De Troch, M.

Gastón, A.

Malanga, G.

Marcelo, H.

Schloss, I.

Varela, D.

Open Marine Archive

423 
 
S18: The use of novel biomarkers in Antarctic ecology 
Facing climate change: Effects of temperature and salinity on fatty 
acid content in Antarctic plankton 
De Troch Marleen8, Hernando Marcelo1; Schloss Irene2,3,4; Almandoz Gastón3,5; Malanga Gabriela6 and  
Varela Diana7   
1 Depto. Radiobiología, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650, San 
Martín Buenos Aires, Argentina 
2 Instituto Antártico Argentino, 25 de Mayo 1143, San Martín, Buenos Aires, Argentina 
3 CONICET Godoy Cruz, 2290, Buenos Aires, Argentina 
4 Institut des sciences de la mer de Rimouski, Universite du Quebec à Rimouski, 310 allee des 
Ursulines, Rimouski, G5L 3A1 Canada 
5 División Ficología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. 
Paseo del Bosque s/n La Plata, Argentina 
6 IBIMOL-Fisico Química, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junin 
954, CABA, Argentina  
7 Department of Biology & School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty 
Road, Victoria B.C. V8P 5C2, Canada 
8 Ghent University, Faculty of Sciences, Marine Biology,Krijgslaan 281-S8, B-9000 Ghent, Belgium 
E-Mail: Marleen.DeTroch@UGent.be 
 
Marine planktonic communities in Antarctica are increasingly exposed to higher surface 
temperatures from global ocean warming and to reduced salinities from enhanced glacial melting. 
We performed a 7-day microcosm experiment on the shores of Potter Bay in King George Island, in 
which we assessed the effects of an increase (4 ºC) in temperature (T) and a decrease (4 units) in 
salinity (S) on plankton composition, carbon content, fatty acid (content and composition) and 
Thiobarbituric Acid Reactive Substances (TBARS) content as a measure of lipid damage from 
oxidative stress. Triplicate microcosms were exposed to four treatments: ambient T&S (control), 
ambient T-lower S, higher T-ambient S, and higher T-lower S. Phytoplankton assemblages showed 
an increase in the relative abundance of diatoms >20 µm in size in the manipulation treatments 
compared to the control, an increase in smaller diatoms (10-20 µm) only at higher T-ambient S, and 
a decrease in prasinophytes at higher T-lower S. Carbon content increased significantly in the higher 
T-ambient S and higher T-lower S treatments, with maximum values after 5 days. A significant 
increase in the relative abundance of unsaturated fatty acids EPA, C18:4ω3 and C16:1ω7, was 
measured in all treatments, compared to the control, after only 24 h. However, after 48 h, the 
increase in abundance of unsaturated fatty acid was only sustained at ambient T-lower S and at 
higher T-ambient S. The fatty acid composition changes measured under both ambient T-lower S 
and higher T-ambient S treatments, resulted in an increase in TBARS content by 48 h. However, at 
higher T-lower S, the increase in the proportion of unsaturated fatty acids was not different than 
that in the control. This may indicate that at low salinity, elevated temperatures increase enzymatic 
activity, which decreases the fluidity of cell’s membranes, and therefore helps to avoid osmotic 
stress and the production of reactive oxygen species. Interestingly, although fatty acid composition 
showed variations for at least 48 h, there was no change in phytoplankton assemblages during this 
period in any of the manipulation treatments compared to the control. Physiological changes on 
plankton carbon fixation and fatty acid levels due to these stressors can have serious implications 
for food-web energy flow and the overall functioning of Antarctic coastal ecosystems.  


Facing climate change: Effects of temperature and salinity on fatty acid content in Antarctic plankton

Abstract

Similar works

Full text

Available Versions

Open Marine Archive