Predation by fish threatens recovery efforts of an Endangered soft coral

Restoration programs are increasingly essential for supporting the recovery of threatened species, yet their success depends on identifying and mitigating key threats. This study presents the first direct video evidence of fish predation on transplants of the Endangered soft coral Dendronephthya australis by yellowfin leatherjackets (Meuschenia trachylepis) in the Port Stephens estuary, New South Wales, Australia. Fish predation, previously undocumented for D. australis, now joins a growing list of stressors, including physical damage, sedimentation and freshwater influx, that are collectively impeding the coral recovery. It was observed that M. trachylepis fed on both stalks and polyps of outplanted coral fragments, although polyps appeared less vulnerable once retracted, potentially owing to the defensive role of sclerites. Experiments in the wild demonstrated that transplant survival was significantly improved when soft corals were placed under predator exclusion cages. Predation events such as these represent a substantial bottleneck to restoration success, particularly in the early post-transplant phase of corals. These findings highlighted the complex, multi-stressor environment facing D. australis and emphasised the need for restoration strategies that include protective measures, such as caging, to reduce fish predation until transplants mature. A more holistic understanding of these threats is critical for improving conservation outcomes for this threatened species.