Energetic consequences of diet shifts in Lake Erie rainbow smelt (<i>Osmerus mordax</i>)
Bibliographic record
Abstract
The diet of eastern Lake Erie rainbow smelt (Osmerus mordax) has changed since the 1960s, reflecting food resource shifts due to phosphorus reductions and the invasion of exotic species (dreissenid mussels and Bythotrephes longimanus). Since rainbow smelt growth was lower in the 1990s than in the 1960s, we considered diet changes as an explanation. A decrease in the proportion of zooplankton occurred in the summer (MayAugust) diet of two size classes (6388 and 89114 mm fork length) between 1961 and 1999. Within the zooplankton, the proportion of Bythotrephes increased. In spite of these changes, energy density (joules per gram) of the summer (JuneAugust) diet has not changed since 1961. However, during the late-summer and fall, predation on Bythotrephes, and therefore the proportion of indigestible spines in the stomach, increases. Using bioenergetics models, we show that Lake Erie rainbow smelt could achieve 66%155% greater growth between June and October if Bythotrephes spines were replaced with digestible prey items, resulting in end-of-season weights and lengths similar to the 19851990 period. Our results indicate that indigestible Bythotrephes spines may reduce growth by occupying space in the stomach but providing no nutritional value to the fish, thereby reducing the realized daily ration for rainbow smelt.
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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 | 0.001 |
| 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".