Aquatic Ecosystems and Food Webs

The video explains the structure of aquatic food webs, starting from bacteria and algae, moving up to planktivores and predator fish like lake trout. It discusses the challenges of fish stocking in the Great Lakes due to habitat loss and human impact, such as dam construction. The complexity of aquatic ecosystems and the difficulties in modeling them are highlighted, emphasizing the need for better understanding to achieve ecosystem stability.

What is the starting point of an aquatic food web?

• Small fish

• Planktivores

• Bacteria

• Algae

What do microorganisms feed on in an aquatic food web?

• Bacteria

• Algae

• Small fish

• Planktivores

Which of the following is an example of a planktivore?

• Rainbow trout

• Lake trout

• Bass

• Smelt

What role do juvenile fishes play in the aquatic food web?

• They are top predators

• They feed on algae

• They are prey for planktivores

• They eventually become predators

Why are lake trout and Atlantic salmon stocked in the Great Lakes?

• They are overpopulated

• They are locally extinct

• They are invasive species

• They reproduce too quickly

What is a major challenge in sustaining lake trout populations?

• Lack of food

• Overfishing

• Pollution

• Inability to reproduce naturally

How do dams affect fish populations?

• They block access to spawning habitats

• They provide shelter

• They improve water quality

• They increase food supply

What is the first part of a lake affected by human activity?

• Open waters

• Mid-lake areas

• Near shore area

• Deep waters

Why is modeling aquatic ecosystems challenging?

• They are well understood

• They are complex and large

• They are too simple

• They are too small

What does the failure to reintroduce lake trout indicate?

• Overpopulation of lake trout

• Lack of understanding of ecosystem stability

• Understanding of food webs

• Success in ecosystem management