Evaluating the effect of temperature on photosynthesis and respiration of articulated coralline algae using oxygen evolution and chlorophyll a fluorescence

Coralline algae form abundant and ecologically important submerged aquatic vegetation habitats throughout the world. However, algal performance is threatened by climate change ocean acidification. Previous studies suggest that their photosynthetic will be compromised mainly at elevated temperatures. Understanding impact of diverse scenarios requires a clear thorough comprehension response to temperature gradients. The objective this study was evaluate short-term effect (10–35 °C) on gross photosynthesis (GPS), respiration, electron transport rates (ETRs) 3 articulated coralline (Lithothrix aspergillum, Corallina officinalis, Bossiella orbigniana) for better understanding metabolism investigate relationship between GPS ETR as function temperature. results showed highly sensitive temperature, but responses were species-specific can related light adaptation/acclimation; high-light-adapted L. aspergillum least negatively affected. respiration ratio optimal 20 25 °C according local thermal regime significantly reduced toward higher temperatures, indicating strong carbon imbalances highlighting relevance stress performance. A correlation found 10 30 in all species, both above saturation irradiances temperatures (≥30 °C), deviation from linearity occurred. This suggests not good proxy estimate activity under or stress. information should useful implementing global pulse amplitude modulated (PAM) fluorometry algae.