Kole wetlands, an internationally important Ramsar site of high value biodiversity, has been facing the threat of alien invasive species.
Cabomba furcuta, popularly called as Pink Bloom due its massive flowering, has been a new threat to the kole fields, in addition to water hyacinth and Salvinia molesta. Many parts of the water canals, crisscrossing the vast kole fields, have turned pink now.
Though it has added new colour to the already picturesque landscape of kole, scientists are worried.
“Cabomba furcuta, is repeating its presence for the third year in a row in kole fields. A native of central and south America, Cabomba furcuta was brought to Kerala as an aquarium plant and has escaped to the wild,” notes T.V. Sajeev, Senior Principal Scientist, Kerala Forest Research Institute (KFRI).
Alien plants that are invasive pose a major threat to the biodiversity both in the terrestrial system as well as the aquatic landscape . While water hyacinth and Salvinia molesta are the most impacting species in kole fields so far, regular presence of the pink bloom is a threat to the kole fields , which produce a major chunk of paddy requirements of the State.
The Pink bloom had emerged as a tourist attraction a few years ago during the COVID period near Perambra in Kozhikode. Red Cabomba attracts people due to the massive flowering, which turns the entire water body pink.
A research team of the KFRI, led by Dr. Sajeev, observes that the plant is a major threat to the fresh water bodies in the State.
The submerged perennial aquatic plant grows in stagnant to slow-flowing freshwater. The fast growing Cabomba is a visual treat but becomes a potential outspread in water bodies by active stem propagation, hindering penetration of light into the water.
Cabomba, which requires a large quantity of oxygen for its growth will choke water bodies and drainage canals. It causes decline in diversity of native aquatic plants and causes economic losses by affecting yield of freshwater fishes. The key to controlling the species is to mechanically remove them from the waterbody and dry them in terrestrial spaces, the team notes.
“The plant has been seen in most of the canals in the kole fields recently. However, farmers have not realised its threat yet,” notes P. Parameswaran, one of the kole farmers.
“Currently the plants have filled canals besides the bunds and have not crossed over to the fields as they are rooted and not flowing with water. But once blooming is over, it would spread out to the paddy fields as seeds quickly spread into them,” says Dr. Sajeev, who coordinates activities of the Nodal Centre for Biological invasions at the KFRI.
