Experts identify 36 fish species in Karnali River

  • Environmental DNA method of identifying fish debuts in Nepal, a first in South Asia
- Post Report, Kathmandu

Apr 22, 2018-

A new scientific method of identifying different fish species has debuted in Nepal with researchers listing 36 unique varieties from 12 different families in Karnali River.Experts used the Environmental DNA (eDNA) identification method for the first time in all of South Asia. They say this pioneering method will help in conservation of biodiversity.

Country Co-ordinator for the US Forest Service International Program in Nepal Nicolai Stoehr said, “Nepal can do cutting-edge science. Three years ago, a major scientific journal described eDNA an ‘emerging tool in conservation’. The project marks the first use of this technology—not just in Nepal, but also in all of South Asia. You should all be proud of the great scientific research and the minds behind it.”

The eDNA identifies fish using meta-barcoding method. The researchers identified 13 new species not detected earlier during catchment and genetic analysis. eDNA makes the method more scientific and significant in conservation. 

“The eDNA technology enables users identify different species of fishes at a specific site by analysing the DNA traces in water samples. Analysing a scoop of water can now replace weeks of labour-intensive sampling work. This eDNA tool can provide a quick and accurate input for environment impact assessment and other research,” said Stoehr.

The Nepal Fish Biodiversity Project (NFBP) carried out the study. NFBP is a two-year project implemented by the Centre for Molecular Dynamics - Nepal (CMDN).

The NFBP aims to build a morphological and genetic database of fish species in the Karnali River that helps to define and conserve country’s fish biodiversity. The project used three different methods to identify fish.

The project conducted three field samplings at nine sites in two different seasons between May 2016 and October 2017. Researchers with the help of local fishermen collected fish samples for morphological and genetic analysis.  

Of the 629 fish captured during all three phases, experts identified 51 species through genetic analysis.  They identified 33 unique species in the first phase and 35 in the second phase of the studies through genetic analysis.

The researchers used DNA barcoding genes12S, 16S and COI for accurate results. 

Identifying fish by morphological features is often misleading since it relies on their external features, CMDN Executive Director Dibesh Karmacharya said, “Through the eDNA method the experts identified more species of fishes. They were highly cryptic species and low in abundance, therefore, they could not be easily caught using traditional fishing methods. The eDNA study also found some fishes non-native to the region.

“Biodiversity is understudied in Nepal. The situation is more profound when it comes to aquatic biodiversity. With just a scoop of water, it can said be that what living organisms are in the water.

“The technology can make things easier for policy makers and conservationists by giving them access to information. It is different compared to conventional methods of studying biodiversity as it gives reliable data with limited resources,” he said. 


Published: 22-04-2018 07:00

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