Policy and decision makers often seek guidance as to the benefits of conservation and repair of coastal seascapes, to justify and underpin any potential investments. Much is already known about the broad habitat and nursery values of seascapes among the science community, but there is also a need for estimation of clear and unambiguous market-based benefits that may arise from investment in repair. Recognising that this economic knowledge is imperfect for Australian seascapes, three case studies spanning tropical, subtropical and temperate environments explored the benefits in question. The case studies focus on saltmarsh habitats in particular, which have received very little investment in repair despite subtropical and temperate coastal saltmarsh listed as vulnerable ecological community under Australian Federal legislation. A subset of economically important species and conservative judgments were used to characterise the minimum potential economic benefit. For each of the case studies the conclusion was that while the biological information will remain imperfect, the business case for investment in the repair and conservation of coastal seascapes is compelling. We outline priorities for further research to make the business case more tangible to policy makers, stakeholders and the general public.

Water level heights were measured every 5 minutes at five station locations in the 70km length Tamar estuary, Tasmania, for six months. Pressure loggers deployed in the water recorded total pressure and the inverse barometer effect was accounted for by two additional pressure loggers deployed above ground within 15km of a station. The data include barometric pressure, water temperature, and water level relative to Australian Height Datum (AHD83). The data captures tidal amplification and asymmetry between ebb and flood tides in the estuary for the purpose of a research project completed in 2018 by Karen Palmer. Based on the Tamar estuary model created for NRM North by BMT WBM Pty Ltd using TUFLOW FV (with permission), a new hydrodynamic model was created and calibrated with observed water levels. Different scenarios of sea level rise and bathymetry change were then simulated to model the effects on tidal amplitude and phase.