Climate Change–Induced Shifts in Fish Availability and Their Impacts on the Socio- economic Life of Small-scale Fishers in Kerala

Abstract

Climate change is restructuring marine ecosystems globally, but its impacts are especially
pronounced in tropical coastal regions where small-scale fishing communities rely directly on
ocean resources for livelihood, food security, and cultural continuity. Kerala, situated along the
south-western coast of India, is one of the world’s most densely populated coastal belts where
approximately one million people depend on marine fisheries, either directly or indirectly. Over
the last three decades, the coastal waters of Kerala have undergone substantial physical and
biogeochemical transformations: increasing sea surface temperatures, shifts in monsoon timing,
altered upwelling phenology, increasing salinity variability, expansion of oxygen minimum zones,
and more frequent extreme events such as marine heatwaves and cyclonic disturbances. These
environmental perturbations have led to profound changes in fish behaviour, migration, survival,
spawning success, and population dynamics, resulting in observable shifts in species composition,
spatial distribution, and overall availability of fish — particularly small pelagic species such as
the Indian oil sardine (Sardinella longiceps), which historically formed the backbone of Kerala’s
marine economy. This article synthesizes more than two decades of scientific, socioeconomic, and
policy literature to evaluate how climate- induced changes in fish availability affect the
socioeconomic life of Kerala’s small-scale fishermen. Using an interdisciplinary framework, the
article examines environmental drivers, ecological responses of key fish species, long-term
landing patterns, income and livelihood disruptions, community-level vulnerabilities, adaptation
strategies, and the emerging governance challenges. Special attention is given to the collapse of
oil sardine stocks after 2015, which triggered a livelihood shock across multiple districts,
highlighting the interconnectedness of climate, ecology, and society. The background finds that
declines in fish availability have reduced catch per trip, increased the cost of fishing effort,
deepened household debt, triggered occupational shifts, amplified food insecurity, and increased
psychological stress within fisher communities. While adaptation strategies such as gear
diversification, deeper-water fishing, aquaculture uptake, and cooperative models are emerging,
structural and financial constraints limit their effectiveness. The paper concludes by identifying
key research gaps and proposing pathways for climate-resilient fisheries governance in Kerala.