Resistance of Two Mediterranean Cold-Water Coral Species to Low-pH Conditions

• Published in: Water
• Main Authors: Juancho Movilla, Andrea Gori, Eva Calvo, Covadonga Orejas, Àngel López-Sanz, Carlos Domínguez-Carrió, Jordi Grinyó, Carles Pelejero
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2013
• Subjects: ocean acidification; cold-water corals; Lophelia pertusa; Madrepora oculata; Mediterranean Sea; aquaria experiment; calcification rate; porosity; microdensity; Hydraulic engineering; TC1-978; Water supply for domestic and industrial purposes; TD201-500; Ocean acidification
• Online Access: https://doi.org/10.3390/w6010059; https://doaj.org/article/3144ecd91b7a4767821c8bc7ee2d0a5a

Deep-water ecosystems are characterized by relatively low carbonate concentration values and, due to ocean acidification (OA), these habitats might be among the first to be exposed to undersaturated conditions in the forthcoming years. However, until now, very few studies have been conducted to test how cold-water coral (CWC) species react to such changes in the seawater chemistry. The present work aims to investigate the mid-term effect of decreased pH on calcification of the two branching CWC species most widely distributed in the Mediterranean, Lophelia pertusa and Madrepora oculata. No significant effects were observed in the skeletal growth rate, microdensity and porosity of both species after 6 months of exposure. However, while the calcification rate of M. oculata was similar for all colony fragments, a heterogeneous skeletal growth pattern was observed in L. pertusa, the younger nubbins showing higher growth rates than the older ones. A higher energy demand is expected in these young, fast-growing fragments and, therefore, a reduction in calcification might be noticed earlier during long-term exposure to acidified conditions.