Sea lions are among the most popular zoo and aquarium animals. Their welfare depends on appropriate social grouping, water quality, space, and enrichment programmes that meet their cognitive needs.
Sea lion welfare in zoos and aquariums centres on social needs, environmental complexity, and training methods. As highly social colonial animals, sea lions require appropriate groupings — mixed-sex groups with managed social dynamics where possible. Pool size and water quality are fundamental: sea lions in inadequate volumes develop eye disease from poor water quality and show stereotypic behaviours from insufficient swimming opportunity. Positive reinforcement training, where animals voluntarily participate in behaviours for rewards, is both the welfare-preferred and most effective training approach — it enables veterinary procedures without restraint and provides cognitive enrichment. Sea lion shows and performances remain controversial; their welfare impact depends entirely on whether training uses force or positive reinforcement. Modern accredited facilities have moved away from coercive training methods.