Survival rates of coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) released from hatcheries on the U.S. and Canadian Pacific coast 1972-1998, with respect to climate and habitat effects
Bibliographic record
Abstract
Smolt-to-adult survival rates were estimated for 18 659 coho and chinook coded wire tag (CWT) groups released in 1972–1998 from 206 hatcheries on the U.S. and Canadian Pacific coast. Survival rates of 153 wild CWT groups showed similar trends as those of hatchery fish. The long-term trend or both coho and chinook was a decline in all regions south of Alaska, while survival rates increased in Alaska. Regional and annual variation explained 46% of the total variation for coho, 34% for fall chinook, and 42% for spring chinook. Regression analysis was used to explore the relationship between survival rate and climate during the year of release, and the variable that showed the strongest relationship was summer sea surface temperature (SST) at the place where the fish reach the ocean. The estimated relationship is quadratic in log space, with an optimum around 13°C for coho (95% confidence interval: 12.87°C–13.08°C) and fall chinook (12.44°C–13.42°C), but such an optimum could not be accurately determined for spring chinook (2.56°C–12.24°C). The SST variable alone explained 41% of the regional and annual variation of coho survival rates, only 12% for fall chinook, but 44% for spring chinook due to low survival rates at high SST values. Little is known about the ecological dynamics that link SST and survival rate, but SST is highly correlated with a suite of physical and biological factors in the ocean. There has been a long-term increase in SST from the early 1970s to the late 1990s, corresponding to the declining survival rates south of Alaska and increasing survival rates in Alaska. During a cooler period in the mid 1980s, survival rates increased for some years south of Alaska, but decreased in Alaska. These results suggest that the decline in wild salmon abundance in the 1990s was due in considerable part to changes in ocean conditions and increases in wild stock abundance may be expected if ocean conditions change.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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 teacher head, 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".