Select the search type
  • Site
  • Web
Search

The natural world. Looking pretty for 3.5b years.

High School chemistry & biology

Author: Hugh Bollinger/Monday, February 23, 2015/Categories: natural history, marine life, sustainability, environment, climate change, Archive Pick of the Week

Some aspects of climate change science and the consequences of increasing atmospheric carbon dioxide are easy to understand with high school textbooks and two examples show how.

Chemistry 101: The reaction of carbon dioxide gas (CO2), when dissolved in water (H2O), produces  carbonic acid  (H2CO3). The formula for the process is:

                                                          CO2 + H2O → H2CO3


The European Space Agency used the  SMOS  Earth Explorer satellite capabilities to gather "big data" measurements of ocean salinity to determine ocean pH levels from space. Until now, this basic chemistry information was available only from samples taken by ships or made by lab experiments. One of the leaders of the ESA efforts noted:


"by capitalizing on salinity measurements from SMOS, we can generate novel, value-added, data products to produce a global surface ocean pH atlas."

       
                      Global Map of Ocean pH   (credit: European Space Agency, SMOS satellite)

The researchers published their findings in  Environmental Science & Technology  and the new maps will be available to other ocean and marine biology researchers anywhere. Their abstract notes:

"Approximately a quarter of the carbon dioxide (CO2) emitted into the atmosphere is absorbed by the oceans. This oceanic CO2 uptake leads to a change in marine carbonate chemistry resulting in a decrease of seawater pH and carbonate ion concentration, a process commonly called: Ocean Acidification”.

Biology 101: The textbook formula of the effect of carbonic acid on calcium carbonate (CaCO3) is:

                                                           CaCO3 + H2CO3   Ca + 2HCO3

There is a fundamental biological issue relating to this formula: a significant portion of all ocean life relies on calcium carbonate for their hard "exoskeletons". Marine micro-organisms like the photosynthetic diatoms  and algae produce more than 70% of the Earth's oxygen; the symbiotic associations of bacterias and animals
( polyps ) that create the world's coral reefs, and mollusks including clams, mussels, and oysters as well as lobsters and crabs all require the calcium compound to build the hard structures they inhabit.

Carbonic acid dissolves calcium carbonate. This basic fact of chemistry interacting on biology is made clear by a new report in:  Nature Magazine 

                 
                                    Deformed Oyster Shells in Oregon Hatchery  (credit: NSF)

The process of connecting the atmosphere with ocean chemistry is cleverly explained by this short animation:



The Nature report highlights impacts on marine shellfish industries of declining harvests due to deformed and weak shells due to ocean acidification and these impacts are happening already. Commercial oysters and clams produced by aquaculture combined with crab and lobster harvests represent an industry of over a $1 billion supplying harvests to restaurants and markets.One of the authors noted:

“Ocean acidification has already cost the oyster industry in the Pacific Northwest nearly $110 million and jeopardized about 3,200 jobs.”

Losses to lovers of shellfish aside, the researchers didn't include any valuations for the environmental services shellfish beds provide in purifying water or reducing the destructive energy of coastal storm surges.

    
                              US Coastal Zones most Affected by Ocean Acidification  (credit: NRDC)

So, the next time you order a nice bucket of steamers, a platter of shucked oysters, or a steamed lobster tail and the restaurant bill has gone thru the roof, remember your high school chemistry and biology lessons.

WHB
Print

Number of views (5462)/Comments (0)

Please login or register to post comments.

Name:
Email:
Subject:
Message:
x