Biochemical responses to ocean acidification contrast between tropical corals with high and low abundances at volcanic carbon dioxide seeps

At two natural volcanic seeps in Papua New Guinea, the partial pressure of carbon dioxide (pCO sub(2)) in the seawater is consistent with projections for 2100. Here, the cover of massive scleractinian corals Porites spp. is twice as high at elevated compared with ambient pCO sub(2), while that of br...

Full description

Saved in:
Bibliographic Details
Published in:ICES journal of marine science 2016-03, Vol.73 (3), p.897-909
Main Authors: Strahl, J, Francis, D S, Doyle, J, Humphrey, C, Fabricius, K E
Format: Article
Language:English
Subjects:
Acropora millepora
Biochemistry
Biomass
Carbon dioxide
Corals
Lipids
Marine
Millepora
Pigments
Porites
Proteins
Reefs
Scleractinia
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:At two natural volcanic seeps in Papua New Guinea, the partial pressure of carbon dioxide (pCO sub(2)) in the seawater is consistent with projections for 2100. Here, the cover of massive scleractinian corals Porites spp. is twice as high at elevated compared with ambient pCO sub(2), while that of branching corals such as Acropora millepora is greater than twofold reduced. To assess the underlying mechanisms for such community shifts under long-term exposure to elevated pCO sub(2), biochemical parameters related to tissue biomass, energy storage, pigmentation, cell protection, and cell damage were compared between Porites spp. and A. millepora from control (mean pH sub(total) = 8.1, pCO sub(2) = 323 mu atm) and CO sub(2) seep sites (mean pH sub(total) = 7.8, pCO sub(2) = 803 mu atm) each at two reefs. In Porites spp., only one of the biochemical parameters investigated (the ratio of photoprotective to light-harvesting pigments) responded to pCO sub(2), while tissue biomass, total lipids, total proteins, and some pigments differed between the two reefs, possibly reflecting differences in food availability. Furthermore, some fatty acids showed pCO sub(2) -reef interactions. In A. millepora, most pigments investigated were reduced at elevated pCO sub(2), while other parameters (e.g. tissue biomass, total proteins, total lipids, protein carbonyls, some fatty acids and pigments) differed between reefs or showed pCO sub(2)-reef interactions. Tissue biomass, total lipids, and cell-protective capacities were distinctly higher in Porites spp. than in A. millepora, indicating higher resistance to environmental stress in massive Porites. However, our data suggest that important biochemical measures remain relatively unaffected in these two coral species in response to elevated pCO sub(2) up to 800 mu atm, with most responses being smaller than differences between species and locations, and also when compared with responses to other environmental stressors such as ocean warming.
ISSN:1054-3139
1095-9289
DOI:10.1093/icesjms/fsv194