Manta Ray Bycatch and Welfare in Fisheries

Manta rays are vulnerable to bycatch in commercial fisheries, and their large size, long lifespan, and low reproductive rate make population recovery from bycatch mortality extremely slow.

Key Facts

Oceanic and reef manta rays are listed as vulnerable by the IUCN due to fishing pressure and bycatch
They can live 40+ years and females produce only one pup every 2-3 years, making population recovery very slow
Gill nets used for tuna and other species are a primary bycatch threat due to mantas' large wingspan
Mantas caught in nets experience prolonged struggling and drowning that involves significant suffering
Some mantas survive bycatch entanglement if disentangled quickly, but injuries from netting often cause delayed mortality
Mexico and several Pacific island nations have established manta ray sanctuaries to reduce targeted and incidental capture

Welfare Considerations

Manta ray bycatch causes acute welfare harm through drowning in gear designed for other species. Their large size means they are often dragged significant distances before detection, increasing the duration of suffering. Even mantas that survive entanglement and are released may die days later from injuries, infections, or internal damage from pressure changes during retrieval. The welfare and conservation cases for bycatch reduction align perfectly: the same low reproductive rate that makes population recovery slow also means each bycaught individual has outsized population importance. Gear modifications including larger mesh sizes, acoustic deterrents, and observer coverage can reduce manta bycatch.

What You Can Do

Support Manta Trust and similar organizations working to document and reduce manta bycatch
Choose seafood certified by schemes with meaningful bycatch monitoring and reduction requirements
Advocate for mandatory observer coverage on vessels operating in manta ray habitat
Support manta ray sanctuary designations in critical habitat areas