Karachi — Environmentalists and conservation groups have raised urgent alarms over the growing presence of exotic fish species in Pakistan’s rivers, lakes, and canals, warning that these invasive species are disrupting ecosystems, endangering native fish, and posing long-term risks to the country’s biodiversity and fishing economy.
The concern intensified after an unusual specimen, later identified as the Amazon sailfin catfish, was caught at the Karachi Fish Harbour, having been brought from a shallow pond near Sukkur. Local handlers were initially puzzled by the fish’s appearance, as it is not native to Pakistan’s waters.
Native to Latin America, the sailfin catfish is a popular aquarium species but is classified as a highly invasive fish capable of spreading rapidly if released into natural habitats. Experts warn that the species has already been detected in parts of Sindh and Lower Punjab, making control and eradication extremely challenging.
According to WWF-Pakistan, the sailfin catfish is just one of at least 26 exotic fish species now present in the country’s freshwater ecosystems. These invasive species outcompete native fish for food and habitat, spread diseases, and can lead to the local extinction of important aquatic species if left unchecked.
Over the decades, various exotic fish such as brown trout, rainbow trout, tilapia, and carp were introduced to boost aquaculture or control aquatic vegetation. While initially beneficial for commercial purposes, many of these species have now established themselves in natural water bodies, displacing native species and upsetting ecological balance.
The ecological disruption has direct economic implications as well. Declining native fish populations reduce fishing yields, affect livelihoods of communities dependent on freshwater resources, and increase water turbidity, making aquatic management more difficult.
WWF-Pakistan has urged the government to strengthen monitoring systems, establish quarantine measures for imported fish, and conduct research on the ecological impacts of invasive species. The organisation also highlighted that invasive fish are now included in the National Biodiversity Strategy and Action Plan, recognizing them as a serious threat under the Convention on Biological Diversity.
Experts warn that without immediate action, Pakistan’s aquatic biodiversity could face irreversible damage, threatening both the environment and the communities that rely on it for food and livelihood. Proactive measures, strict regulation of fish imports, and public awareness campaigns are seen as critical to protecting the country’s freshwater ecosystems.
This story has been reported by PakTribune. All rights reserved.