Marine protected areas designed for conservation purposes also provide welfare benefits to billions of fish and invertebrates by reducing fishing pressure, habitat destruction, and anthropogenic stressors.
Marine protected areas provide welfare benefits to fish and other marine animals by reducing the direct welfare harms of fishing including capture stress, barotrauma in fish brought from depth, discard mortality, and chronic fishing pressure that maintains populations in a state of depletion stress. Fish in heavily fished areas outside MPAs show behavioral changes consistent with chronic predation stress that MPAs mitigate. The establishment of well-enforced no-take MPAs covering substantial proportions of ocean area would represent one of the most significant wildlife welfare improvements achievable through conservation policy. However, MPAs without adequate enforcement are often paper protections that provide little actual welfare benefit to marine life within their boundaries.