These organisms from other countries tend to dominate and threaten native species.
Kozhikode: The ecological, economic and health impact of different plants, animals and insects such as African weed, mosquito fish and coconut mites that belong to the Invasive Alien Species (IAS), were in focus at a two-day exhibition of organisms held by the Western Ghats Field Research Station of the Zoological Survey of India (ZSI) in Kozhikode on Friday.
The exhibition, organised in connection with the International Day for Biological Diversity declared by the United Nations on May 22, has 35 varieties of IAS organisms, including 16 plant and 19 animal.
IAS are plants, animals and organisms from other countries and ecosystems that have a tendency to dominate and threaten the communities of native species, thereby causing economic and environmental harm and adversely affecting human health. “Interestingly, many of the plant and animal species that have become common in our places or are familiar to our people belong to IAS,” says C. Radhakrishnan, additional director of ZSI.
Plant varieties such as Spanish flag (‘arippoovu’/ ‘kongini poovu), Touch me not (‘thottavadi’), water hyacinth (‘kulavazha’) and aquarium fish, including gold fish, mosquito fish and carp besides African Giant Snail, Asian Tiger Mosquito and Cotton White Fly are some the prominent variety IAS seen in Kerala and are displayed here.
The semi aquatic turtle ‘Red-eared Slider,’ which is native to the Southern U.S. and feeds on aquatic plants, snails and insects and has become common in many parts of India, is one of the major attractions of the show. “It establishes very fast in our climatic conditions and poses grave threat to the native variety of turtles,” said a scientist from ZSI.
Many of these IAS varieties displayed at the show were introduced to Kerala as ornamental plants (eg. Asparagus Densiflorus (mayoori) and Spanish Flag (aripoovu)) or as food and aquarium fishes (eg. gold fish, grass carp and thilapia).
According to ZSI scientists, the mosquito fish (Gambusia Affinis) that was introduced to Kerala as an organic remedy to the mosquito menace, as it feeds on mosquito larva, later proved to be a major threat to other native varieties of fishes and several other micro-organisms.
“Looks gorgeous, though even gold fish brings about several negative impacts to the ecosystem it lives,” says a scientist.
The collection of IAS exhibited here includes a variety of huge starfish that pose threat to the coral ecosystem, coffee berry borer, coconut mite (known as ‘mandari’ in Kerala) cotton white fly and a variety of plants such as siam weed (‘communist pacha’ in Malayalam), congress weed (‘congress pacha’ in Malayalam) and the “dangerous” creeper commonly known as Mile-a minute, (popularly known as ‘dhridarashtra pacha), which proves fatal to the ecosystem, among others.