Dead Zones in Lake Erie

The video explores the mystery of the growing dead zone in Lake Erie, examining various potential causes such as botulism, mercury, overfishing, and invasive species. It concludes that phosphates and oxygen-demanding wastes are the primary contributors. The video also discusses the global prevalence of dead zones and their impact on human activities. Solutions and future expectations are proposed, emphasizing the need for better nutrient management and support for decision-makers.

What is the primary reason botulism is not considered the cause of the dead zone in Lake Erie?

• Botulism affects only birds, not fish.

• Botulism occurs in spring and fall, not late summer.

• Botulism is caused by mercury.

• Botulism is a result of overfishing.

Why can't mercury be blamed for the dead zones in Lake Erie?

• Mercury is only harmful to humans, not fish.

• Mercury levels have always been low in Lake Erie.

• Mercury is only found in the air, not in water.

• Mercury levels decreased in the 1990s and are not directly linked to dead zones.

What is the main reason overfishing is not the cause of dead zones in Lake Erie?

• Overfishing only affects small fish species.

• The fish population in Lake Erie is increasing.

• Overfishing is controlled by strict regulations.

• Lake Erie is still a significant fishery despite overfishing.

How do zebra mussels indirectly affect the food chain in Lake Erie?

• They filter plankton, concentrating mercury up the food chain.

• They provide a habitat for invasive species.

• They reduce the water temperature.

• They increase the oxygen levels in the water.

What is the primary nutrient responsible for the formation of dead zones in Lake Erie?

• Phosphates

• Sulfur

• Calcium

• Carbon dioxide

How does the stratification of Lake Erie contribute to dead zones?

• It creates layers that trap nutrients and deplete oxygen at the bottom.

• It prevents fish from swimming to the surface.

• It increases the water temperature uniformly.

• It causes rapid water movement.

Which of the following is NOT a major dead zone in the world?

• Gulf of Mexico

• Lake Victoria

• Arabian Sea

• Baltic Sea

What is a significant threat posed by dead zones to humans?

• Safe drinking water

• Increased fish population

• Improved water clarity

• Toxic algae blooms

Which action is NOT recommended to mitigate dead zones in Lake Erie?

• Controlling water runoff

• Improving sewage treatment

• Using more fertilizers

• Utilizing wetlands

What is a personal action individuals can take to help reduce dead zones?

• Avoid consuming fish

• Ignore environmental policies

• Support decision-makers making the right choices

• Increase personal fertilizer use