USGS SedTrap

Sediment trap studies help scientists better understand the environmental factors (e.g., temperature, salinity, ocean circulation, nutrient supply, etc.) that control the chemical composition, ecology, and life history of planktonic organisms living in the water column. These planktonic organisms, preserved in ocean sediments as microfossils or molecular fossils, can be used to reconstruct oceanographic conditions in the Gulf of Mexico over the past few centuries to the past few millions of years. Scientists at the USGS are using a long-running sediment trap (2008-2018+) in the northern Gulf of Mexico to calibrate foraminifera, biomarker, and other micropaleontological proxies for use in climate reconstructions. The sediment trap mooring has been deployed in the Gulf of Mexico (27.5 ºN, 90.3 ºW) at 700 meters water depth from 2008-2018. It is programmed to rotate every 7-14 days throughout the year, resulting in a weekly to bi-weekly resolution time series of sinking particle flux. Samples are recovered from the sediment trap once every 9-12 months. On these cruises water is collected via the CTD for isotopic and trace metal analysis, as well as to measure parameters of the carbonate system (dissolved inorganic carbon, total alkalinity, pH). Sometimes live foraminifera are collected with a plankton net for additional geochemical and genetic analyses.