Assessing residency and movement dynamics of swordfish Xiphias gladius in the Eastern North Pacific Ocean using stable isotope analysis

Swordfish are migratory fish that inhabit tropical to temperate waters, but little is known about movement patterns or mixing between subpopulations of this species. This study examines carbon (δ 13 C) and nitrogen (δ 15 N) stable isotope ratios in growth rings of the anal fin spine and muscle tissue of swordfish from 3 different areas of the Eastern North Pacific Ocean (ENPO)—off Baja California Sur (Mexico) and California (USA), and in the...