Deep sea research activities disturb fragile deep ocean ecosystems and the animals that inhabit them, with welfare implications that are poorly understood due to the inaccessibility of this environment.
Deep sea animal welfare is particularly difficult to assess because of the inaccessibility of the environment and the limited understanding of deep sea animal physiology and behavior. Animals collected from deep water by trawls experience rapid decompression that is lethal for most species. Research operations that disturb deep sea habitats cause welfare harm to the animals disrupted regardless of whether those animals experience that harm subjectively. The precautionary principle argues for minimal disturbance research approaches — camera surveys, acoustic monitoring, and careful ROV protocols — that achieve scientific objectives with minimal animal harm in an environment where recovery from disturbance is extremely slow.