Third workshop on appropriate sampling schemes for protected, endangered and threatened species bycatch (WKPETSAMP3)

The workshops WKPETSAMP2 and WKPETSAMP3 were convened following a special request from the European Union’s Directorate-General for Environment (DG ENV) on appropriate sampling schemes for endangered, threatened and protected (ETP) species. In particular, these workshops were tasked with providing concrete inputs and results to inform ICES advice to DG ENV on ‘appropriate bycatch monitoring systems at Member State level and on regional coordination’. An aim of the PETSAMP workshops was to generate improved insights into how aspects of sampling design may impact the precision and accuracy of bycatch estimates and the detection probability of bycatch events. The workshop considered key issues such as: how sampling coverage (percentage of monitored fishing operations) impacts the precision of bycatch estimates and how this is dependent on the bycatch probability (how often a bycatch is encountered); if stratification improves precision and if this is dependent on bycatch probability; if it is better to sample few vessels but many trips (e.g. typical of reference fleets and Electronic Monitoring programmes) or many vessels but fewer trips (e.g. typical of at-sea observer programmes). To do this the WKPETSAMP2 extended the simulation framework (SCOTI) developed by WGBYC in 2022. This framework was used in WKPETSAMP3 and was parameterized with data from several case studies. The case studies are from ongoing or historical sampling programs and represent different waters across Europe and different fisheries.