- As a population of organisms increases , the resources used by those organisms will decrease
- An bacterium requires oxygen for survival / to breathe
- Therefore, as a population of bacteria increases the amount of oxygen will decrease

- As a population of bacteria increases the amount of oxygen will decrease
- An algal bloom causes an increase of bacteria in an environment
- Hence, an algal bloom causes the amount of oxygen in an environment to decrease

- An animal / bacterium requires oxygen for survival / to breathe
- A fish is a kind of animal
- Hence, fish require oxygen to survive

- Fish require oxygen to survive
- A required resource being low in availability has a negative impact on the something that requires that resource
- Hence, oxygen being low in availablilty has a negative impact on fish

- Oxygen being low in availablilty has a negative impact on fish
- Danger has a negative impact on a thing
- So, oxygen being low in availabliltyis a danger to fish

- An algal bloom causes the amount of oxygen in an environment to decrease
- Oxygen being low in availabliltyis a danger to fish
- So, an algal bloom is a danger to fish because it decreases the amount of oxygen in an environment

- An algal bloom is a danger to fish because it decreases the amount of oxygen in an environment
- Oxygen levels are a measure of the amount of oxygen in an environment
- Therefore, an algal bloom is a danger to fish because it decreases the oxygen levels in an environment

Therefore, an algal bloom is a danger to fish because it decreases the oxygen levels in an environment
[Question]The danger posed to fish in an aquarium by an overpopulation of bacteria caused by an algal bloom is most likely a
[Context]- As a population of organisms increases , the resources used by those organisms will decrease 
- Danger has a negative impact on a thing 
- A required resource being low in availability has a negative impact on the something that requires that resource 
- Oxygen levels are a measure of the amount of oxygen in an environment 
- An algal bloom causes an increase of bacteria in an environment 
- An animal / bacterium requires oxygen for survival / to breathe 
- An bacterium requires oxygen for survival / to breathe 
- A fish is a kind of animal