Overwintering Ability of Juvenile Ocean-type Chinook Salmon: Effect of Water Temperature and Food Deprivation on Growth, Energetics, and Survival
Bibliographic record
Abstract
Juvenile sub-yearling Chinook salmon were obtained from a local hatchery and transported in an aerated live well by a University of Victoria (UVic) aquatic transport vehicle to the UVic Aquatic Research Facility. At the beginning of the experimental period, eleven fish were transferred into one of sixteen experimental 240-L aquaria. The experimental aquaria were assigned to treatments with one of two temperatures (6.5°C and 10.5° ±0.5°C) simulating the 1940-1970 winter average (hereafter termed cool) sea surface temperature (SST) recorded from the SOG, and a 50-year projected average winter (hereafter termed warm) SST, respectively. Fish were also subjected to three feeding regimes (fed once daily to satiation continuously throughout the entire study period, food deprived for two weeks from the beginning of the experimental period, and food deprived for four weeks from the beginning of the experimental period) to create the factorial design (temperature x feeding regime) with single replicates per treatment combination. The six-week experimental period was divided into three phases consisting of two weeks per phase. During phase one, both of the experimental treatments were food deprived. During phase two, feeding was restored to the two-week food deprived treatment while food deprivation continued in the four-week food deprived treatment. During phase three, feeding was restored to the four-week food deprived treatment. The control groups were fed to satiation once daily during all three phases. All treatment tanks were monitored at least three times per day (morning, afternoon, and evening). During each monitoring event, water quality and quantity, and treatment parameters were maintained and all tanks were checked for mortalities. Survival was examined graphically for each treatment level using cumulative survival curves. Growth was estimated from randomly sampling six fish for length (TL) and weight (g) from each tank at the beginning of each twoweek study phase. Respiration rate (number of buccal cycles per minute) was recorded three times per week from direct observation of one focal fish per tank. Activity was measured three times per week as the proportion of fish in each tank that crossed the vertical and/or horizontal midlines over a one-minute direct observation period. Aggression was measured three times per week as the number of nips, charges, and chases in each tank over a one minute direct observation period. Preliminary results showed that survival of the juvenile Chinook salmon was high throughout the study period (> 85%). Overall survival was similar between warm (89%) and cool (85%) temperature treatments irrespective of feeding regime. The warm temperature/continuously fed and cool temperature/two-week food deprived treatments experienced 100% survival (Fig. 1) throughout the experimental period. Fish in the cool water temperature/continuously fed treatment suffered the highest mortality (40%) by the end of phase three. The majority of the fish in this treatment died during the initial three weeks of the study and no mortality was observed during phase three (Fig. 1). Survival of fish in the warm water treatments declined the greatest in those deprived of food for two weeks.
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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 | 0.000 | 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".