Results for the section A of sensitivity runs requested by the penguin review panel

• Main Authors: Andrea Ross-Gillespie, Doug Butterworth
• Format: Report
• Language: unknown
• Published: 2023
• Subjects: Biological mathematics; Applied statistics; Biostatistics; MARAM; African penguin; Spheniscus demersus; 2023 penguin review; penguin island closure experiment; closure and catch-based estimates; Penguin Island
• Online Access: https://doi.org/10.25375/uct.24545671.v1; https://figshare.com/articles/report/Results_for_the_section_A_of_sensitivity_runs_requested_by_the_penguin_review_panel/24545671

Results are presented for the section A of sensitivity runs requested by the penguin review panel, the main aim of these having been to assess what impact the non-negligible catches near St Croix in 2011 and 2017 (when the island was supposed to be closed to the fishery) might have had on the estimates of the fishing effect. The sensitivities comprised of two sets. The first set utilized the standard closure estimators but made adjustments to the input data and closure assumptions for Bird and St Croix Islands. The second set of tests implemented the catch estimator for both the EC and WC. The results indicate little sensitivity compared to original closure estimator Base case, though there is a tendency for the point estimates to be closer to zero than for that Base case. They suggest that the impact of some catches taken in the neighbourhood of St Croix in the years this island was intended to be closed do not compromise the broad results from the ICE for St Croix. Overall, the results of these sensitivity tests do not change the general impression from the results originally tabled that any impact of fishing in the vicinity of the islands on the penguins is small. Note that these results include data only to 2018; results including also recently available data for the West Coast (only) for 2019 will be tabled very shortly.