Pre-industrial ecology and foraging behavior of swordfish Xiphias gladius in the eastern North Pacific
Bibliographic record
Abstract
The historical ecology and foraging behavior of many apex marine predators are poorly known. This includes highly mobile pelagic species such as billfish (Xiphiidae and Istiophoridae), which have long held cultural significance for coastal peoples. In California’s Santa Barbara Channel Region, Chumash people have hunted billfish for >2000 yr, providing a deep historical record of these species. We present bulk tissue δ13C and δ15N data for 15 Late Holocene archaeological swordfish Xiphias gladius and 1 striped marlin Kajikia audax previously identified to species through collagen fingerprinting. When compared to data sets of modern northeastern Pacific and archaeological Gulf of Maine swordfish, we identified significant overlap in the isotopic values of modern and archaeological swordfish from the Pacific, indicating that pre-industrial swordfish were reliant on food webs of the North Pacific Subtropical Gyre and the California Current System. We also identified differences in the isotopic composition of swordfish captured by island vs. mainland communities, with swordfish remains from mainland sites having lower and more variable δ13C values, potentially indicating different source populations. The isotopic range of swordfish from California archaeological sites was much broader than those from the Gulf of Maine, suggesting a wider range of habitats used by Pacific swordfish. Our results provide important pre-industrial data for an apex marine predator.
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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 | 0.000 |
| 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) | 0.001 | 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".