Technical mitigation techniques to reduce bycatch of sharks: there is no silver bullet

This paper is also listed for the 2024 CMS/COP14 meeting.

Fisheries bycatch and finding solutions to the problem has received increasing attention in recent times. Most bycatch research to date has focused on charismatic species such as seabirds (Løkkeborg 2011), cetaceans (Leaper and Calderan 2018) and pinnipeds (Hamilton and Baker 2019). Shark bycatch has only recently become an active area of research, with most studies occurring over the past 15-20 years. Mitigation reviews generated from these studies have focused on particular aspects of mitigation or gear type (e.g., Gilman et al. 2008, Waugh et al. 2013, Favaro and Cote 2015, Howard 2015, Gilman et al. 2016); sensory biology (e.g., Hart and Collin 2015, Lucas and Berggren 2022); geographical areas (e.g., Stobutzki et al. 2006, Ardill et al. 2011, Molina and Cooke 2012, Sacchi 2021); certain species or species groups (e.g. Dagorn et al. 2013); or for particular fisheries (e.g., Clarke et al. 2014, Poisson et al. 2016, Restrepo et al. 2017). This paper presents the first comprehensive global review of technical mitigation measures (i.e., gear modifications and mitigation devices) designed to reduce shark bycatch in commercial fishing gear, building on the work of Fowler (2016). It includes assessments of mitigation testing, effectiveness and a synthesis of best practice mitigation, identifying areas requiring greater attention and covers all shark and ray species and fishing techniques.