The biodiversity of coral reef habitats is rapidly declining due to the effects of anthropogenic climate change, prompting the use of active restoration as a mitigation strategy.Sexual propagation can maintain or enhance genetic diversity in restoration of these ecosystems, but these approaches suffer from a range of inefficiencies in rearing and husbandry.Algal overgrowth of juveniles is a major bottleneck in the production of sexually propagated corals that may be alleviated by co-culture with Hat herbivores.We reared juvenile Montipora capitata alongside juvenile native Hawaiian collector urchins, Tripneustes gratilla, for 15 weeks and documented significant ecological benefits of co-culture.Urchin treatments significantly increased the survivorship of coral aggregates (14%) and individual settlers (24%).
We also documented a significant increase in coral growth in the presence of urchins.These results demonstrate the Treatment-Serums utility of microherbivory in promoting coral growth and survivorship in ex situ conditions, providing valuable insight for restoration pipelines of native Hawaiian coral species.