Comparative study of sterols in shelf and slope sediments off northeasternTaiwan

Bottom sediments and suspended matter from the shelf and slope areas off no rtheastern Taiwan were analyzed for sterol, n-alkanol and n-alkane composit ions. The Sigma (algal sterols/cholesterol) ratios (mean +/- 1 sigma) were 1.00 +/- 0.31 (n = 7) for the shelf sediments, 3.29 +/- 0.61 (n = 7) for th e slope sediments, and 1.54 +/- 0.19 (n = 3) for the suspended matter. The much higher proportion of cholesterol in the shelf sediments is most likely derived from mollusks in the relict sediments. An additional sterol source for the shelf sediments probably is suspended matter in the water column a lthough the shelf has no apparent sedimentation. Results from phytol and n- alkanols suggest recent inputs of lipids from the water column to the shelf . The stanol/stenol ratios are lower for the older shelf sediments than for the younger slope sediments. (C) 2000 Elsevier Science Ltd. All rights res erved.