Journal article
CO2-driven compromises to marine life along the Chilean coast
Biogeosciences Discuss., Vol.7, pp.8895-8918
2010
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Abstract
<p>CO<sub>2</sub>-driven compromises to marine life were examined along the Chilean sector of the Humboldt Current System, a particularly vulnerable hypoxic and upwelling area, applying the Respiration index (RI = log<sub>10</sub> <em>p</em>O<sub>2</sub>pCO<sub>2</sub>) and the pH-dependent aragonite saturation (Ω) to delineate the water masses where aerobic and calcifying organisms are stressed. There was a remarkable negative relationship between oxygen concentration and pH or <em>p</em>CO<sub>2</sub> in the studied area, with the subsurface hypoxic Equatorial Subsurface Waters extending from 100 m to about 300 m depth and supporting elevated <em>p</em>CO<sub>2</sub> values. The RI reached a minimum at about 200 m depth and decreased towards the Equator. Increased <em>p</em>CO<sub>2</sub> in the hypoxic water layer reduced the RI values by as much as 0.59 RI units, with the upper water layer that presents conditions suitable for aerobic life (RI>0.7) declining by half between 42° S and 28° S. The intermediate waters hardly reached those stations closer to the equator so that the increased <em>p</em>CO<sub>2</sub> lowered pH and the saturation of aragonite. A significant fraction of the water column along the Chilean sector of the Humboldt Current System suffers from CO<sub>2</sub>–driven compromises to biota, including waters corrosive to calcifying organisms, stress to aerobic organisms or both. The habitat free of CO<sub>2</sub>-driven stresses was restricted to the upper mixed layer and to small water parcels at about 1000 m depth. <em>p</em>CO<sub>2</sub> acts as a hinge connecting respiratory and calcification challenges expected to increase in the future, resulting in a spread of the challenges to aerobic organisms.</p>
Details
- Title
- CO2-driven compromises to marine life along the Chilean coast
- Creators
- E Mayol - Pontificia Universidad Católica de ChileSergio Ruiz-Halpern - Instituto Mediterráneo de Estudios AvanzadosC M Duarte - Pontificia Universidad Católica de ChileJ C Castilla - Pontificia Universidad Católica de ChileJ L Pelegri - Pontificia Universidad Católica de Chile
- Publication Details
- Biogeosciences Discuss., Vol.7, pp.8895-8918
- Identifiers
- 3004; 991012822125202368
- Academic Unit
- Centre for Coastal Biogeochemistry; School of Environment, Science and Engineering; Faculty of Science and Engineering
- Resource Type
- Journal article