Why in News?
Water Hyacinth (Pontederia crassipes) is currently in the news due to the launch of a revolutionary bio-remediation project in the Vembanad Lake (Kerala) on April 17, 2026, which turns this invasive weed into high-value textile fiber.
Biological Profile
- Origin: Native to the Amazon Basin (South America); introduced to India by the British in the late 19th century for its beautiful flowers.
- Growth Rate: It is the fastest-growing plant known; it can double its population in just 10 to 12 days.
- Reproduction: Spreads both by seeds (which can stay viable for 20 years) and by vegetative "runners."
Environmental Impact (The "Terror")
- Oxygen Depletion: It forms thick mats that block sunlight and prevent oxygen exchange, leading to "dead zones" where fish cannot survive.
- Water Loss: It increases water loss through evapotranspiration at a rate 3–4 times higher than an open water surface.
- Clogging: Obstructs navigation, irrigation channels, and hydroelectric power intake pipes.
- Health Hazard: Provides a breeding ground for mosquitoes (malaria/dengue) and snails (schistosomiasis).
Economic Uses (Waste to Wealth)
While harmful to the environment, it is being reimagined as a resource:
- Handicrafts: Stems are dried and woven into bags, mats, furniture, and paper.
- Bio-Fertilizer: It is rich in nitrogen and is used to make high-quality organic compost.
- Water Purification: Ironically, it can absorb heavy metals (like arsenic and lead) from polluted water, though it must be harvested and disposed of carefully.
- Livestock Feed: When processed, it serves as a protein-rich supplement for cattle and poultry.
Control Measures
- Physical: Manual removal (labour-intensive) or mechanical harvesters.
- Chemical: Herbicides like Glyphosate (effective but controversial due to water toxicity).
- Biological: Using natural enemies like the Neochetina weevils or specific fungal pathogens.
- The plant was nicknamed the "Terror of Bengal" because it once nearly destroyed the fishing and rice-growing economy of the state, causing a massive food security crisis in the early 20th century.
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