Quantification of Compositional Changes of Petroleum Hydrocarbons by GC/FID and GC/MS during a Long-Term Bioremediation Experiment

2000 ◽  
Vol 9 (6) ◽  
pp. 549-577 ◽  
Author(s):  
Trine S. Jensen ◽  
Erik Arvin ◽  
Bo Svensmark ◽  
Per Wrang
Keyword(s):  
Petroleum Hydrocarbons ◽  
Compositional Changes

scholarly journals Assessing the Contribution of Seasonality, Tides, and Microbial Processing to Dissolved Organic Matter Composition Variability in a Southeastern U.S. Estuary

2021 ◽  
Vol 8 ◽  
Author(s):  
Rachel P. Martineac ◽  
Alexey V. Vorobev ◽  
Mary Ann Moran ◽  
Patricia M. Medeiros
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Critical Role ◽  
Bacterial Cells ◽  
Secondary Importance ◽  
Relative Contribution ◽  
Doc Concentration ◽  
Compositional Changes ◽  
Dom Composition

Uncovering which biogeochemical processes have a critical role controlling dissolved organic matter (DOM) compositional changes in complex estuarine environments remains a challenge. In this context, the aim of this study is to characterize the dominant patterns of variability modifying the DOM composition in an estuary off the Southeastern U.S. We collected water samples during three seasons (July and October 2014 and April 2015) at both high and low tides and conducted short- (1 day) and long-term (60 days) dark incubations. Samples were analyzed for bulk DOC concentration, and optical (CDOM) and molecular (FT-ICR MS) compositions and bacterial cells were collected for metatranscriptomics. Results show that the dominant pattern of variability in DOM composition occurs at seasonal scales, likely associated with the seasonality of river discharge. After seasonal variations, long-term biodegradation was found to be comparatively more important in the fall, while tidal variability was the second most important factor correlated to DOM composition in spring, when the freshwater content in the estuary was high. Over shorter time scales, however, the influence of microbial processing was small. Microbial data revealed a similar pattern, with variability in gene expression occurring primarily at the seasonal scale and tidal influence being of secondary importance. Our analyses suggest that future changes in the seasonal delivery of freshwater to this system have the potential to significantly impact DOM composition. Changes in residence time may also be important, helping control the relative contribution of tides and long-term biodegradation to DOM compositional changes in the estuary.

scholarly journals Differential arthropod responses to warming are altering the structure of Arctic communities

2018 ◽  
Vol 5 (4) ◽  
pp. 171503 ◽  
Author(s):  
Amanda M. Koltz ◽  
Niels M. Schmidt ◽  
Toke T. Høye
Keyword(s):  
Community Composition ◽  
Primary Productivity ◽  
Species Interactions ◽  
Ecosystem Processes ◽  
The Arctic ◽  
Individual Species ◽  
Freeze Thaw ◽  
Compositional Changes ◽  
Arctic Communities

The Arctic is experiencing some of the fastest rates of warming on the planet. Although many studies have documented responses to such warming by individual species, the idiosyncratic nature of these findings has prevented us from extrapolating them to community-level predictions. Here, we leverage the availability of a long-term dataset from Zackenberg, Greenland (593 700 specimens collected between 1996 and 2014), to investigate how climate parameters influence the abundance of different arthropod groups and overall community composition. We find that variation in mean seasonal temperatures, winter duration and winter freeze–thaw events is correlated with taxon-specific and habitat-dependent changes in arthropod abundances. In addition, we find that arthropod communities have exhibited compositional changes consistent with the expected effects of recent shifts towards warmer active seasons and fewer freeze–thaw events in NE Greenland. Changes in community composition are up to five times more extreme in drier than wet habitats, with herbivores and parasitoids generally increasing in abundance, while the opposite is true for surface detritivores. These results suggest that species interactions and food web dynamics are changing in the Arctic, with potential implications for key ecosystem processes such as decomposition, nutrient cycling and primary productivity.

Variations in beech bark disease and its effects on species composition and structure of northern hardwood stands in central New England

1984 ◽  
Vol 14 (4) ◽  
pp. 565-574 ◽  
Author(s):  
Mark J. Twery ◽  
William A. Patterson III
Keyword(s):  
Species Composition ◽  
New England ◽  
Beech Bark Disease ◽  
Northern Hardwood ◽  
Disease Mortality ◽  
Composition And Structure ◽  
Understory Composition ◽  
Bartlett Experimental Forest ◽  
Compositional Changes

The extent of beech bark disease was examined on 41 permanent inventory plots in western Massachusetts and on 25 plots in Bartlett Experimental Forest in New Hampshire. The amounts of disease-caused mortality and defect were correlated to differences in species composition and 12 other site variables. Stands dominated by hemlock had significantly more beech mortality than other stands. Importance of both beech and yellow birch decreased on plots with beech bark disease mortality. Hemlock benefited most from the loss of beech. Beech bark disease has not noticeably changed understory composition on these plots. In the long term, beech bark disease appears to have caused minor compositional changes on most of the areas studied.

THE EFFECTS OF CHEMICALLY AND PHYSICALLY DISPERSED OIL ON THE BRAIN CORAL DIPLOMA STRIGOSA (DANA)—A SUMMARY REVIEW

1985 ◽  
Vol 1985 (1) ◽  
pp. 547-551 ◽  
Author(s):  
Anthony H. Knap ◽  
Sheila C. Wyers ◽  
Richard E. Dodge ◽  
Thomas D. Sleeter ◽  
Harold R. Frith ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Lipid Synthesis ◽  
Staining Technique ◽  
Skeletal Growth ◽  
Long Term Effects ◽  
Alizarin Red ◽  
Total Recovery ◽  
Dispersed Oil ◽  
Chemically Dispersed Oil

ABSTRACT The Coroil project in Bermuda has been an intensive, multidisciplinary study of the effects of physically and chemically dispersed Arabian light crude oil on the main reef-building coral in Bermuda, Diploria strigosa. This paper reviews the results of this three year study. Corals were exposed to dispersed oil in a flow system, using spectrofluorimetry and gas chromatography to characterize and quantify the dose. Appropriate controls were included in all experiments. The studies included effects of dispersed oil on survival and behavior, the uptake and depuration of petroleum hydrocarbons, photosynthesis by symbiotic zoo-xanthellae, and skeletal growth. In behavioral and growth studies, corals were dosed in the laboratory or in the field. Laboratory-dosed colonies were returned to the field to determine long-term effects. Exposure to 20 ppm of chemically dispersed oil for 24 hours induced various behavioral reactions, including tentacle retraction, tissue contraction and mesenterial filament extrusion. However, effects were typically sublethal, and recovery was usually evident within four days. These symptoms were not significant in long-term transplants. Using the alizarin red staining technique, no long-term effects on skeletal growth could be detected following any of our treatments. Depuration studies using (9-I4C) -phenanthrene and gas chromatographic analysis showed that the uptake of petroleum hydrocarbons by the tissue of Diploria was rapid, but 75 percent of the hydrocarbon dose was eliminated within 14 days. Photosynthesis studies showed a short-term inhibition of photosynthesis only by chemically dispersed oil, with lipid synthesis being most severely affected. Total recovery occurred within 24 hours of exposure.

scholarly journals Long-term increase in snow depth leads to compositional changes in arctic ectomycorrhizal fungal communities

2016 ◽  
Vol 22 (9) ◽  
pp. 3080-3096 ◽  
Author(s):  
Luis N. Morgado ◽  
Tatiana A. Semenova ◽  
Jeffrey M. Welker ◽  
Marilyn D. Walker ◽  
Erik Smets ◽  
...  
Keyword(s):  
Snow Depth ◽  
Fungal Communities ◽  
Compositional Changes

scholarly journals DEPOSITION OF PETROLEUM HYDROCARBONS WITH SEDIMENT TRAPPED IN SNOW IN ROADSIDE AREAS

2014 ◽  
Vol 22 (3) ◽  
pp. 237-244 ◽  
Author(s):  
Larysa Mykhailova ◽  
Tomas Fischer ◽  
Valentina Iurchenko
Keyword(s):  
Petroleum Hydrocarbons ◽  
Total Petroleum Hydrocarbon ◽  
Hydrocarbon Mixture ◽  
Roadside Soils ◽  
Ftir Microscopy ◽  
Deposition Rates ◽  
Sediment Extract ◽  
Natural Snow ◽  
Daily Deposition

Total petroleum hydrocarbon (TPH) deposition rates were determined along various roads using the natural snow cover as deposition trap. Daily deposition rates decreased with distance from the roads, which coincided with long-term TPH accumulation in roadside soils. Scanning electron microscopy (SEM-EDX) of the snow meltwater sediment revealed occurrence of carbon-rich plaques, which were identified as hydrocarbons using FTIR-microscopy. GC-MS revealed that the compounds extracted from the sediment consisted of an unresolved complex hydrocarbon mixture (UCM). Individual n-alkanes could not be resolved in the sediment extract, whereas TPHs extracted from soils contained a series of n-alkanes peaking at C25-C27. The proportion of UCM compounds from TPHs decreased with distance from road. We conclude that high-boiling hydrocarbons bind to coarse mineral dust and/or to splash water and vehicle spray, which preferentially deposit within a 10 m roadside strip.

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