Influence of intermittent estuary outflow on coastal sediments of adjacent sandy beaches

► We examine the influence of estuary outflow on coastal sediments following an artificial opening and a separate natural flood. ► We examine changes in sediment organic matter, microphytobenthic chlorophyll a and microbiota. ► Increasing information will provide an assessment of the impact of estuarine discharge on sediment productivity. ► Estuary outflow does change sediment characteristics of adjacent sandy beaches.