nagpur salvinia molesta commonly known as giant salvinia or kariba weed is playing havoc by shrinking freshwater bodies and destroying indigenous plant and animal biodiversity and also causing livelihood loss to traditional fishermen communities in the regionlakes constitute important habitats and food resources for a diverse array of fish aquatic life and wildlife but the kariba weed destroys water bodies and will gradually lead to drying up of these lakes if not tackled effectively and in time says dr kishor mankar conservator of forests cf gadchirolimankar who was posted in tadoba two years ago had observed thick mats of kariba weed in a portion of irai dam near mohurli in gadchiroli too some water bodies are infested by salvinia molestadr sh patil chairman maharashtra state biodiversity board msbb says the weed is a doubleedged sword though kariba can be used as satisfactory mulch for crops there is no doubt that it destroys aquatic biodiversityforester rundan katkar working in central chanda said on the chandrapurnagpur highway the ghodpeth lake shows no water but only kariba weed the plant has also infested zarpat river and junona lake near chandrapur its infestation has led to migratory birds on these water bodies declining by over 50 katkar saidaccording to biodiversity expert dr mankar the plant originated in southeast brazil and was probably exported as part of the ornamental and pet industry to be used in aquaria and garden ponds from there it might have escaped or was deliberately released into the wild in kerala it has become an established danger occupying large areas of open water causing navigational problemsthe h2s generated in the decaying weed mass in the water is destructive it also causes a reduction in stored water of reservoirs and over the long term leads to gradual drying up of natural and manmade water bodies this is a serious matter which needs to be tackled on warfooting before it becomes another menace like water hyacinth or congress grass said mankarthe official said increasing infestation of kariba weed is impeding access to water bodies ponds and lakes and fishermen feel helpless as they cant catch fish as nets get entangled in these aquatic weeds and boats cant move freely mankar said the thick mat of weeds prevents light penetration in the water killing primary producers like algae and zooplanktons which are a major food of fishes it also lowers nutrients in the water and makes the water acidicthe decomposition of biomass and its settlement decrease the depth and gradually lead to the death of water bodies the other disadvantages include loss of recreation value due to lack of water sports or boating for tourists loss of livelihood to traditional fishermen reduction in indigenous plant and animal biodiversity he said mankar called for controlling the spread at initial stage when the infestation is on a smaller scale if we dont prevent its spread in future it may become alarming and difficult to tackle it needs to be mechanically removed otherwise it might infest most