Paper No. 11
Presentation Time: 10:45 AM


SCOTT, D.B., Earth Sciences, Dalhousie University, PO Box 15000, 1659 Oxford St, Halifax, NS B3H 3V2, Canada and MEDIOLI, Franco, Earth Sciences, Dalhousie University, PO Box 15000, Halifax, NS B3H3V2, Canada,

Thecamoebians and marsh foraminifera from eastern Canada in the Great Lakes to small ponds on Sable Island.

In the last 30 years there have been several studies and published reports on thecamoebians (testate rhizopods) from a variety of areas. Here we present data from 6 areas not published before together with one area previously published (Lake Erie) for comparison. Since 1980 many papers have been published on distributions of thecamoebians from Eastern Canada in both modern sediments as well as material as old as the Pre-Cambrian. In this paper we present new information from three of the Great Lakes (Lakes Erie, Ontario and Superior) as well as data from a remote location, Sable Island, 150km off the coast of Nova Scotia, at the edge of the Scotian Shelf. The inland lakes are completely fresh-water (0-1‰) while the one of Sable ponds is brackish (0-10%). All four sites have abundant thecamoebians but only the Sable Island ponds have both thecamoebians and foraminifera living together in abundance (1000’s/10cc). The assemblages in the Great Lakes are similar to other inland lakes except that below 40-50m depth, the number of testates decreases by 2 to 3 orders of magnitude because of lack of food resources. However, on Sable Island the thecamoebians (and marsh foraminifera) have been transported on bird’s feet over 100km of ocean between this island and the mainland and contain some of the highest living numbers/10cc anywhere else reported. The data from the deep water Lake Superior and are the first thecamoebian assemblages reported from this lake.