3. Contents
Introduction
What is ocean acidification?
Carbon cycle
Chemistry in ocean acidification
How are humans causing ocean acidification?
Impacts
Preventive measures
4. Introduction
oOceans cover more than 70% of the earth’s
surface.
o30–40% of the carbon dioxide from human
activity released into the atmosphere
dissolves into oceans, rivers and lakes.
oHuman activities have increased the amount
of carbon dioxide emitted to the atmosphere
and the amount that dissolve into the ocean.
5. Cont….
oMassive amount of carbon dioxide into the
sea
-altering water chemistry
-causing ocean to become more acidic.
oSince the beginning of industrial era, an
increase of almost 30% in H+ ion
concentration in the world's ocean.
6. What is Ocean Acidification?
“Ocean Acidification is a term used to
describe the changes in the chemistry of the
earth’s ocean ie ongoing decrease in the pH
and increase in acidity ,caused by the uptake
of anthropogenic carbon dioxide from the
atmosphere”
7. Carbon Cycle
The fluxes of carbon dioxide (Co2) between
the oceans, terrestrial biosphere,
lithosphere and the atmosphere.
It maintain a natural balance of carbon in
the atmosphere , land and ocean.
The ocean absorb carbon in two ways-
physical and biological.
8.
9.
10. How humans are causing ocean
acidification?
By burning of fossil fuels:
Causing increased level of carbon dioxide
in the atmosphere.
By deforestation:
It also emits a lot of carbon dioxide in the
atmosphere.
11. Impacts of ocean acidification
Impacts on calcification:
• Production of shells and plates out of calcium
carbonate (CaCO3).
• Increased acidity in oceans, causes dissolution of
calcified structures such as cocoliths.
Impacts on calcifying organisms:
• Increased acidity increases, the rate of dissolution
of calcareous material of calcifying organisms.
12.
13. Impacts on coral reef:
Coral reefs habitat destruction.
Destruction of habitat of million of species.
Coral reefs bleaching out.
Coral Bleaching:
• Coral bleaching occurs when coral polyps
expel algae that live inside their tissues.
14.
15.
16. How does ocean acidification cause
coral bleaching?
Make worse the bleaching effects of thermal stress.
Effects the coral’s ability to create calcareous
skeletons, essential to their survival.
Due to ocean acidification;
-the resilience of reefs goes down, making easier
for them to erode and dissolve.
-change coral-dominated ecosystems to algal-
dominated ecosystems
17. Other biological impacts:
Decrease food resources.
Reduce metabolic rates.
Decreased reproduction in marine organisms.
Non biological impacts:
Decrease in the burial of carbonate
sediments.
Dissolution of existing carbonate sediments.
18. Cont…
Elevation of ocean alkalinity.
More CO2 leaves the atmosphere form the
ocean.
