Ocean acidification and the development of calcifying organisms
What is ocean acidification?
Increased CO2 results in a lowering of pH in the ocean, making it more acidic.
Since cold water absorbs CO2 more easily than warm water, polar regions are more at risk.
How does it impact calcifying organisms?
It decreases the saturation state of CaCO3 (calcium carbonate), meaning that animals which produce calcium carbonate shells or skeletons (such as molluscs, echinoderms, and corals) will be severely impacted. Their skeletons and shells may become stunted, deformed, and more porous (see below).
Echinoderm larvae from tropical, temperate and polar sea urchins under different pH levels (note: the lower the pH, the more acidic). This figure shows that increasing acidity significantly inhibits their development (Byrne et al., 2013). Scale bars = 200 µm.
Whats going to happen?
- Species extinctions
- A decrease in biodiversity, species richness, and biomass of coral reefs
- Food webs will be simplified
- Habitat complexity will be reduced
- A shift from coral reefs to seagrass/algae based ecosystems in some areas