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Ocean acidification (OA), an alteration of seawater chemistry caused primarily by anthropogenic carbon emissions, is a global issue. However, the local expression of OA can vary widely in nearshore waters around the world. This is due to localized factors such as river input, eutrophication, topography, location (e.g., temperature), and sensitivity of local species. Human impacts from OA also vary depending on societal uses of the ocean and its resources. Managers, policy­makers, and governments need to understand the status and susceptibility of their regions in order to make effective decisions and drive policy. In the early 2000s, scientists recognized the need for a global ocean acidification observing system and called for a coordinated approach to effectively assess global as well as local status with consistent methods. As a result, the Global Ocean Acidification Observing Network (GOA-ON) was formed in 2012 with three goals: (1) to improve understanding of global OA conditions, (2) to improve understanding of ecosystem responses to OA, and (3) to acquire and exchange data and knowledge necessary to optimize modeling of OA and its impacts (Newton et al., 2015; Tilbrook et al., 2019). 

Abstract The iconic and threatened Caribbean coral,Acropora palmata, is an essential reef-ecosystem engineer. Understanding the processes underpinning this coral’s survival and growth is essential to restoring this foundational species. Here, we compared replicateA. palmatacolonies transplanted along 350 km of Florida’s offshore coral reef to determine holobiont and/or environmental variables that predict transplant success. We found a west-to-east gradient in coral physiology coupled with site-specific coral-associated microbiomes. Interestingly, no variables were linked to coral genet. Our results suggest that the unique oceanographic conditions with periodic upwelling events in the Dry Tortugas provide corals with greater opportunity for heterotrophy that in turn enhances coral growth and survivorship, and positively influences the microbiome. Our findings indicate that restoration efforts in the Dry Tortugas, and other places exhibiting higher food availability, could be most effective forA. palmata. 

Abstract Coral reefs are declining worldwide, yet some coral populations are better adapted to withstand reductions in pH and the rising frequency of marine heatwaves. The nearshore reef habitats of Palau, Micronesia are a proxy for a future of warmer, more acidic oceans. Coral populations in these habitats can resist, and recover from, episodes of thermal stress better than offshore conspecifics. To explore the physiological basis of this tolerance, we compared tissue biomass (ash-free dry weight cm⁻²), energy reserves (i.e., protein, total lipid, carbohydrate content), and several important lipid classes in six coral species living in both offshore and nearshore environments. In contrast to expectations, a trend emerged of many nearshore colonies exhibiting lower biomass and energy reserves than colonies from offshore sites, which may be explained by the increased metabolic demand of living in a warmer, acidic, environment. Despite hosting different dinoflagellate symbiont species and having access to contrasting prey abundances, total lipid and lipid class compositions were similar in colonies from each habitat. Ultimately, while the regulation of colony biomass and energy reserves may be influenced by factors, including the identity of the resident symbiont, kind of food consumed, and host genetic attributes, these independent processes converged to a similar homeostatic set point under different environmental conditions.