Why seaweeds need to be conserved urgently

Context

• Indiscriminate collection severely damages the algae which is critical for balancing marine ecosystems and plays a role in thwarting climate change

What are Seaweeds?

• Seaweeds are the primitive, marine non-flowering marine algae.
• The plant body is not differentiated in root, stem and leaves.
• Seaweeds, found mostly in the intertidal region, in shallow and deep waters of the sea and also in estuaries and backwaters.
• The seaweeds derive nutrition through photosynthesis of sunlight and nutrients present in seawater.
• These aqautic organisms heavily rely on iron for photosynthesis.
• The conservation status of seaweeds is yet to be evaluated by the IUCN.

How the seaweeds are ecologically important?

They play a major role in marine ecosystems.

• Habitat:The thousands of species of this organism provide habitats for marine lifeforms and protect them from threats. 
• Kelp Forests: Large seaweeds form dense underwater forests known as kelp forests, which act as underwater nurseries for fish, snails and sea urchins.
• Food support: The herbivorous marine animals also feed on its thallus. They also supply organic nutrients, which they are capable of producing, to other marine life forms.
• Enrich O2:They release oxygen through every part of their bodies. 
• Reduce toxicity:Some nutrients found in large water bodies are toxic to the marine life and can even kill them. It absorbs the excess nutrients and balance out the ecosystem.
• Bio-indicator:They also act as a bio-indicator. When waste from agriculture, industries, aquaculture and households are let into the ocean, it causes nutrient imbalance leading to algal blooming, the sign of marine chemical damage.
• Metals removal: Most heavy metals found in marine ecosystems are trapped and removed by seaweeds.
• Climate Change:Seaweed has a significant role in mitigating climate change. By afforesting 9 per cent of the ocean with seaweed, it is possible to sequester 53 billion tons of carbon dioxide annually.
• Agriculture and animal husbandry: They can be used as fertilizers and to increase fish production. Also, when livestock is fed with seaweed, methane emission from cattle may be reduced substantially.
• Beach Erosion: They may be buried in beach dunes to combat beach erosion.
• Commercial benefits:It is used as an ingredient in preparing toothpaste, cosmetics and paints. 

Where it is found in abundance?

• The southeast Indian state of Tamil Nadu has 1,076km coastline with the convergence of the Bay of Bengal, Arabian Sea and the Indian Ocean.
• The southern Gulf of Mannar’s rocky intertidal and lower intertidal regions maintain rich populations of several seaweed species.

What are the threats to Seaweeds?

• Mechanical dredging causes damage to the kelp forests formed by large seaweeds.
• Indiscriminate collection of seaweed also causes severe damage to the useful algae.

How Seaweeds pose a threat to corals?

• The exotic, invasive Kappaphycus alvarezii seaweed is posing a serious threat to the coral reefs.
• They have started smothering the coral reefs and slowly killing them.
• Fisher folk collect tonnes of seaweeds daily around the islands. And while doing so, they break the corals.