Diversity and Functional Patterns of Benthic Amphipods in the Coralline Intertidal Zones of a Marine National Park, India

Coralline intertidal habitats of marine protected areas (MPAs) are important model systems to investigate species diversity and ecological functioning of benthic communities. Spatial variability of amphipod species composition and functional traits were studied over a 3 year period during the summer season at five intertidal transects of the Gulf of Kachchh (GoK) MPAs, India. A total of 22,706 individuals, comprising 71 species belonging to 40 genera and 23 families, were identified. Aoridae, Dexaminidae, Eriopisidae, Lysianassidae, and Maeridae were the best represented families (68.2% of total abundance). Distinct spatial patterns in the amphipod assemblage structure and functional traits were observed along the horizontal and vertical axes. The results demonstrated that the amphipod assemblage functioning was greatly influenced by the vertical gradient, with generally higher functional diversity (FD) in the lower intertidal zones suggesting increased diversity in resource use strategies, whereas the upper zones showed very little FD possibly due to the prevalence of environmental filtering. As higher species and functional diversities promote better resource partitioning and resilience of the ecosystem, these results are important for the management of MPAs facing the dual challenges of global climate change and anthropogenic pressures.