INTRODUCTION

An estuary is a partially enclosed body of water along the coast where freshwater from rivers and streams meets and mixes with salt water from the ocean. Estuaries are the potential source for feeding, spawning and are nursery grounds for most of the fin-fishes and shellfishes. (S. Brinda 2010) apart from fishery development. Despite high productivity, estuaries are among the most modified and threatened of aquatic environments, causing imbalances at various trophic levels leading to loss of ecological services and biodiversity, with most Indian estuaries making no exceptions (Blaber et.al 2000; Jha et.al., 2008).

This communication is based on the investigations in two adjoining estuaries of rivers Aghanashini and Sharavathi, within 20-25 km distance from each other, in the Uttara Kannada district (hereafter referred to as UK) of Karnataka State. Aghanashini is unaffected by any major developmental activity, in the context of this paper without anyhydro-electric projects or other kinds of dams, unlike Sharavathi which contributes towards major share of the hydro-electricity of the State.  Estuarine fisheries are a major traditional economic activity of the coast. The present work highlights as to how the dams affected the fish diversity and fisheries income in the Sharavathi estuarine belt as compared to dam free Aghanashini estuary.