Why in News?

Recently, two new red algal seaweed species Hypnea indica, and Hypnea bullata were discovered along India’s long coastline.

About Seaweeds:

• These are the primitive, marine non-flowering algae without root, stem and leaves.
• They play a major role in marine ecosystems.
• Large seaweeds are known to form dense underwater forests called as kelp forests.
  • The kelp forests act as underwater nurseries for fish, snails and sea urchins.
• Seaweeds, are mostly found in:
  • in the intertidal zone,
  • in the shallow and deep waters of the sea
  • in estuaries and backwaters.
• In Indian Ocean, Gulf of Mannar have rich populations of several seaweed species.

Ecological Importance of Seaweeds:

• Seaweeds absorb the excess nutrients and balance out the ecosystem, when waste from agriculture, industries, aquaculture and households cause nutrient imbalance leading to algal blooming in the ocean.
• Seaweeds trap and remove excess amount of iron and other metals including heavy metals in the ocean water.
• The seaweeds derive nutrition through photosynthesis of sunlight and nutrients present in seawater. They are known to release oxygen through every part of their bodies.
• They also supply organic nutrients to other marine life forms in the ecosystem.
• Ocean afforestation: Seaweed has a significant role in mitigating climate change. It can sequester much Carbon dioxide from the atmosphere. Hence, there is a proposal referred as ‘Ocean afforestation’ for farming seaweed to remove carbon.

Other uses:

• They can be used as fertilizers.
• When livestock is fed with seaweed, methane emission from cattle is known to be reduced substantially.
• They can also be buried in beach dunes to combat beach erosion.
• It is actively used as an ingredient in preparing toothpaste, cosmetics, and paints.