Biological traits of corals under electro-mineral accretion at a coral restoration site in Indonesia

Abstract

Abstract. Taylor ACF. 2026. Biological traits of corals under electro-mineral accretion at a coral restoration site in Indonesia. Indo Pac J Ocean Life 10 (1): o100102. https://doi.org/10.13057/oceanlife/o100102. Coral reef restoration efforts risk creating habitats that appear functional yet lack key ecological roles. Electro-Mineral Accretion (EMA)—a method applying low-voltage current to promote calcium carbonate deposition—has been used to enhance coral growth, but its effects on other biological traits remain poorly understood. This study investigated whether corals grown under EMA exhibit trade-offs between growth, reproduction, and skeletal structure compared to natural colonies. At restoration sites in Lombok, Indonesia, colonies of Stylophora pistillata were assessed for fecundity, polyp density, skeletal density, and growth. Growth comparisons of Acropora muricata were also measured between EMA treatments and naturally growing corals. EMA-treated corals showed significantly higher skeletal growth rates but reduced reproductive output, with fecundity 40% lower than natural colonies. Skeleton density was also reduced, suggesting lighter, less robust structures, while differences in polyp density were minor. These patterns indicate that enhanced growth under EMA may occur at the expense of reproduction and structural strength. The findings highlight a key ecological trade-off: faster-growing EMA corals may contribute to short-term reef cover but potentially compromise long-term population viability and resilience. Coral restoration success depends not only on promoting rapid growth but also on preserving reproductive capacity and skeletal integrity. This study underscores the importance of evaluating multiple biological traits when assessing restoration methods and cautions against relying solely on growth enhancement as a measure of ecological success.