Living Reference Work Entry

Marine Animal Forests

pp 1-25

Date: Latest Version

Contrasting Effects of Ocean Acidification on Coral Reef “Animal Forests” Versus Seaweed “Kelp Forests”

  • S. ComeauAffiliated withSchool of Earth and Environment, ARC Centre of Excellence in Coral Reef Studies, & Oceans Institute, University of Western Australia Email author 
  • , C. E. CornwallAffiliated withSchool of Earth and Environment, ARC Centre of Excellence in Coral Reef Studies, & Oceans Institute, University of Western Australia Email author 

Abstract

Ocean acidification is the sustained absorption of anthropogenically derived CO2 and is a major threat to marine ecosystems. Ocean acidification results in the decline of seawater pH (increase in protons) and carbonate ions and increased CO2. Added CO2 could benefit terrestrial forests, but changes in the concentration of any one of aspect of the carbonate system could affect various marine organisms both positively and negatively. One ecosystem under particular threat from ocean acidification is tropical coral reefs, formed predominately by scleractinian coral species that are predicted to be negatively impacted by ocean acidification. In contrast, temperate shallow rocky reefs are dominated by seaweed that forms extensive kelp/seaweed forests; these noncalcareous seaweeds are not predicted to be as negatively impacted by ocean acidification. Tropical coral reef “animal forests” and temperate “kelp forests” both provide three-dimensional habitat for tens of thousands of species, but are characterized by vastly different environmental regimes. The present chapter outlines differences in key environmental parameters (such as nutrients, water motion, and temperature) in these two habitats that could dictate the relative magnitudes of the effects of ocean acidification within them. The vulnerability of key habitat-forming organisms within these habitats and the potential mechanisms behind specific responses to ocean acidification are also discussed.

Keywords

Calcification Photosynthesis CO2 concentrating mechanisms Coralline algae Climate change Environmental variability Light Water motion Nutrients Warming