Deep sea fishing accesses previously unexploited fish populations while causing significant disturbance to deep sea ecosystems. The welfare of deep sea fish and the invertebrates of the deep sea floor deserve consideration alongside conservation concerns.
Deep sea fishing welfare involves both the acute welfare of captured fish and the ecosystem welfare implications of habitat destruction. Fish brought from deep water experience barotrauma — damage to gas-filled organs as external pressure drops rapidly — that causes injuries ranging from minor discomfort to fatal damage. The slow-life-history nature of many deep sea species means individual fish live for decades to centuries, making their capture welfare-relevant for longer-lived individuals. Cold water coral reef destruction from trawling eliminates habitat that recovers over centuries, creating long-term welfare losses for the diverse communities these ecosystems support. The regulatory gap in deep sea fisheries — where international waters are less managed than coastal zones — means welfare and sustainability concerns have less regulatory traction than in more accessible fisheries.