Distribution of chlorophyll a, organic carbon, nitrogen and carbohydrate of particulate matter of Visakhapatnam harbour waters, east coast of India

Abstract

Highest values of chl <i>a</i> (315 µg l^-1), organic carbon (3.98 mg l^-1), total particulate nitrogen (2 mg l^-1) and carbohydrate (3.8 mg l^-1) were obtained in surface waters in August and lowest values respectively of 1.38 µg l^-1 and 1.19, 0.12 and 0.2 mg l^-1 in bottom waters in March/July. Below a chl a value of 45 µg l^-1 at the surface and 16 µg l^-1 at the bottom, a progressively smaller fraction of it seemed to be associated with particulate organic carbon, while beyond this value, a uniform fraction of chl <i>a</i> may be associated with particulate organic carbon. At the maxima (in August), most part of all the organic constituents appeared to be associated with living phytoplankton while at other times, a sizable quantity of each constituent appeared to be associated with detritus, originating predominantly from run-off.