Effect of elevated CO2 on the community metabolism of an experimental coral beef

Chris Langdon, Wallace S. Broecker, Douglas E. Hammond, Edward Glenn, Kevin Fitzsimmons, Steven G. Nelson, Tsung Hung Peng, Irka Hajdas, Georges Bonani

Research output: Contribution to journalArticle

164 Citations (Scopus)

Abstract

The effect of elevated pCO2 on the metabolism of a coral reef community dominated by macroalgae has been investigated utilizing the large 2650 m3 coral reef mesocosm at the Biosphere-2 facility near Tucson, Arizona. The carbonate chemistry of the water was manipulated to simulate present-day and a doubled CO2 future condition. Each experiment consisted of a 1-2 month preconditioning period followed by a 7-9 day observational period. The pCO2 was 404 ± 63 μatm during the present-day pCO2 experiment and 658 ± 59 μatm during the elevated pCO2 experiment. Nutrient levels were low and typical of natural reefs waters (NO-3 0.5-0.9 μM, NH+4 0.4 μM, PO34- 0.07-0.09 μM). The temperature and salinity of the water were held constant at 26.5 ± 0.2°C and 34.4 ± 0.2 ppt. Photosynthetically available irradiance was 10 ± 2 during the present-day experiment and 7.4 ± 0.5 mol photons m-2 d-1 during the elevated pCO2 experiment. The primary producer biomass in the mesocosm was dominated by four species of macroalgae; Haptilon cubense, Amphiroa fragillisima, Gelidiopsis intricata and Chondria dasyphylla. Algal biomass was 10.4 mol C m-2 during the present-day and 8.7 mol C m-2 and during the elevated pCO2 experiments. As previously observed, the increase in pCO2 resulted in a decrease in calcification from 0.041 ± 0.007 to 0.006 ± 0.003 mol CaCO3 m-2 d-1. Net community production (NCP) and dark respiration did not change in response to elevated pCO2. Light respiration measured by a new radiocarbon isotope dilution method exceeded dark respiration by a factor of 1.2 ± 0.3 to 2.1 ± 0.4 on a daily basis and by 2.2 ± 0.6 to 3.9 ± 0.8 on an hourly basis. The 1.8-fold increase with increasing pCO2 indicates that the enhanced respiration in the light was not due to photorespiration. Gross production (GPP) computed as the sum of NCP plus daily respiration (light + dark) increased significantly (0.24 ± 0.03 vs. 0.32 ± 0.04 mol C m-2 d-1). However, the conventional calculation of GPP based on the assumption that respiration in the light proceeds at the same rate as the dark underestimated the true rate of GPP by 41-100% and completely missed the increased rate of carbon cycling due to elevated pCO2. We conclude that under natural, undisturbed, nutrient-limited conditions elevated CO2 depresses calcification, stimulates the rate of turnover of organic carbon, particularly in the light, but has no effect on net organic production. The hypothesis that an increase pCO2 would produce an increase in net production that would counterbalance the effect of decreasing saturation state on calcification is not supported by these data.

Original languageEnglish
Pages (from-to)11-1
JournalGlobal Biogeochemical Cycles
Volume17
Issue number1
StatePublished - Mar 1 2003
Externally publishedYes

Fingerprint

Beef
Metabolism
coral
respiration
metabolism
Reefs
calcification
experiment
Experiments
mesocosm
Nutrients
coral reef
Water
Biomass
Biosphere 2
nutrient
Carbonates
biomass
Organic carbon
Isotopes

Keywords

  • Calcification
  • Community metabolism
  • Coral reefs
  • Elevated CO
  • Gross production
  • Light respiration
  • Photosynthesis

ASJC Scopus subject areas

  • Global and Planetary Change
  • Atmospheric Science
  • Environmental Science(all)
  • Environmental Chemistry

Cite this

Langdon, C., Broecker, W. S., Hammond, D. E., Glenn, E., Fitzsimmons, K., Nelson, S. G., ... Bonani, G. (2003). Effect of elevated CO2 on the community metabolism of an experimental coral beef. Global Biogeochemical Cycles, 17(1), 11-1.

Effect of elevated CO2 on the community metabolism of an experimental coral beef. / Langdon, Chris; Broecker, Wallace S.; Hammond, Douglas E.; Glenn, Edward; Fitzsimmons, Kevin; Nelson, Steven G.; Peng, Tsung Hung; Hajdas, Irka; Bonani, Georges.

In: Global Biogeochemical Cycles, Vol. 17, No. 1, 01.03.2003, p. 11-1.

Research output: Contribution to journalArticle

Langdon, C, Broecker, WS, Hammond, DE, Glenn, E, Fitzsimmons, K, Nelson, SG, Peng, TH, Hajdas, I & Bonani, G 2003, 'Effect of elevated CO2 on the community metabolism of an experimental coral beef', Global Biogeochemical Cycles, vol. 17, no. 1, pp. 11-1.
Langdon C, Broecker WS, Hammond DE, Glenn E, Fitzsimmons K, Nelson SG et al. Effect of elevated CO2 on the community metabolism of an experimental coral beef. Global Biogeochemical Cycles. 2003 Mar 1;17(1):11-1.
Langdon, Chris ; Broecker, Wallace S. ; Hammond, Douglas E. ; Glenn, Edward ; Fitzsimmons, Kevin ; Nelson, Steven G. ; Peng, Tsung Hung ; Hajdas, Irka ; Bonani, Georges. / Effect of elevated CO2 on the community metabolism of an experimental coral beef. In: Global Biogeochemical Cycles. 2003 ; Vol. 17, No. 1. pp. 11-1.
@article{8978d5e35f9f4fe6b167c995114a4b87,
title = "Effect of elevated CO2 on the community metabolism of an experimental coral beef",
abstract = "The effect of elevated pCO2 on the metabolism of a coral reef community dominated by macroalgae has been investigated utilizing the large 2650 m3 coral reef mesocosm at the Biosphere-2 facility near Tucson, Arizona. The carbonate chemistry of the water was manipulated to simulate present-day and a doubled CO2 future condition. Each experiment consisted of a 1-2 month preconditioning period followed by a 7-9 day observational period. The pCO2 was 404 ± 63 μatm during the present-day pCO2 experiment and 658 ± 59 μatm during the elevated pCO2 experiment. Nutrient levels were low and typical of natural reefs waters (NO-3 0.5-0.9 μM, NH+4 0.4 μM, PO34- 0.07-0.09 μM). The temperature and salinity of the water were held constant at 26.5 ± 0.2°C and 34.4 ± 0.2 ppt. Photosynthetically available irradiance was 10 ± 2 during the present-day experiment and 7.4 ± 0.5 mol photons m-2 d-1 during the elevated pCO2 experiment. The primary producer biomass in the mesocosm was dominated by four species of macroalgae; Haptilon cubense, Amphiroa fragillisima, Gelidiopsis intricata and Chondria dasyphylla. Algal biomass was 10.4 mol C m-2 during the present-day and 8.7 mol C m-2 and during the elevated pCO2 experiments. As previously observed, the increase in pCO2 resulted in a decrease in calcification from 0.041 ± 0.007 to 0.006 ± 0.003 mol CaCO3 m-2 d-1. Net community production (NCP) and dark respiration did not change in response to elevated pCO2. Light respiration measured by a new radiocarbon isotope dilution method exceeded dark respiration by a factor of 1.2 ± 0.3 to 2.1 ± 0.4 on a daily basis and by 2.2 ± 0.6 to 3.9 ± 0.8 on an hourly basis. The 1.8-fold increase with increasing pCO2 indicates that the enhanced respiration in the light was not due to photorespiration. Gross production (GPP) computed as the sum of NCP plus daily respiration (light + dark) increased significantly (0.24 ± 0.03 vs. 0.32 ± 0.04 mol C m-2 d-1). However, the conventional calculation of GPP based on the assumption that respiration in the light proceeds at the same rate as the dark underestimated the true rate of GPP by 41-100{\%} and completely missed the increased rate of carbon cycling due to elevated pCO2. We conclude that under natural, undisturbed, nutrient-limited conditions elevated CO2 depresses calcification, stimulates the rate of turnover of organic carbon, particularly in the light, but has no effect on net organic production. The hypothesis that an increase pCO2 would produce an increase in net production that would counterbalance the effect of decreasing saturation state on calcification is not supported by these data.",
keywords = "Calcification, Community metabolism, Coral reefs, Elevated CO, Gross production, Light respiration, Photosynthesis",
author = "Chris Langdon and Broecker, {Wallace S.} and Hammond, {Douglas E.} and Edward Glenn and Kevin Fitzsimmons and Nelson, {Steven G.} and Peng, {Tsung Hung} and Irka Hajdas and Georges Bonani",
year = "2003",
month = "3",
day = "1",
language = "English",
volume = "17",
pages = "11--1",
journal = "Global Biogeochemical Cycles",
issn = "0886-6236",
publisher = "American Geophysical Union",
number = "1",

}

TY - JOUR

T1 - Effect of elevated CO2 on the community metabolism of an experimental coral beef

AU - Langdon, Chris

AU - Broecker, Wallace S.

AU - Hammond, Douglas E.

AU - Glenn, Edward

AU - Fitzsimmons, Kevin

AU - Nelson, Steven G.

AU - Peng, Tsung Hung

AU - Hajdas, Irka

AU - Bonani, Georges

PY - 2003/3/1

Y1 - 2003/3/1

N2 - The effect of elevated pCO2 on the metabolism of a coral reef community dominated by macroalgae has been investigated utilizing the large 2650 m3 coral reef mesocosm at the Biosphere-2 facility near Tucson, Arizona. The carbonate chemistry of the water was manipulated to simulate present-day and a doubled CO2 future condition. Each experiment consisted of a 1-2 month preconditioning period followed by a 7-9 day observational period. The pCO2 was 404 ± 63 μatm during the present-day pCO2 experiment and 658 ± 59 μatm during the elevated pCO2 experiment. Nutrient levels were low and typical of natural reefs waters (NO-3 0.5-0.9 μM, NH+4 0.4 μM, PO34- 0.07-0.09 μM). The temperature and salinity of the water were held constant at 26.5 ± 0.2°C and 34.4 ± 0.2 ppt. Photosynthetically available irradiance was 10 ± 2 during the present-day experiment and 7.4 ± 0.5 mol photons m-2 d-1 during the elevated pCO2 experiment. The primary producer biomass in the mesocosm was dominated by four species of macroalgae; Haptilon cubense, Amphiroa fragillisima, Gelidiopsis intricata and Chondria dasyphylla. Algal biomass was 10.4 mol C m-2 during the present-day and 8.7 mol C m-2 and during the elevated pCO2 experiments. As previously observed, the increase in pCO2 resulted in a decrease in calcification from 0.041 ± 0.007 to 0.006 ± 0.003 mol CaCO3 m-2 d-1. Net community production (NCP) and dark respiration did not change in response to elevated pCO2. Light respiration measured by a new radiocarbon isotope dilution method exceeded dark respiration by a factor of 1.2 ± 0.3 to 2.1 ± 0.4 on a daily basis and by 2.2 ± 0.6 to 3.9 ± 0.8 on an hourly basis. The 1.8-fold increase with increasing pCO2 indicates that the enhanced respiration in the light was not due to photorespiration. Gross production (GPP) computed as the sum of NCP plus daily respiration (light + dark) increased significantly (0.24 ± 0.03 vs. 0.32 ± 0.04 mol C m-2 d-1). However, the conventional calculation of GPP based on the assumption that respiration in the light proceeds at the same rate as the dark underestimated the true rate of GPP by 41-100% and completely missed the increased rate of carbon cycling due to elevated pCO2. We conclude that under natural, undisturbed, nutrient-limited conditions elevated CO2 depresses calcification, stimulates the rate of turnover of organic carbon, particularly in the light, but has no effect on net organic production. The hypothesis that an increase pCO2 would produce an increase in net production that would counterbalance the effect of decreasing saturation state on calcification is not supported by these data.

AB - The effect of elevated pCO2 on the metabolism of a coral reef community dominated by macroalgae has been investigated utilizing the large 2650 m3 coral reef mesocosm at the Biosphere-2 facility near Tucson, Arizona. The carbonate chemistry of the water was manipulated to simulate present-day and a doubled CO2 future condition. Each experiment consisted of a 1-2 month preconditioning period followed by a 7-9 day observational period. The pCO2 was 404 ± 63 μatm during the present-day pCO2 experiment and 658 ± 59 μatm during the elevated pCO2 experiment. Nutrient levels were low and typical of natural reefs waters (NO-3 0.5-0.9 μM, NH+4 0.4 μM, PO34- 0.07-0.09 μM). The temperature and salinity of the water were held constant at 26.5 ± 0.2°C and 34.4 ± 0.2 ppt. Photosynthetically available irradiance was 10 ± 2 during the present-day experiment and 7.4 ± 0.5 mol photons m-2 d-1 during the elevated pCO2 experiment. The primary producer biomass in the mesocosm was dominated by four species of macroalgae; Haptilon cubense, Amphiroa fragillisima, Gelidiopsis intricata and Chondria dasyphylla. Algal biomass was 10.4 mol C m-2 during the present-day and 8.7 mol C m-2 and during the elevated pCO2 experiments. As previously observed, the increase in pCO2 resulted in a decrease in calcification from 0.041 ± 0.007 to 0.006 ± 0.003 mol CaCO3 m-2 d-1. Net community production (NCP) and dark respiration did not change in response to elevated pCO2. Light respiration measured by a new radiocarbon isotope dilution method exceeded dark respiration by a factor of 1.2 ± 0.3 to 2.1 ± 0.4 on a daily basis and by 2.2 ± 0.6 to 3.9 ± 0.8 on an hourly basis. The 1.8-fold increase with increasing pCO2 indicates that the enhanced respiration in the light was not due to photorespiration. Gross production (GPP) computed as the sum of NCP plus daily respiration (light + dark) increased significantly (0.24 ± 0.03 vs. 0.32 ± 0.04 mol C m-2 d-1). However, the conventional calculation of GPP based on the assumption that respiration in the light proceeds at the same rate as the dark underestimated the true rate of GPP by 41-100% and completely missed the increased rate of carbon cycling due to elevated pCO2. We conclude that under natural, undisturbed, nutrient-limited conditions elevated CO2 depresses calcification, stimulates the rate of turnover of organic carbon, particularly in the light, but has no effect on net organic production. The hypothesis that an increase pCO2 would produce an increase in net production that would counterbalance the effect of decreasing saturation state on calcification is not supported by these data.

KW - Calcification

KW - Community metabolism

KW - Coral reefs

KW - Elevated CO

KW - Gross production

KW - Light respiration

KW - Photosynthesis

UR - http://www.scopus.com/inward/record.url?scp=0038372158&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038372158&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0038372158

VL - 17

SP - 11

EP - 11

JO - Global Biogeochemical Cycles

JF - Global Biogeochemical Cycles

SN - 0886-6236

IS - 1

ER -