Assessing population recovery inside British Columbia’s Rockfish Conservation Areas with a remotely operated vehicle
Bibliographic record
Abstract
Between 2004 and 2007, Fisheries and Oceans Canada undertook a management action to conserve overfished populations of Inshore Rockfishes by designating 164 Rockfish Conservation Areas (RCAs) closed to most recreational and commercial fishing. However, no research has yet assessed the effectiveness of the RCA network at promoting groundfish population recoveries. We surveyed the fish communities of 35 RCAs and adjacent unprotected areas in southern British Columbia using a remotely operated vehicle (ROV) between 2009 and 2011. We investigated the effect of protection and habitat on fish densities for six species or species groups (Quillback, Yelloweye, Greenstriped Rockfish, Kelp Greenling, Lingcod and all Inshore Rockfish combined) on transects inside and outside of RCAs. Habitat features such as percent rocky substrates and depth influenced fish density while reserve status did not. Next, we calculated habitat-based average densities and used the mean log response ratio (RR) of the density inside to outside of RCAs to determine if the amount of fishing outside the RCA, previous fishing history, the age, area or perimeter to area ratio influenced population recovery. Few positive reserve effects were apparent for any species/group. No clear patterns of RR with age were found for the RCAs, which ranged from 3 to 7 years old at the time of sampling (mean = 4.6). In addition, the intensity of fishing, size, and perimeter-to-area ratio failed to explain RR for most species. There were also no differences in size structure (length) of fish between RCAs and unprotected areas. The results give little indication that demersal fish populations have recovered inside the RCA system. Ongoing monitoring is essential to assess population recovery over time and evaluate the RCAs in terms of criteria such as habitat quality, habitat isolation and the level of compliance in order to enhance their effectiveness.
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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".