Historical loading and current sorption capacity of phosphorus in the sediments of Delta Marsh
Bibliographic record
Abstract
Delta Marsh is a freshwater inland coastal wetland located along the southern basin of Lake Manitoba, Canada. Spanning over 19,000 hectares, Delta Marsh is a eutrophic wetland complex that was formerly a world-renowned destination for waterfowl hunting. Over the past half century, the marsh has been in a state of decline due to invasive plant and animal species, stabilized water levels, and eutrophication due to increased nutrient loading from surrounding development. This prompted a coalition of organizations, including Ducks Unlimited Canada, to begin the “Delta Marsh: Restoring the Tradition” project in 2008 aimed at revitalizing the ecological processes and human traditions of the marsh. The objectives of this study were to investigate the marsh sediments to determine their historic rates of phosphorus accumulation and the current ability to bind phosphorus. I determined how nutrient levels have changed in the marsh over time as well as the ability for surface sediments to act as a sink or a source of phosphorus to the marsh. This was accomplished by collecting two sets of core samples; ten 50-cm cores dated using 210Pb and 137Cs and twenty-two 5-cm cores utilized for phosphorus sorption experiments. All core samples were analyzed for sediment physiochemical parameters including phosphorus concentrations, metal cations, and organic matter. For the most part, surficial sediments acted as a phosphorus sink with some inter-season variability. Furthermore, I found that phosphorus in the sediments, and by proxy the marsh waters, have been both increasing and becoming more labile over the past century (particularly since 1960), potentially indicating increasing eutrophic conditions in the marsh. These results varied across the marsh, with the largest nutrient increases occurring in the west side of the marsh, and higher phosphorus concentrations in the emergent and wet meadow vegetation zones relative to the open-water. Overall, these results indicate that although the marsh sediments are acting as a sink for phosphorus, the marsh is an increasingly eutrophic system, with a particular risk for algal blooms on the west side.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| 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".