Question

frequent occurance of water bloom in a lake indicates
1: excessive nutrient
2: oxygen deficiency

please give the appropriate answer ....
with proper explanation... ​

Answer 1

Answer:

excessive nutrient

The occurrence of excess organic matter inside water due to sewage disposal and eutrophication. This leads to an increase in biological oxygen demand (BOD) for putrefaction by microorganisms. Also, explosive multiplication of blue-green alga leads to an algal bloom. These conditions result in a decrease in dissolved oxygen in the water. Both toxicity due to algal toxins and decreased levels of dissolved oxygen kill aquatic animals.