Why do some seas become unusually red or brown?
Quick Answer
These color changes usually happen when algae or other microorganisms bloom in huge numbers. Pigments in the water can make the sea look red, brown, green, or even purple.
The Full Story
Red or brown water is often caused by blooms of microscopic plankton, including certain dinoflagellates and algae. Some blooms produce strong pigments that tint the water, while others create dense concentrations that change the light seen from the surface. The term “red tide” is commonly used, although the water is not always red and the phenomenon is not tied to tides. Some blooms can produce toxins that affect fish, shellfish, and human health, while others are harmless. Nutrients, temperature, and currents can all influence when and where these blooms appear.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Why does the sea sometimes turn red?"
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.