Programme on Seagrasses
Part of: GS-Prelims and GS-III: Biodiversity, Ecology
- These are flowering plants that grow submerged in shallow marine waters like bays and lagoons.
- These have tiny flowers and strap-like or oval leaves.
- Seagrasses evolved from terrestrial plants that recolonised the ocean around 70-100 million years ago.
- Seagrasses also produce food by photosynthesis.
- They reproduce sexually as well as asexually.
- Some of the important seagrasses:
- Sea Cow Grass (Cymodocea serrulata)
- Thready Seagrass (Cymodocea rotundata)
- Needle Seagrass (Syringodium isoetifolium)
- Flat-tipped Seagrass (Halodule uninervis), etc.
- Location: These are found in muddy and sandy substrates. These also occur along our coastline of Gulf of Mannar and Palk Bay regions on the east coast, Gulf of Kachchh region on the west coast, the lagoons of islands in Lakshadweep in the Arabian Sea and Andaman and Nicobar Islands in the Bay of Bengal.
- They provide many ecosystem services
- These are also called ‘the lungs of the sea’ because they release oxygen into the water through photosynthesis
- Sequesters up to 11% of the organic carbon buried in the ocean
- Absorb carbon from the atmosphere. They can capture carbon from the atmosphere up to 35 times faster than tropical rainforests
- Help maintain water quality
- Filter nutrients released from land-based industries
- Prevent soil erosion
- Provide food as well as habitat for fishes, octopuses, shrimp, blue crabs, oysters, etc.
- Seagrass beds are facing decline all over the world at the rate of 2-5% annually.
- Threats: Grazing, storms, ice-scouring (abrasion and erosion of seabeds by glaciers), desiccation, eutrophication, mechanical destruction of habitat, overfishing, coastal engineering construction, etc.
- Based on field surveys and satellite data, the National Centre for Sustainable Coastal Management has estimated the total extent of seagrass ecosystem in India to be 516.59 km2. The CO2sequestration rate of seagrass ecosystem is estimated to be up to 434.9 tonnes/km2/year with an annual net CO2 sink of 0.75 million tonnes for an area of 517 km2.
The Government has also initiated a project across the States of Andhra Pradesh, Maharashtra, and Odisha on enhancing climate resilience of India’s coastal communities at a total cost of US $130.269 million which includes a grant of US$ 43.419 million by Global Climate Fund (GCF) covering 24 ecosystems in these selected States which aims to strengthen the climate resilience of coastal communities by protecting and restoring India’s natural ecosystems such as mangroves and seagrasses.
News Source: PIB