Fouling release coatings reduce colonisation of coral seeding devices

The increasing frequency and severity of coral bleaching underscores the need for effective coral reef restoration programs. These initiatives include deploying coral fragments or early recruits (spat), with large-scale coral seeding success dependent on improving coral survival by minimizing competition from algae and benthic invertebrates. This study presents a proof-of-concept field experiment assessing the effectiveness of two commercial non-biocidal fouling release coatings (FRCs) and an FRC wax coating in reducing fouling on coral seeding devices. Ceramic devices treated with FRCs were deployed with Acropora millepora microfragments and monitored over 46 weeks. Coated devices experienced significantly less fouling than uncoated controls, particularly during the critical early months when coral spat are most vulnerable. The best performing coating maintained over 10 times more clear surface area than uncoated devices, providing sustained protection without affecting coral survival. Corals also successfully overgrow the coatings by trial's end. These findings suggest that FRCs could protect smaller coral spat from overgrowth, reducing early mortality until they reach a size escape threshold. Such coatings also hold promise for large-scale restoration projects, coral nurseries, and aquaculture. Future research should evaluate their efficacy across diverse habitats, particularly areas with high macroalgal cover, to optimize their application in restoration strategies.