Invasive 'alien' fish spreads in Pakistani waters, threatens biodiversity

WWFPakistan has cautioned that an invasive fish species has been detected in water bodies across Sindh and Lower Punjab warning that its spread poses a serious threat to aquatic biodiversity and the fisheries economy Geo TVIn a statement released on January 4 the environmental organisation said an unusual fish was brought to Karachi Fish Harbour from a dhand near Sukkur The species was initially described as alien because it could not be identified by those who encountered itThe fish was later confirmed to be an Amazon sailfin catfish According to WWFPakistan the species has a thick armoured body covered with bony plates and is not native to Pakistan It was accidentally introduced into natural water bodies and has now established itself in Sindh and Lower Punjab Geo TV reportedThe Amazon sailfin catfish is native to Latin America and is popular around the world as an aquarium fish This species is known to be a highly successful invader and since this species is now widely spread in Pakistan its eradication and control are impossible the statement saidWWFPakistan noted that the Amazon sailfin catfish is among 26 invasive fish species that have been introduced into Pakistan either accidentally or deliberately These species the organisation said have become invasive are harming aquatic biodiversity and threatening the fragile balance of local ecosystemsInvasive fish species are known to severely disrupt aquatic ecosystems by outcompeting natives for food and space preying on them introducing diseases and altering habitats leading to biodiversity loss economic damage to fisheries and even ecosystem collapse with impacts ranging from increased water turbidity to native fish extinctions and significant losses in commercial fishing revenue WWFPakistan saidThe organisation added that the spread of invasive species is considered a major threat to sensitive aquatic ecosystems in Pakistan including rivers streams and lakes Geo TV reportedProviding historical context WWFPakistan said brown trout and rainbow trout were the first exotic fish species introduced in Pakistan brought to Khyber Pakhtunkhwa in 1928 In the 1960s several other exotic species including Mozambique tilapia common carp goldfish and grass carp were introduced to boost fish production and control aquatic weeds but all later became invasive and adversely affected native fish populationsDuring the 1980s additional species such as silver carp bighead carp Nile tilapia and blue tilapia were introduced while grass carp was reintroduced to enhance aquaculture All these species also established themselves in natural ecosystems impacting local flora and fauna as environmental consequences were not adequately considered at the time Geo TV reportedThere is no disagreement that these introductions including those of trouts have affected aquatic biodiversity and the natural ecosystem the statement saidReferring to tilapia the organisation said its introduction in the 1960s had devastating consequences for indigenous fish species leading to partial or complete eradication of commercial fish from key water bodies in warmwater regionsFish production from Manchar and Keejhar Lakes was drastically reduced due to prolific breeding and growth of tilapias having a serious socioeconomic impact on the fishermen of the areaWWFPakistan further said that over the past three decades several catfish species including North African catfish walking catfish magur catfish blunttoothed African catfish and channel catfish have been introduced and are now spreading rapidly causing serious harm to local fish faunaIn addition to intentional introductions for aquaculture the organisation said species such as the Amazon sailfin catfish guppies and mollies have entered natural ecosystems due to poor regulation and handling in the aquarium trade as per Geo TVThese fish are creating havoc in natural water bodies especially around cities and towns throughout Pakistan WWFPakistan is cognizant of the ill effects of the introduction of exotic and known invasive species in the countryThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever