Great hammerhead (Sphyrna mokarran) and scalloped hammerhead (Sphyrna lewini) sharks are listed as Critically Endangered due to overfishing and the fin trade. The practice of shark finning — removing fins from live sharks and discarding the body — causes extreme and prolonged suffering.
Finned sharks die slowly on the seafloor: unable to swim and therefore unable to pass water over their gills, they suffocate progressively over hours. The welfare harm of finning is severe and prolonged — one of the most inhumane commercial fishing practices currently documented. Even where finning is banned, sharks caught as bycatch in longline fisheries are often retained only for their fins. Hammerhead sharks killed in drift nets may drown after entanglement, suffering acute oxygen deprivation. Conservative bycatch reduction measures including circle hooks, minimum gill mesh sizes, and real-time observer coverage would reduce hammerhead bycatch mortality.