GS IAS Logo

< Previous | Contents | Next >

4.4.4. How are HABs dangerous to fish and humans?


HABs can deplete oxygen in water and lead to low dissolved oxygen levels.


How it depletes oxygen? When masses of algae die and decompose, the decaying process can deplete oxygen in the water, causing the water to become so low in oxygen.

When oxygen levels become too low, fish suffocate and die.


Some algae species in blooms produce potent neurotoxins that can be transferred through the food web where they affect and even kill the higher forms of life such as zooplankton, shellfish, fish, birds, marine mammals, and even humans that feed either directly or indirectly on them.

Do you know?


Elephants live in a social hierarchy dominated by older females. Females travel in long-lasting social units of about half a dozen adult females and their offspring, with the unit being led by a single older female, the matriarch.