Impacts of Ocean Acidification on Marine Life

Young bivalves such as oysters, coral reefs, and other organisms that rely on calcite or aragonite to grow their shells and structures are fighting a battle with ocean acidification. We provide links to several recent articles on the issue, which would serve as an excellent topic for a classroom discussion or writing exercise.

Background Article: Larvae, Climate and Calcification

The absorption of atmospheric CO2 by the oceans results in a decline in ocean pH, hence ‘ocean acidification’, and reduces carbonate ion availability. This presents a problem to calcifying organisms (those that deposit calcium as either calcite or aragonite as hard parts) because they cannot produce their shells, valves (in the case of bivalves), or tests (in the case of diatoms) as readily.

Article: Natural Underwater Springs Show How Coral Reefs Respond to Ocean Acidification

Ocean acidification due to rising carbon dioxide levels reduces the density of coral skeletons, making coral reefs more vulnerable to disruption and erosion. The results are from a study of corals growing where underwater springs naturally lower the pH of seawater. (The lower the pH, the more acidic.)

Article: Acidifying seawater sees oysters in race to grow shells

Bad news for oyster lovers. As the ocean acidifies, oyster larvae are struggling to build their shells, reducing the number that reach adulthood.

Article: How do oysters spell climate change relief? A-N-T-A-C-I-D

Oyster hatcheries are dropping the equivalent of Tums and other antacids into water to make it easier for naked mollusk larvae to build their shells. The remedy is working, for now, to keep hatcheries in business and oyster bars well stocked with the slimy delicacies, a hatchery scientist said.