Negative effects of ocean acidification on two crustose coralline species using genetically homogeneous samples.
We evaluated acidification effects on two crustose coralline algal species common to Pacific coral reefs, Lithophyllum kotschyanum and Hydrolithon samoense. We used genetically homogeneous samples of both species to eliminate misidentification of species. The growth rates and percent calcification of the walls of the epithallial cells (thallus surface cells) of both species decreased with increasing pCO₂. However, elevated pCO₂ more strongly inhibited the growth of L. kotschyanum versus H. samoense. The trend of decreasing percent calcification of the cell wall did not differ between these species, although intercellular calcification of the epithallial cells in L. kotschyanum was apparently reduced at elevated pCO₂, a result that might indicate that there are differences in the solubility or density of the calcite skeletons of these two species. These results can provide knowledge fundamental to future studies of the physiological and genetic mechanisms that underlie the response of crustose coralline algae to environmental stresses.
Takehara Marine Science Station, Setouchi Field Science Center, Hiroshima University, Minato-machi, Takehara, Hiroshima 725-0024, Japan. Electronic address: katoa@hiroshima-u.ac.jp.
Aki
A
Kato
Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
Mana
M
Hikami
Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan.
Naoki H
NH
Kumagai
Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8567, Japan.
Atsushi
A
Suzuki
Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan.
Yukihiro
Y
Nojiri
Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Motobu, Okinawa 905-0227, Japan.
Kazuhiko
K
Sakai
D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects / Q000502:physiology; D002245:Carbon Dioxide / Q000494:pharmacology*; D057894:Coral Reefs; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D010140:Pacific Ocean; D000461:Rhodophyta / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D012623:Seawater / Q000737:chemistry*
D002245:Carbon Dioxide
Acidification; Algae; Calcification; Crustose coralline algae; Epithallial cell; Growth; Hydrolithon samoense; Lithophyllum kotschyanum; Ryukyu Islands