Protecting threatened species from coastal infrastructure upgrades: The importance of evidence-based conservation

Increased coastal development and rising sea levels as a result of continuing climate-change put coastal regions at risk from flooding and inundation. A common mitigation response is the construction and upgrade of hard coastal protection structures, such as breakwaters, seawalls, and groynes. The alteration of the coast, together with the introduction of novel materials into coastal waters can negatively impact adjacent habitats and associated organisms. The implementation of management plans that involve scientists, as well as a variety of other stakeholders offer an opportunity to minimise adverse effects to biodiversity or even enhance it, while still protecting infrastructure and people. This study examines the management of an Australian breakwater upgrade and the progressive design finding process, including stakeholder engagement, determination of assessment criteria, and environmental impact assessment. In the course of the latter, scientific research led to the rediscovery of a presumed extinct algal species, Nereia lophocladia, which created an additional challenge and temporarily halted the upgrade. To accommodate this, the breakwater design solution was modified to avoid any impacts on the algal population and, in order to maximise the species' survival, novel ecological engineering approaches were proposed as mitigation strategies. Our case study underpins the value of evidence-based conservation and cooperation among stakeholders as important tools for minimising ecological impacts from coastal infrastructure upgrades.