NGT Directs Delhi, Neighbouring States To Restore Native Fish In Yamuna, Curb Exotic Species
Pranav B Prem
The National Green Tribunal, Principal Bench, comprising Justice Prakash Shrivastava (Chairperson) and Dr. A. Senthil Vel (Expert Member), has directed Delhi and neighbouring states to take urgent steps to restore native fish populations and control the spread of exotic species in the Yamuna river. The directions were issued while disposing of a suo motu original application registered on the basis of a news report highlighting the decline of native fish species and the rise of exotic species in the Yamuna. The report referred to a survey conducted by the ICAR–Central Inland Fisheries Research Institute (ICAR-CIFRI), Prayagraj, which recorded 126 fish species across a 1,368-kilometre stretch of the river from Yamunotri to Prayagraj.
The Tribunal noted that the survey found a decline in native species such as Catla, Rohu, Mahseer, and Eel, while exotic species including Common Carp, Tilapia, and Thai Mangur had increased, particularly in polluted stretches. It observed that the minimum number of fish was found in the stretch from Delhi to Mathura, where in certain areas only Thai Mangur was present because of its ability to survive in polluted water.
Referring to the reports of the Central Pollution Control Board and the fisheries authorities, the Tribunal observed that one of the main reasons for the decline of native fish in the Yamuna was pollution, which had reduced dissolved oxygen levels and affected water quality at several monitored locations. It also noted other contributing factors such as dam construction blocking migration routes, habitat alteration, overfishing, illegal gear, climate change, and the introduction of invasive species.
The Tribunal took note of the ICAR-CIFRI study conducted between 2020 and 2024, which found significant variations in fish diversity across the river. While some stretches such as Yamuna Nagar and Pachnada recorded high species richness, the ITO stretch in Delhi, identified as the most polluted site, recorded only one species due to near-zero dissolved oxygen levels.
It also observed that although several agencies had undertaken programmes for preservation of native species, the population of native fish in the Yamuna continued to decline, indicating the need for more effective implementation of conservation measures.
The Tribunal directed the states of Uttarakhand, Himachal Pradesh, Delhi, Haryana, and Uttar Pradesh to consider and implement the recommendations made by ICAR-CIFRI. These included prohibiting illegal fishing gear, strengthening monitoring during fishing ban periods, maintaining proper fish catch records, and undertaking strategic ranching of native species in different stretches of the river.
It further directed the concerned authorities to ensure strict enforcement of effluent standards, continuous water quality monitoring, maintenance of minimum ecological flow, regulation of sand mining, and construction of fish ladders at barrages such as Wazirabad, Okhla, and Hathnikund to facilitate migration of native species.
The Tribunal also directed fisheries authorities to prohibit farming of invasive species like Thai Mangur, promote aquaculture of native species, release fingerlings in identified stretches, and establish hatcheries for species such as Mahseer and Indian carps to restore ecological balance. In view of these directions, the Tribunal disposed of the original application, requiring the concerned states and authorities to take effective steps for restoration of native fish populations and control of exotic species in the Yamuna.
Cause Title: News Item titled "सर्वेक्षण यमुना नदी मेंदेसी प्रजति की मछतियाां घटी, तर्वदेशी बड़ी, सर्वेमें तमिी 126 प्रजाति की मच्छतिया " appearing in Amar Ujala dated 09.05.2024
Case No: Original Application No. 718/2024
Coram: Hon’ble Mr. Justice Prakash Shrivastava, Chairperson Hon’ble Dr. A. Senthil Vel, Expert Member
