Natural mortality and movement of juvenile cod (Gadus spp.) inhabiting eelgrass (Zostera marina) in coastal Newfoundland waters
Bibliographic record
Abstract
The natural mortality of teleost populations is age-dependent - young, small-bodied individuals experience comparatively higher mortality rates than older, larger individuals. The use of structurally complex habitat, such as eelgrass (Zostera marina) and macroalgae, is believed to increase survival of early stages by providing protective cover from predators and increased food availability. However, few studies have actually quantified natural mortality rates for juvenile cod associated with nearshore habitat. I determined mortality rates for juvenile Greenland cod (Gadus ogac) and Atlantic cod (G. morhua) associated with eelgrass in the coastal zone of Newman Sound, Newfoundland. During Oct-Nov 2002, I fin-clipped 818 age-0 Greenland cod; an additional 1442 age-1 Atlantic cod were fin-clipped during June-July 2003. During Oct-Nov 2003, a further 765 age-0 Greenland cod were individually marked with visible implant alphanumeric (VIalpha™) tags. Re-sampling revealed that juvenile cod remained near the site of release, rarely venturing beyond a distance of a few hundred metres. For age-1 Atlantic cod in eelgrass habitat, the mortality rate was M = 0.068day⁻¹ (estimated using the Jolly-Seber method), which was significantly higher than that predicted (M = 0.010day⁻¹) using an age-dependent mortality model based on published cod mortality rates. High mortality rates may be attributed to high predation and other biotic and abiotic sources of mortality (i.e., starvation, environmental extremes). Juvenile cod mortality rates were high despite the availability of areas with complex structure; however, consistently low cod abundances in structurally simple habitats suggest such areas may be too risky to frequent for extended periods.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
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) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.002 |
| 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 teacher head, 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".