Coral larvae under ocean acidification: survival, metabolism, and metamorphosis.
Ocean acidification may negatively impact the early life stages of some marine invertebrates including corals. Although reduced growth of juvenile corals in acidified seawater has been reported, coral larvae have been reported to demonstrate some level of tolerance to reduced pH. We hypothesize that the observed tolerance of coral larvae to low pH may be partly explained by reduced metabolic rates in acidified seawater because both calcifying and non-calcifying marine invertebrates could show metabolic depression under reduced pH in order to enhance their survival. In this study, after 3-d and 7-d exposure to three different pH levels (8.0, 7.6, and 7.3), we found that the oxygen consumption of Acropora digitifera larvae tended to be suppressed with reduced pH, although a statistically significant difference was not observed between pH conditions. Larval metamorphosis was also observed, confirming that successful recruitment is impaired when metamorphosis is disrupted, despite larval survival. Results also showed that the metamorphosis rate significantly decreased under acidified seawater conditions after both short (2 h) and long (7 d) term exposure. These results imply that acidified seawater impacts larval physiology, suggesting that suppressed metabolism and metamorphosis may alter the dispersal potential of larvae and subsequently reduce the resilience of coral communities in the near future as the ocean pH decreases.
Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan. m_coral29@yahoo.co.jp
Masako
M
Nakamura
Shun
S
Ohki
Atsushi
A
Suzuki
Kazuhiko
K
Sakai
D000818:Animals; D037421:Anthozoa / Q000254:growth & development* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008660:Metabolism; D008675:Metamorphosis, Biological; D009792:Oceans and Seas
J Exp Biol. 2006 Nov;209(Pt 22):4574-9
17079727
J Membr Biol. 1986;90(1):1-12
3009822
Int J Dev Biol. 2002;46(4):679-86
12141457
Science. 2007 Mar 30;315(5820):1811
17395821
Science. 2007 Dec 14;318(5857):1737-42
18079392
J Exp Biol. 1996;199(Pt 8):1801-7
9319709
BMC Genomics. 2008 Nov 14;9:540
19014561
Biol Bull. 2000 Jun;198(3):346-56
10897448
Biol Rev Camb Philos Soc. 1999 Feb;74(1):1-40
10396183
Zygote. 2010 May;18(2):103-7
20370935
Dev Genes Evol. 1998 Jul;208(5):267-73
9683742
Proc Natl Acad Sci U S A. 2008 Nov 11;105(45):17442-6
18988740
Biol Bull. 1996 Dec;191(3):402-412
29215931
Science. 2004 Jul 16;305(5682):362-6
15256664
Aquat Toxicol. 2004 Oct 18;70(1):55-61
15451607
Gene. 2000 May 30;250(1-2):127-35
10854786
Nature. 2003 Sep 25;425(6956):365
14508477
Proc Natl Acad Sci U S A. 2007 Nov 20;104(47):18866-70
17962418