Guwahati: Beneath Kaziranga’s world-famous grasslands and floodplains lies a lesser-known but equally vibrant world — one alive with shimmering fins and flowing life.
A new scientific survey led by the Kaziranga National Park and Tiger Reserve (KNPTR) in collaboration with the Wildlife Institute of India (WII) has revealed that the park’s rivers, beels, and marshes are home to 77 species of freshwater fish, making it one of the richest aquatic ecosystems in the Brahmaputra basin.
The report, titled Ichthyofaunal Diversity of Kaziranga National Park and Tiger Reserve, documents 44 species from 18 families recorded between July and September 2025.
When combined with earlier studies, the total count rises to 77 unique fish species, highlighting Kaziranga’s role as a critical refuge for freshwater biodiversity in Northeast India.
The study, spanning 16 sites across Kohora, Bagori, Agoratoli, Burhapahar, Lahorijan, and the Karbi Anglong foothills, paints a dynamic picture of how fish diversity thrives in the park’s ever-changing waters.
The Cyprinidae family (carps and minnows) emerged as the most dominant group, followed by Danionidae, together accounting for nearly half the total fish species.“Kaziranga’s aquatic world is as rich and complex as its terrestrial ecosystem,” said Dr Sonali Ghosh, Field Director, Kaziranga National Park, who led the study.
“The rivers, beels, and marshes here are not just habitats for fish — they are lifelines that sustain otters, fishing cats, waterbirds, and local livelihoods beyond the park’s boundaries.”
The Kohora and Bagori Ranges emerged as biodiversity hotspots, hosting the highest fish richness, while Lahorijan and Karbi Anglong supported rare, localized assemblages. Researchers say these distinct communities reflect both the ecological diversity and vulnerability of Kaziranga’s aquatic habitats.
Among the 77 species documented, several are of conservation concern under the IUCN Red List — including Wallago attu (Vulnerable), Clarias magur (Endangered), Botia rostrata (Vulnerable), and Chitala chitala (Near Threatened).
These species form vital links in Kaziranga’s aquatic food web, supporting predators like otters and fish-eating birds such as the Grey-headed Fish Eagle.“Fish are not just food for larger animals — they are ecosystem engineers,” explained Dr Abhijit Das, Scientist at WII.
“They recycle nutrients, regulate aquatic vegetation, and even influence water quality. The loss of fish diversity can disrupt the entire floodplain ecosystem.”
The report warns that climate change, siltation, and altered hydrology from upstream dams pose growing threats to Kaziranga’s aquatic balance.
These factors can disrupt the natural flood pulse — the seasonal rhythm that connects rivers to wetlands and drives breeding, feeding, and migration in fish populations.“Maintaining hydrological connectivity between the Brahmaputra and Kaziranga’s wetlands is crucial,” the authors note.
“When that link weakens, both biodiversity and ecosystem resilience decline.”
While fishing is prohibited inside the park, the study also highlights the cultural link between fish and the communities living around Kaziranga. Traditional fishing practices, especially during festivals like Bhogali Bihu, remain a cherished part of Assamese life. The report calls for greater community engagement to protect fish populations through awareness and regulated fisheries outside the park boundaries.
The findings position Kaziranga as a living laboratory for studying floodplain ecology — a place where the flow of the Brahmaputra creates, nourishes, and renews life in endless cycles. “This survey gives us a snapshot of an ecosystem in motion,” said Dr Ghosh. “It reminds us that Kaziranga’s strength lies not just in its rhinos and elephants, but in the hidden, flowing life beneath its waters.”
With 77 species — from the delicate Parambassis lala to the powerful Wallago attu — the study redefines Kaziranga not only as India’s wildlife crown jewel but also as one of its most significant freshwater biodiversity strongholds.
Also Read: Not just rhinos: Kaziranga home to over 108 species of frogs and reptiles
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