Ervilia castanea (Mollusca, Bivalvia) populations adversely affected at CO₂ seeps in the North Atlantic

• Published in: Science of The Total Environment
• Main Authors: Martins, Marta, Silva, Marina Carreiro, Martins, Gustavo M., Ramos, Joana B., Viveiros, Fátima, Couto, Ruben P., Parra, Hugo, Monteiro, João, Gallo, Francesca, Silva, Catarina, Teodósio, Alexandra, Guilini, Katja, Hall-Spencer, Jason M., Leitão, Francisco, Chícharo, Luís, Range, Pedro
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: Global Change; Seawater Carbonate Chemistry; Coastal Variability; Submarine Volcanic Vents; Population Structure; Semelidae; Sultan; North Atlantic; Ocean acidification
• Online Access: http://hdl.handle.net/10400.1/14714; http://hdl.handle.net/10400.3/5799; https://doi.org/10.1016/j.scitotenv.2020.142044

Sites with naturally high CO₂ conditions provide unique opportunities to forecast the vulnerability of coastal ecosystems to ocean acidification, by studying the biological responses and potential adaptations to this increased environmental variability. In this study, we investigated the bivalve Ervilia castanea in coastal sandy sediments at reference sites and at volcanic CO₂ seeps off the Azores, where the pH of bottom waters ranged from average oceanic levels of 8.2, along gradients, down to 6.81, in carbonated seawater at the seeps. The bivalve population structure changed markedly at the seeps. Large individuals became less abundant as seawater CO₂ levels rose and were completely absent from the most acidified sites. In contrast, small bivalves were most abundant at the CO₂ seeps. We propose that larvae can settle and initially live in high abundances under elevated CO₂ levels, but that high rates of post-settlement dispersal and/or mortality occur. Ervilia castanea were susceptible to elevated CO₂ levels and these effects were consistently associated with lower food supplies. This raises concerns about the effects of ocean acidification on the brood stock of this species and other bivalve molluscs with similar life history traits. Fundação para a Ciência e a Tecnologia [FCT, grant numbers: EXPL/MAR-EST/0604/2013, SFRH/BDP/63040/2009, SFRH/BPD/69959/2010, SFRH/BPD/100032/2014, DL57/2016/CP1361/CT0008 and UIDB/04326/2020]; Direção Regional da Ciência e Tecnologia [DRCT, grant numbers: M2.1.2/I/021/2011, M3.1.7/F/003/2010, M3.1.7/F/006/2011 and M3.1.2/F/025/2011]; Agencia Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação [ARDITI, grant number: M1420-09-5369-FSE-000001]; Khaled Bin Sultan Living Oceans Foundation; and the Flemish Fund for Scientific Research [FWO, grant number: 1242114 N]. info:eu-repo/semantics/publishedVersion