Ocean AcidificationEffects on Pacific Northwest Marine Life

Mark JohnsonPortland Oregon

United States

The Ocean Habitat

• Oceans cover almost 2/3 of the earth surface

• Their importance to human life is unquestioned

• Now something is causing rapid change in oceans

• Coral reefs are some of the earth’s most fertile places

• Home to about 1/4 of all species living in the seas

• Now something is threatening these productive ecosystems

The Victim

• Aquatic farming is the keystone of a $250M shellfish industry in the Pacific Northwest

• The cash crop oysters are Crassostrea gigas, commonly called the Pacific oyster

• These “giant oysters” measure from 3 to 15 inches long

• Aquatic farming starts by growing baby shellfish called larvae

• Significant changes started in 2007 with deformed shells and dying baby oysters

Pacific Oysters

The Culprit

• pH is the standard measurement for acidity – the lower the pH the higher the acidity

• The acidity of seawater in bays nearby aquatic farms has reach 6x higher than normal

• Baby oyster larvae cannot handle these extremely acidic conditions

• Adding soda ash to aquatic farm water is a costly and non-optimal temporary fix

Seawater pH

The Chemistry CO 2 H2 O

• Carbon Dioxide (CO2) emissions are why ocean acidity is increasing

• One quarter of the worlds CO2 emissions are absorbed into the oceans

• Estimated 30 metric tons of CO2 is dissolved into ocean surface water every day

• This occurrence is dramatically changing the chemistry of ocean water

CO2 reacts with H2O to form Carbonic Acid (H2CO3)

H2CO3 immediately breaks apart releasing Hydrogen Ions

Hydrogen Ions are what increase ocean water acidity

The Effect• Baby oysters use Calcium (Ca) and Carbonate to build their shells

• Too much CO2 in the seawater radically alters the supply of Carbonate

• Hydrogen Ions further reduce an already limited supply of Carbonate

• Without enough Carbonate baby oysters cannot build their shells

• As a result, they die…

The Solution Decrease CO2 Emissions!

Act NowOtherwise options disappear and costs increase as the world commits itself to high-carbon pathways and largely irreversible warming trajectories.

Act TogetherCommon cause and action are key to keeping the costs down and effectively tackling both adaptation and mitigation of the effects of climate change.

Act DifferentlyInnovative economic, technological and social strategies are required to enable a sustainable future in a world affected by climate change.