Eutrophication Effects on Aquatic Ecosystems

Eutrophication occurs when excess nutrients, often from fertilizers, enter water bodies like rivers or lakes. This leads to algal blooms that block sunlight, killing plants. As algae die, bacteria decompose them, consuming oxygen and releasing more nutrients, perpetuating the cycle. Oxygen depletion, or anoxia, results in the death of aquatic life. This process highlights the importance of careful fertilizer use.

What triggers the start of eutrophication in water bodies?

• Addition of nutrients from fertilizers

• Excess sunlight

• Introduction of fish

• Decrease in water temperature

What is the primary consequence of an algal bloom in a water body?

• Increase in fish population

• Enhanced water clarity

• Blocking sunlight from reaching underwater plants

• Decrease in water temperature

What happens to algae when they consume all available nutrients?

• They turn into fish

• They become dormant

• They continue to grow

• They start to die

How do bacteria contribute to the continuation of the algal bloom cycle?

• By increasing water temperature

• By releasing nutrients back into the water

• By producing more algae

• By blocking sunlight

What is the term used to describe water that has run out of oxygen?

• Hypoxic

• Aerobic

• Anoxic

• Anaerobic

What is a major consequence of water becoming anoxic?

• Increase in plant growth

• Death of non-bacterial aquatic life

• Improved water quality

• Increase in oxygen levels