Salmon poisoning disease in grizzly bears with population recovery implications
Bibliographic record
Abstract
ABSTRACT Wildlife restoration programs depend on having animals that have evolved to handle the constraints, including disease, posed by the new environment. Grizzly bears (Ursus arctos horribilis) once thrived while feeding on salmon (Onchorhynchus spp.) and other foods in California, Oregon, Washington, and Idaho, USA. Unlike Canadian and Alaskan salmon, salmon in lower latitudes often carry an encysted fluke (Nanophyetus salmincola) containing an endosymbiont (Neorickettsia spp.) that can produce a deadly disease in ursids and canids called salmon poisoning disease (SPD). Current recovery plans for grizzly bears in the North Cascades of Washington and the mountains of central Idaho, where infected salmon currently occur, call for using bears from several interior populations. We hypothesized that such bears with no history of salmon consumption will be sensitive to SPD. To test that idea, we fed a limited amount of fresh Chinook salmon (O. tshawytscha) harvested from rivers draining the east and west sides of the Cascades to 11 captive grizzly bears in which both parents were from populations with no history of SPD. We detected N. salmincola ova in the feces, and 8 bears exhibited typical SPD symptoms, which included decreased or no appetite, lethargy, vomiting, and diarrhea. We identified N. helminthoeca and Stellantchasmus falcatus (SF) agent (Neorickettsia sp.) in the salmon, but only SF agent occurred in the sick bears. Stellantchasmus falcatus agent is a relatively new arrival in the Pacific Northwest. Because of the severity of the disease and the potential for mortality without treatment, additional studies should be conducted to determine the distribution and prevalence of SF agent in salmon and kokanee (O. nerka) in the recovery area, develop a serum antibody test that could be used to determine exposure of bears to SF agent, and use that test to determine if grizzly bears or American black bears (U. americanus) currently living in the Pacific Northwest have been infected and recovered. If either of the latter have occurred, SPD may not prevent the successful restoration of grizzly bears where SF agent‐infected salmon will be consumed. © 2018 The Wildlife Society.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 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".