Every morning for the past few weeks, crowds gather at the streams and inland waters at Avala Pandi village near Perambra of Kozhikode district. They show up to witness the beautiful site of a blanket of pink flowers that cover the surface of the water; these flowers bloom at around 11 am, and transform the place into a feast for the eyes. The aquatic plant has been identified as belonging to the Cabomba furcata family, which is not endemic to India. Since the blooming of this flower is a novel experience, people from neighbouring districts and their families come to witness it, as well. Many visitors arrive at the spot before 10 am, and wait for more than an hour to see the flower bloom.
Cabomba furcata, or the pink forked fanwort, is originally found in South America, Cuba and some parts of Florida in the USA. It has pink-coloured petals and a yellow pistil; its narrow leaves are mainly submerged. And though the blossoms provide a mesmerising view, environmental experts are not happy about the presence of this plant. They say that it is an invasive species that can easily destroy the native aquatic plants, which are endemic to Kerala.
"This plant was grown here as an aquarium plant, which later got spread in to the inland waters. Any aquatic weeds can destroy our native aquatic fauna. It is okay to grow them in a controlled water bodies like aquariums or a pond inside a park. But is harmful in natural flowing waters," AK Pradeep, a Professor at the Botany department at the Calicut University told TNM. "These plants are rooted in the mud below the water. They grow rigorously in flowing water and spread very fast," he added.
The local residents of Avalapandi say that they are not sure how Cabomba furcata spread so fast in the area. However, experts say that the point of origin may have been someone who dropped a flower into the water, as they look pleasing when they bloom.
"They look very beautiful, but the native varieties under the species Blyxa, Nuphar etc have started disappearing. The plants like Eichornia, which is commonly known as the water hyacinth, produce beautiful flowers but they are invasive," Professor Pradeep said.
Once the invasive plants are established in the waterbodies, it is very difficult to remove them and allow other plants to grow, which raises concerns among the botanists. "Once the native species are vanished, we cannot bring them back. Also, more studies are required in the field of invasive species, whether it would affect the fish community in inland water bodies," Professor Pradeep pointed.
He also said that invasive species like the giant water lily, once they spread, are difficult to remove as they have huge thorns.
Another species of invasive aquatic plants that severely affected the aquatic flora of Kerala was Salvinia molesta, known locally as ‘African Payal’. "Salvinia molesta may form dense vegetation mats that reduce water-flow and lower the light and oxygen levels in the water. This stagnant dark environment negatively affects the biodiversity and abundance of freshwater species, including fish and submerged aquatic plants. Salvinia molesta can alter wetland ecosystems and cause wetland loss and also poses a severe threat to socio-economic activities dependent on inland waters," a report by Environmental Information System (ENVIS) Centre, Kerala says.