Marine Birds as Indicators of Arctic Marine Ecosystem Health: Linking the Northern Ecosystem Initiative to Long-Term Studies

Marine birds are sensitive indicators of the condition of marine ecosystems in the Arctic, partly because they feed at the top of the arctic food chain. The Northern Ecosystem Initiative (NEI) recently supported four separate studies that investigated aspects of Arctic marine bird science which simultaneously addressed goals of the NEI to better understand northern ecosystems and their response to environmental stressors. The projects used both scientific and traditional knowledge to examine the relationship between sea-ice, contaminants, and the ecology of marine birds, and to transfer environmental knowledge to students. Results from these investigations confirm that changes are occurring in Arctic environments, and that these are captured through marine bird research. Collectively these studies provided new data that supported NEI objectives of monitoring the health of the Arctic ecosystem, and contributed to Canada's international obligations for Arctic science.     

Analysis of per- and polyfluoroalkyl substances in Houston Ship Channel and Galveston Bay following a large-scale industrial fire using ion-mobility-spectrometry-mass spectrometry

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants of concern because of their ubiquitous presence in surface and ground water; analytical methods that can be used for rapid comprehensive exposure assessment and fingerprinting of PFAS are needed. Following the fires at the Intercontinental Terminals Company (ITC) in Deer Park, TX in 2019, large quantities of PFAS-containing firefighting foams were deployed. The release of these substances into the Houston Ship Channel/Galveston Bay (HSC/GB) prompted concerns over the extent and level of PFAS contamination. A targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based study of temporal and spatial patterns of PFAS associated with this incident revealed presence of 7 species; their levels gradually decreased over a 6-month period. Because the targeted LC-MS/MS analysis was focused on about 30 PFAS molecules, it may have missed other PFAS compounds present in firefighting foams. Therefore, we utilized untargeted LC-ion mobility spectrometry-mass spectrometry (LC-IMS-MS)-based analytical approach for a more comprehensive characterization of PFAS in these water samples. We analyzed 31 samples from 9 sites in the HSC/GB that were collected over 5 months after the incident. Our data showed that additional 19 PFAS were detected in surface water of HSC/GB, most of them decreased gradually after the incident. PFAS features detected by LC-MS/MS correlated well in abundance with LC-IMS-MS data; however, LC-IMS-MS identified a number of additional PFAS, many known to be components of firefighting foams. These findings therefore illustrate that untargeted LC-IMS-MS improved our understanding of PFAS presence in complex environmental samples.     

Reduction of CO2-emissions by using biomass in combustion and digestion plants

Climate protection is one of the main aims of environmental policy. One way to advance and push the progress is to reduce the use of fossil fuels for energy production through an increasing production of renewable and CO₂-neutral energy for example through application of biomass. This paper sets the focus on biomass streams that can be used both thermal and biological for energy production like grass or energy crops. To calculate the potentials of decrease of CO₂-emissions for treatment of biomass in either combustion or digestion plants some scenarios were set up with different assumptions regarding degree of efficiency of treatment plants which depends on size of plants and the treatment process itself. The energetic utilisation of the considered biomass streams is divided in different utilisation scenarios: combined heat and power generation (CHP) and heat generation or power generation only. Additionally four groups of plant sizes referring to electrical power (from 0.1 up to 10.0 MW) were taken into consideration. The calculations of potential savings of CO₂-emission in both types of treatment scenarios lead to the result that in comparison to biological technologies thermal processes show a much higher utilisation of the energy content in biomass.     

Differences in microbial biomass,organic carbon,and dye sorption between flow and no-flow regions of unsaturated soil

Transport models in which the liquid phase is partitioned between conducting and nonconducting regions allow the possibility that degradation and sorption are different in these regions. However, there is little information on biological or chemical differences between conducting and nonconducting regions of the soil matrix. Previous work by the authors on Br transport through unsaturated, intact soil cores of Dundee silty clay loam (fine-silty, mixed, active, thermic Typic Endoaqualf) indicated non-equilibrium conditions that could be well-described by a two-region model. Fitted parameters indicated little solute transfer between flow regions, suggesting that dye movement in unsaturated soil might delineate conducting and nonconducting regions of this soil. Steady-state, unsaturated flow was established in intact cores (10 by 30 cm) of the Dundee soil, then Br and erioglaucine dye were displaced through these cores. The soil cores were then sectioned into 5-cm segments and stained soil was separated from unstained soil. Microbial biomass C, organic C, and dye sorption K(D) (= g(sorbed) kg(-1)soil/g L(-1)) values for stained and unstained soil were determined. Stained soil had higher microbial biomass C but generally lower organic C and lower affinity for dye sorption than unstained soil from the same depth increment. Fraction of immobile water, dispersion, and mass transfer between conducting and nonconducting regions were consistent with previous results.     

Effects of chemical contaminants on the health of Mytilus edulis from Puget Sound,Washington. II. Cytochemical detection of subcellular changes in digestive cells

Activities of the enzymes NADPH-dependent ferrihemoprotein reductase (NFR), NADH-dependent DT-diaphorase (DTD), gamma-glutamyl transpeptidase (GGT), and catalase (CAT) and peroxisome proliferation (PP) in the digestive cells of Mytilus edulis from nine sites in Puget Sound, Washington (USA) sampled in September 1992 were measured cytochemically using image analysis. Mussels from these areas are known to be exposed to a wide range of chemical contaminants. At urban-associated sites, mussels generally showed increased activities of NFR, DTD, and CAT, suppressed GGT activity, and peroxisome proliferation, relative to mussels from the non-urban reference sites. Significant positive relationships were observed between tissue concentrations of polyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and DDTs and activities of NFR, DTD, CAT, and peroxisome proliferation. Structural changes in the digestive gland of mussels also appear to be more responsive to chemical contaminant exposure than changes in enzyme activity. These relationships suggest that NFR, CAT, and the induction of peroxisome proliferation represent complimentary indicators of biological effects from chemical-contaminant exposure in the marine bivalve M. edulis. The current findings support the use of selected cytochemically measured subcellular responses as biomarkers of contaminant exposure in environmental monitoring programs.     

Use of forest inventories and geographic information systems to estimate biomass density of tropical forests: Application to tropical Africa

One of the most important databases needed for estimating emissions of carbon dioxide resulting from changes in the cover, use, and management of tropical forests is the total quantity of biomass per unit area, referred to as biomass density. Forest inventories have been shown to be valuable sources of data for estimating biomass density, but inventories for the tropics are few in number and their quality is poor. This lack of reliable data has been overcome by use of a promising approach that produces geographically referenced estimates by modeling in a geographic information system (GIS). This approach has been used to produce geographically referenced, spatial distributions of potential and actual (circa 1980) aboveground biomass density of all forests types in tropical Africa. Potential and actual biomass density estimates ranged from 33 to 412 Mg ha^–1 (10⁶g ha^–1) and 20 to 299 Mg ha^–1, respectively, for very dry lowland to moist lowland forests and from 78 to 197 Mg ha^–1 and 37 to 105 Mg ha^–1, respectively, for montane-seasonal to montane-moist forests. Of the 37 countries included in this study, more than half (51%) contained forests that had less than 60% of their potential biomass. Actual biomass density for forest vegetation was lowest in Botswana, Niger, Somalia, and Zimbabwe (about 10 to 15 Mg ha^–1). Highest estimates for actual biomass density were found in Congo, Equatorial Guinea, Gabon, and Liberia (305 to 344 Mg ha^–1). Results from this research effort can contribute to reducing uncertainty in the inventory of country-level emission by providing consistent estimates of biomass density at subnational scales that can be used with other similarly scaled databases on change in land cover and use.     

Cellular response of mouse splenocytes to heavy metals exposure

Among the environmental contaminants recognised for their toxicity and their global presence, heavy metals are certainly a major concern. They can elicit a number of immunomodulatory effects leading ultimately to an enhanced susceptibility (sensitivity) of immune cells to microbial agents and the appearance of neoplastic diseases and autoimmune phenomena. Heavy metals also provoke changes in the function(s) of immune cells. A striking biological effect of heavy metals is the induction of intracellular thiols (cysteine, glutathione, metallothioneins). Thiols are involved in many physiological processes, including protection from free radical damage and detoxification of chemicals. The purpose of this study was to assess the differences of susceptibility (sensitivity) in both pre-activated (concanavalin A was used) and non-pre-activated cells in the presence of heavy metals. Five were evaluated on murine splenocytes. The lymphoblastic proliferation test was performed for lymphocytes and a phagocytosis test for macrophages. Data showed that the levels of thiols in the pre-activated cells are greater than non-pre-activated cells following exposure to various heavy metals; macrophages were more resistant than lymphocytes to the toxic effects of heavy metals, and pre-activated cells were more resistant than cells at rest. One possible explanation is that macrophages produce more thiols than lymphocytes and this provides an increased protection from the deleterious effects of heavy metals.