Atharbanki, a mangrove waterway of Mahanadi Estuary(17°49’N-22°34’’N; 81°24’-87°29’E) on the east coast of India has been under considerable anthropogenic pressure. Due to lack of sufficient information on benthos from lesser recognized tropical tidal flats, a one-time (21.01.2015) investigation (N=21) from seven GPS fixed locations along a shore transect (1km) parallel to the channel course revealed 30 benthic species represented by five diverse groups and 1065 individuals. Polychaetes were dominant (55%) followed by the amphipod Eriopisa chilkensis (40%) and others. While Margalef d exhibited relatively high values (mean 2.35) near the mouth (stations1, 2) sites (stations 6, 7) subject to runoff from industries depicted lower values (mean 1). Multivariate measures (PRIMER) revealed two distinct benthic assemblages: Group-1 Namalycastis-amphipod association (stations 1, 4 & 6 exposed to port/industrial activity) noticed within Kandelia, Aegiceras and mixed mangrove foliage (low elevation) and Group-2 amphipod- Dendronereis heteropoda assemblage (stations 2, 3) associated with Excoecaria sp. Station 5 with Acanthus sp. on high grounds of gypsum dumps, populated
mostly with nephtyids and station 7 surrounded by Fisher hamlets) remained similar to stations 2 and 3. K-dominance plots indicated
maximum diversity for sites with mangroves subject to neritic influence (stations 1, 2) whereas mangrove impacted stations 6 &7 subject to human interference recorded least diversity. Mangrove denudation, aquaculture, industrial dump sites appeared to structure the benthic faunal communities of Atharbanki tidal flats.

Estuary, industrialization, macrobenthos, mangroves, polychaetes, tidal flats.