Impact of Algal Blooms on Aquatic Life

The video explains the concept of dead zones in water bodies, where dissolved oxygen is nearly absent. It discusses how algal blooms, caused by excess nutrients, block light and affect submerged vegetation. The decomposition of algae consumes oxygen, leading to further depletion. Eventually, environmental conditions may allow for reoxygenation of the water.

What is a dead zone in a water body?

• An area with high levels of nutrients

• A region with abundant aquatic life

• A zone with almost no dissolved oxygen

• A place with excessive sunlight

What causes algal blooms in water bodies?

• Lack of sunlight

• Excess nutrients absorbed by algae

• Presence of submerged aquatic vegetation

• High levels of dissolved oxygen

How do algal blooms affect submerged aquatic vegetation?

• They decrease water turbidity

• They provide nutrients for vegetation growth

• They block sunlight, reducing vegetation depth

• They increase the water's oxygen levels

What happens to algae after it dies?

• It decomposes, consuming oxygen

• It turns into aquatic vegetation

• It floats on the water surface

• It increases water clarity

What gases are released during the decomposition of algae?

• Oxygen and nitrogen

• Sulfur dioxide and ozone

• Hydrogen and helium

• Methane and carbon dioxide

What is the result of limited oxygen production in water bodies?

• Higher water temperatures

• Enhanced photosynthesis

• Increased aquatic life

• Formation of dead zones

How can oxygen levels in water be restored over time?

• By increasing pollution

• By reducing water temperature

• Through environmental and meteorological changes

• Through constant algal blooms