TY - JOUR
T1 - Effects of exposure duration on the response of Pocillopora damicornis larvae to elevated temperature and high pCO2
AU - Cumbo, V. R.
AU - Fan, T. Y.
AU - Edmunds, P. J.
PY - 2013/1
Y1 - 2013/1
N2 - Efforts to evaluate the response of coral larvae to global climate change (GCC) and ocean acidification (OA) typically employ short experiments of fixed length, yet it is unknown how the response is affected by exposure duration. In this study, we exposed larvae from the brooding coral Pocillopora damicornis to contrasts of temperature (24.00°C [ambient] versus 30.49°C) and pCO2 (49.4Pa versus 86.2Pa) for varying periods (1-5days) to test the hypothesis that exposure duration had no effect on larval response as assessed by protein content, respiration, Symbiodinium density, and survivorship; exposure times were ecologically relevant compared to representative pelagic larval durations (PLD) for corals. Larvae differed among days for all response variables, and the effects of the treatment were relatively consistent regardless of exposure duration for three of the four response variables. Protein content and Symbiodinium density were unaffected by temperature and pCO2, but respiration increased with temperature (but not pCO2) with the effect intensifying as incubations lengthened. Survival, however, differed significantly among treatments at the end of the study, and by the 5th day, 78% of the larvae were alive and swimming under ambient temperature and ambient pCO2, but only 55-59% were alive in the other treatments. These results demonstrate that the physiological effects of temperature and pCO2 on coral larvae can reliably be detected within days, but effects on survival require ≥5days to detect. The detection of time-dependent effects on larval survivorship suggests that the influence of GCC and OA will be stronger for corals having long PLDs.
AB - Efforts to evaluate the response of coral larvae to global climate change (GCC) and ocean acidification (OA) typically employ short experiments of fixed length, yet it is unknown how the response is affected by exposure duration. In this study, we exposed larvae from the brooding coral Pocillopora damicornis to contrasts of temperature (24.00°C [ambient] versus 30.49°C) and pCO2 (49.4Pa versus 86.2Pa) for varying periods (1-5days) to test the hypothesis that exposure duration had no effect on larval response as assessed by protein content, respiration, Symbiodinium density, and survivorship; exposure times were ecologically relevant compared to representative pelagic larval durations (PLD) for corals. Larvae differed among days for all response variables, and the effects of the treatment were relatively consistent regardless of exposure duration for three of the four response variables. Protein content and Symbiodinium density were unaffected by temperature and pCO2, but respiration increased with temperature (but not pCO2) with the effect intensifying as incubations lengthened. Survival, however, differed significantly among treatments at the end of the study, and by the 5th day, 78% of the larvae were alive and swimming under ambient temperature and ambient pCO2, but only 55-59% were alive in the other treatments. These results demonstrate that the physiological effects of temperature and pCO2 on coral larvae can reliably be detected within days, but effects on survival require ≥5days to detect. The detection of time-dependent effects on larval survivorship suggests that the influence of GCC and OA will be stronger for corals having long PLDs.
UR - http://www.scopus.com/inward/record.url?scp=84868688894&partnerID=8YFLogxK
U2 - 10.1016/j.jembe.2012.10.019
DO - 10.1016/j.jembe.2012.10.019
M3 - Article
AN - SCOPUS:84868688894
SN - 0022-0981
VL - 439
SP - 100
EP - 107
JO - Journal of Experimental Marine Biology and Ecology
JF - Journal of Experimental Marine Biology and Ecology
ER -