title: Pacific-wide contrast highlights resistance of reef calcifiers to ocean acidification.
abstract: Ocean acidification (OA) and its associated decline in calcium carbonate saturation states is one of the major threats that tropical coral reefs face this century. Previous studies of the effect of OA on coral reef calcifiers have described a wide variety of outcomes for studies using comparable partial pressure of CO2 (pCO2) ranges, suggesting that key questions remain unresolved. One unresolved hypothesis posits that heterogeneity in the response of reef calcifiers to high pCO2 is a result of regional-scale variation in the responses to OA. To test this hypothesis, we incubated two coral taxa (Pocillopora damicornis and massive Porites) and two calcified algae (Porolithon onkodes and Halimeda macroloba) under 400, 700 and 1000 μatm pCO2 levels in experiments in Moorea (French Polynesia), Hawaii (USA) and Okinawa (Japan), where environmental conditions differ. Both corals and H. macroloba were insensitive to OA at all three locations, while the effects of OA on P. onkodes were location-specific. In Moorea and Hawaii, calcification of P. onkodes was depressed by high pCO2, but for specimens in Okinawa, there was no effect of OA. Using a study of large geographical scale, we show that resistance to OA of some reef species is a constitutive character expressed across the Pacific.
authors: Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA steve.comeau@csun.edu.
authors: S
authors: S
authors: Comeau
authors: Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA.
authors: R C
authors: RC
authors: Carpenter
authors: Center for Global Environment Research, National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
authors: Y
authors: Y
authors: Nojiri
authors: Hawaii Institute of Marine Biology, University of Hawaii, PO Box 1346, Kaneohe, HI 96744, USA.
authors: H M
authors: HM
authors: Putnam
authors: Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Sesoko, Motobu, Okinawa 905-0227, Japan.
authors: K
authors: K
authors: Sakai
authors: Department of Biology, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8303, USA.
authors: P J
authors: PJ
authors: Edmunds
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000737:chemistry* / Q000378:metabolism; D002245:Carbon Dioxide / Q000737:chemistry; D057894:Coral Reefs; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010140:Pacific Ocean; D000461:Rhodophyta / Q000502:physiology*; D012623:Seawater / Q000737:chemistry*
chemical_list: D002245:Carbon Dioxide; D002119:Calcium Carbonate
keywords: Pacific Ocean; calcification; calcifying alga; coral; ocean acidification; regional scale