Ecological and Socio-Economic Contribution of Artificial Reefs to Small Scale Fisheries in Palk Bay, Southeast India

Abstract

Artificial reefs (ARs) are increasingly deployed as a non-destructive tool for enhancing marine habitat and supporting small-scale coastal fisheries. This study assessed the ecological development and socio-economic contribution of 300 artificial reef modules deployed at three nearshore stations off eight fishing villages in Palk Bay, southeast India, over two consecutive years. Following a six-month post-deployment period without fishing, reef modules underwent progressive colonization by algae and sessile invertebrates, increasing habitat complexity and establishing localized fish aggregations. Monitoring recorded 6,173 individuals across 37 genera in the first year (Shannon diversity H′ = 3.36, evenness J′ = 0.93), rising to 27,756 individuals in the second year, an increase of approximately 350%, while genus richness and diversity indices remained largely stable (H′ = 3.33, J′ = 0.92), indicating that reef maturation enhanced fish abundance without altering community composition. Seasonal abundance peaked during post-monsoon and summer periods in both years, and station wise catch patterns converged as the reef matured, suggesting a spatially uniform aggregation effect. Local fishermen exploited the reefs almost exclusively using low-impact trap fishing, generating monthly incomes of ₹2,000–₹15,000. These findings indicate that the artificial reefs functioned as effective, low-disturbance fish aggregation structures that concentrated fishing effort in accessible nearshore grounds, potentially reducing pressure on adjacent natural coral reefs while supporting livelihood diversification. The results support artificial reefs as a viable complementary strategy for biodiversity conservation and sustainable fisheries management in heavily utilized coastal waters, while highlighting the need for long-term monitoring to confirm associated coral reef recovery benefits.