Climate Change Impact on Fish Population in Northeast India Rivers

Introduction and Local Context

Climate change has emerged as a significant environmental challenge in India, impacting various sectors including agriculture, health, and natural resources. Among the most affected regions is Northeast India, renowned for its lush biodiversity, intricate river systems, and vibrant cultural mosaic. This region, comprising states such as Assam, Manipur, Meghalaya, Mizoram, Nagaland, Tripura, Arunachal Pradesh, and Sikkim, is shaped by the mighty Brahmaputra and Barak rivers along with their numerous tributaries. The unique topography of hills and valleys, coupled with heavy monsoon rainfall, makes these river systems not only crucial for local livelihoods but also highly sensitive to climatic variations. Traditional communities in Northeast India have long relied on freshwater fisheries for sustenance and income, weaving fishing practices into their cultural heritage. However, rising temperatures, erratic rainfall patterns, and increasing frequency of floods pose serious threats to both the aquatic ecosystem and the socio-economic fabric of this region. Understanding how climate change specifically affects the fish populations in these rivers is vital for developing adaptive strategies that respect local knowledge while ensuring food security and ecological sustainability.

Significance of Fisheries in Northeast India

Fisheries play an indispensable role in the lives of people residing along the rivers of Northeast India, such as the Brahmaputra, Barak, and their tributaries. The riverine fish not only serve as a staple dietary component but also hold deep cultural and economic significance for diverse communities like the Assamese, Khasi, Tripuri, Mizo, and others. Changes brought by climate change directly threaten these interconnected aspects.

Cultural Importance

For many ethnic groups in Northeast India, fish is much more than food. Festivals like Bihu in Assam or Wangala among the Garo often feature traditional fish dishes as central offerings. Rituals and ceremonies frequently incorporate specific river fishes as symbols of prosperity and good fortune. In some tribes, fishing skills are a rite of passage for youth.

Economic Importance

The fisheries sector supports thousands of families through direct fishing activities, local fish markets, and related trades like boat-making and net-weaving. Riverine fisheries provide both full-time and part-time employment opportunities to men and women alike. Below is a simplified table showing some key communities and their economic dependence on river fisheries:

Dietary Significance

River fish is a major source of protein and essential micronutrients for the majority of Northeast Indian households. Traditional recipes—such as Assam’s Masor Tenga or Tripura’s Mui Borok—utilize indigenous fish varieties and form an important part of daily meals. Any decline in fish availability due to climate change could result in nutritional deficiencies and loss of culinary heritage.

The profound reliance on river fisheries means that any climate-driven impact on fish populations reverberates through multiple facets of life in Northeast India, from food security to cultural preservation.

3. Observed Climate Change Effects in the Region

Climate change has brought noticeable shifts in the natural dynamics of Northeast India’s rivers, especially the Brahmaputra and Barak, which are lifelines for millions. Over recent years, local communities and researchers have observed significant alterations in monsoon patterns. The monsoon is arriving either earlier or later than usual, with unpredictable intensity. This variability directly influences river flow, often resulting in sudden floods or prolonged dry spells. Fishers along the Brahmaputra frequently mention that heavy rainfall sometimes leads to flash floods, washing away fish eggs and juvenile fish, thus impacting the future fish population.

Temperature rise is another major concern. The region, once known for its relatively cooler climate, is now experiencing warmer days during both summer and winter seasons. Warmer river water affects the breeding cycles of native fish species like Rohu and Catla, which depend on specific temperature ranges for spawning. Fishermen from Assam often recall how traditional fishing spots no longer yield the same catch as before, attributing this to increased water temperature and changes in river flow patterns.

Extreme weather events have also become more frequent. Cyclones and intense storms not only damage riverbanks but also increase sedimentation in rivers like Barak and Brahmaputra. This sediment overload decreases water quality and disrupts fish habitats, making it harder for indigenous species to survive. Fishers from Manipur narrate how certain stretches of river that once teemed with life are now almost barren after successive flood events.

These changes are not just scientific observations but are deeply felt by local communities who rely on these rivers for their daily sustenance and cultural practices. As climate change continues to reshape monsoon behaviour, river flow, and temperature regimes across Northeast India, the impact on fish populations becomes a pressing concern that demands immediate attention from policymakers and stakeholders.

Impacts on Fish Diversity and Livelihoods

Climate change has brought significant transformations to the rivers of Northeast India, especially impacting fish diversity and the livelihoods of those who depend on these aquatic resources. The region, known for its rich biodiversity, is witnessing a worrying decline in native fish populations and marked changes in species composition. These shifts are not only ecological concerns but also threaten the very fabric of traditional communities along the Brahmaputra, Barak, and their tributaries.

Declining Fish Populations and Changing Species Composition

The erratic rainfall patterns, rising temperatures, and frequent floods attributed to climate change have led to substantial drops in fish catches. Indigenous species such as Labeo rohita (Rohu), Catla catla, and Puntius sophore are becoming less common, while hardy invasive species are gaining dominance. This alteration in riverine ecosystems disturbs the balance and affects overall biodiversity.

Traditional Livelihoods at Risk

The majority of local communities in Assam, Manipur, Meghalaya, and Arunachal Pradesh rely on fishing for both subsistence and income. With shrinking fish populations, many traditional fishers—known locally as Mishing, Bodo, or Karbi—are struggling to maintain their way of life. The drop in daily catches means reduced earnings, making it difficult for families to afford education or healthcare. Some households have been forced to migrate seasonally to urban areas or take up alternative work like day labour or petty trading.

Local Voices: Stories from the Riversides

“Earlier, our nets were always full during the monsoon,” says Ranjan Das, a fisher from Majuli Island. “Now we wait for hours with little catch. The river is changing.”

“My father and grandfather were both fishermen,” shares Pushpa Devi from Barak Valley. “Today, my son wants to move to Guwahati because there is no fish left here.”

Cultural Implications and Urgent Need for Adaptation

The loss of fish diversity strikes at the heart of local festivals, cuisines, and rituals that revolve around river life. As traditional knowledge becomes less relevant under new ecological realities, there is an urgent call for adaptive practices and sustainable fisheries management tailored to Northeast Indias unique socio-cultural context.

5. Community Knowledge and Local Adaptations

In the face of climate change, the indigenous communities of Northeast India—such as the Mishing, Bodo, and Khasi tribes—have shown remarkable resilience by relying on their traditional ecological knowledge (TEK). For generations, these riverine communities have observed seasonal cycles, fish migration patterns, and water quality changes in rivers like the Brahmaputra and Barak. Today, they are some of the first to notice irregularities caused by erratic rainfall, rising temperatures, and shifting river courses.

Traditional Ecological Knowledge (TEK)

The elders and experienced fishers possess a deep understanding of the aquatic ecosystem. They can predict spawning seasons or identify early signs of fish population decline simply by observing subtle changes in water color, flow, or the arrival of certain bird species. This knowledge is often shared orally during community gatherings or family discussions. For instance, many villagers report that Hilsa (Tenualosa ilisha) migrations are delayed or less abundant than before—a direct observation tied to changing water temperatures and rainfall patterns.

Local Grassroot Initiatives

Communities are not just passive observers; they are active adaptors. In Assam’s Majuli island, local groups have started regulating fishing periods during breeding seasons to allow fish stocks to recover. Fisherfolk in Tripura have revived the use of traditional bamboo fish traps instead of modern nets to reduce by-catch and protect juvenile fishes. Additionally, several villages have established “no-fishing zones” based on communal consensus—a grassroots adaptation rooted in both tradition and necessity.

Integration with Modern Approaches

Many NGOs and research bodies now recognize the value of TEK and involve local leaders in participatory river management programs. Workshops conducted in regional languages encourage the blending of scientific data with indigenous practices. By respecting and incorporating community wisdom, adaptation strategies become more effective and culturally relevant for Northeast India’s unique context.

Ultimately, the collective memory and adaptive strategies of these communities highlight a sustainable pathway forward. By valuing local experiences alongside scientific research, Northeast India stands a better chance at protecting its precious riverine fish populations against the unpredictable impacts of climate change.

6. Policy Recommendations and Future Directions

Given the unique ecological, cultural, and socio-economic realities of Northeast India, it is crucial that policy responses to climate change impacts on riverine fish populations are both context-specific and inclusive. The following recommendations outline essential directions for effective intervention.

Need for Context-Specific Policies

The rivers in Northeast India are diverse in their hydrology, biodiversity, and community dependence. Policymaking must therefore move away from a “one-size-fits-all” approach. Policies should be tailored to local climatic conditions, indigenous fishing practices, and specific river systems such as the Brahmaputra and Barak. This can include region-wise vulnerability assessments and adaptive management plans that account for both seasonal variations and long-term climate projections.

River Conservation Strategies

Conserving river ecosystems requires a focus on restoring natural flow regimes, controlling pollution sources, and curbing unsustainable sand mining. Protecting riparian vegetation and maintaining floodplain connectivity are essential to support fish breeding cycles. Strengthening enforcement of existing regulations like the Indian Fisheries Act in collaboration with state-level authorities is also vital for habitat protection.

Promoting Sustainable Fishing Practices

To ensure long-term fishery resources, there must be widespread adoption of sustainable fishing techniques. This involves setting seasonal bans during spawning periods, restricting destructive gear types, and encouraging the use of traditional knowledge. Government agencies and NGOs can facilitate capacity-building workshops and offer incentives for compliance among local fishers.

Community Involvement: The Heart of Effective Action

Communities living along these rivers possess invaluable traditional wisdom regarding local species, migratory patterns, and environmental changes. Their active participation is key to successful policy implementation. Initiatives like community-led monitoring programs, co-management models, and participatory decision-making platforms should be scaled up. Empowering women and youth within fishing communities will also enhance resilience against climate shocks.

Looking Forward: Building Resilience Together

Addressing the climate change impact on Northeast India’s riverine fish populations demands an integrated approach that respects local realities while embracing innovation. By combining scientific research with grassroots action, fostering inter-state cooperation, and prioritising education on climate adaptation, it is possible to secure both livelihoods and biodiversity for generations to come.