Sustainable management of Australia's coastal seascapes:\ud a case for collecting and communicating quantitative\ud evidence to inform decision-making

Australia's developed coasts are a heavily competed space, subject to urban, industrial and agricultural development. A diversity of habitats, such as mangroves, saltmarshes and seagrasses, comprise Australia's coastal seascape and provide numerous benefits including fish productivity, carbon sequestration, nutrient cycling, coastal protection and recreation. Decision makers need to be able to weigh up the relative costs and benefits of coastal development, protection or repair and to do this they need robust, accessible and defensible data on the ecological function and economic value of Australia’s coastal seascapes. We reviewed the published literature, with a focus on saltmarsh as a vulnerable ecological community, to determine the availability of information on key ecological functions that could inform ecosystem service valuation. None of the publications we reviewed quantified nutrient cycling, coastal protection or recreation functions. Only 13 publications presented quantitative information on carbon sequestration and fish productivity. These were limited geographically, with the majority of studies on sub-tropical and temperate saltmarsh communities between south-east Queensland and Victoria. This demonstrates a lack of quantitative information needed to substantiate and communicate the value of Australia’s saltmarshes in different locations, scales and contexts. Research should focus on addressing these knowledge gaps and communicating evidence in a relevant form and context for decision-making. We discuss four principles for research funding organisations and researchers to consider when prioritising and undertaking research on key ecological functions of Australia’s saltmarshes, and coastal seascapes more broadly, to support sustainable coastal development, protection and repair for long-term economic and community benefit