Ocean acidification and carbon limitation affect photosynthetic capacity of the seagrass (Amphibolis antarctica) and its calcifying epiphytes ...

• Main Author: Grove, Daniel
• Format: Article in Journal/Newspaper
• Language: English
• Published: University of Plymouth 2021
• Subjects: Ocean Acidification; Climate Change; Seagrass; Amphibolis; ResM; Antarc*; Antarctica; Ocean acidification
• Online Access: https://dx.doi.org/10.24382/387; https://pearl.plymouth.ac.uk/bms-theses/11

Amphibolis antarctica seagrass meadows, and their associated calcifying epiphytes, are abundant on Australia’s west coast, but have declined in recent years due to anthropogenic factors such as marine heatwaves, damaging fishing practices and increased turbidity resulting from eutrophication which causes light limitation. Burning fossil fuels has increased the flux of CO2 in to the ocean, lowering surface seawater pH, and making more carbon available for photosynthetic life. There are benefits of increasing CO2 for those seagrasses that are carbon limited, as this alleviates their energetic use of carbon concentrating mechanisms (CCM’S) which are less efficient, and more energy costly than passive diffusion of CO2 across cell walls. This study used pulse amplitude modulation fluorometry to quantify relative electron transport rates (rETR) at a range of pH levels both above and below current ocean pH of 8.1, and found that A. antarctica has significantly decreased rETR at pH treatments of 7.81 and 7.61. ...