Bycatch is the principal threat to at-risk marine vertebrates.

Total number of species of cetaceans, sharks, sea turtles, and seabirds in the IUCN red list database (http://www.iucnredlist.org/) affected by the following threat categories: NNS = invasive non-native species; Habitat = habitat destruction and degradation; Harvest = harvesting; Bycatch = accidental mortality from fisheries bycatch; Pollution = pollution (land and water); Climate = pollution relating to the atmosphere and climate change; Disturb = human disturbance, persecution, noise pollution, and collisions (from Doak et al. [66]). Although not listed as a primary threat in the IUCN database, non-native species are also known to impact sea turtles on their breeding grounds [67].