Sedimentation of particulate material in stratified and nonstratified water columns in the Bombay high area of the Arabian sea

Abstract

Sedimentation of particulate material at 22, 42 and 62 m was recorded at a station in the Bombay High area of the Arabian Sea from September 1985 to March 1986. Diatom numbers and physical structure, especially thermal stratification, played an important role in controlling both magnitude of total flux and nature of sedimented material. Changes in suspended diatom numbers were, with some exceptions, reflected in the sedimented material caught by the traps. Sedimentation of organic carbon was correlated with sedimentation of biogenic silica, especially during January to March. There were positive and highly significant relationships between the flux of TCHO and those of TPM, POC, Chl a equiv. and PSi. From the latter 2 relationships, it was deduced that diatoms were the major source of TCHO at this station. High sedimentation of TPM was associated with high flux of organic carbon and TCHO. This may have a stimulatory effect on benthic organisms and may also enhance the chances of burial of organic matter in sediments