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Ocean acidification reduces feeding rates in the scleractinian coral S tylophora pistillata
Author(s) -
Houlbrèque Fanny,
Reynaud Stéphanie,
Godinot Claire,
Oberhänsli François,
RodolfoMetalpa Riccardo,
FerrierPagès Christine
Publication year - 2015
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.1002/lno.10003
Subject(s) - stylophora pistillata , ocean acidification , coral , seawater , coral reef , nutrient , biology , reef , heterotroph , scleractinia , ecology , calcification , environmental chemistry , cnidaria , zoology , chemistry , bacteria , medicine , genetics
A general decline in coral calcification has been observed in response to ocean acidification. It has recently been shown that heterotrophic feeding (the acquisition of organic nutrients) enables one massive coral species to maintain its calcification rates while exposed to ocean acidification but the consequences of higher seawater partial pressure of CO 2 ( p CO 2) on coral feeding capacities themselves have never been investigated. Exposing long‐term acclimated starved and fed colonies of the major reef builder Stylophora pistillata to either ambient pH T (8.06 ± 0.05; 417 Pap CO 2) or low pH T (7.51 ± 0.06; 1697 Pap CO 2) showed that higher feeding rates can counterbalance the negative effects of seawater acidification on coral calcification. Indeed, relative to unfed corals under ambient pH T conditions, calcification rates in unfed corals decreased by 53.6% but remained constant in fed corals under highp CO 2conditions. Results also clearly show that acidification affects the feeding capacity and feeding effort of the branching coral S. pistillata . Organic nutrient acquisition was severely reduced under highp CO 2, with a simultaneous decrease in the dissolved free amino acid uptake rates, the alkaline phosphatase activities, and the feeding rates on Artemia salina nauplii. Considering that all these processes are needed to fulfill the nutrient needs of the symbiotic association, on a long‐term basis, lower feeding rates will likely aggravate the already fragile physiological state of many corals under warmer, more acidic conditions.