A tale of two islands: Decadal changes in rocky reef fish assemblages following implementation of no-take marine protected areas in New South Wales, Australia

Marine Protected Areas (MPAs) are used worldwide as a management tool for the protection of marine biodiversity. To assess decadal changes in rocky reef fish assemblages following MPA protection, fish assemblages were monitored regularly in the Port Stephens-Great Lakes Marine Park (PSGLMP), New South Wales, Australia, using Baited Remote Underwater Video (BRUVs) comparing between fished and non-fished zones. Spatial and temporal heterogeneity of fish assemblages and fishery targeted species were assessed from 2006-2016 at two no-take zones at Broughton and Fingal Islands, and compared with nearby fished areas. A total of 102 species from families was observed over the study, with fish assemblage response being dependent on both the spatial scales of MPA zoning and locations within the park, and the temporal scales assessed. Five fishery targeted families, Labridae, Scorpaenidae, Sparidae, Monacanthidae and Cheilodactylidae, increased in relative abundance within no-take zones, compared with fished zones, although the response was variable among families and between locations. While abundance increased at both locations following the implementation of no-take zones, a significant zoning effect was only detected at Broughton Island, with the Labridae and Sparidae displaying the greatest increases in relative abundance within the no-take zone. This study demonstrates that the response of fish assemblages and targeted fishery families to the implementation of no-take MPA zones varies both temporally, and between locations. Differences in the assemblage response between locations are likely driven by the size and habitats within the no-take zones and these factors need to be adequately considered in MPA planning.