Diatoms

Diatoms are a diverse group of microscopic, photosynthetic algae that thrive in aquatic and moist environments, including oceans, freshwater bodies, and even damp soils. These tiny organisms play a crucial role in the planet’s ecology and climate systems.

Key Characteristics

• Structure:
  Diatoms possess intricate, silica-based cell walls (called frustules) that display a wide range of beautiful geometric patterns. These glass-like shells are unique to each species.
• Habitat:
  Found almost everywhere water is present—from the deep oceans and coastal waters to rivers, lakes, and wet soils.

Ecological Importance

1. Photosynthesis:
   Diatoms utilize chlorophyll a and c to capture sunlight and convert it into energy through photosynthesis.
2. Oxygen Production:
   They contribute significantly to the global oxygen cycle, generating around 20–25% of Earth’s oxygen—more than all the world’s rainforests combined.
3. Carbon Sequestration:
   Diatoms help in removing carbon dioxide (CO₂) from the atmosphere and releasing oxygen (O₂), making them important agents in climate regulation.
4. Base of the Food Chain:
   As primary producers, diatoms synthesize long-chain fatty acids that are essential for aquatic life. They serve as a key food source for zooplankton, insects, fish, and even large marine animals like whales.
5. Environmental Indicators:
   Due to their sensitivity to changes in pH, salinity, nutrient levels, sedimentation, and human activity, diatoms are widely used to assess water quality and monitor ecosystem health.

Harmful Effects

Some species of diatoms, such as Pseudo-nitzschia, can produce domoic acid, a neurotoxin that enters the marine food web. This toxin can cause neurological disorders in marine animals—most notably aggressive and erratic behavior in sea lions.

 

Also Read
FREE NIOS Books	UPSC Daily Current Affairs
UPSC Monthly Magazine	Previous Year Interview Questions
Free MCQs for UPSC Prelims	UPSC Test Series
ENSURE IAS NOTES	Our Booklist