The article introduces the publication of Volumes 2 and 3 of the Guidelines on Fish Welfare in Spanish Aquaculture, focusing on European seabass and Gilthead seabream. These guidelines, developed in collaboration with the industry, aim to improve welfare standards for these species, going beyond voluntary UNE regulations. The guidelines address humane slaughter, stocking density, fasting, and other aspects, with a focus on transitioning away from ice slurry stunning and advocating for a maximum stocking density of 15 kg/m3. The guidelines also emphasize environmental enrichment, continuous monitoring of welfare indicators, and the adoption of a mortality alert system. Compassion is advocating for the wider adoption of these guidelines and offers support in their implementation.