TY - JOUR
T1 - Endolithic algae
T2 - An alternative source of photoassimilates during coral bleaching
AU - Fine, Maoz
AU - Loya, Yossi
PY - 2002/6/22
Y1 - 2002/6/22
N2 - Recent reports of worldwide coral bleaching events leading to devastating coral mortality have caused alarm among scientists and resource managers. Differential survival of coral species through bleaching events has been widely documented. We suggest that among the possible factors contributing to survival of coral species during such events are endolithic algae harboured in their skeleton, providing an alternative source of energy. We studied the dynamics of photosynthetic pigment concentrations and biomass of endoliths in the skeleton of the encrusting coral Oculina patagonica throughout a bleaching event. During repeated summer bleaching events these endolithic algae receive increased photosynthetically active radiation, increase markedly in biomass, and produce increasing amounts of photoassimilates, which are translocated to the coral. Chlorophyll concentrations and biomass of endoliths were 4.6 ± 1.57 and 1570 ± 427 μg cm-2 respectively, in skeletons of relatively healthy colonies (0-40% bleaching) but up to 14.8 ± 2.5 and 4036 ± 764 μg cm-2 endolith chlorophyll and biomass respectively, in skeletons of bleached colonies (greater than 40% bleaching). The translocation dynamics of 14C-labelled photoassimilates from the endoliths to bleached coral tissue showed significantly higher 14C activity of the endoliths harboured within the skeletons of bleached corals than that of the endoliths in non-bleached corals. This alternative source of energy may be vital for the survivorship of O. patagonica, allowing gradual recruitment of zooxanthellae and subsequent recovery during the following winter.
AB - Recent reports of worldwide coral bleaching events leading to devastating coral mortality have caused alarm among scientists and resource managers. Differential survival of coral species through bleaching events has been widely documented. We suggest that among the possible factors contributing to survival of coral species during such events are endolithic algae harboured in their skeleton, providing an alternative source of energy. We studied the dynamics of photosynthetic pigment concentrations and biomass of endoliths in the skeleton of the encrusting coral Oculina patagonica throughout a bleaching event. During repeated summer bleaching events these endolithic algae receive increased photosynthetically active radiation, increase markedly in biomass, and produce increasing amounts of photoassimilates, which are translocated to the coral. Chlorophyll concentrations and biomass of endoliths were 4.6 ± 1.57 and 1570 ± 427 μg cm-2 respectively, in skeletons of relatively healthy colonies (0-40% bleaching) but up to 14.8 ± 2.5 and 4036 ± 764 μg cm-2 endolith chlorophyll and biomass respectively, in skeletons of bleached colonies (greater than 40% bleaching). The translocation dynamics of 14C-labelled photoassimilates from the endoliths to bleached coral tissue showed significantly higher 14C activity of the endoliths harboured within the skeletons of bleached corals than that of the endoliths in non-bleached corals. This alternative source of energy may be vital for the survivorship of O. patagonica, allowing gradual recruitment of zooxanthellae and subsequent recovery during the following winter.
KW - Bleaching
KW - C
KW - Corals
KW - Endolithic algae
KW - Oculina patagonica
UR - http://www.scopus.com/inward/record.url?scp=0037157451&partnerID=8YFLogxK
U2 - 10.1098/rspb.2002.1983
DO - 10.1098/rspb.2002.1983
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C2 - 12065035
AN - SCOPUS:0037157451
SN - 0962-8452
VL - 269
SP - 1205
EP - 1210
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
IS - 1497
ER -