Migration and growth potential of coho salmon smolts: implications for ecological impacts from growth‐enhanced fish
Bibliographic record
Abstract
Wild-genotype and growth hormone (GH) transgenic coho salmon (with dramatically enhanced growth potential) were used to examine the influence of genotype, age, body size, growth, and rearing conditions on the onset of seaward migration and to assess the potential consequences of the introduction of such transgenic fish on natural ecosystems and wild populations. When reared from the first feeding stage under naturalized stream conditions, there was no difference in survival or migratory timing between the two genotypes. However, larger fish migrated earlier in the season than smaller fish of both genotypes, and transgenic fish with higher specific spring growth rates migrated earlier in the season than slower-growing transgenic fish. Stream-reared fish of both genotypes also displayed increased migratory activity at dawn and dusk. Fish reared in the hatchery for 3 and 15 months before being released into the stream in August differed in onset of seaward migration due mainly to age (older fish migrated earlier in the season) and genotype (transgenic fish migrated before wild-type in younger fish). Further, hatchery-reared fish showed no diel pattern in activity during migration. In older fish, larger individuals migrated later in the season than small individuals, whereas there was no clear size effect in younger individuals. Thus, although small differences in spring migration timing were observed among groups, seaward migration in coho salmon was largely independent of major shifts in size and growth rate induced by GH transgenesis (i.e., transgenic fish migrated at approximately the normal time in the spring, rather than at the typical size). Further, early rearing conditions had a stronger effect on migratory behavior than did the growth-promoting transgene. Taking into account effects of migratory timing, growth, survival, and differential food conversion efficiencies, these data suggest that transgenic fish escaped from hatcheries would have a greater impact on stream ecosystems during early life compared to escaped wild-type fish. However, this difference may be reduced if rearing occurred in subsequent generations under wild conditions where growth rates of transgenic fish are reduced compared with hatchery conditions.
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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 | 0.000 | 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) | 0.000 | 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".