The paper emphasized
that surface water allocations from the Athabasca River used in oil sand mining
are based solely on short-term records. The methods Sauchyn et al. employed were
tree ring reconstruction in water-sensitive conifer species along the Athabasca
River and instrumental hydrologic records. Declines in water flow were found
present in all regions of the Athabasca River Basin, suggesting that current
levels of extraction will not be sustainable long-term.
strength of the paper was the inclusion of greater data ranges, which revealed
previously unknown periods of draught. Sauchyn et al. included tree ring
chronology and instrumental records from 1111 and 1913 onward, respectively,
whereas previous studies were limited to 50-year hydrologic record spans and 200-year
tree ring reconstruction.
The major weakness of the paper was the presence of small
data gaps due to a lack of seasonal records. This missing data could lessen the
accuracy of future surface water allocations, given that climate oscillations
occur during these periods which affect the amount of runoff from the Rocky
Mountains into the Athabasca River.
The paper was well-written, easily accessible and
integrated new approaches in its methods. However, it failed to address what is
considered a sustainable level of water extraction and ways in which this
sustainability could be achieved.
was assigned in order to emphasize the consequences of surface water
exploitation, since the hydrosphere is an essential component of global biogeochemical