The Philippines' Lake Sampaloc is on high alert as a vibrant but unwanted visitor has taken up residence: the 'flowerhorn' cichlid, a human-bred hybrid fish prized by some aquarium enthusiasts. But this invasive species poses a stark threat to the lake's delicate ecosystem and potentially even human health, according to research conducted by Filipino scientists.
These ornamental fish, with their distinctive head humps, are thought to have escaped from local breeding facilities during a recent typhoon and have now integrated into the lake's ecosystem. They're not only competing with native species for resources such as food and shelter but also thriving in the already polluted waters of Lake Sampaloc. The lake's 104-hectare surface area is already under strain due to sewage, household runoff, aquaculture nutrients, and plastic waste, making it a prime candidate for invasive species.
The native ayungin, or silver perch, once a staple catch in the lake, has become increasingly rare and is now classified as endangered by the International Union for Conservation of Nature. The researchers warn that if left unchecked, the flowerhorns could further deplete the lake's biodiversity and have serious implications for local communities who rely on the water for fishing.
But there's another, more sinister reason to be concerned about these ornamental fish: they've been found to carry a roundworm capable of infecting humans. Some local residents are even observed catching them recreationally and incorporating them into their cooking - a practice that experts advise against due to potential health risks.
Rupert Collins, senior curator of fish at London's Natural History Museum, highlighted the broader implications of this study, stating that the release of non-native species outside their natural ranges is a significant contributor to global biodiversity loss. Dr Noël Juvigny-Khenafou, lecturer in aquatic environmental science at the University of Stirling, noted that climate change could exacerbate such problems by altering aquaculture practices and introducing more non-native species into new environments.