Bibliographic record
Abstract
Exotic species introduced to Lake Ontario in the past 100 years have had varied effects on the food web. The exotic cladoceran Cercopagis pengoi is a zooplankton predator, and the effects of its establishment (in 1998) were difficult to predict without research conducted years since its introduction. Little to no work has been conducted at spatial scales necessary to examine the role of C. pengoi on a lakewide basis. This study was conducted to assess the relative importance of C. pengoi as prey and predator by examining its abundance, distribution, and potential impacts based on these variables and its trophic interactions with zooplankton and fish. Data from a number of field studies were used to develop equations relating acoustic size (target strength) to length and mass, which allowed estimation of abundance using acoustic surveys. Target strength varied significantly with length and mass. Target strength equations were significantly different from previously published equations. Field collections revealed that C. pengoi was an important prey item for only for juvenile and adult alewives > 66 mm total length. Due to the planktivorous nature of C. pengoi and similar distributions of these organisms, alewives and rainbow smelt also compete with C. pengoi. The relative importance of C. pengoi as prey and competitor depended on fish size and habitat use; habitat use determined the degree of spatial overlap, while fish size and the defensive spine of C. pengoi influenced the degree to which these fish were able to utilize C. pengoi during periods of spatial overlap. Late summer abundance of bosminids, Diacyclops thomasi, and copepod nauplii was significantly lower in 1998-2000 than 1995-1997, while abundance of Daphnia retrocurva did not vary significantly. Other factors that may have contributed to this decline were excluded by examination of their seasonal patterns. I concluded that predation by C. pengoi caused the observed declines. The relative magnitude of consumption by C. pengoi and alewives indicated that they were important predators and competitors and both were capable of structuring zooplankton community structure through predation.
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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 | 0.001 |
| 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 | 0.001 |
| Scholarly communication | 0.001 | 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".