Medium-term exposure of the North Atlantic copepod Calanus finmarchicus (Gunnerus, 1770) to CO 2 -acidified seawater: effects on survival and development

• Published in: Biogeosciences
• Main Authors: S. A. Pedersen, B. H. Hansen, D. Altin, A. J. Olsen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2013
• Subjects: Ecology; QH540-549.5; Life; QH501-531; Geology; QE1-996.5; Calanus finmarchicus; North Atlantic
• Online Access: https://doi.org/10.5194/bg-10-7481-2013; https://doaj.org/article/8c1fec59271c40aca422f00cf9ae7493

The impact of medium-term exposure to CO 2 -acidified seawater on survival, growth and development was investigated in the North Atlantic copepod Calanus finmarchicus . Using a custom developed experimental system, fertilized eggs and subsequent development stages were exposed to normal seawater (390 ppm CO 2 ) or one of three different levels of CO 2 -induced acidification (3300, 7300, 9700 ppm CO 2 ). Following the 28-day exposure period, survival was found to be unaffected by exposure to 3300 ppm CO 2 , but significantly reduced at 7300 and 9700 ppm CO 2 . Also, the proportion of copepodite stages IV to VI observed in the different treatments was significantly affected in a manner that may indicate a CO 2 -induced retardation of the rate of ontogenetic development. Morphometric analysis revealed a significant increase in size (prosome length) and lipid storage volume in stage IV copepodites exposed to 3300 ppm CO 2 and reduced size in stage III copepodites exposed to 7300 ppm CO 2 . Together, the findings indicate that a p CO 2 level ≤2000 ppm (the highest CO 2 level expected by the year 2300) will probably not directly affect survival in C. finmarchicus . Longer term experiments at more moderate CO 2 levels are, however, necessary before the possibility that growth and development may be affected below 2000 ppm CO 2 can be ruled out.