|
||||||||||||||||||
 |
|
|
|
Location map | |
|
|
Research project 3: New project |
Mercury transport and fate in rivers and lakes of British Columbia |
|
|
||||
|
1- |
Identification |
||
| 2- |
Project summary |
|||
|
(word version) |
|||
|
|
|
|
|
|
|
|
||||||
|
 |
2 |
Work in progress on Hg-DOM dynamics to be completed in 2003/04 involves: |
|||
|
1. Determination of the concentrations and masses of mercury being transported by major BC rivers in the dissolved, particulate and adsorbed phases. This will provide baseline data, partitioning coefficients between dissolved Hg and Hg adsorbed on particles, and help put perspective on the magnitude the human impact on the modern Hg cycle in BC.
2. Determination of the concentrations of total, labile and MeHg in west coast lake sediments and pore waters through the Holocene (12,000 year record) and determination of the total volume and mass of lake sediment and Hg contained in the sediment package by sub-bottom seismic profiling. This work also maps the distribution of methane in lake sediments – of probable importance for the remobilization of Hg to the SWI. As clearly illustrated by atmospheric gases in ice cores, understanding long term history greatly assists in forming perspectives on recent observations. 3. Determination of lake sediment physical properties important for the potential remobilization of Hg. Permeability and diffusion rate constants are being determined by in-situ experiments using dialysis samplers and fluorescent tracers. 4. Method development for the detection of Hg and MeHg by CVAFS-gold trap and ICP-MS in several media including fish, zoo-plankton, sediments, and waters and participation in the COMERN interlaboratory calibration program. Important for enabling Hg research on the west coast and for developing new better methods. 5. Method development for characterizing DOC species and their associated Hg contents through a combination of HPLC size exclusion chromatography, fraction collection, stable isotope spiking, and ICPMS. New work on Hg-DOC dynamics: during the last 2 years considerable efforts has been put into developing liquid chromatography methods for the speciation of DOM into size fractions and to determine the concentrations of elements complexed to them. [spiking experiments with stable isotopes of Hg followed by ICPMS detection are also possible but have not yet been performed]. In collaboration with another project (the NSERC NCE Geomatics for Informed Decisions subproject: Spatial Data Fusion to Assess Coastal Environments) we would like to (1) continue to investigate the relationship between size fractions of DOM and Hg with the ultimate aim of finding aqueous partitioning coefficients; (2) optimize methods for detecting DOM and its spectrally discernable components with remote sensing tools; (3) empirically calibrate this effort to concentrations of complexed metals on a watershed by watershed basis; and (4) extrapolate these relationships to large areas and through time (seasonally) using hyper spectral airborne sensors and perhaps ultimately satellites. This methodology will also be applied to other spectrally active components of the water column such as plankton, which have important relationships to Hg. Other researchers in this project will be determining land use and land use changes for the study areas and so the impacts of land use on fluxes of DOM, plankton communities, and suspended sediments and their associated mercury can also be investigated. A hierarchical method will be used: (i) discrete water sampling combined with field spectro-radiometry, (ii) airborne image acquisition and processing, and (iii) satellite image acquisition and processing. Field data will be acquired in natural conditions which will then be up scaled to airborne and possibly to satellite imagery. The process of up scaling will involve applying semi-empirical and analytical optical models to determine optical water constituents from above water reflectance and defining the optimal wavelengths and width of spectral bands for the determination of water quality parameters that can be related to Hg. This project was previously part of section 3133 (Mazumder et al), but will now on be separated and incorporated into Research Theme 2: “Hg dynamics in aquatic ecosystems”. |
|||||
|
COMERN Head Office: Université du Québec à Montréal, President-Kennedy Bldg – Suite PK-7150 C.P.8888, Downtown STA (Qc) H3C 3P8. Phone: (514) 987-3601, Fax : (514) 987-3635 www.unites.uqam.ca/comern -- email: comern@uqam.ca |
|||||