More than 70% of all fish thrown overboard as discards die afterwards.

Omissions

• The claim presents a single universal figure, but the scientific literature reports discard mortality as highly variable (0–100%) across species, gear types, depth of capture and handling practices.
• A 2025 study on commercial elasmobranch species found low discard mortality (8–21% on average), which is inconsistent with a blanket '>70% of all fish die' figure for at least some groups.
• No primary or secondary source was found stating a global average post-discard mortality above 70% for all discarded fish; the studies retrieved are species-specific and do not support the claimed universal magnitude.

Sources

• PrimaryNOAA Fisheries — Fish Discard and Release Mortality ScienceNOAA Fisheries summarizes 15 years of discard and release mortality research, identifying data gaps and compiling estimates; discard mortality varies by species and fishery conditions rather than a single universal rate.
• AcademicScienceDirect — Journal of Environmental Management (Pytka et al. 2025)Survival rates of commercial elasmobranch species: AVM (at-vessel mortality) averaged 21.3%, while STM (post-release short-term mortality) averaged 8%, indicating overall high survival for discarded sharks and rays.
• AcademicOxford Academic — North American Journal of Fisheries Management (Rudershausen et al. 2025)Discard mortality rates of Red Snapper after barotrauma estimated via Cox modeling of post-release survival; species-specific discard mortality estimates, not a global average for all fish.