GeoSoc - Presentation by Nawaf Nasser


The Carleton University GeoSoc presents... 

A presentation by Nawaf Nasser

When: Friday, November 21st @ 5:30 p.m.
Where: 2130 HP
Refreshments: Snacks and pop will be for sale  

This event is free and open to everyone



Arcellaceans (Testate Lobose Amoebae) as Proxies for Arsenic and HeavyMetal Contamination in the Baker Creek Watershed Region, Northwest Territories, Canada

Heavy metal contamination has been noted to be an issue of concern in lakes and streams throughout the Great Toronto Area (GTA), and many other areas of Canada. Air dispersal of Arsenic (As) and other metals (e.g. Al, Cd, Cu, Hg) resulting from smelting of gold bearing ore is a major environmental issue in the Yellowknife, NT area. Before the installation of efficient scrubbers as much as 10,000 kg of Arsenic trioxide (As203) was released into the atmosphere per day in the early 1950s, resulting in considerable ecological damage. To test arcellacean (well preserved shelled protists) efficacy as bioindicators we carried out Detrended Correspondence Analysis (DCA) and Redundancy Analysis (RDA) on the special distribution of arcellaceans, water property data and ICP-MS metal analysis results from 61 Yellowknife area lakes. Results indicate that in that region As concentration in lake substrate has the greatest influence on arcellacean distribution (10.7% of variance).

Stress-indicating arcellacean taxa (e.g. centropyxids) correlate closely with high arsenic and metal concentrations, while species characteristic of more healthy lake conditions (e.g.difflugids) dominated sites with uncontaminated sites. Research carried out by our group on the distribution of arcellaceans in lakes in the Cobalt mining area of northeastern Ontario yielded similar results.

The preliminary data presented in this study indicates that arcellaceans hold considerable potential as indicators for arsenic and heavy metal contamination. As arcellaceans are shelled and well preserved, temporal changes in species assemblage makeup as preserved in cores, provides a valuable tool for assessing rates of remediation. The success in utilizing this cosmopolitan microorganism in the Yellowknife  area suggests that the group holds great potential as a tool to monitor metal contamination elsewhere in Canada (e.g. GTA).


Nawaf Nasser is a Ph.D. candidate under the supervision of Professor Tim Patterson. His research focuses on utilizing various proxies (e.g. micropaleontological, geochemical and sedimentological) to assess contamination and success of remediation in lakes.

Nawaf holds a B.Sc. in Geology with a Minor in Marine Science from Kuwait University. He recently graduated with an M.Sc. in Earth Sciences from Carleton University, where he investigated the spatial response of arcellaceans, a group of benthic protists, to mining related contamination in lakes in the Yellowknife area, Northwest Territories, Canada.