The fish family Syngnathidae (seahorses, pipefish, pipehorses and seadragons) became fully protected in NSW in 2004. Syngnathids are threatened by unsustainable collecting, capture as incidental bycatch and habitat degradation. Although marine protected areas (MPAs) are an effective conservation strategy for many fishes, their value for syngnathids is untested. This project is assessing the benefits of an MPA (Fly Point-Halifax sanctuary zone, Port Stephens-Great Lakes Marine Park) for syngnathid conservation by comparing populations of White’s seahorse Hippocampus whitei, tiger pipefish Filicampus tigris and other syngnathids within and outside the sanctuary zone. Four study sites (two inside the sanctuary zone, two outside) have been monitored for 18 months. Syngnathids have been individually marked using visible implant elastomer tags. Population data on syngnathids have been collected using underwater visual census techniques and a comparison of different census techniques will be presented. Results will also be presented on the abundance of syngnathids in protected and non-protected sites, the relationship to predator abundance, and the habitat and depth usage of male and female seahorses.