Stable isotope study of riverine benthic food webs influenced by anthropogenic developments
Bibliographic record
Abstract
Stable carbon and nitrogen isotopes were used to assess the potential impacts of hydroelectric development and pulp mill activity on benthic food web interactions in the tributaries of the Moose River Drainage Basin in Northeastern Ontario. Secondly, the applicability of stable carbon isotopes as a tool to indicate exposure to pulp mill effluent in wild white sucker ('Catostomus commersoni') located downstream of hydroelectric facilities and pulp mill effluent discharges was assessed. Stable isotope analysis (SIA) of the benthivorous white sucker from an undeveloped tributary (Missinaibi River) showed no significant spatial or temporal variability in the [delta]13C (mean ± SE (n) = -29.3% ± 0.2 (47)) and [delta]15N values (mean ± SE (n) = 8.3% ± 0.1 (47)) of muscle tissue. The range of [delta] 13C (-31.4 to -26.5 96) and [delta]15N (6.3 to 9.4) were used as an indicator of normal fluctuation in the isotopic composition of white sucker in an undeveloped river in the Moose River Basin. Stable isotope analysis of white sucker muscle from a regulated river (Groundhog River) were found to be 13C and 15N depleted upstream of hydroelectric development. Downstream, there were indications (from pre-impoundment and post-impoundment liver comparisons) of 13 C depletion and 15N enrichment of white sucker tissues associated with this recent hydroelectric development (commissioned in fall of 1991). Isotopic trends of white sucker established for the Missinaibi and Groundhog Rivers were used as a reference to determine changes in benthic food web interactions associated with historical log drives and pulp mill effluent discharges on regulated rivers (Mattagami and Kapuskasing Rivers). Bark and wood accumulations from historical log drives did not appear to influence benthic food web dynamics. 13C depleted particulate organic material from upstream of the dam combined with 13C enriched particulate organic material from pulp mill effluent discharges resulted in the combined 13C values detected in white sucker. The ability to differentiate the [delta] 13C of white sucker exposed to pulp mill effluent versus the [delta] 13C of white sucker from non-impacted sites may be dependent on several factors, including the size of the reservoir, water discharge, effluent composition and discharge, and fish mobility. [delta]15N of white sucker did not appear to be influenced by pulp mill activities. The implications of this study of benthic invertebrates and benthivorous fish from the tributaries of the Moose River were discussed with regard to the use of stable isotopes to define fish exposure to pulp mill effluent, and to define suitable reference sites for assessing the impacts of anthropogenic developments on wild fish populations.
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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 | 0.001 |
| 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 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".