Spatiotemporal patterns of salmon winter habitat usage in the Northeast Pacific uncovered by environmental DNA
Bibliographic record
Abstract
Abstract The Northeast Pacific harbors the majority of North American and a substantial subset of Asian Pacific salmon stocks (Oncorhynchus spp.), yet little is known about the factors shaping ecosystem composition and salmon distribution during the oceanic winter. Accordingly, fluctuating salmon marine survival, specifically of imperiled southern populations, remains poorly understood. The International Year of the Salmon initiative has conducted three winter expeditions to the Northeast Pacific to uncover these factors using a multidisciplinary approach, including eDNA surveys. Here we report on the results of the 2022 large-scale four vessel ecosystem-wide eDNA survey at the end of the oceanic winter, spanning 2.2 million km2 of open ocean salmon habitat. Through multi-amplicon metabarcoding targeting diverse metazoan lineages, we identify distinct ocean biomes shaped by macroscale oceanographic and bathymetric features like currents and the continental shelf. Salmon exhibited species-specific distribution across the Northeast Pacific and were associated with mesoscale anticyclonic eddies in the open ocean. Salmon showed species-specific positive association with potential prey species and competitors, but some were negatively associated with specific cnidarians and harmful algae. The localized onset of spring blooms lead to a rapid transition of ecosystem composition within weeks from copepod-dominated winter communities to complex communities of forage fish and higher trophic levels, including all salmon species as well as apex predators. This bloom community was composed of members of open ocean and coastal biomes, forming a hybrid community, suggesting targeted migration of mobile species to areas of high biological activity. Together, we document the distinct biomes salmon navigate in a species-specific manner over the oceanic winter at unprecedented taxonomic and spatial scale, identify key species they interact with, and observe rapid temporal transitions in ecosystem composition associated with the onset of spring blooms, improving our understanding of salmon ocean ecology.
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 | 0.001 |
| 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 | 0.000 | 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".