DISCO - Drivers and Impacts of Coastal Ocean Acidification

Research output: ThesisDoctoral Thesis (compilation)

Standard

DISCO - Drivers and Impacts of Coastal Ocean Acidification. / Charrieau, Laurie.

1st ed. Lund : Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology, 2017. 126 p.

Research output: ThesisDoctoral Thesis (compilation)

Harvard

APA

Charrieau, L. (2017). DISCO - Drivers and Impacts of Coastal Ocean Acidification. (1st ed.). Lund: Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology.

CBE

Charrieau L. 2017. DISCO - Drivers and Impacts of Coastal Ocean Acidification. Lund: Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology. 126 p. 1st ed.

MLA

Charrieau, Laurie DISCO - Drivers and Impacts of Coastal Ocean Acidification 1st udg. Lund: Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology. 2017.

Vancouver

Charrieau L. DISCO - Drivers and Impacts of Coastal Ocean Acidification. 1st ed. Lund: Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology, 2017. 126 p.

Author

Charrieau, Laurie. / DISCO - Drivers and Impacts of Coastal Ocean Acidification. 1st ed. Lund : Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology, 2017. 126 p.

RIS

TY - THES

T1 - DISCO - Drivers and Impacts of Coastal Ocean Acidification

AU - Charrieau, Laurie

N1 - Defence details Date: 2017-12-15 Time: 13:00 Place: Lecture hall “Pangea”, Geocentrum II, Sölvegatan 12, Lund External reviewer(s) Name: Husum, Katrine Title: Dr. Affiliation: Norwegian Polar Institute, Tromsø, Norway ---

PY - 2017/11

Y1 - 2017/11

N2 - Ocean acidification, mainly attributed to the increasing anthropogenic CO2 in the atmosphere, is characterised by a lowering pH together with a shift in the sea water carbonate chemistry toward lower concentration of carbonate ions. On the coasts, where the environmental variability is high due to natural and human impacts, ocean acidification mainly affects the frequency, magnitude, and duration of lower pH and lower calcium carbonate saturation events. Coastal ecosystems are adapted to environmental variability such as frequent changes in salinity, temperature, pH, oxygen levels and organic matter content. However, the effects of an increase of the range of this variability on coastal species, and especially on calcifiers, are still not clear. In this context, this thesis explores the impacts of coastal ocean acidification combined with other environmental stressors on benthic foraminifera.In the Skagerrak-Baltic Sea region, foraminifera faunas varied along a strong gradient in terms of salinity, pH, and dissolved oxygen concentration, and species were adapted to local environmental stressors. However, the specimens of Ammonia spp. and Elphidium spp. observed in the south Baltic Sea were partially to completely dissolved, probably due to a combination of different stressors affecting the required energy for biomineralisation.In a culture study, the coastal species Ammonia spp. and E. crispum were found to be resistant to dissolution under varying salinity and pH, which reflects the environmental variations in their natural habitats. However, their resistance to lower pH is decreased when cultured in brackish water conditions, and living decalcified specimens were also observed under a salinity of 5. This underlines the importance of a high salinity in the calcification process of foraminifera.At the entrance of the Baltic Sea, environmental changes during the last 200 years were reconstructed using foraminiferal faunas. Four periods were identified with varying oxygen levels, salinity, organic matter content, and pollution with lower pH. This highlights that foraminiferal faunas were able to adapt to multiple environmental stressors.This thesis concludes that, even if coastal species of foraminifera can tolerate extremely varying conditions in their environment on the short term, it is likely that tolerance thresholds will be passed for benthic ecosystems under the future increase in anthropogenic impacts such as coastal ocean acidification.Further studies of micro-organisms such as foraminifera will be necessary to improve our understanding of past environmental changes and to put present and future changes into a larger context.

AB - Ocean acidification, mainly attributed to the increasing anthropogenic CO2 in the atmosphere, is characterised by a lowering pH together with a shift in the sea water carbonate chemistry toward lower concentration of carbonate ions. On the coasts, where the environmental variability is high due to natural and human impacts, ocean acidification mainly affects the frequency, magnitude, and duration of lower pH and lower calcium carbonate saturation events. Coastal ecosystems are adapted to environmental variability such as frequent changes in salinity, temperature, pH, oxygen levels and organic matter content. However, the effects of an increase of the range of this variability on coastal species, and especially on calcifiers, are still not clear. In this context, this thesis explores the impacts of coastal ocean acidification combined with other environmental stressors on benthic foraminifera.In the Skagerrak-Baltic Sea region, foraminifera faunas varied along a strong gradient in terms of salinity, pH, and dissolved oxygen concentration, and species were adapted to local environmental stressors. However, the specimens of Ammonia spp. and Elphidium spp. observed in the south Baltic Sea were partially to completely dissolved, probably due to a combination of different stressors affecting the required energy for biomineralisation.In a culture study, the coastal species Ammonia spp. and E. crispum were found to be resistant to dissolution under varying salinity and pH, which reflects the environmental variations in their natural habitats. However, their resistance to lower pH is decreased when cultured in brackish water conditions, and living decalcified specimens were also observed under a salinity of 5. This underlines the importance of a high salinity in the calcification process of foraminifera.At the entrance of the Baltic Sea, environmental changes during the last 200 years were reconstructed using foraminiferal faunas. Four periods were identified with varying oxygen levels, salinity, organic matter content, and pollution with lower pH. This highlights that foraminiferal faunas were able to adapt to multiple environmental stressors.This thesis concludes that, even if coastal species of foraminifera can tolerate extremely varying conditions in their environment on the short term, it is likely that tolerance thresholds will be passed for benthic ecosystems under the future increase in anthropogenic impacts such as coastal ocean acidification.Further studies of micro-organisms such as foraminifera will be necessary to improve our understanding of past environmental changes and to put present and future changes into a larger context.

KW - Coastal ocean acidification

KW - Foraminifera

KW - Environmental changes

KW - pH

KW - Salinity

M3 - Doctoral Thesis (compilation)

SN - 978-91-7753-493-8

PB - Lund University, Faculty of Science, Centre for Environmental and Climate Research (CEC) & Department of Geology

CY - Lund

ER -