Characterization of Coral Phenotype Plasticity Across the Pacific Ocean

Reef-building corals, known for their heightened susceptibility to environmental shifts, are expected to experience deleterious repercussions after escalating climate change impacts. Despite the looming threats, the existing body of knowledge concentrates mainly on specific locations and does not fully explore inter- and intraspecific coral sensitivity across various reefs, leaving a substantial void in our comprehension of the broader ecological landscape. Through the TARA Pacific expedition,900 samples from Pocillopora spp. and Porites spp. were collected on 31 islands across the Pacific from 2016 to 2018 to assess the phenotypic signatures using a multi-biomarker approach. The biomarkers analyzed included biomasses of animals and symbiotic dinoflagellates to study the trophic status of the colonies, copies of mitochondrial DNA, and total carbohydrate content as indicators of metabolism and total antioxidant capacities and protein carbonylation as proxies for redox state and cellular damages. The analysis of the unprecedented wide dataset allows us to answer the following questions: (1) How do biomarker profiles vary within and between different species across the Pacific? (2) Which environmental factors correlate with the biomarker profiles? (3) Which biomarkers can be used to monitor coral reefs? The results revealed a broad plasticity phenotype and correlations to specific environmental parameters. Ultimately, this research seeks to provide conservationists with essential tools and insights to improve coral resilience and restoration efforts, thereby supporting sustainable strategies to safeguard these vital ecosystems against ongoing environmental challenges.