How does ocean acidification affect Zostera marina during a marine heatwave?

Extreme ocean events caused by global warming, such as marine heatwaves (MHWs) and ocean acidification (OA), are projected to intensify. A combination of extreme events may have severe consequences for marine ecosystems. Zostera marina was selected to understand how seagrass adapts to OA in extremely hot conditions. By combining morphology, transcriptomics, and metabolomics under mesoscale experimental conditions, we systematically investigated the response characteristics of Z. marina. Extremely high temperatures had a pronounced effect on growth, and the combined effect of OA mitigated the inhibitory effect of MHW. Both transcriptomic and metabolomic results showed that Z. marina resisted OA and MHW by upregulating the TCA cycle, glycolysis, amino acid metabolism, and relevant genes, as well as by activating the antioxidant system. The results of this study serve to improve our understanding of dual effects of factors of climate change on seagrass and may be used to direct future management and conservation efforts.

Automated summary

Extreme ocean events caused by global warming are projected to intensify and may have severe consequences for marine ecosystems. This study focuses on the response of seagrass Zostera marina to ocean acidification in hot conditions using a combination of morphology, transcriptomics, and metabolomics. The results show that Z. marina adapts to ocean acidification and marine heatwaves by upregulating certain metabolic pathways and activating the antioxidant system.