Distribution of the tiger shark (Galeocerdo cuvier) in the North Atlantic Ocean by season, sex, and life stage, based on tag and recapture data

Abstract

— Movements of the tiger shark ( Galeocerdo cuvier ) by life stage are largely unknown yet are necessary to determine essential fish habitat and sustainable fishery management practices. In an effort to elucidate distribution and movements of the tiger shark, we analyzed fishery-dependent and - independent tag (sample size [ n ]=10,516) and recapture ( n =762) records for sharks caught in the North Atlantic Ocean during 1963–2018. Sea-sonal distribution of the tiger shark was examined by life stage— young of the year, juveniles (immature), and adults (mature)— and distribution patterns were used to identify potential nursery habitat. Tiger sharks were caught over a wide area from the Grand Banks of Newfoundland, Canada, south to Brazil and from coastal to offshore waters and into the eastern North Atlantic Ocean. Seasonal north–south movements were observed in all life stages, and 14 immature sharks were found to have migrated from the western to the eastern North Atlantic Ocean. A broad nursery area and a potential birthing area were identified on the continental shelf between Florida and Georgia on the basis of the repeated presence of neonates in summer across years and of the recapture of multiple tagged young- of- the-year