Answer:
Application of nutrients to crops
withdrawls of water for crop irrigation
Explanation:
Algal bloom can occur when excess of nutrients,hot water temperature leads to excessive growth of naturally occurring algae into thick mats on the water surface. Algal bloom occurs when excess nutrient supply to the crops,warmer temperature and low water supply results in rapid growth of algal bloom.Algal blooms are harmful to aquatic life by obstructing the fin of a fish, reduce oxygen content in water,it can discolor the water,form huge smiley piles on beaches change the taste of drinking water.
