Global fish migration collapse threatens food security: systemic drivers and Indigenous solutions under threat

Indigenous communities worldwide have sustained migratory fish populations for millennia through adaptive, place-based practices that integrate ecological, spiritual, and nutritional knowledge. Systems like the Pacific Northwest’s 'Salmon Chief' traditions or the Amazon’s 'taboo zones' for spawning grounds demonstrate how rotational access and seasonal restrictions can maintain biomass without collapse. These practices are often dismissed as 'primitive' in Western narratives, despite evidence that they outperform industrial fisheries in long-term sustainability. The current collapse reflects not just ecological failure but the erasure of these knowledge systems by colonial and capitalist expansion.

The collapse of fish migrations is not an isolated ecological event but a pattern repeated across centuries of colonial water management, from the 19th-century damming of European rivers to mid-20th-century dam-building in the Global South. The Tennessee Valley Authority (1930s) and Egypt’s Aswan Dam (1970s) serve as precedents for how large-scale infrastructure fragments riverine ecosystems, displacing Indigenous communities and disrupting migratory corridors. The Mekong River’s current crisis mirrors the Columbia River’s salmon collapse, where 14 dams and industrial agriculture have reduced wild salmon runs by 90% since the 1960s. These historical patterns reveal a systemic preference for centralized, extractive water governance over decentralized, community-based management.

Cross-cultural comparisons reveal that migratory fish collapse is a symptom of a globalized, industrialized food system that treats rivers as conduits for capital rather than living entities. In Japan, traditional 'satoumi' coastal management practices integrated fish migrations with rice cultivation, sustaining biodiversity for centuries until post-WWII industrialization disrupted these systems. In West Africa, the seasonal flooding of the Niger River once supported massive fish migrations, but colonial-era dams and modern irrigation projects have reduced these runs by 70%. These examples highlight how Indigenous and pre-industrial societies maintained migratory fish populations through reciprocal relationships with water, a model systematically dismantled by Western development paradigms.

Scientific consensus confirms that migratory fish populations are collapsing due to a combination of habitat fragmentation (dams, urbanization), overfishing, pollution (agricultural runoff, microplastics), and climate change (warming waters, altered flow regimes). Studies show that 80% of the world’s major river basins are now fragmented by dams, with migratory fish species declining at twice the rate of non-migratory species. Research also highlights the role of corporate aquaculture in homogenizing aquatic biodiversity, as monoculture fish farms outcompete wild species and spread disease. However, much of this science is siloed within Western institutions, often excluding Indigenous ecological knowledge that could refine conservation strategies.

Artistic and spiritual traditions across cultures frame fish migrations as sacred journeys, embodying themes of reciprocity, renewal, and interdependence. In Hindu cosmology, the Ganges River and its fish migrations are tied to the goddess Ganga, symbolizing purification and cyclical time. In Norse mythology, the salmon of knowledge represents wisdom gained through endurance and transformation. Indigenous art forms, from Coast Salish totem poles to Amazonian body paint designs, encode migratory patterns and seasonal cycles, serving as living archives of ecological knowledge. The erasure of these narratives in mainstream discourse reflects a broader devaluation of spiritual and artistic ways of knowing in favor of mechanistic, extractive worldviews.

Future scenarios for migratory fish recovery must account for climate-induced shifts in river flows, the expansion of industrial agriculture, and the political economy of water governance. Modeling suggests that restoring 30% of river connectivity by 2030 could recover 50% of migratory fish populations, but this requires dismantling corporate agribusiness subsidies and prioritizing Indigenous land rights. Scenario planning also indicates that small-scale, agroecological fisheries could provide 60% more protein per hectare than industrial aquaculture while reducing biodiversity loss. However, these pathways are constrained by neoliberal water policies and the financialization of nature, which treat rivers as tradable assets rather than living systems.

Marginalized voices—particularly Indigenous fishers, women smallholders, and coastal communities—are systematically excluded from decision-making about river governance, despite bearing the brunt of migratory fish collapse. In the Mekong, women fishers, who contribute 60% of household protein, are rarely consulted in dam planning processes, leading to the loss of traditional fishing grounds. In the Pacific Northwest, Indigenous tribes like the Yurok and Nez Perce have long fought for dam removals and co-management of salmon fisheries, yet their knowledge is often dismissed as 'anecdotal' in favor of Western scientific models. The erasure of these voices reinforces colonial power structures that prioritize corporate and state interests over ecological and cultural survival.