safety. What we believe is a more consistent, verifiable, and practical approach is to identify the critical control points that emerge where the scale effects of a human activity diverge between risk and safety. These critical control points are where technical experts can collaborate with publics with different expertise to identify and manage the technology. The use of technical terminology describing biochemical-level phenomena discourages publics that are not technical experts from contesting the embedded cultural perspectives and uncertainty in “scientific” concepts and prejudice the risk discourse by ignoring other issues of significance to society. From our perspective as gene technologists, we confront the use of pseudo-scale language in risk discourse and propose an escape path from clashes over whether risks that arise spontaneously (from nature) can be perfectly mimicked by gene technology to a discussion on how to best control the risks created by human activity. Scale is conceptually implicit and explicit in gene technology regulation, but there is no agreement about what scales are most useful to managing risk and social expectations. Both differentiated governance (risk-tiered) and responsible research and innovation models could accommodate the critical control points mechanism that we describe.

Description: Leafy greens cause a growing proportion of foodborne illness outbreaks despite heavy investment in surveillance technologies designed to control pathogenic hazards in agriculture. To understand how the governing regime maintains authority despite continual lapses in control, I examine a deadly 2018 outbreak of Escherichia coli O157: H7 linked to romaine lettuce. By comparing the outbreak investigation and regulatory response to the questions not asked and actions not taken, I show how the regime’s methods of understanding the outbreak also organized its ignorance of dangers outside its carefully constructed field of vision. Applying agnotology theory, I argue that the industrial organization of leafy greens agriculture and the institutionalized non-knowledge of emergent social–ecological vulnerabilities coproduce one another, allowing the industrial food regime to avoid fundamental reforms that might enhance resilience. This case demonstrates that critical examination of organized non-knowledge in complex environmental governance systems can reveal limits to institutional learning and systemic reflexivity that impede sustainability transitions.

Description: Reply to Kamil Łuczaj and Magdalena Holy Łuczaj (2019). Live streaming at international academic conferences: Cooling down the digital optimism. DOI: https://doi.org/10.1525/elementa.435

Description: Agricultural practices such as fertilization considerably influence soil greenhouse gas fluxes. However, the effects of fertilization on greenhouse gases fluxes remain unclear in tea soil when soil nitrogen is low. In the present study, soil CO2 and CH4 fluxes under various fertilization treatments in tea soil were investigated during a 50-day period. The experiment consisted of five treatments: no fertilizer (CK), single nitrogen (urea, N), single oilseed rape cake fertilizer (R), nitrogen + cake fertilizer (2:1, NR1), and nitrogen + cake fertilizer (1:2, NR2). The fertilization proportion of NR1 and NR2 was determined by the nitrogen content of nitrogen fertilizer and cake fertilizer. The results revealed that the single application of nitrogen had no significant effect on soil CO2 flux. However, the addition of cake fertilizer significantly increased CO2 emissions through enhanced soil microbial biomass carbon (MBC). Additionally, CO2 emissions were directly proportional to the amount of carbon (C) in the fertilizer. All treatments were minor sinks for CH4 except for the treatment NR1. Specifically, the cumulative CH4 fluxes of NR1 and NR2 were significantly higher than rest of the three treatments, which implies that application of urea and oilseed rape cake reduced the capability of CH4 oxidation in tea soil. Structural equation models indicated that soil CO2 flux is significantly and positively correlated with soil dissolved organic carbon, MBC and soil pH, while mineral nitrogen content was the main factor affecting CH4 flux. Overall, the application of oilseed rape cake increased the oxidation of CH4 and promoted soil C sequestration but inevitably increased the soil CO2 emissions.