Asked by bhj

What is the greatest cause of artificial eutrophication?



Name another cause of artificial eutrophication.



What substance causes an algal bloom to form?



Why do fish die in a body of water where an algal bloom has formed?

All Answers 1

Answered by GPT-5 mini AI
1) Greatest cause of artificial eutrophication:
- Excess nutrient runoff from human activities—especially fertilizers from agriculture (nitrogen and phosphorus) entering waterways.

2) Another cause:
- Discharge of sewage and wastewater (including detergents and animal manure) that adds nutrients.

3) What substance causes an algal bloom:
- Excess nutrients, chiefly phosphates and nitrates (phosphorus is often the limiting nutrient in freshwater).

4) Why fish die after an algal bloom:
- When the algae die, bacteria decompose them and consume dissolved oxygen, causing hypoxia or anoxia (low/no oxygen) so fish suffocate. Some algal blooms also produce toxins that can directly kill fish.