Environment / Ocean

Species evolve alongside each other in intricate relationships, so when one group is disrupted, another may flourish. Should ocean acidification proceed unfettered, we will be left with winners, losers, and a pile of rubble and slime.

The Losers

• Coral: the species. Unable to cope with the decrease in available calcium carbonate, these creatures will start to die.
• Coral reefs: the ecosystems. The demise of coral spells trouble for a million other species that feed near, live in, or derive protection from the reef environment: microalgae, also known as diatoms, sea urchins and other echinoderms, grazing fish, and foraminifera.
• Shelled sea creatures. Anything with a calcium carbonate shell, from microscopic plankton to clams and oysters to pteropods.

The Winners

• Cyanobacteria. These nitrogen-fixing, photosynthetic bacteria, also known as blue-green algae, are found in numerous habitats—in soil and lakes as well as the oceans. Unlike calcifying ocean species, they will very likely benefit from an increase in marine C02, which provides them with more raw material for manufacturing chemical energy.
• Dinoflagellates. Like cyanobacteria, these generally single-celled organisms draw energy through photosynthesis, with many living as symbionts inside coral. Temperature-stressed corals will discharge their dinoflagellate partners, resulting in coral “bleaching,” but the organisms can also live independently and may do so more easily in an ocean where CO2 is becoming more readily available.
• Seaweed. Otherwise known as macroalgae, seaweed competes with coral for light and space. Since most seaweed grows much more rapidly than coral, once the balance is tipped, any chance of coral recovery is all but completely choked off.

Carl Brenner