Seagrasses

• Context (DTE): Seagrass meadows are rapidly expanding near inhabited islands in the Maldives.
• Seagrasses are marine flowering plants. They are not true grasses and are more closely related to terrestrial lilies and gingers than grasses.

Credit: Hudson Alpha

• They often grow in large groups giving the appearance of terrestrial grassland – an underwater meadow.
• They have roots, stems and leaves and produce flowers and fruits. They are the only flowering plants that can live underwater.
• They are found in salty and brackish waters from the tropics to the Arctic Circle.

Credit: TechOceanScience

• They thrive in shallow coastal waters where there is shelter from drying winds, wave action, and strong currents.
• The depth of seagrass is usually controlled by the availability of light for photosynthesis.
• Seagrasses reproduce through both sexual and asexual methods.
• Important seagrasses: Sea Cow Grass, Thready Seagrass, Needle Seagrass, Flat-tipped Seagrass, etc.
• In India, Seagrasses occur all along the coastal areas of India and are abundant in the Palk Strait and Gulf of Mannar in Tamil Nadu.

Significance

• Globally, seagrass captures carbon up to 35 times faster than tropical rainforests, accounting for 10-18% of total ocean carbon storage despite covering less than 0.1% of the seafloor.
• They reinforce coastal protection by protecting the coast from damaging storms and erosion by dampening the force of waves.
• They are called ‘the lungs of the sea’ as they release oxygen into the water through photosynthesis.
• They help maintain water quality. They trap fine sediments and suspended particles in the water column and increase water clarity.
• Seagrass habitats protect juvenile and small adult fish from large predators.
• Seagrass leaves support seaweeds by providing anchoring facilities. Seahorses and lizardfish are found living in seagrass meadows almost throughout the year.