Zooplanktivory ameliorates the effects of ocean acidification on the reef coral Porites spp

• Published in: Limnology and Oceanography
• Main Author: Edmunds, Peter J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2011
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.4319/lo.2011.56.6.2402; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.2011.56.6.2402; https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2011.56.6.2402

I tested the hypothesis that the effects of high pCO 2 and temperature on massive Porites spp. (Scleractinia) are modified by heterotrophic feeding (zooplanktivory). Small colonies of massive Porites spp. from the back reef of Moorea, French Polynesia, were incubated for 1 month under combinations of temperature (29.3°C vs. 25.6°C), pCO 2 (41.6 vs. 81.5 Pa), and feeding regimes (none vs. ad libitum access to live Artemia spp.), with the response assessed using calcification and biomass. Area‐normalized calcification was unaffected by pCO 2 , temperature, and the interaction between the two, although it increased 40% with feeding. Biomass increased 35% with feeding and tended to be higher at 25.6°C compared to 29.3°C, and as a result, biomass‐normalized calcification statistically was unaffected by feeding, but was depressed 12–17% by high pCO 2 , with the effect accentuated at 25.6°C. These results show that massive Porites spp. has the capacity to resist the effects on calcification of 1 month exposure to 81.5 Pa pCO 2 through heterotrophy and changes in biomass. Area‐normalized calcification is sustained at high pCO 2 by a greater biomass with a reduced biomass‐normalized rate of calcification. This mechanism may play a role in determining the extent to which corals can resist the long‐term effects of ocean acidification.