Traveling through beautiful Goa, once cannot miss the bright greenery with its pretty flowers floating in great mats on the edge of the river Sal and other water bodies. On closer inspection, the leafy growth is not as innocent as first sighting might make us believe: what we are spotting is the Water Hyacinth (Eichhornia crassipes), a perennial aquatic plant closely related to the lily family. Curiosity overcame me so I did a little research on this plant, which I will share here:
Water hyacinth is a native of South America but has taken root in water bodies throughout the world’s tropical and subtropical climates. It is not just travelers from all over the world who love Goa, the water hyacinth does, too! Moreover, it thrives in the climate.
To give everyone a sense of why it’s been dubbed the “worst aquatic plant in the world”, look at this:
Water hyacinth is a native of South America but has taken root in water bodies throughout the world’s tropical and subtropical climates. It is not just travelers from all over the world who love Goa, the water hyacinth does, too! Moreover, it thrives in the climate.
To give everyone a sense of why it’s been dubbed the “worst aquatic plant in the world”, look at this:
Water hyacinth damages the water quality by blocking the sunlight and oxygen and slowing the flow of water . Due to the speed of its growth and the thickness of the floating mats, it chokes out other vegetation. This makes the water body unusable by plants and animals that either live or depend on it. Fish spawning areas may vanish.
The mats of hyacinths become habitat for disease-carrying mosquitoes. Irrigation and drainage systems become blocked. Access to the water or docking areas by man and boats becomes limited. Rivers and canals can become impassable due to the thick carpet of plants. It changes water chemistry; affects flora and fauna and causes significant increase in water loss due to evapotranspiration. A study done showed that water loss in plant-infested areas was 1.8 times the water loss of non-infested water.
Another study showed two plants produced over 1000 daughter plants in two month’s time. One single plant can produce up to 5000 seeds. These often are eaten by waterfowl and transported along low mud banks of rivers, or ponds. Once a plant has matured, it can break off the thick floating mat of plants, gets disbursed and starts a new colony elsewhere.
It takes effort and speed to control the growth of these floating mats of greenery. In smaller water bodies like ponds or lakes, where growth is still manageable, manually weeding the plants can make a difference. It should be noted that the plants should not be cut off with a knife but actually has to be pulled out at the root. Then letting them dry in a heap away from the water, it is finally best to burn them. It is hard work because of the weight of the plants. It has also been suggested that reducing the amount of nutrient run off into the water (fertiliser) may reduce growth.
Much money has been spent on chemical and mechanical removal but has been found ineffective. Worldwide research is focused on biological control that is sustainable and affordable. A weevil has been introduced on an experimental basis in some parts of India. I could not find out if this is being tried in Goa at this time.
Water sustains life. We need it to grow our food and for human consumption. Where there is a lack of water, everyone suffers. This simple truth is self-evident. Awareness, exchange of knowledge and participation CAN make a difference.
“When nature gives you lemons, make lemonade!” This seems to be what some ingenious people are trying to do. Cottage industries have developed in several parts of the world where water hyacinth is all-too abundant. The fibrous tissue of the plant is being used to make paper, rope, fibreboard, furniture, animal fodder and fertilizer, and lastly , water hyacinth conversion to biogas.
With this hopeful note, I will sign off for the day.
