Contrasting effects of ocean acidification on reproduction in reef fishes

• Published in: Coral reefs Vol. 35; no. 2; pp. 485 - 493
• Main Authors: Welch, Megan J., Munday, Philip L.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2016; Springer Nature B.V
• Subjects: Acanthochromis polyacanthus; Acidification; Amphiprion percula; Biomedical and Life Sciences; Breeding seasons; Carbon dioxide; Coral reefs; Fish; Freshwater & Marine Ecology; Hatching; Life Sciences; Marine; Marine organisms; Ocean acidification; Oceanography; Oceans; Offspring; Pisces; Reproduction; Ocean acidification; Coral reef fish; Reproduction
• ISSN: 0722-4028; 1432-0975
• DOI: 10.1007/s00338-015-1385-9

Differences in the sensitivity of marine species to ocean acidification will influence the structure of marine communities in the future. Reproduction is critical for individual and population success, yet is energetically expensive and could be adversely affected by rising CO 2 levels in the ocean. We investigated the effects of projected future CO 2 levels on reproductive output of two species of coral reef damselfish, Amphiprion percula and Acanthochromis polyacanthus . Adult breeding pairs were maintained at current-day control (446 μatm), moderate (652 μatm) or high CO 2 (912 μatm) for a 9-month period that included the summer breeding season. The elevated CO 2 treatments were consistent with CO 2 levels projected by 2100 under moderate (RCP6) and high (RCP8) emission scenarios. Reproductive output increased in A. percula , with 45–75 % more egg clutches produced and a 47–56 % increase in the number of eggs per clutch in the two elevated CO 2 treatments. In contrast, reproductive output decreased at high CO 2 in Ac. polyacanthus , with approximately one-third as many clutches produced compared with controls. Egg survival was not affected by CO 2 for A. percula , but was greater in elevated CO 2 for Ac. polyacanthus . Hatching success was also greater for Ac. polyacanthus at elevated CO 2 , but there was no effect of CO 2 treatments on offspring size. Despite the variation in reproductive output, body condition of adults did not differ between control and CO 2 treatments in either species. Our results demonstrate different effects of high CO 2 on fish reproduction, even among species within the same family. A greater understanding of the variation in effects of ocean acidification on reproductive performance is required to predict the consequences for future populations of marine organisms.