Transcript Corals and pH ppt

Objective: We will understand
that
• Coral reefs need a certain pH to survive
• Human alterationsof the atmosphere
are changing the pH of the ocean
• Test whether increased carbon dioxide
is making our oceans more basic or more
acidic
• Learn how a change in oceanic pH is
impacting coral reefs.
Ponder this:
• What do you think your breath is? Acid
or base or neutral?
• Write your answer and think..
• How can you test your prediction?
What is a pH indicator?
• A pH indicator turns color in presence
of acid or base.
• cabbage juice is purple. It turns pink in
presence of acid. It turns blue in
presence of base.
• Bromthymol blue is another type of
indicator.
• Bromthymol blue solution turns yellow or
green in presence of acid.
Develop a Hypothesis
• Will my breath turn bromthymol blue
yellow or green?
• If so, my breath is _____
• If the bromthymol blue stays blue, my
breath is _______
• Hypothesis: If I breathe into bromthymol
blue, the solution will _____
• Materials: Test Tube, straw, bromthymol
blue solution
• Procedure: Put 10 ml of water into a test
tube
• add 3-4 drops of bromthymol blue
• Place a straw in test tube and return to
your seat.
What in your breath is acidic? ____
All animals, including the
dinosaurs of Jurassic
times and we humans,
are part of the carbon
cycle.
Some of the carbon dioxide
in the atmosphere
dissolves and is stored in
ocean waters. The
oceans act as a storage
place or sink for carbon.
What is a source? What is a sink?
The Carbon Cycle
Biogeochemical Cycle
Carbon Cycle
• By eating food, animals gain carbon in the
form of carbohydrates and proteins.
• In each of our bodies' cells, oxygen combines
with food to give energy for daily activity.
Carbon dioxide, a waste product of this
cellular metabolism, is released back into the
atmosphere when we exhale or breathe.
• Some of the carbon dioxide in the
atmosphere dissolves and is stored in ocean
waters. The oceans act as a storage place or
sink for carbon.
Seawater and pH
•
•
If sea water has a pH of 8, is it slightly
acidic or slightly basic?
What might change the pH of sea water?
Corals and pH
What is coral?
• Corals are animals,
related to anemones and
jellyfish.
• Corals consist of a
limestone structure filled
with thousands of small
animals called polyps.
• Each polyp has a
tentacles with stinging
cells, a mouth and
stomach.
What do corals need to survive?
•
•
•
•
•
Warm water
Salinity
Sunlight
Clear water
Slightly basic pH
Where in the world are coral?
What is the effect of acid on coral?
• Acids dissolve carbonates (CaCO3).
• What is made of carbonate?
• 2HCl + CaCO3 ↔ CaCl2 + CO2 + H2O
• Hydrochloric Acid + Calcium Carbonate ↔
• Calcium Chloride + Carbon Dioxide
+Water
What is the source of the Carbon
Dioxide? What is the sink?
• Respiration
• Fossil fuel emissions
• Volcanic eruptions
What is the effect of lower
pH on coral and other
marine animals with
carbonate shells and
exoskeletons?