Productivity parameters in relation to hydrography of the inshore surface waters off Visakhapatnam

Abstract

Time -scale study on physico -chemical and productivity parameters of inshore surface waters was carried out from two fixed stations at the outer harbour off Visakhapatnam during 1986 -90. The inter -relations between various parameters were studied and discussed in the background of upwelling and sinking processes along this coast. High values of chlorophyll -a (14.1 mg m -9), phaeopigments (28.8 mg m -') and primary production (1552.7 mg C mJ d -I) were recorded in the study. SST and dissolved oxygen showed negative relation with productivity and pigments while phosphate, silicate and nitrate showed positive relations with productivity parameters. The anomaly in the trend of SST and salinity during 1987 -88 is attributed to the influence of changes in major ocean -atmospheric processes. Based on the results, the need for continuous monitoring of hydrographic parameters from fixed stations is suggested.