Pierre River Mine Project

TERRESTRIAL AENV SIRS 44 – 78
Question No. 70
Request Volume 2, SIR 458c iv, Page 23-136.
Section 13.1
Shell was requested to discuss the usable corridor width once the buffers, or
zones of influence, along the disturbance edge had been applied. Shell
acknowledges that the corridor may only be used by 50% of black bears all of the
time, or that all black bears will use it 50% of the time. Regardless, the
implication is that the corridor will be 50% effective for black bears given its
proximity to development. Shell does not however describe the effective
corridor width once appropriate buffers have been applied for other KIRs.
Sensory disturbance is known to affect several of the KIRs as indicated in the
model descriptions provided in Appendix 5-4 of the EIA Volume 5 (e.g., Distance
to nearest road was found to contribute negatively (-) to the most strongly
supported RSF model for moose (EIA, Volume 5, Appendix 5-4 Page 14);
Distance to nearest edge C (-) was also a contributing negative factor in the most
strongly supported model for fisher/marten).
70a Discuss the effective corridor width along the Athabasca River after appropriate
disturbance buffers have been applied along the disturbance edge, for all KIRs.
Response 70a Effective habitat quality within the corridor is projected to decrease for some
KIRs. However, a decrease in effective habitat quality should not be interpreted
as a decrease in effective corridor width. To be effective, habitat within a
corridor does not need to satisfy all the life history requirements of the species
that use it (Rosenberg et al. 1997). The purpose of a corridor is to maintain
landscape connectivity, which helps maintain population viability by promoting
gene flow between patches and increasing the effective size of populations (Noss
and Harris 1987, Beier and Noss 1998, Olsen et al. 2007). To be ultimately
effective in maintaining genetic connectivity, the corridor only needs to facilitate
passage of at least one effective migrant per generation (Mills and Allendorf
1996, Wang 2004). Although sensory disturbance may decrease the
attractiveness of the corridor for some species, it is unlikely to exclude species.
Documented evidence of wildlife species using corridors adjacent to operational
mines in the Oil Sands Region that are in some locations less than 250 m wide is
discussed in AENV SIR 69a.
Although sensory disturbance affects all KIRs, buffers are only used to represent
sensory disturbance for black bears. For black bears, a 250 m sensory disturbance
buffer is applied around all roads and industrial facilities, within which HSI
values are multiplied by a disturbance coefficient of 0.5 (EIA, Volume 5,
Appendix 5-4, Section 1.2.5, p. 33). The effects of proximity to disturbance are
incorporated implicitly into the moose, Canada lynx, fisher marten, blackthroated
green warbler and barred owl models, but cannot be partitioned in terms
of disturbance buffers (EIA, Volume 5, Appendix 5-4, Section 1). Canadian toad,
black bear, beaver and yellow rail are also affected by water table drawdown,
which is represented as a 0.1 m isopleth.
April 2010 Shell Canada Limited 13-61
CR029