| Title: | Response of Posidonia oceanica seagrass and its epibiont communities to ocean acidification |
| Author(s): | Guilini K; Weber M; de Beer D; Schneider M; Molari M; Lott C; Bodnar W; Mascart T; De Troch M; Vanreusel A; |
| Address: | "Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium. HGF-MPG Joint Research Group on Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany. HYDRA Institute for Marine Sciences, Elba Field Station, Italy. Microsensor Group, Max Planck Institute for Marine Microbiology, Bremen, Germany" |
| DOI: | 10.1371/journal.pone.0181531 |
| ISSN/ISBN: | 1932-6203 (Electronic) 1932-6203 (Linking) |
| Abstract: | "The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy) and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5), which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to assure that the biological responses observed during a short period reflect long-term dynamics of these parameters" |
| Keywords: | Alismatales/*metabolism Calcium Carbonate/*analysis Carbon Dioxide/*analysis Ecosystem Hydrogen-Ion Concentration Hydrothermal Vents/*chemistry Italy Oceans and Seas Oxygen/*analysis Seawater/*chemistry; |
| Notes: | "MedlineGuilini, Katja Weber, Miriam de Beer, Dirk Schneider, Matthias Molari, Massimiliano Lott, Christian Bodnar, Wanda Mascart, Thibaud De Troch, Marleen Vanreusel, Ann eng 2017/08/10 PLoS One. 2017 Aug 9; 12(8):e0181531. doi: 10.1371/journal.pone.0181531. eCollection 2017" |
