Mon Prof Augmenté
Algae Covers Shallow Water
Extra nutrients in a shallow lake can make algae grow into a thick surface mat. That mat blocks sunlight, so rooted water plants below cannot make food and turn weak and brown.
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Age 13: open this week
Browse Age 13
In the picture
- Bright green bottom plants on the left bed.
- Sunbeams passing through clear water on the left.
- Thick green algal mat floating at the right surface.
- Murky brown water beneath the algal mat.
- Limp brown bottom plant on the right bed.
Examples
- A garden pond after too much fertiliser runs in from the soil.
- A slow river near farm fields after heavy rain.
Key takeaways
- Algae at the surface can block light from reaching underwater plants.
- Without enough light, underwater plants weaken and die back.
Carry on in the app
Three questions on this lesson. It has left the free week, so its quiz is for subscribers.
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