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The yellowfin tuna (Thunnus albacares: YFT) is a widely distributed, migratory species that supports valuable commercial fisheries. Landings of YFT are seasonally and spatially variable, reflecting changes in their availability and accessibility to different fleets and metiers which, in turn, has implications for sustainable management. Understanding the dynamics of YFT behaviour and how it is affected by biological and ecological factors is therefore of consequence to fisheries management design. Archival and pop-up satellite tags (PSAT) were used in the South Atlantic Ocean around St Helena between 2015 and 2020 to collect information on the movements, foraging and locomotory behaviour of YFT. The study aimed to (1) identify vertical behaviour of YFT within St Helena’s EEZ; (2) assess the timing and depth of potential feeding events and (3) to use the information to inform on the catchability of YFT to the local pole and line fishing fleet. Results indicate that the YFT daytime behaviour shifted between shallow with high incidence of fast starts in surface waters in summer months (December to April), to deep with high incidence of strikes at depth in colder months (May to November). Catchability of YFT was significantly reduced between May and November as YFT spent more time at depths below 100 m during the day, which coincides with a reduction in the quantity of YFT caught by the inshore fleet.

Objectives Sports coaches are influential in whether athletes dope, but receive very little antidoping education, particularly within entry-level coaching qualifications. We tested the feasibility of an antidoping intervention, delivered via a mobile application, which was designed to increase coaches’ knowledge of doping and to reduce favourable doping attitudes.Methods A two-arm randomised controlled trial, with grassroots coaches who coach young amateur athletes aged between 14 and 18 years of age, was conducted. The Anti-Doping Values in Coach Education (ADVICE) mobile application included modules on fair play, substances, nutritional supplements, rules and leadership. The primary outcome was the change in doping knowledge, 6 weeks after receiving the mobile application. The secondary outcome was changes in doping attitudes.Results Grassroots coaches (n=200; aged between 18 and 71 years, with between 1 and 42 years of coaching experience) from 29 different countries completed baseline assessments, and 85 completed follow-up assessments, and were included in mixed analysis of variance analyses. The intervention increased coaches’ knowledge about doping and also reduced favourable doping attitudes in the experimental arm.Conclusion The ADVICE mobile application is a feasible method for delivering and increasing grassroots coaches’ knowledge of banned substances and the potential side effects of doping. Mobile application-based resources could facilitate a much wider dissemination of antidoping education.