Sources

"Algal bloom." Wikipedia. 14 Feb. 2014. Web. 16 Feb. 2014. <
http://en.wikipedia.org/wiki/Algal_bloom>.

 
"Algal Blooms - Definition, Glossary, Details - Oilgae." Oilgae.com. n.d. Web. 16 Feb. 2014.
<
http://www.oilgae.com/ref/glos/algal_blooms.html>.

What is Algal Bloom?

An algal bloom is a rapid increase in the population of algae near the surface of a body of water. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by the discoloration of water.  Algal blooms can be green, yellow-brown or red; depending on the species of algae.

Generally, phytoplankton populations are kept in check because their growth is restricted by factors such as light or nutrients. However, when one or more of the factors that limit phytoplankton growth becomes abundant, a plankton bloom, characterized by a sharp increase in the plankton population may occur.

Phytoplankton blooms also known as algal blooms naturally occur in the spring as daylight increases, temperatures rise, and nutrients from land are brought into the body of water all of which feed the algae.