Algal bloom

Definition

An algal bloom is a rapid increase in the population of algae in an aquatic system, often visible as a green or red discoloration of the water. It can result from nutrient pollution and can have harmful ecological and health impacts.

5 Must Know Facts For Your Next Test

1. Algal blooms are primarily caused by excess nutrients, particularly nitrogen and phosphorus, often from agricultural runoff.
2. Some algal blooms produce toxins that can harm aquatic life, humans, and other animals, known as harmful algal blooms (HABs).
3. Eutrophication is a process that can lead to algal blooms due to nutrient enrichment in water bodies.
4. Algal blooms can deplete oxygen levels in water through respiration and decomposition, leading to dead zones where aquatic life cannot survive.
5. Climate change and warmer water temperatures can exacerbate the frequency and intensity of algal blooms.

Review Questions

• What are the primary nutrients responsible for causing algal blooms?
• How do harmful algal blooms (HABs) affect aquatic ecosystems and human health?
• Explain how eutrophication leads to the formation of algal blooms.

Related terms

Eutrophication:

The process by which a body of water becomes overly enriched with nutrients, leading to excessive growth of algae.

Hypoxia:

A condition where oxygen levels in water are reduced, often as a result of decomposing algae from an algal bloom.

Phytoplankton:

Microscopic marine algae that form the base of many aquatic food webs; some species can proliferate quickly during an algal bloom.