The fate of biologically produced methane in an anoxic fjord in British Columbia
Bibliographic record
Abstract
Our climate is currently experiencing changes unlike those seen before in history.An increase of methane gas in the atmosphere has been shown to exacerbate these changes, much more so than an increase in carbon dioxide.Methanogens are microscopic organisms that produce methane, and live in oxygen poor environments.Methanotrophs are other microscopic organisms that consume methane, and can live in environments with or without oxygen.Both of these organisms can live and interact in an anoxic fjord; an environment containing areas with and without oxygen.Methane created by methanogens is consumed by methanotrophs, but it is not known if all the methane produced is consumed or if some reaches the surface and diffuses into the atmosphere.A perfect area to study this is Effingham Inlet, in British Columbia, Canada.Effingham Inlet contains two basins, one with oxygen throughout the basin and one that has both an oxic and anoxic zone.Six water samples were taken in both basins.Methane concentration and cell abundance were measured in each sample.Samples were also taken to determine if genes necessary for methanogenesis and methanotrophy were present.The presence of these genes indicates the presence of methanogens and methanotrophs, respectively.There was a strong increase in cell abundance in the anoxic zone of the upper basin, along with a relatively high methane concentration.The presence of methane in the anoxic zone along with an increase in cell abundance suggests the presence of methanogens.The absence of a high concentration of methane above the anoxic layer suggests that methanotrophs are present, and have consumed most if not all of the methane produced through methanogenesis. ABSTRACTThis study examined an anoxic fjord in British Columbia, Canada, to try to get a better understanding of what happens to biologically produced methane.Six samples were taken in two basins of the fjord, one with oxygen throughout the water column and one with both an oxic and anoxic layer.Methane concentrations were quantified using a gas chromatograph-flame ionization device, and microorganisms were quantified using fluorescence microscopy.DNA extraction and PCR amplification were performed on the key genes of both methanogenesis and methanotrophy, to determine if any methanogens and/or methanotrophs were present in each sample.Microbial abundance increased in the anoxic layer of the upper basin to approximately 1.5x10 6 cells mL -1 , along with relatively high methane concentrations (0 ppm in the surface to ~50 ppm at depth).The presence of methane in the anoxic layer along with an increase in cells suggests the presence of methanogens.The absence of a high concentration of methane above the anoxic layer suggests that methanotrophs were present, and had consumed most if not all of the methane produced through methanogenesis.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.004 | 0.001 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".