SINCE 2006 HIPPOCAMPUS ASSOCIATION IS COLLECTING FIELD DATA TO GATHER VALID EVIDENCE FOR SEAHORSE PROTECTION IN SPAIN. volunteer divers have been collecting data since then and showing huge fish population variations. In 2016 the physical-chemical conditions of the lagoon changed due to agricultural runoff and eutrophication. This enhances the risk for seahorses population and we are trying to claim for a recovery plan for seahorses in Spain, including it into the national Catalogue of Endangered species, and at the same time monitoring and planning new action for population recovery.