Temperature, food and the seasonal vertical migration of key arctic copepods in the thermally stratified Amundsen Gulf (Beaufort Sea, Arctic Ocean)
Bibliographic record
Abstract
We investigated the seasonal vertical migration of seven dominant arctic copepod species from October 2007 to July 2008 in Amundsen Gulf. The large herbivore Calanus hyperboreus resided in the deep Atlantic Layer from December to mid-April, rapidly invaded the surface layer at the onset of the phytoplankton bloom in early May, and started its descent to overwintering depth in July. C. glacialis overwintered at shallower depths than C. hyperboreus, moved into the surface layer in early April as ice algae bloomed, and remained in the subsurface chlorophyll maximum (SCM) until late July. The small omnivore Oithona similis slowly rose into the Polar-Mixed Layer from February to April, reaching the ice–water interface in early April as ice algae developed. The very small Triconia borealis associated with C. hyperboreus in the Atlantic Layer from October to April. The mesopelagic omnivores Metridia longa and Microcalanus pygmaeus could be characterized as mid-depth interceptors, feeding on microzooplankton in winter, the upward flux of C. hyperboreus eggs in late winter-early spring, and on the rain of microalgae in spring-summer. The epipelagic Pseudocalanus spp. distributed in a narrow band centered around 50 m from October to April, then descended under the SCM from May to July. Copepods generally avoided the lens of warm (2–8°C) surface water in summer, but readily migrated across the −1.7°C to +0.3°C gradient from the Polar-Mixed Layer to the Atlantic Layer. The different patterns of seasonal migrations dictated the different temperature regimes experienced over the year by each species and copepodite stage.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".