Impacts of Forest Fires on Water Quality
in the NWT
Suzanne Tank Department of Biological Sciences University of Alberta
Presentation to the NWT Water Stewardship Strategy Implementation Workshop
03 November, 2015
Photo credit: Environment and Natural Resources – Government of the Northwest Territories
Project genesis
Yellowknife workshop in January 2015
• Greater than 100 participants from the GNWT,
and government and university scientists
• Convened as a collaborative effort between the
GNWT and Wilfrid Laurier University
• Focus was to identify research needs coming out
of the 2014 fire season
This research comes as a direct result of the
discussions undertaken during this 2015 workshop
• Input and scientific prioritization from numerous
individuals
• Concerted effort to address GNWT priorities
Fire and Aquatic Ecosystems
Project team
Suzanne Tank (University of Alberta)
Bill Quinton (Wilfrid Laurier University)
Chris Spence (Environment Canada)
David Olefeldt (University of Alberta)
Erin Kelly (GNWT; ENR)
Nicole Dion (GNWT; Water Resources Division)
Two MSc students (Laurier and U. Alberta);
One post-doctoral scientist (U. Alberta)
Grant support: CHARS (now POLAR Canada)
In-kind support: GNWT Water Resources
GNWT CIMP
Wilfrid Laurier-GNWT Partnership
Agreement
Fire and Aquatic Ecosystems
Spence Creek nr. Jean
Marie River, April 2015
PHOTO: Ryan Connon
Over-arching questions
A land-to-water approach to understanding the effects of fire on aquatic ecosystems
How do fire-induced changes to hydrological
flowpaths affect the export of constituents
(nutrients, carbon, toxins) from land to water?
How does fire affect in-stream concentrations and
fluxes of dissolved carbon, nutrients, and toxins?
How do these changes affect aquatic organisms
and aquatic ecosystem health?
How do the effects that we observe within small
landscape units scale to larger landscapes across
a patchy fire mosaic?
Fire and Aquatic Ecosystems
Initial focus
A paired burned-unburned catchment
approach, with catchments located in
the Taiga Shield (Baker Ck, Boundary Ck)
and Taiga Plains (Scotty Ck, Spence Ck)
regions
In both cases, our ‘unburned control’ has
a long history of previous investigation
Baker Creek outflow, June 2015
Boundary Creek burn scar, October 2015
Fire and Aquatic Ecosystems
Initial focus
A paired burned-unburned catchment
approach, with catchments located in
the Taiga Shield (Baker Ck, Boundary Ck)
and Taiga Plains (Scotty Ck, Spence Ck)
regions
Spence Creek, April 2015
In both cases, our ‘unburned control’ has
a long history of previous investigation
Scotty Creek
Fire and Aquatic Ecosystems
Summer 2015 (Year 1) activities
• Snow surveys in burned and unburned catchments
• Installation of meteorological station in the Boundary Creek burn scar
• Installation of wells in runoff producing and receiving areas of burned and unburned
catchments
• Collection of water chemistry samples from catchment mouths, weekly during high
flow, and monthly thereafter
• Water sampled for a broad suite of
constituents, with a focus on nutrients,
organic carbon, PAHs and mercury
• Spence Creek sampling in collaboration
with Jean Marie River First Nation
• Installation of passive samplers in Boundary
and Baker Creek, for integrated
measurements of PAHs
Algal growth in burned catchment nr. Trout River, Taiga Plains
PHOTO: David Olefeldt
Fire and Aquatic Ecosystems
Preliminary results:
Taiga Plains (Scotty Creek) Snow Survey
Data courtesy Elyse Mathieu, MSc student, WLU
Fire and Aquatic Ecosystems
Preliminary results:
Taiga Plains (Scotty Creek) Frost Table
Data courtesy Elyse Mathieu, MSc student, WLU
Late August frost-table depths are 30% greater on
the burned plateau then on the unburned plateau
Fire and Aquatic Ecosystems
Preliminary results:
Taiga Shield Frost Table
Increasing depth
June, 2015
October, 2015
(Burned)
Fire and Aquatic Ecosystems
(Un-burned)
Fire and Aquatic Ecosystems
Conductivity (µS cm-1)
Turbidity (NTU)
Turbidity (NTU)
Conductivity (µS cm-1)
Preliminary results: Water chemistry
Sediments and conductivity
Total P (mg L-1)
Total P (mg L-1)
Total N (mg L-1)
Total N (mg L-1)
DOC (mg L-1)
DOC (mg L-1)
Preliminary results: Water chemistry
Carbon and nutrients
Total Mercury (ng L-1)
Total Mercury (ng L-1)
Total Iron (µg L-1)
Total Iron (µg L-1)
Total Aluminum (µg L-1)
Total Aluminum (µg L-1)
Preliminary results: Water chemistry
Selected metals
Moving forward: Some top-of-mind questions
What do the changes that we see on land mean for:
• Water flowing from land to freshwater systems (well-water chemistry)?
• Overall stream outlet chemistry?
• Will changes on land be reflected in water chemistry during the spring freshet?
Boundary Creek,
October, 2015
PHOTO: Newell Hedstrom
Fire and Aquatic Ecosystems
Selected forthcoming (Years 2-3) activities
• Meteorological station measurements to help understand processes like heat flux,
and effects on thaw depth
• Continued collection of water chemistry samples from catchment mouths, weekly
during high flow, and monthly thereafter
• Sub-catchment sampling in burned an unburned catchments, to target areas of
varying permafrost coverage and other landscape characteristics
• Sampling of algal biomass, and
invertebrate toxin loads
• Sampling of well-water chemistry
• Additional survey-based work, to
assist with extrapolation of findings
to the broader landscape
Spence Creek nr. Jean
Marie River, April 2015
PHOTO: Ryan Connon
Fire and Aquatic Ecosystems