Domoic Acid Production in Toxigenic Pseudo-nitzschia Species Isolated from Narragansett Bay, RI under Nutrient-Limiting Conditions
Bibliographic record
Abstract
Amnesic shellfish poisoning (ASP) has become increasingly relevant in the last few decades as harmful algal blooms have become more frequent and human consumption of shellfish has increased. The onset of ASP occurs after consuming shellfish that have fed on the toxin-producing diatom Pseudo-nitzschia, a type of phytoplankton. Although not all species of Pseudo-nitzschia are known to produce the toxin domoic acid (DA), certain environmental conditions are thought to trigger DA production, which increases risk for incidences of ASP. Since the first significant outbreak of ASP in 1987 on Prince Edward Island, Canada, Pseudo-nitzschia have been tracked and studied globally. Narragansett Bay, Rhode Island (USA), houses several Pseudo-nitzschia species, some of which produce DA. While diatoms in this genus have existed in this area for many decades, only recently have DA levels reached high enough concentrations to require shellfish harvest closures as observed in 2017. After the last closure of Narragansett Bay in 2017, the Jenkins lab at the University of Rhode Island began weekly collections of water from multiple sites throughout the Bay to evaluate nutrient levels, phytoplankton cell counts, DA levels, DNA sequences, chlorophyll levels, and to isolate cells for Pseudo-nitzschia monoculture production in order to better understand environmental drivers stimulating DA production. In continuation of this research, here we present the results from a lab study that evaluated the effects of macronutrient limitation on DA production in Pseudo-nitzschia populations that had been isolated from samples collected from Narragansett Bay during a harmful algal bloom in June 2021. We quantified the biomass and DA production under limiting levels of nitrate (NO3-), phosphate (PO43-), and silicate (SiO32-) relative to controls in two isolates of the species, P. multiseries. Results determined that by limiting the amount of nutrients available, lower biomass levels were observed while the amount of DA produced per cell increased. These results will help predict toxigenic blooms in Narragansett Bay by advancing our understanding of the effect of nutrient availability on Pseudo-nitzschia and DA production. This information is critical for helping shellfisheries and public health officials prevent future disease outbreaks while contributing to a broader knowledge of the toxigenic nature of Pseudo-nitzschia species globally.</
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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 | 0.001 | 0.000 |
| 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) | 0.001 | 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 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".