This presentation is on ocean acidification, it covers (1) a background on ocean acidification, (2) the chemistry between carbon dioxide & the ocean (3) Impact of Ocean acidification on biological processes and the ecosystems. (4) and finally some mitigation measures I hope this ppt be useful & helpful to people working on this topic :) Enjoy

1. OCEAN ACIDIFICATION
Presented by Nabiilah Naraino Majie
Date: 26th February 2016

2. Table of Content
• Introduction
• CO2 and ocean chemistry
• Impact of ocean acidification
• Mitigation
• Conclusion
• References

3. INTRODUCTION

4. Introduction
• Ocean acidification: ongoing decrease in the pH of the
Earth's oceans, caused by the uptake of carbon dioxide
(CO2) 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.
•  CO2 emissions   acidity of the world’s oceans
– 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. CO2 and ocean
chemistry

6. 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.
• However, the absorption of this CO2 has affected ocean
chemistry
– oceans (slightly alkaline)  more acidic.
• 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

8. Impact of ocean
acidification

9. 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

10. Building Shells
• Many animals and some algae
use carbonate ions to make
calcium carbonate shells and
skeletons.
• Ocean acidification: CO3
2-
– Organisms work harder
to produce shells.

11. 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.

12. Boosting photosynthesis
• Carbon dioxide can stimulate plant
growth by boosting the rate of
photosynthesis.
•  growth of seagrasses under
elevated carbon dioxide conditions.
• Seagrasses provide valuable
habitat, but if these plants
overgrow
– reduce the ecosystem’s biodiversity

13. 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.

14. 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

15. 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.

16. NEUROLOGICAL EFFECTS
• Ocean acidification can affect fishes’ sense of smell and
alter their behaviour.
• In more acidic conditions, young clownfish loses the ability
to navigate home using their sense of smell.
• Fish are attracted to odours they normally avoid, such as the
scent of predators, and displayed uncharacteristically bold
behaviours such as roaming far from their home reef.

17. POTENTIAL EFFECTS ON ECOSYSTEMS AROUND THE
GLOBE
• The Effects of ocean acidification will vary
– from place to place, depending on the habitat and
– the types of organisms in the ecosystem.
The Open Ocean Tropical Coral Reefs Polar Ecosystems Deep Water Coral Reefs

18. THE OPEN OCEAN
• Tiny free-floating plants and animals
– live and grow in sunlit 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.

19. 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
– coral bleaching.

20. 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.

21. 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.

22. Mitigation

23. Mitigation
Combating Acidification requires:
• Reducing carbon dioxide emission and
improving the health of the ocean.
• Creating marine protected areas and
stopping destructive fishing practices.
• Addition of Alkali to the Oceans.
• Adding of lime stone carbonate
material.
• Plantation of trees.
• Green belt around the industries.

24. Conclusion

25. Conclusion
• Due to ocean acidification , the
ocean’s capacity as carbon store
house is diminishing.
• If nothing is done to help curb
ocean acidification , its negative
impact may be felt on the marine
environment , local communities ,
and all the way up through the
global economy.

26. REFERENCES
• Elen Barla, 2012, Ocean Acidification, Slideshare. Available at: http://www.slideshare.net/ElenBarla/ocean-acidification-14866953
Accessed on 25th Feb 2016
• Bankoku Shinryokan, 2011, IPCC Workshop on Impacts of Ocean Acidification on Marine Biology and Ecosystems, Intergovernmental
Panel on Climate Change. Available online at: https://www.ipcc-
wg2.gov/meetings/workshops/OceanAcidification_WorkshopReport.pdf Accessed on 25th Feb 2016
• Sebastian Hennige, J. Murray Roberts and Phillip Williamson, 2014, An Updated Synthesis Of The Impacts of Ocean Acidification On
Marine Biodiversity, CBD Technical Series No. 75. Available online at: https://www.cbd.int/doc/publications/cbd-ts-75-en.pdf Accessed
on 25th Feb 2016
• Prof John Raven FR, Dr Ken Caldeira, Prof Harry Elderfield FR, Prof Ove Hoegh-Guldberg, 2005, Ocean acidification due to
increasing atmospheric carbon dioxide, The Royal Society-Report. Available at: http://www.us-
ocb.org/publications/Royal_Soc_OA.pdf Accessed on 25th Feb 2016
• Great Barrier Reef, 2016, Impacts of ocean acidification on the Reef. Managing the reefs. Available online at:
http://www.gbrmpa.gov.au/managing-the-reef/threats-to-the-reef/climate-change/how-climate-change-can-affect-the-reef/ocean-
acidification Accessed on 25th Feb 2016
• The National Oceanic and Atmospheric, 2010, Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean,
NASA, the National Science Foundation, and the U.S. Geological Survey. Available online at: http://dels.nas.edu/resources/static-
assets/materials-based-on-reports/booklets/OA1.pdf Accessed on 25th Feb 2016
• Orr, J.C., K. Caldeira, V. Fabry, J.P. Gattuso, P. Haugan, P. Lehodey, S. Pantoja, H.O. Pörtner, U. Riebesell, and T. Trull, M. Hood, E.
Urban, and W. Broadgate. 2009. Research Priorities for Ocean Acidification, report from the Second Symposium on the Ocean in a
High-CO2 World, Monaco, October 6-8, 2008, convened by SCOR, UNESCO-IOC, IAEA, and IGBP, 25 pp. Available online at:
http://www.nap.edu/read/12904/chapter/13#185 Accessed on 25th Feb 2016
• Kelvin Boot, Jacqueline Alder, Marcella Carew, 2010, Environmental Consequences Of Ocean Acidification:
A Threat To Food Security, UNEP Emerging Issues. Available online at:
http://www.unep.org/dewa/Portals/67/pdf/Ocean_Acidification.pdf Accessed on 25th Feb 2016
• Chen Zu, Howard Alper, 2009, Iap Statement On Ocean Acidification, Interacademy Panel On International Issues. Available online at:
http://www.interacademies.net/10878/13951.aspx Accessed on 25th Feb 2016

27. Thank You