Download Impacts of air pollution on terrestrial and aquatic ecosystem on

Impacts of air pollution on terrestrial and aquatic ecosystem on southern Baffin Island
Introduction. Resource extraction and development is expected to increase as the Arctic becomes more
accessible through climate change, especially in regions along the Hudson Strait and the Davis Strait.
Economic growth may result in elevated atmospheric emissions of sulphur, nitrogen, and heavy metals.
These atmospheric pollutants may have an impact on surrounding ecosystems, as they can travel far
from their sources and be deposited throughout the region. Increased sulphur and nitrogen deposition
can contribute to ecosystem acidification, especially in regions with acid-sensitive terrain that occurs on
Baffin Island. The critical load approach is a method used to estimate the risk of negative impacts from
atmospheric pollution, primarily atmospheric sulphur and nitrogen, to important sensitive biota, e.g.
Arctic char. This is done by linking emissions to the capacity of the ecosystems to resist the effects of
atmospheric deposition
The purpose of this project is to assess the impacts of air pollution on aquatic and terrestrial systems in
the regions of Iqaluit and Kimmirut. Lakes will be sampled for water chemistry to 1) determine critical
loads of acidity for surface waters, and 2) to determine the risk of exceedance (impacts) under modelled
deposition for the years 2010 and 2030. In addition, moss and soil samples will be collected at a sub-set
of the study lakes in the Iqaluit region to assess the spatial variability in atmospheric pollution
concentrations using established moss biomonitoring species (Hylocomium splendens).
Methods. In each study area, i.e., Kimmirut and Iqaluit, approximately 50 lakes will be randomly
selected for sampling. All study sites will be located outside of Inuit Owed Land and Territorial Parks (in
NTS grids: 025N15, 025N16, 025M06, and 025M08). At each lake, a surface water sample (~250 mL) will
be collected from the middle (by Helicopter in the Kimmirut study domain) or from the shoreline (in the
Iqaluit study domain) of the lake for chemical analysis. Moss and soil samples will be collected at a
subset of the lake sites in the Iqaluit region (approximately 20 sites). Where present a sample of the
moss species Hylocomium splendens (~ 5 g) will be collected; in addition, three fixed volume samples of
surface (0 to 10 cm depth) soil (~ 100 g each) will be collected for chemical analysis. Moss is widely used
as a biomonitor of atmospheric deposition, and sampling will be done sustainably, with consideration
for the moss colony's survival. Soil cores will be taken to ensure minimal disturbance to surrounding
vegetation. All samples will be shipped back to Trent University, Ontario, for chemical analyses for major
cations and anions, nutrients, trace metals, and mercury.
Water chemistry results will be integrated in the Steady State Water Chemistry (SSWC) model to
calculate critical loads. Exceedance of critical loads will be calculated for the years 2010 and 2030, from
modelled deposition.
Significance. This project will provide baseline information on lake chemistry and knowledge regarding
the spatial extent and trends of atmospheric pollution. It will inform Environment Canada and Transport
Canada on the impacts of elevated atmospheric deposition including ship-source emissions on Arctic
ecosystems. As such, this project will support the International Maritime Organization’s assessment on
the potential establishment of an emission control area within the Canadian Arctic.