Abundance and distribution of Steller Sea Lions (Eumetopias jubatus) in British Columbia : Updates from 2016-17 aerial surveys
Bibliographic record
Abstract
An aerial survey was conducted during the 2017 breeding season to assess trends in abundance and distribution of Steller Sea Lions (Eumetopias jubatus) in British Columbia (BC). This survey was part of a range-wide assessment of the Eastern population of Steller Sea Lions conducted to fulfill requirements under the Canadian Species at Risk Act and the United States (US) Endangered Species Act. Additional surveys were conducted in fall 2016 and winter 2017 to examine seasonal changes in abundance and distribution. A total of 31,753 (6,640 pup and 25,113 non-pup) Steller Sea Lions were counted during the breeding season survey. Models fit to the counts indicate a possible slowing in the annual rate of pup production since 2013, but not in the rate of growth in the non-pup component of the population. An estimate of the total population size was obtained by applying a correction factor of 1.48 to non-pup counts to account for animals that were at sea and missed during surveys. The adjusted 2017 breeding season population estimate was 43,200 (95% CI of 38,700 to 48,200) suggesting no significant change from the previous assessment. However, there continues to be an increase in the number of rookeries and year-round haulout sites being used by Steller Sea Lions in BC waters. There was evidence of five new major year-round haulout sites and two year-round haulouts were re-classified as rookery sites since 2013. Surveys conducted outside of the breeding season indicated a continuing trend of increased numbers of animals overwintering in BC waters from 2010–17. A total of ~31,400 animals were counted in October 2016, as compared to ~28,700 in fall 2012, while a total of ~22,400 animals were counted during surveys conducted in February 2017, as compared to the average of ~17,700 animals counted from multiple surveys flown during the winters of 2009-10. After applying a correction factor of 2.43 to account for animals that were at sea and missed during winter surveys, there were an estimated 52,700 (95% CI 41,000 to 67,800) Steller Sea Lions overwintering in the coastal waters of BC in 2017. Larger numbers of Steller Sea Lions estimated from winter surveys compared to breeding season surveys appear to be due to a net influx of animals from rookeries outside of BC. The Potential Biological Removal (PBR) for Steller Sea Lions during the summer breeding season is 2,474 for Canadian waters.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.004 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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".