Annual Report: November 29, 2016
Assessing the impact of small, Canadian Arctic River flows to the freshwater budget of the Canadian Archipelago
Matthew B. Alkire, University of Washington
Assessing the impact of small, Canadian Arctic river flows to the freshwater budget of the Canadian Archipelago (or SCARFs) is a scientific research project funded by the National Science Foundation (USA). The purpose of this project is to collect water samples from different rivers and their adjoining estuaries across Nunavut and the Northwest Territories, Canada, in order to determine how their chemical signatures differ from larger North American rivers such as the Mackenzie and Yukon Rivers and whether these signatures can be used within the ocean to discriminate sources.
During the third and final year of this three-year program, river sites initially sampled during the summer of 2014 and 2015 were revisited. These included the Coppermine, Ellice, Back, Hayes, Kuujuua, Thomsen, Cunningham, Koogaaluk, and Kangiqtugaapk Rivers. Identical to the methods used in 2014 and 2015, river water was collected using a 1 L bottle attached to the end of an extendable pole. After wading into the river and using the pole to collect ~4 L of water from near the central channel of the flow, these bulk samples were filtered on the bank of the river and sub-sampled into smaller bottles for chemical analyses. These analyses will include total alkalinity, stable oxygen isotope composition (d18O), barium, nutrients (nitrate, nitrite, ammonium, phosphate, and silicic acid), major cations (sodium, potassium, calcium, and magnesium), major anions (chloride, sulfate, and bicarbonate), strontium, strontium isotope composition (87Sr/86Sr), and dissolved organic carbon. Using a portable probe and meter, the temperature, conductivity, and pH of the rivers were also measured.
In addition to river sampling, small, inflatable boats equipped with portable, outboard motors (6 horsepower) were used to collect water samples from the regions extending both offshore and alongshore of the river mouths. Samples were collected from 43 different locations (or “stations”) at depths of 0.5, 1, 2, 4, 6, 8, 10, and 15 meters below the surface (depending on the total depth of the water). Water was collected from these various depths using weighted tubes of different lengths that were hung over the side. A peristaltic pump head was attached to the end of a battery powered drill and the water pumped up through the tubes to the surface. After flushing the tubes, water was filtered and collected into small bottles for chemical analyses (identical to those conducted on the river water samples). Two CastAway® CTDs were also lowered over the side of the boat and through the water column to measure vertical profiles of Conductivity/salinity, Temperature and pressure/Depth (CTD). A total of 267 profiles were collected during the 2016 field season. This information proved helpful in making decisions regarding where to collect water samples for chemical analyses. This information will also be used to estimate the volume of freshwater in each estuary.
All necessary permits, licenses, and approvals required to conduct the field work were acquired or renewed prior to our work commencing in August 2016. A comprehensive list is presented in Table 1:
Table 1. Summary of permits, licenses, and approvals acquired to conduct field work in Nunavut and the Northwest Territories.
|Institution or Agency||Permit||Status|
|Nunavut Research Institute||Scientific Research License (02 005 16R-M)||Granted|
|Nunavut Water Board||Approval to proceed without a license (File 8WLC-CAR1617)||Approved|
|Ahiak Area Co-management Committee||License to work within Queen Maud Gulf Bird Sanctuary (NUN-MBS-14-03)||Valid between June & October in 2014, 2015, & 2016|
|Nunavut Planning Commission||Conformity to North Baffin Regional Land Use Plan||Screening completed (File #148254); NIRB file 13YN042|
|Aurora Research Institute||Scientific Research License (15787)||Granted|
|Northwest Territories Water Board||Permission to collect water samples without a license||Granted|
|Inuvialuit Land Administration||License to access private lands||License granted (ILA16HN008)|
|Parks Canada||Research and Collection Permit||Permit granted (AUL-2016-21318)|
|Parks Canada||Aircraft Landing Permit||Granted (Registration #2016065)|
|Parks Canada||Bear monitor business license and firearm permit||Issued 19/07/2016 to Jeff Kuptana|
|Environmental Impact Screening Committee||Review (Registry file #03-16-01)||Project does not meet definition of development|
- Community support
Hunters and Trappers Organizations in Kugluktuk, Cambridge Bay, and Ulukhaktok as well as the Illisaqsivik Society (Clyde River) were contacted for guidance, consultation, and support both before and during field work. Representatives from these organizations aided in the hiring of local residents to act as wildlife monitors. In addition, the field technicians were hired to collect water samples from the Coppermine (Johnny Nivingalok and Jorgen Anablak) and Kangiqtugaapk (Esa Qillaq and Niore Iqaluqjuak) Rivers on a weekly basis between June (after the spring floods) and October (just prior to river freeze-up). The full set of samples has been successfully collected from the Kangiqtugaapk River whereas an abbreviated number (n = 4) were collected from the Coppermine River.
- Field activities
The research team consisted of four members: Matthew Alkire (principle investigator) from the University of Washington, Gregory Lehn (postdoctoral scholar) and Gabriella Kitch (graduate student) from Northwestern University, and Robie Macdonald (consultant and co-investigator) from Fisheries & Oceans, Canada. Co-principle investigator Andrew Jacobson (Northwestern) was unable to participate in field work. The Twin Otter flight crew from Kenn Borek Air, Ltd. consisted of pilot Steve King, co-pilot Tyler Best and engineer Stephen Martyniuk.
Table 2. Coordinates denoting river sampling locations and Twin Otter landing sites.
|River or estuary||N Latitude (decimal degrees)||W Longitude (decimal degrees)|
|Kuujuua River estuary||71.270||116.810|
|Thomsen River estuary||74.219||119.626|
|Ellice River estuary||68.068||103.954|
|Back & Hayes Rivers estuary||67.306||95.167|
3.1. Kuujuua River
Samples were collected from the Kuujuua River on August 2, 2016 at a location ~1 km farther upstream from the sampling sites visited in previous years. The water at the typical sampling sites exhibited high conductivity, indicative of significant intrusion of saline waters from the estuary. Therefore, samples were instead collected from a location just upstream of a small set of rapids that effectively halted the progression of saline waters beneath fresher river waters. In addition to the river sampling, two stations were occupied within the estuary using the inflatable boats. Water samples were collected from depths of 0.5, 1, 2, 4, and 6 m at each station. A second trip to the estuary to collect water samples on August 3, 2016 was cut short due to rough sea conditions. The height of the waves was deemed too large to safely conduct sampling operations using the small, inflatable boats. The following day (4 August), sea conditions had calmed significantly and water samples were collected from three additional stations in the estuary (bottom depths < 6 m). Preliminary results from CTD profiles conducted in the estuary during water sampling activities suggests water from the river was mostly confined close to shore on the southern side of the river mouth. These conditions closely resembled those encountered during sampling activities in 2015. This coastally confined distribution of the river plume suggests the surface circulation may be primarily driven by winds.
3.2. Thomsen River
Water samples were collected from the Thomsen River, at the location listed in Table 2, on August 6, 2016. The Kenn Borek pilots also scouted potential landing sites to support the estuary sampling further north near the mouth of the river but no landings were attempted due to low fuel. Unfortunately, there were few sites that appeared promising. The uncertain conditions motivated the research team to come up with alternative options to sample the Thomsen River estuary. We decided to land upstream of the mouth and attempt to motor the boats down the river to the estuary where we hoped to collect samples. The following day (7 August), the pilots landed at a position quite close (< 5 km) to where we sampled the river. However, the mud lining the river banks was too deep to allow us to launch the boats from shore; thus, we were forced to abandon sampling plans for the day and reassess options. The pilots once again scouted potential landing sites near the mouth of the river and found two possible locations that would be accessible depending on wind conditions. On August 8, the pilots were able to land at one of the sites scouted the previous day. Water samples were collected from five stations within the estuary. The majority of the stations occupied were located in shallow (< 3 m) water but one station located farther north was relatively deep (~10 m). Two samples of sea ice were also collected to help gauge the geochemical characteristics of sea ice meltwater in the estuaries. The ice was collected from two separate floes of relatively small size using a stainless steel saw. The pieces were sawed off from locations near the top of the ice floes and suspended out of the water (hopefully minimizing seawater intrusion in the brine channels). The pieces of ice were double bagged in gallon-size Ziploc bags and allowed to melt in the dark over a period of two days. The meltwater was then subsampled for determination of salinity, d18O, total alkalinity, and strontium concentration. Preliminary results from the CTD survey suggest that very little river runoff was present in the estuary during the sampling period. Lower salinities (< 10) were confined primarily to the southwestern side of the estuary, very close to the river mouth. The estuary was also quite shallow and a sand bar (aligned east-west) that was exposed at low tide stretched across most of the estuary. However, the mostly shallow bathymetry apparently did not limit the intrusion of saline waters from the bay into the estuary.
3.3. Ellice River
Water samples were collected from the Ellice River (at the same site visited in 2014 and 2015) and its adjoining estuary on August 10, 2016. Bottom depths at our estuary sampling stations ranged from 4 to 10 m. Preliminary results from the CTD survey suggest a similar distribution of the river plume compared to that observed the previous summer. However, while relatively low salinities (12-15) were measured northward of the river mouth, salinities were somewhat higher in 2016 compared to observations in 2015 (31 July). The shape and size of the river plume seemed to be quite similar between the two years but the lower salinities observed in 2015 indicate significant differences between the two periods. Whether these differences are a result of changes in the discharge of the river or external forcing (e.g., winds) requires further investigation.
3.4. Back and Hayes Rivers
Water samples were collected from the Back and Hayes Rivers on August 11, 2016. The sites visited were identical to those previously sampled in 2014 and 2015. The Back and Hayes Rivers both flow into a single estuary. Water samples from four sites in the estuary were collected on August 12, 2016. Stations were located both close to the mouth where the Back and Hayes Rivers enter the estuary as well as > 10 km offshore of the mouth. Vertical profiles of temperature and salinity were collected between these two locations to assess the size and shape of the river plumes and gain a sense of the estuarine circulation. During this CTD profiling, a relatively deep channel was located that ran north-south (along the length of the estuary). Within this channel, water from the Hayes River seemed to be concentrated into a surface flow moving steadily offshore. Surface waters were relatively turbid on the eastern side of the estuary, (likely dominated by water from the Hayes River) and comparatively clear in the central and western sections of the estuary (likely dominated by the larger Back River). Salinities at all locations sampled and profiled (using the CTD) were relatively low; maximum salinities were found to be < 19. The low salinities indicate a large freshwater influence (most likely from the rivers) and significant mixing, as more saline waters were not encountered even in the deeper parts of the estuary. On August 15, we revisited the estuary to collect water samples from one full station as well as surface samples along an east-west transect that crossed the northern extent of the estuary. The primary motivation for the additional sample collection was to locate higher salinity waters reflecting the inflow from Chantrey Inlet to the estuary; however, no higher salinities were discovered. Thus, we conclude that mixing and/or upwelling occurs north of the estuary, resulting in brackish waters that fill the bottom of the estuary, with fewer/less frequent intrusions of higher-salinity waters possible. Preliminary results from the CTD survey confirmed the concentration of freshwater on the eastern side of the estuary and slightly more saline waters (S < 6) on the northwestern side.
3.5. Coppermine River
Water samples were collected from the Coppermine River on August 17, 2016 using a boat rented from the local Hunters and Trappers Organization and piloted by Jorgen Anablak. The following day (August 18), water samples were collected from four sites within the Coppermine River estuary using the small inflatable boats. The bottom depths of these sampling locations were relatively deep (10-15 m), though one site was only ~4 m deep. On August 19, an additional CTD survey was completed to map the extension of the main river plume. In addition, surface water samples were collected from six locations along the main flow of the plume. These samples were collected by first identifying the position of the plume by reading low salinities using the CastAway CTD. After a surface sample was collected, the boat was allowed to drift for 2-3 minutes before the anchor was dropped and another surface sample collected. This operation was repeated until a total of six surface samples were collected. The collection of samples in this manner ensured a wide range of salinities was captured for chemical analyses.
Preliminary results from the CTD profiles collected between August 18 and 19 indicated low (< 5) salinities nearest the three channels of the river mouth that were surveyed. The main plume, however, flowed predominately out of the westernmost channel and along the shore past town before spreading out northward into the estuary. The flow of the river plume followed along the main, deep channel that is used by local boat traffic. The position and extent of the river plume appeared to be similar to that observed in 2015; however, the CTD survey conducted in 2015 did not cover the full westward extent of the plume but instead focused on sampling river water exiting via the central and eastern channels of the delta.
3.6. Cunningham River
Water samples were collected from the Cunningham River on August 20, 2016. Samples from the adjoining estuary were collected on August 22 after a day of fog and high winds prohibited flights from nearby Resolute. The estuary proved to be fairly shallow (bottom depths < 4 m) except for a single, deeper channel that extended in a south-north direction on the western side. The water column was relatively well mixed and saline (25 < S < 26) over much of its area but fresher waters, likely reflecting influence from the river, were concentrated in the southernmost portion, nearest to the river mouth. More saline ocean waters (S ~ 30) were observed at depth within the western channel. The general concentration of lower saline waters in the south of the estuary closest to the mouth was similar to that observed from the more limited CTD survey conducted in 2015; however, lower salinities were observed in this southern region of the estuary in 2016 (compared to 2015). Although we cannot draw definite conclusions from the observations available, we speculate that relatively fresh river waters pile up on the eastern side of the estuary and mix extensively with the more saline waters entering via the deep, western channel prior to exiting as brackish (S > 20) waters. The apparently small amount of freshwater in the estuary is reflective of the small size of the Cunningham River. Using relationships between the drainage area and mean annual discharge of gauged rivers across Nunavut and the Northwest Territories, we estimated the mean annual discharge of the Cunningham River to be only ~10 m3 s-1 (see Table 3).
3.7 Kangiqtugaapk and Koogaaluk Rivers
The Koogaaluk and Kangiqtugaapik Rivers were sampled on August 25 and 26, respectively. The Koogaaluk River was accessed by traveling over land on ATVs with guides Esa Qillaq and Joamine Qillaq. The sampling site on the Kangiqtugaapik River is a short distance from the center of town and was accessed by truck, again with the help of Esa Qillaq. The estuary receiving waters from the Kangiqtugaapik River is also easily accessible from town but it was decided in 2015 that water samples would not be collected from this estuary. This decision was made based on two primary factors: (1) the mean annual discharge of the Kangiqtugaapik River is very small (< 1 m3 s-1; see Table 3) and (2) the river enters a long (> 10 km) fjord that is somewhat isolated from Baffin Bay. Thus, it is not likely that the discharge from this small river has a large influence on the freshwater volume of the Baffin Island Current. We therefore chose to sample another, larger river (the Koogaaluk River) that flowed directly into Baffin Bay. The Koogaaluk River also has a large influence from glacial runoff and therefore also proves intriguing in its geochemical contrast (compared to the other rivers sampled during this project).
The Koogaaluk River estuary was sampled from two freighter canoes, piloted by Esa Qillaq and Jamie Kautuq, on August 27, 2016. Water samples were collected from various depths at four stations and an additional four surface samples were collected while drifting freely within the river plume (to capture the full salinity gradient) in a manner identical to that conducted in the Coppermine River estuary (see section 3.5). Bottom depths ranged between 6 and > 15 m at the stations occupied. Preliminary results from the CTD survey suggest that the extent of the river plume was relatively small. Surface salinities in the region generally exceeded 20 except in the immediate vicinity of the plume, which extended a short distance northeast from the mouth of the river. Vertical profiles of salinity collected to the west of the river mouth indicated no presence of freshwater (i.e., river water). Thus, we speculate that the river plume is quickly mixed with the saline water of Baffin Bay to form the brackish (20 < S < 25) water observed over most of the study region. There may also be a small boundary current of freshwater located close to shore in very shallow waters, but neither samples nor CTDs were collected too close to shore due to breaking waves.
Field work has now been completed for the project but chemical analyses on the samples most recently collected are on-going. However, we can report results acquired from work conducted in spring 2014 and summer 2015. These results represent only a summary and more complete analyses will be reported in two manuscripts that are planned for submission to peer-reviewed journals for publication within the year.
Table 3. Estimates of mean annual discharge of the rivers studied during this project. Discharge was calculated based on a relationship between drainage area and mean annual discharge data available from rivers that have been routinely gauged by Water Survey Canada (http://wateroffice.ec.gc.ca); these data listed where applicable for comparison.
|River||Computed Drainage Area||Estimated Discharge||
|km2||m3 s-1||m3 s-1|
Rivers displaying higher solute concentrations drain the western and/or northern CAA whereas those with lower concentrations drain the eastern and/or southern CAA. For example, the Ellice, Back, Hayes, Kangiqtugaapik, and Koogaaluk Rivers exhibited generally low total alkalinity, silicic acid, barium, and calcium concentrations. In contrast, the Coppermine, Kuujuua, Thomsen, and Cunningham Rivers were associated with higher concentrations of these parameters. Specific geochemical signatures also largely correlated with differences in bedrock geology, with the western and/or northern CAA comprising carbonate bedrock and the eastern and/or southern CAA comprising silicate bedrock. For most of the rivers, the solute concentrations either increased or did not significantly change between sampling periods conducted during spring 2014 and summer 2015. For example, total alkalinity and barium increased by > 300 meq kg-1 and > 14 nM, respectively, at the Thomsen and Cunningham Rivers (i.e., western CAA rivers) but the Ellice, Back, Hayes, and Kangiqtugaapik Rivers (i.e., eastern CAA rivers) exhibited little change.
The stable oxygen isotope composition (d18O) of rivers varies due to different sources of water (e.g., snowpack, rain, and/or groundwater) rather than differences in the geology, mineralogy, and/or vegetation within the drainage basins. In 2014, the Coppermine, Ellice, Back, and Hayes Rivers, had slightly heavier (more positive) d18O than the Kujjuua, Thomsen, and Cunningham Rivers but the Kangiqtugaapik River water (-17.88‰) exhibited the most positive d18O observed during the 2014 study. In 2015, the Karasok River (-16.99 ‰) proved to be the isotopically heaviest river sampled whereas the Koogaaluk River (-21.07 ‰) was one of the two lightest. All the rivers exhibited either no change in the d18O signature between spring and summer 2015 (Back, Kuujuua, and Kangiqtugaapik Rivers) or a transition to a heavier (more positive) d18O value (Coppermine, Ellice, Hayes, Thomsen, and Cunningham Rivers); thus, similar processes may be responsible for these changes across the CAA. For example, a transition to heavier isotopic signatures could be the result of significant evaporation occurring during the summer compared to the spring or a change in the primary water source from snowmelt to more recent precipitation, groundwater, or lake supported flow.
This report as well as all data collected as part of this project are freely available on the project website: www.canadianriversproject.org.
The data sets will be regularly updated as more results are obtained. In addition to the data, tutorials explaining the use of the chemical parameters to learn about the Arctic and subarctic seas have also been made available.
We would like to acknowledge the help and support provided by the Hunters and Trappers Organizations of Kugluktuk, Cambridge Bay, Ulukhaktok, and Sachs Harbour. We would also like to especially thank Johnny Nivingalok, Beverly Maksagak, Betty Haogak, Victoria Akhiatak, Jakob Gearheard, Shari Gearheard, Nelson Perry, Mary-Anne Francey, and Barbara Masaki for their efforts in helping to plan and support field work. Without their efforts, this work would not have been possible. We also thank Thomas Quinn and Matt Irinaga for their outstanding logistical support and safety planning prior to field operations. We would also like to thank Jorgen Anablak, Esa Qillaq and Niore Iqaluqjuak for their hard work extending the timeseries of the Coppermine and Kangiqtugaapik Rivers over the course of the summer. We also thank Jorgan Artaok, Jack Akhiatak, and Ron Kallak for their help acting as wildlife monitors during field work operations. Finally, we thank Wally Dobchuk, Steve King, Tyler Best, and Stephen Martyniuk from Kenn Borek Air, Ltd. for getting our research team to these various field sites safely and securely.
If there are any questions, concerns, or comments regarding this report or work related to the research project, please feel free to contact the principle investigator:
Matthew B. Alkire
Polar Science Center
Applied Physics Laboratory
University of Washington
1013 NE 40th Street
Seattle, WA 98105
tel: (206) 897-1623