Nagaland University researchers are collaborating with the local communities to study and conserve indigenous fish species in the state’s Dikhu River, officials said on Tuesday.

A varsity official said that this research integrates traditional ecological knowledge from local villagers to better understand fish diversity, fish species assessment, indigenous fishing techniques, and community-based fishing practices, an approach that is uncommon in scientific studies in the region.

Advertisement

The Dikhu River, which flows through the Mokokchung and Longleng districts of Nagaland, is one of the most important tributaries of the Brahmaputra River and is home to many freshwater species crucial for local biodiversity and the economy.

The study underscored an urgent need for focused conservation efforts in the river systems of Nagaland, the official said, adding that these systems support a unique and rich biodiversity but are threatened by increasing human encroachment and unsustainable practices.

It showed that the Dikhu River is not only vital for local communities but also plays an important role in global conservation efforts, he pointed out.

The research team from the Zoology Department, Nagaland University (Lumami Campus) and ICAR-National Bureau of Fish Genetic Resources, Lucknow, aimed to explore and document the ichthyofaunal diversity of the Dikhu River.

The team focused on the lack of comprehensive data on fish species in the river and the pressing threats these species face due to anthropogenic pressures such as habitat destruction, overfishing, and destructive fishing techniques.

The study, funded by ICAR-National Bureau of Fish Genetic Resources recorded 28 fish species across 6 orders, 13 families, and 3 subfamilies, with Cypriniformes being the most dominant order (67.9 per cent).

The research was led by Dr Pranay Punj Pankaj, Associate Professor, Department of Zoology, Nagaland University (Lumami Campus) and Metevinu Kechu, Research Scholar, Nagaland University and their findings were published in the reputed journals.

Elaborating on the need for such research, Dr Pankaj said: “The study is significant because the Dikhu River and its fish species have received limited attention in scientific literature. Thus, this study makes a valuable contribution to the body of knowledge on the freshwater ecosystems of northeastern India.”

The findings are vital for conservation strategies aimed at preserving freshwater biodiversity in northeastern India, a biodiversity hotspot. Documenting threatened fish species and their population trends will support targeted conservation efforts, he said.

Dr Pankaj said that they need collaborative efforts involving local communities, conservationists and government authorities to ensure the sustainability of river ecosystems. There is also a need for stricter regulations on destructive fishing methods, habitat protection and the promotion of traditional, sustainable fishing techniques as part of an integrated conservation strategy.

The research highlights that many of these species face threats from over-exploitation, habitat degradation, and pollution due to human activities, and underscores the urgency of implementing stricter conservation measures to safeguard these vital aquatic resources, he said.

The researchers also focus on providing solutions to improve fish conservation, including promoting sustainable fishing practices, habitat restoration, and leveraging traditional ecological knowledge from local communities.

Additionally, the study aimed to identify and document these fish species’ conservation status and population trends, focusing on threatened species in the region.

Unlike many studies, this research uses seasonal variation in fish diversity and relative abundance to provide a temporal understanding of how fish populations fluctuate throughout the year. The research identified seasonal patterns in fish abundance, with the post-monsoon season supporting the highest fish diversity and abundance.

The same research team also documented the first-ever record of Garrabirostris, a freshwater fish species previously found in Arunachal Pradesh, Assam, and Bhutan and now recorded in the Doyang and Dikhu rivers. This discovery further enriches Nagaland’s ichthyofauna and highlights the ecological significance of these river systems in maintaining biodiversity.