Question

a scientist measured how the population of fish in a lake changed when a new factory was built nearby. based on the data in the graph below, what relationship do you see between water oxygen levels and the fish population? what might be causing the change you noticed, and how could this affect the ecosystem?

Explanation:

1. Relationship: As water oxygen levels (ppm) decrease over years, fish population also decreases. This is a positive correlation (both decline together).
2. Cause: The new factory likely pollutes the lake (e.g., with chemicals, waste), reducing dissolved oxygen. Pollutants can cause eutrophication or direct toxicity, lowering oxygen.
3. Ecosystem Impact: Fewer fish disrupt food chains (predators lose prey, prey of fish may overpopulate). Low oxygen also harms other aquatic life, reducing biodiversity and ecosystem balance.

Answer:

• Relationship: As water oxygen levels decrease, fish population decreases (positive correlation).
• Cause: Factory pollution (e.g., waste, chemicals) reduces dissolved oxygen in the lake.
• Ecosystem Effect: Disrupts food chains, reduces biodiversity, and harms aquatic life balance.