Manta rays are threatened by gill plate trade for traditional medicine and by poorly managed tourism. Both impose direct welfare costs on individual animals and threaten population viability.
Manta ray welfare involves both the acute trauma of targeted gill plate harvesting and the more subtle but cumulative welfare costs of poorly managed tourism. Gill plate extraction requires killing the animal — manta rays cannot be harvested for gill plates and survive. The process of capture (net entanglement, drowning resistance) is extremely stressful. For tourism, the welfare concern is different: mantas that are repeatedly approached, touched, and harassed by snorkellers and divers show cortisol elevation, altered movement patterns, and avoidance of feeding areas near tourism sites. Well-regulated manta tourism with enforced no-touch, minimum approach distance, and maximum diver number policies produces detectable changes in manta behaviour suggesting lower stress and continued area use. The economics of live manta tourism — a single ray can generate thousands of dollars in tourism revenue over a lifetime — make the financial case for conservation and regulated tourism stronger than for gill plate harvest.