PARENT SESSION
MA9- Contaminant Mass Budgets in Urbanized Estuaries
Chair: Baker, Joel1, 1 PO Box 38, 1 Williams Street, Solomons, MD, USA
8:00 AM to 12:00 PM - Monday, 18 November 2002
Room Ballroom E
(244) Organic contaminant mass budgets in the northern Chesapeake Bay: Role of particle quantity and quality.
Ko, Fung-Chi*,1, Baker, Joel1, Lee, Chon-Lin2, 1 Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, USA2 Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC
ABSTRACT- High levels of primary production and subsequent grazing, deposition, settling and burial of organic matter combines with river runoff, erosion, and sediment resuspension to drive complex biogeochemical processes in the water column of estuaries. Hydrophobic organic contaminants (HOCs) such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are particle-reactive; their partitioning into particles controls their transport and retention in estuaries. HOCs in urbanized estuaries come from a variety of sources, including industrial and agricultural activities, municipal effluents, atmospheric deposition and tributaries within the basin. During the last decade, we have investigated the distribution and movement of particle-associated HOCs in the urbanized Baltimore Harbor subestuary. The magnitude and relative abundances of HOCs are distinct in different types of particles and in specific areas of the estuary. The spatial and temporal variation of particle characteristics is reflected in the HOC distribution, sources and transport. In this study, the HOC partition coefficients (i.e. Kp = Cp/Cd) of 136 water samples from 22 sites in Baltimore Harbor estuary from 1999 to 2000 were calculated and related to the ambient particle characteristics including total suspended particle concentrations, total particulate carbons, and C/N ratios. Additionally, samples collected every ninth day from one site in Baltimore Harbor between 1997 to 1998 were analyzed to assess temporal variability in HOC levels and partitioning. Statistical comparisons of the concentrations, proportions, and specific patterns of HOC are related to various particle characteristics by using regression analysis and principle component analysis to determine their impact on contaminant mass budgets in the northern Chesapeake Bay.
Key words: PAHs, PCBs, particles, Chesapeake Bay