A review of the influence of low ambient calcium concentrations on freshwater daphniids, gammarids, and crayfish
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The widespread decline in aqueous calcium (Ca) is emerging as a newly recognised stressor in freshwater ecosystems in regions with historically high acid deposition, especially when coupled with multiple logging cycles. Currently, Ca and other base cations are being depleted in the soils of acid-sensitive watersheds of eastern North America and western Europe, resulting in falling Ca levels in streams and lakes. Freshwater crustaceans have high Ca demands due to their heavily calcified exoskeleton and regular moult cycle. Because they rely on Ca in the external environment for the majority of their Ca uptake, aquatic crustaceans are restricted to waters at or above the Ca concentration needed to satisfy their demands. The zoogeographic distributions along ambient Ca gradients, and Ca requirements and metabolism of three groups of freshwater crustaceans — daphniids, crayfish and gammarids — have been relatively well studied. Here we have four objectives: (1) We briefly review biological features of the above three taxa that relate to Ca metabolism. (2) We review the literature regarding minimum Ca thresholds permitting survival, Ca saturation points, and the individual and population scale costs of existence at suboptimal Ca concentrations. (3) Using Daphnia as an example, we explore the ecological consequences of falling environmental Ca concentrations. (4) We identify gaps and weaknesses in the literature that may inhibit the development of environmental risk assessments for Ca decline for these three crustacean groups. We conclude that crayfish are especially vulnerable to ongoing Ca decline, and that all three taxa are probably living under suboptimal conditions in areas of Ca decline, and are therefore likely under chronic metabolic stress.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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 it