Approximately 30-50% of global anthropogenic CO₂ emissions are absorbed by the world's oceans. Increased CO₂ uptake by the oceans is expected to reduce surface ocean pH by 0.3 – 0.5 units over the next century, which would be the largest change in pH to occur in the last 20-200 million years. Ocean acidification likely will impact the ability of marine calcifiers, such as corals and mollusks, to make shells and skeletons from calcium carbonate. Ocean acidification may indirectly affect fish and marine mammal species through reduced abundance of marine calcifiers at the base of the food web. In addition, ocean acidification may elicit broad physiological and ecological responses from non-calcifying organisms through less obvious pathways ranging from internal CO₂ concentrations of marine animals to coldwater corals that provide shelter for structure-oriented species such as rockfish.

The North Pacific Ocean is a sentinel region for signs of ocean acidification. Corrosive waters reach shallower depths more so there than in any other ocean basin, especially in Alaska, and so impacts of ocean acidification on marine calcifiers will likely occur earlier there than in many other places. Waters below the CaCO₃ saturation horizon are corrosive to calcifying organisms. The CaCO₃ saturation horizon is relatively shallow in the North Pacific Ocean. For example, the aragonite saturation horizon is about 200 m in the North Pacific Ocean compared to about 2,000 m in the North Atlantic Ocean.

AFSC scientists have begun research on ocean acidification effects on king crab, pollock, cod and herring and have described their research plan in an AFSC Ocean Acidification Research Plan.

Related Reports and Activities

• Cooperative Workshop on Ocean Acidification and Marine Protected Areas
  
  
• AFSC Ocean Acidification Research Plan Published
  
  
• Blue King Crab Ocean Acidification Research
  
  

• AFSC Ocean Acidification Research Plan
   
• Preliminray Ocean Acidification Research Plan