[Dr R Sangno]
A growing ecological crisis beneath the waters
Across the pristine hills and valleys of Arunachal Pradesh, rivers and mountain streams have long been considered the lifeline of local communities and one of the richest freshwater ecosystems in the eastern Himalayas. However, a worrying environmental crisis is gradually unfolding beneath these waters.
During several of my angling expeditions across different districts of the state, disturbing patterns have emerged in many rivers, rivulets, and forest streams. Areas that were once biologically vibrant and teeming with fish now appear alarmingly depleted. Local observations indicate that unregulated and ecologically destructive fishing methods – particularly electrocution fishing and fish bombing – are severely damaging the freshwater ecosystem of the region.
Environmental observers and anglers fear that if immediate corrective measures are not implemented, many aquatic habitats in Arunachal may suffer irreversible ecological degradation in the coming years.
Destructive fishing practices threatening river ecosystems
- Electrocution fishing: Among all illegal fishing methods, electrofishing is considered one of the most destructive. In this practice, electric current is passed through water using batteries or generators to stun or kill fish for easy capture.
While this method may provide quick catches, its ecological consequences are devastating.
The electric shock does not selectively target edible fish alone. It indiscriminately kills juvenile fish, fish eggs, small baitfish species, aquatic insects, larvae and nymphs, amphibians and other freshwater organisms.
These smaller aquatic organisms form the base of the freshwater food chain. Their disappearance directly affects larger predatory game fish species like goonch catfish (Bagarius yarelli), golden mahseer (Tor putitora), and chocolate/copper mahseer (Neolisdochil ushexagonolepis), leading to a collapse in the ecological balance of rivers and streams.
It’s a general consensus among the local anglers that repeated use of electrocution techniques can convert once-living streams into biologically barren water channels with drastically reduced biodiversity.
- Fish bombing and explosive fishing: Another alarming practice increasingly reported from remote river systems is fish bombing, where locally made explosives are detonated in water bodies.
The explosion instantly kills fish within a large radius, including mature breeding fish, fingerlings, and rare indigenous species,
Additionally, the shockwaves destroy aquatic vegetation, disturb riverbed habitats, and wipe out microorganisms essential for maintaining water quality and nutrient cycling.
Unlike sustainable fishing methods, explosive fishing leaves long-term ecological scars on freshwater ecosystems.
Decline of indigenous fish diversity
Arunachal is home to numerous indigenous freshwater species adapted to fast-flowing Himalayan rivers. Many of these species depend on healthy populations of small baitfish and aquatic insects for survival.
However, continuous ecological disturbance has significantly reduced natural breeding grounds, food availability, and habitat stability. As a result, anglers and local communities have observed a sharp decline in fish abundance in many rivers that were once considered highly productive.
The disappearance of smaller aquatic organisms is particularly concerning because it disrupts the entire aquatic food web. Without them, larger commercially and ecologically important fish species struggle to survive.
Lack of scientific monitoring and institutional research
One of the major concerns raised by environmental enthusiasts is the absence of a dedicated institutional mechanism in the state to systematically study anthropogenic impacts on freshwater biodiversity river ecosystem degradation, fish population decline, and impacts of illegal fishing techniques.
Despite possessing one of the richest river networks in India, Arunachal still lacks comprehensive freshwater ecological monitoring systems.
Environmental experts believe that scientific research and long-term biodiversity assessment are urgently required to understand the scale of damage and to formulate evidence-based conservation policies.
Ecotourism potential at risk
The rivers of Arunachal possess enormous untapped ecotourism potential. Adventure angling, river tourism, biodiversity exploration, and nature-based tourism could generate substantial livelihood opportunities for local communities while promoting conservation.
Globally, sustainable recreational angling has emerged as an important ecotourism sector capable of generating rural employment, encouraging conservation awareness, promoting local homestays and tourism, and supporting community-based resource management.
However, the continued destruction of aquatic ecosystems threatens these future economic opportunities.
If freshwater biodiversity continues to decline, the state risks losing not only its ecological wealth but also a valuable sustainable tourism resource.
Possible solutions and the way forward
A multi-dimensional strategy is necessary to protect Arunachal’s fragile freshwater ecosystems.
- Public awareness campaigns:
Many local communities may not fully understand the long-term ecological consequences of destructive fishing practices. Awareness programmes in villages, schools, and fishing communities can help promote responsible resource use.
- Promotion of sustainable fishing practices: Traditional and sustainable fishing methods that allow selective harvesting without damaging the ecosystem should be encouraged.
Training programmes on seasonal fishing regulations, catch-size limitations, community river conservation, and scientific fishery management can help reduce ecological pressure on rivers.
- Incentives for conservation:
Community participation is essential for river conservation. The government can introduce conservation incentives, community-managed fish sanctuaries, ecotourism partnerships, and alternative livelihood programmes to reduce dependence on destructive fishing techniques.
- Strong legal enforcement: Strict penal deterrence is necessary to curb illegal activities such as electrocution and fish bombing.
Stronger enforcement of fisheries and wildlife laws, including seizure of illegal equipment, and heavy penalties for offenders should be enforced.
Without effective law enforcement, conservation measures may remain ineffective.
Conclusion
The rivers and streams of Arunachal are not merely water bodies; they are living ecosystems that sustain biodiversity, local livelihoods, and future ecotourism opportunities. However, destructive and unsustainable fishing practices are rapidly pushing these fragile aquatic ecosystems towards collapse.
Unless immediate scientific, administrative, and community-driven interventions are implemented, many freshwater habitats may soon become biologically lifeless.
Protecting Arunachal’s rivers today is essential not only for conserving aquatic biodiversity but also for safeguarding the ecological and economic future of the state. (The writer is an avid angling enthusiast)
