Abstract
This study provides the first detailed assessment of the spatio‐temporal distribution of benthic amphipods in Chilika Lagoon. Seasonal changes in species composition, diversity, and distribution were analyzed across four lagoon sectors, along with environmental factors influencing these patterns. Thirteen species belonging to seven genera and families were recorded, with Aoridae, Eriopisidae, and Maeridae being dominant. Permutational Multivariate Analysis of Variance (PERMANOVA) and Canonical Analysis of Principal Coordinates (CAP) analyses revealed clear separation between post‐monsoon/winter assemblages and those from pre‐monsoon/monsoon seasons. Amphipod communities differed markedly from earlier records, likely due to long‐term ecological changes in the lagoon, though Quadrivisio bengalensis and Victoriopisa chilkensis persisted, indicating their resilience. Principal Component Analysis (PCA) and Distance‐based Linear Models (DistLM) showed amphipod diversity significantly correlated positively with dissolved oxygen and pH, and negatively with depth and temperature. General Linear Model (GLM) identified dissolved oxygen as the primary driver that can model the amphipod distribution in the studied area. The results of Canonical Correspondence Analysis (CCA) demonstrated that amphipod species show varying degrees of specialization, with F. odishi exhibiting a strong environmental affinity, while most taxa display broader ecological tolerance. In contrast, Quadrivisio bengalensis , Quadrivisio chilikensis , and Ampelisca sp. were associated with higher temperature and higher total organic carbon (TOC). Overall, this study establishes a much‐needed ecological baseline for benthic amphipods in Chilika Lagoon, demonstrating the species‐specific responses to environmental conditions and offering a framework for detecting future ecological change.