Lesson C4 - Ocean acidification

MAIN SUBJECTS

Natural sciences

DURATION

Preparation: 10min

Activity: 1h30

SUMMARY

The students perform an experiment to understand the link between acidity and pH, and also between CO2 concentration in the atmosphere and ocean acidification. They discuss the effects of ocean acidification on marine organisms.

KEY IDEAS

The oceans’ CO2 uptake is increasing.
The oceans are an important CO2 sink. They have absorbed almost 30% of anthropogenic CO2 in the past 200 years.
Once dissolved in the ocean, CO2 reacts with water to form carbonic acid, and contributes to an increase in ocean acidity.
The seashells of marine organisms dissolve in very acidic water.
Building new shells becomes increasingly difficult as ocean acidity increases.
Shellfish, corals, plankton, sea urchins and starfish are some of the marine organisms that are affected.