Effects of seeding density, substrate depth, and tray type on the growth and survival of juvenile Pacific geoduck clams <i>Panopea generosa</i> in suspended nursery culture
Bibliographic record
Abstract
ABSTRACT Objective Nursery culture of Pacific geoduck clams Panopea generosa involves placing hatchery-produced juveniles in trays of sand in the field for grow out to a size at which they can be transplanted to the benthos for intertidal/subtidal grow out to market size. A 5-month experiment was conducted in Deep Bay, British Columbia, Canada, to determine the effects of nursery tray type (two types), sand depth (two levels), and initial seeding density (two levels) on the growth and percent survival of young Pacific geoduck clams. Methods Hatchery-produced juveniles (shell length [mean ± SD] = 5.8 ± 0.1 mm; wet weight = 32.9 ± 1.8 mg) were placed in two types of trays (black plastic oyster trays [OTs] or specially designed experimental aluminium trays [ATs]) at two sand depths (10 cm [10D] or 20 cm [20D]) and at two seeding densities (low [LD] = 1,615 individuals/m2 or high [HD] = 3,230 individuals/m2). The deeper sand depth could not be accommodated in the OTs, leading to six treatments: OT/LD/10D (n = 18), OT/HD/10D (n = 18), AT/LD/10D (n = 21), AT/HD/10D (n = 17), AT/LD/20D (n = 19), and AT/HD/20D (n = 17). The effects of those factors on shell length, wet weight, and percent survival were examined after 5 months of tray deployment. Results Tray type, sand depth, and initial seeding density all significantly affected the growth of the juvenile clams. The 20D and LD treatments produced significantly larger (shell length) and heavier (wet weight) individuals than the 10D and HD treatments. The ATs produced significantly heavier (but not larger) individuals than the OTs. Percent survival was relatively high (88.3–97.6% in the various treatments) and was not significantly impacted by any of the studied variables. Conclusions The study showed that ATs seeded with a density of 1,615 individuals/m2 in a sand depth of 20 cm resulted in the greatest shell length and individual wet weight for the systems tested for rearing juvenile Pacific geoduck clams during the nursery phase. The results will be useful in optimizing standard nursery practices in the Pacific geoduck clam industry.
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".