4. Introduction
Ocean acidification: Ongoing decrease in the pH of
the Earth's oceans, caused by the uptake of carbon
dioxide from the atmosphere.
Oceans play a critical role in the global carbon cycle
by absorbing about a quarter of the CO2 emitted to
the atmosphere from human activities.
It Affects marine plants and animals especially those
that require calcium carbonate to grow and survive,
and other species that rely on these for food.
5. Cumulative Carbon Sources And Sinks
Over The Last Two Centuries
Sources Sinks
Land Use
(31%)
Fossil
Emission
(69%)
Atmospheric
Accumulation
(46%)
Terrestrial Sink
(29%)
Ocean Sink
(25%)
7. CO2 And Ocean Chemistry
Ocean absorbed 1⁄4 of CO2 from the atmosphere.
This CO2 would otherwise have accumulated in the
atmosphere leading to greater climate change.
The average pH of oceanic surface waters has been
lowered by 0.1 units since the pre-industrial period.
This represents a 30% increase in hydrogen ion
activity
10. Biological Processes Affected By
Ocean Acidification
Increasing acidity, combined with other
environmental stressors like increasing ocean
temperature and pollution, has the potential to affect
many biological processes.
Building shells
Maintaining metabolism
Boosting photosynthesis
Obtaining essential minerals & nutrients
11. Building Shells
Many animals and some
algae use carbonate ions
to make calcium carbonate
shells and skeletons.
Ocean acidification:- CO3
2–
Organisms has to work harder
to produce shells.
12. Maintaining Metabolism
Many physiological processes operate within a
narrow pH range; outside of that range,
biochemical reactions may be too slow or
in efficient to keep the organism healthy.
Species can adjust to changes in their surroundings
by
actively maintaining a constant
internal environment,
this maintenance requires a
significant expenditure of energy.
13. Boosting Photosynthesis
Carbon dioxide can stimulate plant growth by
boosting the rate of photosynthesis.
Growth of seagrasses under elevated carbon dioxide
conditions gets Increased.
Seagrasses provide valuable
habitat, but if these plants
overgrow it will reduce the
ecosystem’s biodiversity.
14. Obtaining Essential Minerals And
Nutrients
Ocean acidification could make it harder for marine
organisms to absorb nitrogen, phosphorus, iron, and
other elements essential for growth.
For example, when seawater
becomes more acidic, iron
attaches to organic
compounds, preventing
marine life from using this
essential element.
15. Effects On Shellfish, Corals, And Other
Calcifiers
Calcifiers organisms with shells or skeletons made from
calcium carbonate are among
the most abundant forms of marine
life.
Ocean acidification decreases
the availability of carbonate ions.
Dissolving pteropod
shells
Neurological effects
16. Dissolving Pteropod Shells
Tiny sea snail- called the pteropod.
Despite their small size, pteropods are an important
source of food for many species, including fish, seals, and
whales.
But pteropods have delicate calcium carbonate shells that
are vulnerable to ocean acidification.
17. Neurological Effects
Ocean acidification can affect fishes’ sense of smell and
alter their behavior.
In more acidic conditions, young clownfish loses the
ability to navigate home using their sense of smell.
Fish are attracted to odors they normally avoid, such as
the scent of predators, and displayed uncharacteristically
bold behaviors such as roaming far from their home reef.
18. Potential Effects On Ecosystems Around
The Globe
The Effects of ocean acidification will vary
From place to place, depending on the habitat.
The types of organisms in the ecosystem.
The Open Ocean Tropical Coral Reefs The Polar Ecosystem Deep Water Coral
Reefs
19. The Open Ocean
Tiny free-floating plants and animals live and grow in sun
lighted surface waters and serve as the foundation of the
marine food chain.
Planktonic species need carbonate ions to build their
shells.
If ocean acidification increases, these carbonate-based
plankton species may decline.
Range of species, including fish, seals, and whales, could
lose their preferred foods, or have less food altogether.
20. Tropical Coral Reefs
Corals must grow rapidly to outpace predation by fish
and other organisms, and to compete for space with
algae and sea grasses.
Ocean acidification prevents reef building corals from
growing fast enough to escape predation and
competition, or to repair physical damage sufficiently.
Slowed growth is not the only impact that ocean
acidification could have on coral reefs
21. Polar Ecosystems
The polar waters of the Arctic and Southern oceans
harbor many protected and endangered marine
mammals and support some of the most productive
fisheries in the world.
Carbon dioxide dissolves more readily in cold water,
acidifying polar waters faster than in lower latitudes.
Ocean will begin to become corrosive to some types of
carbonate structures by the year 2050 if carbon dioxide
emissions continue to increase at the current rate.
22. Deep Water Coral Reefs
Corals are also found in the deep sea, up to 1000 meters
below the surface of the ocean, where they create habitat
for many species of fish.
Ocean acidification will take longer to reach the deeper
waters but for tropical reefs, over time it could reduce
calcification, decreasing the rate of growth of deep-water
corals.
Deep-water species may be :-
less able to tolerate changing conditions than their shallow
water counterparts.
less able to cope with an increasing ocean acidity.
24. Mitigation
Combating Acidification requires :-
Reducing carbon dioxide emission and improving the
health of the ocean.
Creating marine protected areas and stopping destructive
fishing practices.
Adding of lime stone
carbonate material.
Plantation of trees.
Green belt around the
industries.
26. Conclusion
Due to ocean acidification , the ocean’s capacity as
carbon store house is diminishing.
If nothing is done to help cure ocean acidification , its
negative impact may be felt on
the marine environment , local
communities , and all the way
up through the global economy
