4.6. Ocean acidification

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Ocean Acidification

OCEAN ACIDIFICATION

PRE-VIEWING ACTIVITIES

  • Is there any relation between fossil fuels, carbon dioxide (CO2) and climate change?
  • How do you think global warming is affecting sea life?

Watch the following video and do the activities below it. When you finish, ask your teacher to help you check your answers in the key document.

ACTIVITIES  

1.- How much CO2 have oceans absorbed since we started burning fossil fuels?

2.- Is it good for the atmosphere that oceans absorb CO2?

3.- Is it good for the seas?

4.- What is weakening the shells and skeletons of marine animals?

5.-  What’s the relation between weaker oysters and coral and hunger in the world?

6.- Why can’t our eco-system adapt to acidification?

7.- What can happen if oceans become more acidic?

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Ocean Acidification: The other carbon dioxide problem

 Ocean acidification:

The other carbon dioxide problem

PRE-VIEWING ACTIVITIES

1. Before watching the video look at these pictures:

Ocean acidification is the term given to the chemical changes in the ocean as a result of carbon dioxide emissions.

The pteropod, or “sea butterfly”, is a tiny sea creature about the size of a small pea. Pteropods are eaten by many other sea organisms : from tiny krill to whales and are a major food source for salmon. The photos below show what happens to a pteropod’s shell when placed in sea water with pH and carbonate levels projected for the year 2100. The shell slowly dissolves after 45 days.

2. Match the words with their definition

1.fossil fuels

a) to let a substance or energy spread into the area or atmosphere around it, especially as part of a chemical reaction

“Oxygen from the water is released into the atmosphere.”

2.release

b) with only a short distance from the top or surface to the bottom.

3.deep

c) a fuel such as coal or oil, made from decayed material from animals or plants that lived many thousands of years ago.

4.availability

d) going a long way down from the top or the surface

“The river is quite deep here.”

5.shallow

e) Present and ready for use; at hand; accessible

  2. Capable of being gotten; obtainable

Watch the following video and do the activities below it. When you finish, ask your teacher to help you check your answers in the key document.

ACTIVITIES  

3. Complete the text and answer the questions

1.The burning of fossil fuels produces carbon dioxide and __________% of it is absorbed by the ocean .When Co2 reacts with _____________ the water it forms carbonic acid which releases a hydrogen ion or H+,  ___________ hydrogen ions the________________ or more acidic a solution is.

2.How will ocean PH change over time?

3. The acidification of the ocean is dangerous for corals and  species that depend on shells because it _________________ their availability of dissolved calcium and carbonate which these species use to make __________________ so these shells may begin to ______________

4. How long have scientists been measuring these chemical changes in the ocean?

5.The  ocean acidification is impacting _____________ much more than deep ones because the _______________concentrations of available shell minerals are found in the surface water, deeper waters have very _________ availability of these minerals.

6.Why is important that the acidification  takes place in shallower areas?

7.Are these changes taking place is just  some parts of the ocean?