This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project B4 - "Underpinning the repair and conservation of Australia’s threatened coastal-marine habitats". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The primary objective of this project is to provide essential research to underpin restoration efforts to increase the success and efficiency of shellfish and saltmarsh repair. The secondary objective is to quantify clear easily understood benefits of repair to further increase groundswell, Indigenous and interest group support for repair efforts. For Phase 2 this involves: Shellfish reefs 1. Providing critical research to underpin the success of companion works investments into Sydney rock oyster (Saccostrea glomerata) restoration in Qld and NSW 2. Ongoing engagement with Indigenous groups, focused around especially SEQ and NSW to match the emphasis on Sydney rock oyster; 3. Through the Nature Conservancy, linking to shellfish restoration works in Port Phillip Bay (Vic), St Vincent’s Gulf (SA) and Oyster Harbour (WA) so that a National Business Case complete with examples of successes to date can be developed; 4. Underpinning this succinct business case with an information base for any follow-on activities such as assessment of shellfish reefs as an endangered community. Salt marshes 1. Estimating the benefits of salt marsh repair for an easily publicly understood indicator - prawn species. 2. Undertaking this work in NSW and Qld in parallel with proposed repair works so that very concrete case studies are available to demonstrate the benefits of repair. Planned Outputs Shellfish reef project outputs: • A scientific paper published in an eminent, peer-reviewed journal describing the ecology and biodiversity of shellfish reefs and biodiversity comparison against other marine habitats; • A scientific paper published in an eminent, peer-reviewed journal which identifies trajectories of change from past baselines to current condition and develops achievable targets for repair; • News stories, web articles, social media, brochures and oral presentations at national/international conferences, which communicate the key research findings to coastal stakeholders such as fishers, divers, NRM groups and government agencies; • News stories, web articles and social media which communicate the importance of shellfish reefs and shellfish food sources to Indigenous Australians; • Summary of community benefit and business propositions for coastal wetland repair expanding on the vision of a rejuvenated coastal ecology and written at the level required for input to various investors, agencies and public policy; • Updates at the end of 2016 as part of stakeholder engagement and continued communication. Salt marsh prawn productivity outputs: • A scientific paper published in an eminent, peer-reviewed journal quantifying and contrasting prawn productivity in healthy and degraded salt marsh communities in tropical and temperate environments; • Publicly accessible communication resources (brochures, social media, media releases and webpages) which articulate simply the prawn productivity values of salt marshes and links this to the need for the protection, conservation and restoration of degraded salt marsh communities.

Total organic carbon (TOC) sediment stocks as a CO2 mitigation service require exclusion of allochthonous black (BC) and particulate inorganic carbon corrected for water–atmospheric equilibrium (PICeq). For the first time, we address this bias for a temperate salt marsh and a coastal tropical seagrass in BC hotspots that represent two different blue carbon ecosystems of Malaysia and Australia. Seagrass TOC stocks were similar to the salt marshes with soil depths < 1 m (59.3 ± 11.3 and 74.9 ± 18.9 MgC ha-1, CI 95% respectively). Both ecosystems showed larger BC constraints than their pristine counterparts did. However, the seagrass meadows’ mitigation services were largely constrained by both higher BC/TOC and PICeq/TOC fractions (38.0% ± 6.6% and 43.4% ± 5.9%, CI 95%) and salt marshes around a third (22% ± 10.2% and 6.0% ± 3.1% CI 95%). The results provide useful data from underrepresented regions, and, reiterates the need to consider both BC and PIC for more reliable blue carbon mitigation assessments.