Ecological response to anthropogenic climate change in the Beaufort Sea: Biennial-scale evidence from proxy and instrumental records during the last ~70 years
Bibliographic record
Abstract
We analyzed ostracode and foraminifera assemblages, silicoflagellates, biogenic silica, and sediment grain size from two high-resolution box cores collected in the Alaska and Canadian Beaufort Sea during the 2022 Arctic Challenge for Sustainability (ArCSII) expedition. These cores provide biennial-scale, multi-proxy records of ecological change over the past ~70 years. At BC2, located east of Barrow Canyon, faunal assemblages over the last 41 years showed three distinct ecological periods: (1) the 1980s-1990s, dominated by species indicative of stable, ice-covered conditions; (2) a shift post-2000 with warmer temperatures, longer ice-free seasons, and increased sandy sediments; and (3) a recent period (2018–2022) characterized by subarctic and Pacific-affiliated species, reflecting productive, summer ice-free waters. Similarly, at MT1 near the Mackenzie Trough, three periods were identified: (1) cold, stable conditions with high sea-ice cover (1950-1980); (2) a transition in the 1990s marked by increased productivity and longer ice-free periods; and (3) a shift (2002–2022) toward more dynamic, productive conditions, with reduced sea-ice extent and increasing Mackenzie River discharge. The faunal transitions among ostracodes, foraminifera, and silicoflagellates correspond closely with changes in ocean conditions, providing key insights into the timing of ecological responses to anthropogenic climate change. By integrating instrumental data—such as temperature, sea-ice extent, and river discharge—with the biological proxy records, we constrained the timing of when these environmental shifts began affecting biological organisms. This analysis revealed that changes in faunal composition are tightly linked to warming, sea-ice loss, and altered freshwater inputs, and underscores the complex, cascading impacts of climate change on Arctic ecosystems. These ecological shifts are also influenced by large-scale ocean-atmosphere dynamics, such as the Pacific Decadal Oscillation, which further modulate the timing and magnitude of ecological responses in the Beaufort Sea ecosystem.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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".