Physiological response of the symbiotic gorgonian Eunicella singularis to a long-term temperature increase.
Increase in seawater temperature is one of the major effects of global climate change that affects marine organisms, including Cnidaria. Among them, gorgonians from the NW Mediterranean Sea, such as the species Eunicella singularis, have suffered spectacular and extensive damage. We thus investigated in a controlled laboratory experiment the response of E. singularis to a long-term increase in temperature and we took a special interest in its photosynthetic and calcification response to the stress. Two populations collected at 15 and 35 m depths were studied in order to determine whether there was a difference in sensitivity to thermal stress between living depths. Our results show: (a) that calcification and photosynthesis were impacted only when gorgonians were maintained for more than two weeks at 26 degrees C, and (b) that colonies of E. singularis living in shallow waters were less tolerant than those living in deep waters. Because E. singularis is a symbiotic species, we have also discussed the potential role of symbiosis in the thermotolerance response.
Ferrier-Pagès
Christine
C
Centre Scientifique de Monaco, MC-98000 Monaco, Principality of Monaco.
Tambutté
Eric
E
Zamoum
Thamilla
T
Segonds
Natacha
N
Merle
Pierre-Laurent
PL
Bensoussan
Nathaniel
N
Allemand
Denis
D
Garrabou
Joaquim
J
Tambutté
Sylvie
S
D000818:Animals; D002113:Calcification, Physiologic; D002734:Chlorophyll / Q000378:metabolism; D057231:Climate Change; D003063:Cnidaria / Q000502:physiology*; D017753:Ecosystem; D008522:Mediterranean Sea; D010788:Photosynthesis / Q000502:physiology; D012623:Seawater; D013312:Stress, Physiological; D013559:Symbiosis; D013696:Temperature
D002734:Chlorophyll