Nearly 50% of terrigenous materials delivered to the world's oceans are delivered through just twenty-one major river systems. These river-dominated coastal margins (including estuarine and shelf ecosystems) are thus important both to the regional enhancement of productivity and to the global flux of C that is observed in land-margin ecosystems. The tropical regions of the biosphere are the most biogeochemically active coastal regions and represent potentially important sinks of C in the biosphere.

The important attributes of macrobenthic community structure viz., species composition and number, population density, biomass, and dominance and diversity indices were measured at different depths and discussed in relation to pollution of Lake Naini Tal. The zone below 7 m depth, where anoxic conditions prevailed for most part of the year, showed complete absence of macrobenthos.