Eastern Canadian Arctic Research Articles

Decadal Response of Arctic Freshwaters to Burgeoning Goose Populations

The Arctic is faced with rapid climatic changes, but in some areas, drastic changes in the abundance of herbivores represent an even greater agent of change. Increasing goose populations, especially midcontinent lesser snow geese (Chen caerulescens), have led to an extensive loss of vegetation in terrestrial habitats in the Arctic through heavy grazing and destructive foraging. Our aim was to evaluate the effect of geese on the freshwater systems in their Arctic breeding grounds. We sampled the water chemistry of lakes and ponds across a major goose breeding area in the Eastern Canadian Arctic and compared results to samples taken 13 years earlier to determine whether the changes in water chemistry, if evident, were consistent with effects of geese or of climate. Our results suggest that nutrient loadings have increased while most other parameters associated with the underlying geology and hydrology of the region have stayed in a similar range as a decade ago. The most significant changes were linked to nitrogen and phosphorus; phosphorus concentrations doubled between 2001/2002 and 2015, with the highest levels and greatest changes observed for wetlands inside versus outside of goose breeding areas. Our results suggest that geese are most strongly affecting nutrient loads in freshwaters inside breeding areas, which show evidence of ornithological eutrophication. Nutrient changes of this magnitude, especially in typically oligotrophic Arctic lakes, can have profound consequences on ecosystem structure and function and demonstrate how burgeoning waterfowl populations can act as a vector of rapid environmental change in Arctic freshwaters.

What Do Place-Names Tell about non-Human Beings among Canadian Inuit?

Typologies have been proposed to organise Inuit placenames in several categories based on the meaning of and glosses on the names. One possible category gathers those toponyms that are related to beings that are neither human nor animal (“other-than-animal non-human beings”). In Nunavut and Nunavik (Canadian Eastern Arctic), this category is used quantitatively to name an almost insignificant number of sites. On the other hand, however, such particular place-names are to be found all over the lands inhabited by Inuit, witnessing the “other” nature of this space by comparison to the space commonly frequented by people and animals.

Life history variation across latitudes: observations between capelin (Mallotus villosus) from Newfoundland and the eastern Canadian Arctic

Life history trait variation within a species promotes regional-specific strategies that optimize fitness in a particular environment. Capelin (Mallotus villosus) is an important forage fish species with a circumpolar, temperate distribution, but has increased in relative abundance in Arctic regions recently. To examine for region-specific life history strategies, we compared life history characteristics (length, body condition, age of sexual maturity and growth) of spawning male capelin collected from the eastern Canadian Arctic, in Pangnirtung Fjord, Nunavut (66°N; July 2014 and June–July 2015) with a sub-Arctic location on the northeast coast of Newfoundland (49°N; July 2014 and 2015). First year growth was higher for sub-Arctic relative to Arctic capelin. In contrast, body condition (regression of total length versus mass) was lower for capelin in the Arctic compared to the sub-Arctic population. The age structure of spawning males suggested that Newfoundland capelin reached sexual maturity earlier, as the youngest spawners in Newfoundland were age 2+ (median age: 3+) relative to Pangnirtung where the median spawning age was 4+ (maximum age 5+). Overall, Arctic capelin were generally characterized by lower growth, especially in the first year, later age of reproduction, and lower body condition, relative to the sub-Arctic population. These differences may be the result of limited gene flow on the northern margins of this species’ geographical distribution. They also support previously reported genetic distinction among the sub-Arctic and Arctic clades in the North Atlantic.

Using Inuit traditional ecological knowledge for detecting and monitoring avian cholera among Common Eiders in the eastern Canadian Arctic

Henri, D. A., F. Jean-Gagnon, and H. G. Gilchrist. 2018. Using Inuit traditional ecological knowledge for detecting and monitoring avian cholera among Common Eiders in the eastern Canadian Arctic. Ecology and Society 23(1):22. https://doi.org/10.5751/ES-09289-230122

Cultural Continuity from Pre-Dorset to Dorset in the Eastern Canadian Arctic Highlighted by Bone Technology and Typology

Cultural Continuity from Pre-Dorset to Dorset in the Eastern Canadian Arctic Highlighted by Bone Technology and Typology

Surface Water pCO2 Variations and Sea‐Air CO2 Fluxes During Summer in the Eastern Canadian Arctic

AbstractBased on a 2 year data set, the eastern Canadian Arctic Archipelago and Baffin Bay appear to be a modest summertime sink of atmospheric CO2. We measured surface water CO2 partial pressure (pCO2), salinity, and temperature throughout northern Baffin Bay, Nares Strait, and Lancaster Sound from the CCGS Amundsen during its 2013 and 2014 summer cruises. Surface water pCO2 displayed considerable variability (144–364 μatm) but never exceeded atmospheric concentrations, and average calculated CO2 fluxes in 2013 and 2014 were −12 and −3 mmol C m−2 d−1 (into the ocean), respectively. Ancillary measurements of chlorophyll a reveal low summertime productivity in surface waters. Based on total alkalinity and stable oxygen isotopes (δ18O) data, a strong riverine signal in northern Nares Strait coincided with relatively high surface pCO2, whereas areas of sea‐ice melt occur with low surface pCO2. Further assessments, extending the seasonal observation period, are needed to properly constrain both seasonal and annual CO2 fluxes in this region.

Evidence of molting and the function of "rock-nosing" behavior in bowhead whales in the eastern Canadian Arctic.

Bowhead whales (Balaena mysticetus) have a nearly circumpolar distribution, and occasionally occupy warmer shallow coastal areas during summertime that may facilitate molting. However, relatively little is known about the occurrence of molting and associated behaviors in bowhead whales. We opportunistically observed whales in Cumberland Sound, Nunavut, Canada with skin irregularities consistent with molting during August 2014, and collected a skin sample from a biopsied whale that revealed loose epidermis and sloughing. During August 2016, we flew a small unmanned aerial system (sUAS) over whales to take video and still images to: 1) determine unique individuals; 2) estimate the proportion of the body of unique individuals that exhibited sloughing skin; 3) determine the presence or absence of superficial lines representative of rock-rubbing behavior; and 4) measure body lengths to infer age-class. The still images revealed that all individuals (n = 81 whales) were sloughing skin, and that nearly 40% of them had mottled skin over more than two-thirds of their bodies. The video images captured bowhead whales rubbing on large rocks in shallow, coastal areas—likely to facilitate molting. Molting and rock rubbing appears to be pervasive during late summer for whales in the eastern Canadian Arctic.

Deglaciation of the Laurentide Ice Sheet from the Last Glacial Maximum

The last deglaciation of the Laurentide Ice Sheet (LIS) was associated with major reorganisations in the ocean-climate system and its retreat also represents a valuable analogue for understanding the rates and mechanisms of ice sheet collapse. This paper reviews the characteristics of the LIS at its Last Glacial Maximum (LGM) and its subsequent deglaciation, with particular emphasis on the pattern and timing of ice margin recession and the driving mechanisms of retreat. The LIS initiated over the eastern Canadian Arctic ~116-110 ka (MIS 5d), but its growth towards the LGM was highly non-linear and punctuated by several episodes of expansion (~65 ka: MIS 4) and retreat (~50-40 ka: MIS 3). It attained its maximum position around 26-25 ka (MIS 2) and existed for several thousand years as an extensive ice sheet with major domes over Keewatin, Foxe Basin and northern Quebec/Labrador. It extended to the edge of the continental shelf at its marine margins and likely stored a sea-level equivalent of around 50 m and with a maximum ice surface ~3,000 m above present sea-level. Retreat from its maximum was triggered by an increase in boreal summer insolation, but areal shrinkage was initially slow and the net surface mass balance was positive, indicating that ice streams likely played an important role in reducing the ice sheet volume, if not its extent, via calving at marine margins. Between ~16 and ~13 ka, the ice sheet margin retreated more rapidly, particularly in the south and west, whereas the north and east underwent only minimal recession. The overall rate of retreat decreased during the Younger Dryas (YD), when several localised readvances occurred. Following the YD, the ice sheet retreated two to five times faster than previously, and this was primarily driven by enhanced surface melting while ice streams reduced in effectiveness. Final deglaciation of the Keewatin and Foxe Domes, left a remnant Labrador Dome that disappeared ~6.7 ka.

Taxonomy of the Poa laxa group, including two new taxa from Arctic Canada and Greenland, and Oregon, and a re‐examination of P. sect. Oreinos (Poaceae)

The Poa laxa Haenke species group, comprising four alpine–arctic taxa in P. sect. Oreinos, has a complicated and confusing taxonomic history. Here we re‐examine the taxonomy of the group and section based on sequences of three plastid and two nuclear ribosomal DNA markers. Poa laxa s.l. resolved in a clade with species of sections Abbreviatae, Oreinos, Stenopoa, and Tichopoa. In the plastid analyses, Poa laxa s.s. (type of sect. Oreinos) was placed in a subclade with P. glauca and other sect. Stenopoa species, while all other P. laxa s.l. taxa were placed in a subclade with species of sect. Abbreviatae. We maintain P. laxa s.s. (mainly 2n = 28) of west–central Europe in sect. Oreinos, while the other P. laxa s.l. taxa from northern Europe and North America (all 2n = 42 or higher ploid) are referred to P. sect. Abbreviatae. In North America only one collection of the northern European P. flexuosa subsp. flexuosa is accepted (Greenland, Jensen's Nunatakker), and P. flexuosa subsp. fernaldiana is accepted based on populations in eastern Canada and northeast USA. A new subspecies, P. flexuosa subsp. consauliae, is described from eastern Arctic Canada and Greenland; its variable morphological characteristics suggest introgression with P. glauca and it is predicted to be apomictic. Rocky Mountain P. laxa subsp. banffiana is treated as P. banffiana. Oregon material formerly considered to belong to P. laxa s.l. is named P. wallowensis. Poa sect. Oreinos is thus found to be polyphyletic, and is here emended to comprise only three continental European species, including P. laxa. Lectotypes are designated for P. aspera var. laxiuscula, P. fernaldiana, P. flexuosa, and P. laxa var. debilior. New chromosome numbers are reported for P. flexuosa subsp. consauliae (ca 2n = 42), and P. glauca (2n = 63) from Baffin Island. A key to the species and subspecies found in North America is given.

Sea ice thickness in the Eastern Canadian Arctic: Hudson Bay Complex & Baffin Bay

Past observations of sea ice thickness in the Eastern Canadian Arctic (ECA) have generally been restricted to drill-hole measurements at a few local sites on landfast ice. Here we use data from the laser altimeter ICESat and the radar altimeter Cryosat-2 to present a 14-year record (2003–2016) of high-resolution and spatially extensive ice thickness observations for the ECA and identify 12 sub-regions with distinct patterns. The mean sea ice growth rate within the seasonally ice-covered ECA from November to April is 23cmmo−1 (565km3mo−1), with the fastest increase in thickness occurring through strong ice convergence and deformation in eastern Hudson Bay and Foxe Basin. Our results demonstrate characteristically asymmetrical distributions of sea ice thickness in both Hudson Bay and Baffin Bay, but in opposing directions. In Hudson Bay the spring ice cover is 40cm thicker in the eastern region compared to the northwestern region, whereas in Baffin Bay the ice is 20cm thicker in the western half of the bay compared to the eastern half. In Hudson Bay we find that years with strong and positive ice drift vorticity (i.e. cyclonic and convergent conditions) correlate with increasingly asymmetrical sea ice covers, with the level of west-east asymmetry varying from 2 to 11cm per 100km. However, in Baffin Bay the ice drift vorticity is typically negative (i.e. anticyclonic and divergent) with no obvious link to the asymmetry of the spring ice cover. Finally, we estimate that large interannual variations in spring sea ice volume within the ECA lead to ±15% variations in the volume of freshwater available at the ocean surface during summer.

Hepatic trace element concentrations of breeding female common eiders across a latitudinal gradient in the eastern Canadian Arctic

We examined hepatic concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), manganese (Mn), mercury (Hg), rubidium (Rb), selenium (Se) and zinc (Zn) in 10 breeding female common eiders (Somateria mollissima) from each of three colonies across 20° of latitude. Levels of many elements were elevated in eiders, although generally below levels of toxicological concern. We found significant differences in concentrations of As, Rb, Hg, Mn and Se among colonies, but not in a consistent pattern with latitude, and Hg:Se molar ratios did not vary among colonies. Furthermore, overlap in element concentrations from birds at different colonies meant that we could not reliably differentiate birds from different colonies based on a suite of their hepatic trace element concentrations. We encourage other researchers to assess baseline trace element levels on this important, harvested species, as a means of tracking contamination of nearshore benthic environments in the circumpolar Arctic.

Combining chert provenance and least-cost pathway analyses to reconstruct Pre-Dorset and Dorset mobility on southern Baffin Island

We combine chert provenance and least cost path analyses to investigate Palaeo-Eskimo mobility on southern Baffin Island, in the eastern Canadian Arctic. ICP-AES trace element analysis links chert artifacts from coastal and inland sites to quarries in the interior of the study area. Using a multi-criteria cost surface, we model least cost paths between quarry and occupation sites linked by the results of provenance analysis. These pathways will be used to structure a future program of pedestrian survey in the area between the coast and interior of southern Baffin Island.

Spatiotemporal patterns and relationships among the diet, biochemistry, and exposure to flame retardants in an apex avian predator, the peregrine falcon

Flame retardants (FR) are industrial chemicals and some are proven environmental contaminants that accumulate in predatory birds. Few studies have examined the influence of diet on FR profiles in nestling raptors and the possible physiological implications of such FR exposure. The objectives of this research were (1) to determine spatial patterns of ≤ 48 polybrominated diphenyl ether (PBDE) congeners and ≤ 26 non-PBDE FRs, including organophosphate esters (OPEs), in nestling peregrine falcons (Falco peregrinus) across the Canadian Great Lakes-St. Lawrence River Basin (GL-SLR; 2010) and in the eastern Canadian Arctic (2007); (2) to identify temporal changes in FR concentrations from the mid-2000s to 2010 in GL-SLR peregrine nestlings; (3) to investigate the role of diet using stable isotopes on exposure patterns of quantifiable FRs; and (4) to assess possible associations between circulating FRs and total (T) thyroxine (TT4) and triiodothyronine (TT3), tocopherol, retinol and oxidative status (isoprostanes). The summed concentrations of the top 5 PBDEs (Σ5) (BDE-47, -99, -100, -154, -153) were significantly higher in rural nestlings than urban nestlings in the GL-SLR, followed by the eastern Arctic nestlings. The PBDE congener profile of rural nestlings was dominated by BDE-99 (34‰), whereas BDE-209 (31‰) became dominant in the 2010 urban PBDE profile marking a shift since the mid-2000s. Low (ppb) concentrations of 25 novel non-PBDE FRs (e.g., 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE)) were measured in the nestlings in at least one region, with the first report in peregrines of 15 novel non-PBDE FRs (e.g., 2-ethyl-1-hyxyl 2,3,4,5-tetrabromobenzoate (EHTBB), pentabromo allyl ether (PBPAE), tetrabromoethylcyclohexane (α-, β-DBE-DBCH)) as well as of tris (2-butoxyethyl) phosphate (TBOEP) (0–7.5ng/g ww) > tris(2-chloroisopropyl) phosphate (TCIPP) (0.1–5.5ng/g ww) > tris(2-chloroethyl) phosphate (TCEP) (0.02–2.0ng/g ww) > tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) (0–1.0ng/g ww). Within the GL-SLR, the urban nestlings’ diet had significantly more terrestrial sources (greater δ13C values) than the broader, more aquatic-based diet of rural peregrines. Dietary source (δ13C) was significantly associated with concentrations of Σ5PBDE, BDE-209, EHTBB, and 2,2–4,4′,5,5′-hexabromobiphenyl (BB-153), with trophic level (δ15N) also positively associated with BDE-209 levels. Compared to urban nestlings, the rural nestlings had significantly lower circulating concentrations of thyroxine (TT4), triiodothyronine (TT3), a greater proportion of TT3 relative to TT4 (TT3:TT4), tocopherol and oxidative status (isoprostanes), but higher retinol levels; the most recalcitrant PBDE congener, BDE-153, in combination with low concentrations of some novel FRs, particularly octabromotrimethylphenyllindane (OBIND), may influence circulating thyroid hormones, especially TT4, and retinol levels of peregrine falcon nestlings. These associations of FR-endocrine-biochemical measures suggest possible exposure-related changes in these birds and further study is warranted.

Mercury and persistent organic pollutants in native and invading forage species of the Canadian Arctic: Consequences for food web dynamics

Contaminant dynamics within Arctic marine food webs may be altered through the climate-driven northward invasions of temperate/boreal species. Here, we compare tissue concentrations of total mercury (THg) and legacy and emerging persistent organic pollutants (POPs) in native versus invading forage species sampled from 2012 to 2014 near Arviat, Clyde River, and Resolute Bay, NU, representing, low, mid- and high eastern Canadian Arctic regions, respectively. Concentrations of THg, legacy Σ-polychlorinated biphenyls (ΣPCB) and Σ-organochlorine (ΣOC) pesticides were detected in all forage species, whereas emerging halogenated flame retardants were detected in only a few individuals. Concentrations of major contaminant groups among regions did not vary for Arctic cod (Boreogadus saida), while for sculpin (Cottoidea) there was no clear latitudinal trend. Thus, considering interspecific variation, native sculpin and northern shrimp (Pandalus borealis) had the highest overall concentrations of THg (0.17 ± 0.02 and 0.21 ± 0.01 μg g−1 wet weight, respectively), ΣPCB (322 ± 35 and 245 ± 25 ng g−1 lipid weight (lw), respectively), and ΣOC (413 ± 38 and 734 ± 64 ng g−1 lw, respectively). Comparing the keystone native species, Arctic cod, to its ‘replacement’ species, capelin (Mallotus villosus) and sandlance (Ammodytes spp.), THg concentrations were higher in Arctic cod compared to capelin (p < 0.001), which was partly explained by differences in fish length. Conversely, capelin and sandlance had higher concentrations of most POPs than Arctic cod (p < 0.02). Neither feeding habitat (based on δ13C), trophic position (based on δ15N), nor fish length significantly explained these differences in POPs between Arctic cod, capelin and sandlance. Higher POPs concentrations, as well as variation in congener/compound patterns, in capelin and sandlance relative to Arctic cod seem, therefore, more likely related to a more “temperate”-type contaminant signature in the invaders. Nevertheless, the relatively small (up to two-fold) magnitude of these differences suggested limited effects of these ecological changes on contaminant uptake by Arctic piscivores.

Variability in stable isotopes of snowy owl feathers and contribution of marine resources to their winter diet

The snowy owl is an elusive arctic predator known for its nomadic behaviour. Satellite tracking has revealed that some adult snowy owls could make an extensive use of the marine environment during the non‐breeding season. However, the relative contribution of marine resources to their diet is unknown. Stable isotope analyses can be useful to document the diet of mobile animals during periods of the year when individuals are less accessible. This study aimed to assess variation in isotopic values (δ13C and δ15N) of various feather types, and the usefulness of feathers to determine the contribution of the marine environment to the winter diet of snowy owls captured in summer. We sampled feathers coming from 6 body regions of 18 breeding females at two sites in the eastern Canadian Arctic in 2013 and 2014. Prior to analyses, diet‐tissue discrimination factors of snowy owl feathers were established in captivity. Variability in isotopic values among feather types was relatively low and pairwise correlations in isotopic values between feathers on the same individual were variable and often low, which suggests differences in the diet at the time when various feathers were synthesized. Diet reconstruction models detected a contribution of marine sources to snowy owl feathers ranging from 4 to 19% among feather types. However, the marine contribution was highly variable when single feathers were examined within individuals, ranging from 3 to 71%. This indicated that no single feather type could be used alone to reliably infer the contribution of marine resources to the winter diet of owls, possibly due to a high variability in the timing and sequence of molt. For asynchronous molters like snowy owls, we recommend sampling multiple feathers from various body regions, excluding wing feathers, to investigate winter diet or habitat use.

Mercury biomagnification in food webs of the northeastern Chukchi Sea, Alaskan Arctic

Predictive tools and a large new dataset for the northeastern Chukchi Sea (NECS) are used here to help identify regional differences and potential future shifts in the magnitude of Hg biomagnification in the Arctic. At the base of the food web in the NECS, concentrations of total mercury (THg) in phytoplankton (20-µm mesh) ranged from 4–42ngg−1 dry weight, partly in response to variations in algal biomass and water temperature. A >3-fold increase in monomethylmercury (MMHg) was observed in zooplankton (4.3±0.7ngg−1) relative to phytoplankton (<1.5ngg−1), even though concentrations of THg in zooplankton (150-µm mesh) were not significantly different than in phytoplankton. Concentrations and % MMHg increased with trophic level (TL) by >150-fold and from <10 to >85%, respectively, from phytoplankton to muscle in the whelk Plicifusus kroeyeri (279ngg−1, TL 4.5). For muscle tissue in 10 species plus whole phytoplankton and zooplankton, the trophic magnification slope (TMS) for MMHg (log10[MMHg]=m(δ15N)+b; where m=TMS) was 0.23±0.02 (SE). No significant differences in TMS were found for the NECS plus three other studies from the eastern Canadian Arctic (average TMS=0.24±0.02). Nevertheless, all data for MMHg in biota from the NECS plotted below the combined best fit line for all four studies. Results from an ANCOVA showed that statistically different (p=0.001) intercept values (b), not TMS, best explained the >2-fold lower concentrations of MMHg in biota from the NECS (b=−1.85) relative to the same species from the eastern Canadian Arctic (b=−1.29). Future changes that affect bioaccumulation of MMHg in the Arctic may impact the biomagnification equation by shifting the TMS, intercept or both. The intercept is more likely to respond to changes in productivity and concentrations of dissolved Hg whereas the TMS may respond to changing growth rates due to fluctuations in productivity and food availability. In either case, small changes in the intercept or TMS coincide with predictably large increases or decreases in MMHg concentrations in apex predators.

Outlier analyses to test for local adaptation to breeding grounds in a migratory arctic seabird

Investigating the extent (or the existence) of local adaptation is crucial to understanding how populations adapt. When experiments or fitness measurements are difficult or impossible to perform in natural populations, genomic techniques allow us to investigate local adaptation through the comparison of allele frequencies and outlier loci along environmental clines. The thick‐billed murre (Uria lomvia) is a highly philopatric colonial arctic seabird that occupies a significant environmental gradient, shows marked phenotypic differences among colonies, and has large effective population sizes. To test whether thick‐billed murres from five colonies along the eastern Canadian Arctic coast show genomic signatures of local adaptation to their breeding grounds, we analyzed geographic variation in genome‐wide markers mapped to a newly assembled thick‐billed murre reference genome. We used outlier analyses to detect loci putatively under selection, and clustering analyses to investigate patterns of differentiation based on 2220 genomewide single nucleotide polymorphisms (SNPs) and 137 outlier SNPs. We found no evidence of population structure among colonies using all loci but found population structure based on outliers only, where birds from the two northernmost colonies (Minarets and Prince Leopold) grouped with birds from the southernmost colony (Gannet), and birds from Coats and Akpatok were distinct from all other colonies. Although results from our analyses did not support local adaptation along the latitudinal cline of breeding colonies, outlier loci grouped birds from different colonies according to their non‐breeding distributions, suggesting that outliers may be informative about adaptation and/or demographic connectivity associated with their migration patterns or nonbreeding grounds.

An initial exploration of whether ‘female flight’ is a demographic problem in Eastern Canadian Arctic Inuit communities

ABSTRACTEmigration of indigenous women from small, isolated communities in Alaska and Greenland is seen as a pattern of female flight that results from modernization. As women see more options for a satisfying life, many are leaving remote northern communities. Female flight can result in social, cultural and economic problems for small communities and decrease the sustainability of such locales. We conducted an initial review of census data and found little evidence of female flight across the Canadian Territorial North, in Nunavut specifically, nor in any Nunavut communities. Two study communities in Nunavut, Clyde River and Qikiqtarjuaq were surveyed in an attempt to better understand the factors that affect movement decisions of Canadian Inuit women. Two explanations for the apparent lack of female flight were examined. First, that Nunavut is in an early phase of the demographic transition and thus could expect high migration as it modernizes. The second is that Nunavut communities are modernizing in such a way that young women are choosing to remain at home, and thus the territory is experiencing a unique path to modernity that does not fit the demographic transition model. The evidence more strongly supports the second explanation, although further research is recommended.

Rare earth elements in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic.

Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environmental impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. Northern ecosystems are potentially vulnerable to REE enrichment from prospective mining projects at high latitudes. To understand how REEs behave in remote northern food webs, we measured REE concentrations and carbon and nitrogen stable isotope ratios (∂15N, ∂13C) in biota from marine, freshwater, and terrestrial ecosystems of the eastern Canadian Arctic (N = 339). Wildlife harvesting and tissue sampling was partly conducted by local hunters through a community-based monitoring project. Results show that REEs generally follow a coherent bioaccumulation pattern for sample tissues, with some anomalies for redox-sensitive elements (Ce, Eu). Highest REE concentrations were found at low trophic levels, especially in vegetation and aquatic invertebrates. Terrestrial herbivores, ringed seal, and fish had low total REE levels in muscle tissue (∑REE for 15 elements <0.1 nmol g-1), yet accumulation was an order of magnitude higher in liver tissues. Age- and length-dependent REE accumulation also suggest that REE uptake is faster than elimination for some species. Overall, REE bioaccumulation patterns appear to be species- and tissue-specific, with limited potential for biomagnification. This study provides novel data on the behaviour of REEs in ecosystems and will be useful for environmental impact assessment of REE enrichment in northern regions.

Chironomidae (Insecta: Diptera) from the eastern Canadian Arctic and subarctic with descriptions of new life stages, a possible new genus, and new geographical records

Chironomidae larvae constituted the largest proportion of benthic invertebrates collected from 99 rivers stretching from northern Labrador (latitude 58°N) to northern parts of Ellesmere Island (82°N). We describe 92 species of Chironomidae (mainly larval forms) providing new descriptions, a revision for the adult female of &lt;em&gt;Parametriocnemus boreoalpinus&lt;/em&gt; Gowin &lt;em&gt;et&lt;/em&gt; Thienemann, a possible new genus (larval form only), and 9 larval forms that may represent a new species. In addition, new geographical distribution records are specified for 1 Nearctic species, 6 species in Canada, 10 for Labrador, and 17 for Nunavut. This work contributes to Environment Canada’s International Polar Year output (2007-2009).