Environmental Chemistry U6220

Lab #1

Sediment and contaminant dispersion:

Part I:

Prior to coming to lab, please read the following two articles that discuss the dispersion of point-source and non point-source contaminations in river systems.

- "Impact Quantification in trace metal-contaminated river sediments": Helgen, S.O. and Moore J.N. (1996). Environmental Science and Technology. Vol. 30. p. 129-135.

- "Mercury in the sediments of the Gulf of St. Lawrence": Loring, D.H. (1975). Canadian Journal of Earth Sciences. Vol. 12. p. 1219-1237.

Keep in mind these two papers as you establish your set of hypotheses and test them in the following lab. Later on, you will be asked to assess the appropriateness of this initial model based on additional information.

Using these readings, please develop a conceptual model of contaminant transport in the St. Lawrence Estuary system. To do this, answer the following hypothetical situation:

The date is September 1994 and you are a scientist embarking on a oceanographic mission on to test contaminant transport and dispersion within a large-scale coastal system. You will be retrieving 5 sediment cores along the Saguenay River-St. Lawrence Estuary gradient to study both the temporal and spatial distribution of mercury and lignin in this system (See Figure below). The stations are Sag05 (just at the mouth of the Saguenay River), Cap Eternite (about halfway between Sag15 and the mouth of the Saguenay Fjord), StaG2, Sta23, and Sta22 (approximately where the "E" of Estuary appears on the map). Develop a 1-2 pages paper on what you expect to find both vertically in each core and along the flow gradient. Remember, develop the points for both mercury and lignin. This section should be about half of your work. Write concisely and with bullets. In the second half of the paper, develop a discussion on how you anticipate demonstrating your hypothesis about contaminant transport. Particularly, what data and trends in these data you’ll look for to provide supporting evidence for your hypothesis (you will be provided with the actual data later on).