Planting small trees on roofs of buildings in dense urban areas can reduce flood volume and runoff

Water Hyacinth—Invasion with good intent?

Read time: 2 mins 1 June, 2019 - 08:00

Water Hyacinth (Eichhornia crassipes) is a free-floating perennial aquatic plant, native to the Amazon basin in South America. The beautiful, large, purple flowers make it a favourite ornamental plant. However, its beauty is only surface deep, since it has a bad reputation of being one of the worst aquatic weeds in the world. Known as the “German weed” in Bangladesh, the “Florida Devil” in South Africa, the “Terror of Bengal” in India and the “Japanese Trouble” in Sri Lanka, the plant grows extremely fast - it can double its population in a matter of two weeks.

Interestingly, the Water Hyacinth was a gift of the British to India, introduced towards the end of the 18th century. Lady Hastings, the wife of the First British Governor-General, who was enchanted by the beauty of the flowers, brought it to India, which has now spread to most water bodies.

Now here comes the problem—water hyacinth causes dense mats of biomass on the water surface, which reduces dissolved oxygen in the water and the amount of light available to the underground vegetation. This growth causes an imbalance in the aquatic ecosystem and affects the fish population, thereby adversely impacting the livelihood of the fishermen. The plant also destroys natural wetlands and causes flooding by blocking rivers and canals, and is a severe menace in flooded rice fields, where it reduces the yield considerably.

However, it's not all that bad; there are certain unique advantages of the plant. The plant thrives in highly polluted waters and can reduce the level of pollutants in the water, thus helping in tackling the widespread issue of water pollution through a process called phytoremediation. Research has shown that the plant is capable of cleaning up polluted industrial wastewater of toxic heavy metals like chromium and crude oil. Also, technologies are currently being developed to utilise water hyacinth as a green fuel and to make paper and paper boards. It is also providing a source of income to villagers in the vicinity of Harike Wildlife Sanctuary in Punjab as the villagers produce handicrafts made from the plant.

So, how do we make the best of the evil? Perhaps, instead of trying to destroy the species, the invasiveness and massive proliferation of the plant could be utilised for the good of the environment. Water hyacinth might have some good intent after all.