Physical, chemical, and microbial regimes in an anoxic fjord (Nitinat Lake)
Bibliographic record
Abstract
New observations of physical, biological, and chemical parameters were obtained between July 2003 and February 2005 in Nitinat Lake, British Columbia, a permanently anoxic seawater fjord. These observations include continuous profiles of nitrate and bisulfide using a new instrument for in situ ultraviolet spectrophotometry. Anoxic seawaters in this 200‐m—deep basin can be found as shallow as 7 m. However, Nitinat Lake is surprisingly dynamic, with a deep‐water renewal time of only about 5 yr and significant spatial and temporal variability. Exchange with the ocean is limited by the size of the linking channel, and during low tides the outflow is subject to an hydraulic control. This nonlinearity causes a relatively large fortnightly cycle in water level and explains flooding events associated with heavy rainstorms. In addition, the restricted flow makes deep‐water renewal gradual so that anoxic conditions are preserved. Intermediate waters (5‐40 m in depth) are renewed alternately by oxygenation from surface mixing in winter and by upwelling of anoxic water and horizontal inflow of subducted ocean water in summer. The horizontal inflow results in a subsurface region of suboxic water in mid‐fjord during summer. No suboxic regime is evident at either the river end of Nitinat Lake (where oxygen and sulfide‐rich regions adjoin in a nitrate‐depleted water column) or at the ocean end of Nitinat Lake (where oxygen and nitrate‐rich regions sometimes overlap with sulfide‐rich regions). Maximum phytoplankton levels near the surface are high in both winter and summer. A second peak in biological activity appears near the anoxic boundary, possibly as a result of sulfur‐oxidizing bacteria. Sulfate‐reducing bacteria are also present in anoxic water in both seasons and just above the oxic/anoxic interface in winter and just above the suboxic/anoxic interface in summer.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".