Which type of eukaryotic microbes are responsible for "blooms" in bodies of water and pond scum?

Question

Which type of eukaryotic microbes are responsible for "blooms" in bodies of water and pond scum?​

Quizplus · Accepted Answer

Diatoms are responsible for "blooms" in bodies of water and form much of the basis of the aquatic food chain. They are single-celled organisms with a hard outer shell made of silica, and when conditions are right (such as high nutrient levels and warm temperatures), they can reproduce rapidly and form large colonies known as blooms. These blooms can discolor the water and create pond scum.

Which Type of Eukaryotic Microbes Are Responsible for "Blooms" in Bodies