Mobulid ray by-catch in longline fisheries in the south-western Atlantic Ocean

摘要: This paper presents the first by-catch assessment focussed on mobulid rays in pelagic longline fisheries based on-board scientific observer data (1998–2013) over south-western Atlantic. Mobulid diversity, as well their catch distribution and disposition, were investigated. frequency was low, but probability increased at lower bottom depths (i.e. continental shelf slope), higher fishing effort during warm period (summer–autumn). Photographic video records allowed identification of two devil ray species, spinetail (Mobula japanica) bentfin thurstoni), number species interacting with longliners region could also be greater. Southernmost captures both (36°S) exceed previous reported by almost 12°, therefore greatly expanding known ranges towards southern waters Mobulids never retained board, most them released alive. However, hooks often not removed from bodies several occasions fishermen caused injuries while trying to cut branch line, so some uncertainty remains regarding post-capture mortality. More specific studies that assess these particular aspects are needed better understand potential effect populations.