Global alteration of ocean ecosystem functioning due to increasing human CO2 emissions

Area of Science:

• Marine Biology
• Oceanography
• Climate Change Science

Background:

• Rising anthropogenic carbon dioxide (CO2) emissions are altering ocean chemistry and temperature.
• A comprehensive understanding of the biological impacts of these changes across diverse ecosystems is needed.

Purpose of the Study:

• To quantify the direction and magnitude of ecological change due to ocean acidification and warming.
• To develop a conceptual framework of biological change based on a meta-analysis of experimental data.

Main Methods:

• Conducted a meta-analysis of 632 published experiments examining ocean acidification and warming effects.
• Included data from multiple ecosystems and latitudes to ensure broad applicability.
• Analyzed responses across different trophic levels and species types.

Main Results:

• Primary production responses varied: temperate noncalcifying plankton increased, while tropical plankton decreased.
• Secondary production declined due to acidification, impacting both calcifying and noncalcifying species.
• Species diversity and abundances decreased, favoring novel communities dominated by noncalcifiers and microorganisms.
• Calcification in reef-building species was reduced by both warming and acidification.
• Dimethylsulfide production by plankton declined, affecting climate regulation.
• Little evidence of acclimation to acidification or warming was found, except in microbes.

Conclusions:

• Ocean acidification and warming pose significant threats to marine biodiversity and ecosystem function.
• Observed changes indicate potential mismatches in trophic linkages and reduced ecosystem resilience.
• Future marine ecosystems may feature reduced diversity and altered community structures.