A Method to Consistently Approach the Target Total Fishing Fraction of Pacific Sardine and Other Internationally Exploited Fish Stocks
Bibliographic record
Abstract
Abstract The “northern” stock of Pacific Sardine Sardinops sagax is fished by Mexico, the USA, and Canada. Without an international management agreement, the U.S. Pacific Fishery Management Council prorates its target total fishing fraction (F) in its harvest control rule (HCR) by 0.87. This is the proportion of the stock that it deemed in 1998 to be present, on average, during summer–fall 1964–1992 in the U.S. Exclusive Economic Zone. However, the portion of the stock in U.S. waters is variable, depending on the environment and stock biomass and demographics. Furthermore, irrespective of the stock distribution, the combined foreign and U.S. landings may exceed those determined by an F of 0.15, potentially reducing the stock biomass and yield. This occurred each year during 2001–2014, and the F (mean = 0.22; SD = 0.06) trended upward. To more consistently approximate the target F, a method was proposed to set harvest quotas with accounting for predicted foreign landings. We refined the method by adding a prediction error term and showed that the U.S. HCR, solved with predicted foreign landings and stock biomass from each annual assessment in 2001–2014, better stabilized F about the target F relative to the historical values (original method: mean = 0.16, SD = 0.02; new method: mean = 0.16, SD = 0.05). We also compared the historical F (mean = 0.18, SD = 0.07) and optimized F (original method: mean = 0.16, SD = 0.06; new method: mean = 0.17, SD = 0.08) calculated using updated biomass estimates from the 2013 assessment. Results showed that irrespective of the assessment and its assumptions, quotas that were optimized with respect to F better approached the target F-value. Although the new method reduces bias due to trend in the foreign landings, its performance may be less precise than the original method if—as recently occurred—the assessments are significantly revised and the stock migration is abruptly abbreviated.
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 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 | 0.007 | 0.030 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 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".