Recent and historical deposition of mercury (Hg) was examined over a broad geographic area from southwestern Northwest Territories to Labrador and from the U.S. Northeast to northern Ellesmere Island using dated sediment cores from 50 lakes (18 in midlatitudes (41-50 degrees N), 14 subarctic (51-64 degrees N) and 18 in the Arctic (65-83 degrees N)). Distinct increases of Hg overtime were observ...

Interest in calcifying coralline algae has been increasing over the past years due to the discovery of extensive coralline algal dominated ecosystems in Arctic and Subarctic latitudes, their projected sensitivity to ocean acidification and their utility as palaeoenvironmental proxies. Thus, it is crucial to obtain a detailed understanding of their calcification process. We here extracted calcif...

Bacterial community structures and their activities in the ocean are tightly coupled with organic matter fluxes and thus control ocean biogeochemical cycles. Bromodeoxyuridine (BrdU), halogenated nucleoside and thymidine analogue, has been recently used to monitor actively growing bacteria (AGB) in natural environments. We labelled DNA of proliferating cells in seawater bacterial assemblages wi...

Stephen L. Peterson* Ecological succession and climate change are pushing tundra as well as Arctic and subarctic Robert F. Rockwell† lowland plant communities toward increased woody vegetation cover. However, areas Christopher R. Witte† and along the Hudson Bay Lowlands that are over-grazed by hyper-abundant lesser snow geese David N. Koons‡ are experiencing drastic losses of grass, sedge, and ...

This study examined the effects of micro-scale, site and 19 and 21 years of experimental warming on Collembola in three contrasting alpine subarctic plant communities (poor heath, rich meadow, wet meadow). Unexpectedly, experimental long-term warming had no significant effect on species richness, effective number of species, total abundance or abundance of any Collembola species. There were mic...

The paper studies fish population of an isolated lake in the subarctic zone. study features distribution fish, assessment their abundance and size structure were carried out by echometric method using hydroacoustic complexes geoinformation systems. research found that is represented 4 species fish: roach, perch, pike peled, with absolute dominance cyprinids. Their share total number reservoir w...