Temporal Variations of Molecular Records of Sea Surface Temperatures & Plankton Productivity: Assessment of High Resolution signals in Sediment Trap particulates, etc. This research is determining the temporal variability in alkenone production and in the alkenone unsaturation index (UK37) used in the evaluation of sea surface temperature (SST) variations. Analyses are being done on sediment trap materials collected in the Gulf of California at 2 week intervals during the period August 1990 to February 1993. The samples provide an opportunity to test fluctuations in UK37 through multiple nutrient and plankton productivity cycles (including bloom periods of Emiliania huxleyi) over an annual temperature range of ca. 15 Degree C and to directly compare the molecular temperature values with measured SST. Thus, the proposed study will test the veracity of UK37, as defined for normal marine conditions in Pacific waters, over multiple seasonal oscillations and through a broad temperature range. The investigation is also evaluating the molecular record of marine plankton biomass and their diversity through multiple seasonal cycles. The concentration profiles observed for biologically specific compounds will be compared with independent plankton counts obtained from concurrent micropaleontological studies on the same samples by other investigators. Thus, molecular trends will be tested as signals of temporal variability in plankton population dynamics. The analyses will enhance the of molecular signals of environmental and climatic change in the sediment record.//
