HR: 0800h
AN: OS51C-03    [Abstracts]
TI: Multi-biomarker Characterization of Sedimentary Organic Carbon along the Mullica River, NJ
AU: * Medeiros, P M
EM: medeiros@marine.rutgers.edu
AF: Rutgers University, Institute of Marine and Coastal Sciences, 71 Dudley Road, New Brunswick, NJ 08901, United States
AU: Sikes, E L
EM: sikes@marine.rutgers.edu
AF: Rutgers University, Institute of Marine and Coastal Sciences, 71 Dudley Road, New Brunswick, NJ 08901, United States
AB: Located in southeastern New Jersey, the Mullica River is approximately 90 km long, extending from the Indian Mills headwaters, through the Pinelands National Reserve to the Great Bay Estuary. The land cover vegetation of the Mullica River watershed (~ 1700 km²) encompasses pine-oak forests (50%) predominantly in the Pinelands followed by wetlands (36%) especially towards the estuary, representing one of the most pristine areas in the state. Sources and potential transformations of sedimentary organic carbon along the Mullica River were assessed using a natural multi-biomarker approach. Sediment samples were collected from the Pinelands to the bay and analyzed as silylated total extracts by gas chromatography-mass spectrometry. The primary biomarker classes found in the samples included n-alkanoic acids, n-alkanols, phytosterols, triterpenoids and saccharides. In general, sediment extracts composition reflected changes in the characteristic main cover vegetation along the river. The major biomarker contributions in the Pinelands sediments were phytosterols (sitosterol, stigmasterol, campesterol), their reduced products (i.e., stigmastanol, campestanol) and triterpenoids (β-amyrin, oleanoic acid) derived from higher plants detritus, followed by n-alkanoic acids and n- alkanols from epicuticular plant wax. Diterpenoids, mainly dehydroabietic acid (a biomarker for conifers), as well as the monosaccharide glucose and the fatty acids 16:0, 16:1, 18:0, 18:1, 18:2 (ubiquitous in biota) were important organic tracers observed in these sediments. The higher plants biomarkers tended to decrease downstream to trace levels in the bay extracts. An exception was the triterpenoid taraxerol (previously identified as a mangrove biomarker) derived mainly from the salt marsh vegetation draining the Great Bay. The higher abundances of the low molecular weight fatty acids (< C₁₉) observed in the estuarine sediments are likely derived from marine phytoplanktonic inputs.
DE: 4825 Geochemistry
DE: 4843 Natural products chemistry
DE: 4850 Marine organic chemistry (0470, 1050)
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly