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Ocean Acidification

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Climate change and ocean acidification effects on seagrasses and marine macroalgae

Ocean Acidification

Ocean Acidification. Image Credit: NOAA

Climate change causes two carbon dioxide-related problems--heating Earth’s oceans and acidifying them, causing problems for marine and land plants alike. Ocean acidification occurs because atmospheric carbon dioxide (CO2) concentrations are rising rapidly and the oceans act as a big sponge, capturing about 30% of the CO2 from man-made sources every year.  When CO2 dissolves in the ocean, it releases H+, which lowers the pH of the water, causing ocean acidification. Oceans also store a large component of the earth’s heat from greenhouse gases. 

Marine plants fix inorganic carbon into organic food resources for fish and other marine animals, forming the natural agricultural sector for the oceans.  The plants create entire ecosystems, such as sea grasses forming meadows and macroalgae making up kelp forests. Fishermen look to the Sargasso seaweed “weedline” off the coast as a good place to fish--the algae create structure for an entire fishery. Sea turtles and other marine animals live in the seaweed, too.  These foundation marine plant communities are appropriately called “Ecosystem Engineers.”

FAU Professor Dr. Marguerite Koch published a comprehensive review on climate change and ocean acidification effects on marine plants in a highly ranked international Journal entitled “Global Change Biology.” She attended a conference on Ocean Acidification “Third International Symposium on the Ocean in a High CO2 World in Monterey, California (September 23-27th) where she presented research being conducted at FAU’s Gumbo Limbo Marine Laboratory. 

In her review and research, Dr. Koch examines three important outcomes of climate change and ocean acidification on marine plants and their ecosystems. 

  1. Elevated dissolved inorganic carbon may increase ocean productivity.  Fleshy algae and sea grasses may thrive, creating overly large blooms, thus becoming nuisance species. 
  2. Tropical marine plants, with calcified bodies that create the sediment on reefs and sites for corals to settle, may be negatively affected by ocean acidification. Their chalklike bodies can dissolve in acid or have trouble forming the calcium carbonate crystals needed for growth. 
  3. Finally, because Dr. Koch’s lab is focused on tropical species, she examines their thermal thresholds. 

For more information on Dr. Koch’s research and information on ocean acidification see the links below. 

Related Publication:

Koch, M., Bowes, G., Ross, C., & Zhang, X. H. 2012. Climate change and ocean acidification effects on seagrasses and marine macroalgae. Global Change Biology.

 


 Last Modified 11/8/16