Northeastern Manitoba Research Articles

Foxes engineer hotspots of wildlife activity on the nutrient-limited Arctic tundra

Predators largely affect ecosystems through trophic interactions, but they also can have indirect effects by altering nutrient dynamics and acting as ecosystem engineers. Arctic foxes (Vulpes lagopus) are ecosystem engineers that concentrate nutrients on their dens, creating biogeochemical hotspots with lush vegetation on the nutrient-limited tundra. Red foxes (V. vulpes) similarly engineer subarctic environments through their denning behavior, and have recently expanded onto the tundra where they now often occupy historical Arctic fox dens. We evaluated the impact of fox denning activity on the spatial behavior of other tundra wildlife by comparing predator and herbivore visits to 12 natal dens and adjacent control sites over two years using camera traps in northeastern Manitoba, where both fox species are sympatric. Both the capture rates and species richness of wildlife were significantly greater at fox dens relative to control sites. Predators were detected almost exclusively on dens occupied by foxes, where they were observed investigating and scavenging prey remains (carrion, feathers), suggesting carcass presence or fox presence attracts predators to den sites. Caribou (Rangifer tarandus) also visited dens more often than control sites, likely attracted by the enhanced vegetation typically found on dens. Our results suggest fox ecosystem engineering affects the spatial distribution of herbivores by enriching vegetation at dens, and other predators by providing carrion. Understanding how predators affect other organisms via non-trophic interactions provides an enriched view of their functional roles within ecosystems.

12 - Examining the Role of the HNF-1a G319S Variant in Liver Function and Early-Onset Type 2 Diabetes

Type 2 diabetes (T2D) diagnoses in Anishininiiwuk (Oji-Cree) linguistic group of northeastern Manitoba and northwestern Ontario are among the highest in the world, and a genetic variant known as HNF-1a G319S in this population has been associated with earlier onset of T2D. Historically, T2D in Anishininiiwuk communities was rare when Anishininiiuk people lived a traditional lifestyle as nomadic hunter-gatherers; a lifestyle associated with long periods of fasting and significant energy exertion.

A midge-salinity transfer function for inferring sea level change and landscape evolution in the Hudson Bay Lowlands, Manitoba, Canada

We compared water chemistry and environmental data with midge assemblage data, using multivariate analysis to assess the environmental gradients that limit midge (Chironomidae, Chaoboridae and Ceratopogonidae) distributions in the Hudson Bay Lowlands, northeastern Manitoba, Canada. Midge remains, comprising 62 taxa, were obtained from surficial sediments of 63 ponds. Ponds were sampled to maximize the salinity gradient. Specific conductance ranged from 46 to 29,000 μS cm−1. Proximity to the coast was a principal determinant of pond salinity, with ponds closer to Hudson Bay shoreline more saline that those farther away. Multivariate analysis indicated that midge distributions have a significant relationship (\( {\text{r}}_{\text{boot}}^{2} = 0.68 \)) with salinity in the data set. This work will allow paleolimnological inferences of midge community responses to changing sea level (i.e. salinity) via isostatic rebound within the Hudson Bay Lowlands, and will provide essential limnological information to scientists and managers in a region where understanding of aquatic ecosystems is limited. One undescribed midge taxon was dominant in ponds with the highest salinities and may be a key indicator for inferring highly saline environments.

Golden Eagles (<em>Aquila chrysaetos</em>) breeding in Wapusk National Park, Manitoba

The North American subspecies of the Golden Eagle (Aquila chrysaetos) is of conservation concern throughout Canada. The species is not currently known to breed in Manitoba. In 2011 and 2012, during the course of surveys in Wapusk National Park of Canada in northeastern Manitoba, seven pairs of Golden Eagles and one sub-adult were observed. The identification of nests in proximity to three pairs, the presence of an adult at one nest, and visible white down feathers on two nests confirm breeding and extend the breeding range of the Golden Eagle into Manitoba, where breeding was previously uncertain. The three occupied nests were 14 km (n = 2) and 31 km (n = 1) from the nearest adjacent occupied nest identified. Foraging on Canada Goose (Branta canadensis) goslings was observed. Further research is needed to determine the overall nest density and the diet of Golden Eagles in northeastern Manitoba.

The northern and southern sections of the western ca. 1880 Ma Circum-Superior Large Igneous Province, North America: The Pickle Crow dyke connection?

The ca. 1880Ma Circum-Superior Large Igneous Province (LIP) consists of a number of discontinuous segments known to cover a significant portion of the margin of the Superior Province craton in North America. New geochemical and isotopic data from western segments of this LIP support a common origin for the these segments and suggest that magmatism in the Lake Superior region may have been fed through the ~600km long Pickle Crow dyke from a source north of the Fox River Belt in northeastern Manitoba. The Fox River Belt, Pickle Crow dyke and sections of the Hemlock Formation in the Lake Superior region possess trace element signatures which are similar to those of more recent oceanic plateaux. The Hemlock Formation displays a heterogeneous geochemical signature. This chemical heterogeneity can in part be explained by lithospheric contamination and possibly by source heterogeneity. The tectonomagmatic setting in which these igneous rocks were formed could have involved a mantle plume. Evidence supporting a plume origin includes high MgO volcanic rocks, high calculated degrees of partial melting and geochemical signatures similar to those of oceanic plateaux.

Glacial terrain zone analysis of a fragmented paleoglaciologic record, southeast Keewatin sector of the Laurentide Ice Sheet

A highly fragmented subglacial landscape is recognized at the regional to sub-regional scales in northeastern Manitoba, Canada, in the southeast Keewatin Sector (a core region) of the Laurentide Ice Sheet. New field-based ice-flow indicator measurements, mapping of subglacial landforms (remote-sensing and aerial photograph), and a re-examination of previously published data from an 8100km2 area in northeastern Manitoba show that the preserved subglacial record reflects a complex and potentially long glacial history. Five streamlined landform flowsets are mapped. A much higher degree of inheritance in the field-based ice-flow indicator data, than previously reported, allows for recognition of multiple ice-flow phases. Analysis of the characteristics of the subglacial landscape combined with a relative-age chronology established with field-based indicators, led to the recognition of disjoint zones with internally-consistent glacial histories – termed glacial terrain zones (GTZ). These GTZ were then classified as (1) relict glacial, (2) palimpsest, or (3) deglacial in nature.Our data suggest that while the southern Keewatin Sector was affected by regional ice-divide translocation, this alone cannot explain the fragmented, high inheritance landscape. We suggest that the subglacial landscape was continually evolving and subject to spatio-temporal variations in intensity of erosion, transportation and/or deposition throughout multiple glacial events (subglacial bed mosaic). Preservation of relict and palimpsest terrain likely occurred under large ‘sticky’ low-erosion regions. These regions could have formed by at least two different mechanisms: heterogeneous switch from warm-based to cold-based ice or within a warm-based subglacial environment from wet to stiff, dewatered till. Establishment of the regionally extensive (∼700km wide by at least 500km long) dendritic esker channel-system may have caused rapid spatially-variable dewatering of the substrate far back under the ice sheet. The GTZ approach integrates all available data (e.g. flowsets and other landform data, striations) to advance our interpretation of the spatio-temporal evolution of subglacial dynamics in areas where the degree of landscape inheritance and overprinting is spatially highly variable. This mosaic may be a characteristic net-effect of landscape evolution beneath the core regions of ice sheets.

Spatial and temporal patterns of problem polar bears in Churchill, Manitoba

Human–bear interactions near the town of Churchill, Manitoba occur annually because the Western Hudson Bay polar bear population spends 4–5 months on-land each year when the sea ice melts completely. Significant changes have occurred in the Hudson Bay ecosystem and in the bear population as a result of climate warming; however, how these changes may have influenced human–bear interactions near Churchill is unclear. This study examined the temporal and spatial patterns of 1,487 problem bears captured in the Churchill area from 1970 to 2004. We also examined the relationship between problem bears and environmental variables as well as the Nunavut harvest. The number of individual problem bears caught near Churchill varied from 10 to 90 individuals per year and increased over time. Subadult males comprised 39%, subadult females 23%, adult males 18%, females with young 14%, and solitary females 6% of captures. Bears that became problem individuals were in closer proximity to the Churchill area. Nutritional stress and a northward shift in the distribution of the bears that spend the summer on-land in northeastern Manitoba may account for the increase in problem bear numbers. The date of sea ice freeze-up, which is getting progressively later, was the best predictor explaining the annual variation in the occurrence of problem bears. These results provide an understanding of how a warming climate may directly impact polar bear behaviour. This information may allow wildlife managers to predict relative levels of human–bear interactions and thereby implement effective management strategies to improve human safety and the conservation of polar bears.

Grizzly Bears, <em>Ursus arctos</em>, in Wapusk National Park, Northeastern Manitoba

We report on nine sightings of Grizzly Bears (Ursus arctos) in northeastern Manitoba in what is now Wapusk National Park. Although biological research in the region has been conducted regularly since 1965, all sightings have been made since 1996. The Grizzly Bears were seen either along rivers known to harbor fish or in an area known for berries.

A Survey of Lichens and Bryophytes in White Spruce, <em>Picea glauca</em>, Tree Islands on a Calcareous Beach Ridge in Northeastern Manitoba

Studies on the diversity of lichens and bryophytes in northern ecosystems have focused on open tundra and boreal forests. Krummholz tree islands have received little attention. This study examined species’ diversity of lichens and bryophytes among islands of White Spruce trees in northern Manitoba. Thirty-three species were found in the tree islands with 11 additional species forming the understorey layer. The trees were dominated by epiphytic lichens and the understorey was dominated by pleurocarpous mosses. The most common lichens were widespread species. Rare lichens in the study area included Protopannaria pezizoides and Alectoria nigricans growing in the shaded interior of the tree islands. The age and density of the tree islands may produce habitat conditions different from those in mature White Spruce boreal forests. Comparative studies between White Spruce krummholz and other White Spruce stands are needed.

Palsa and peat plateau development in the Hudson Bay Lowlands, Canada: timing, pathways and causes

The Holocene development of a treed palsa bog and a peat plateau bog, located near the railroad to Churchill in the Hudson Bay Lowlands of northeastern Manitoba, was traced using peat macrofossil and radiocarbon analyses. Both sites first developed as wet rich fens through paludification of forested uplands around 6800 cal. yr BP. Results show a 20th‐century age for the palsa formation and repeated periods of permafrost aggradation and collapse at the peat plateau site during the late Holocene. This timing of permafrost dynamics corroborates well with that inferred from previous studies on other permafrost peatlands in the same region. The developmental history of the palsa and peat plateau bogs is similar to that of adjacent permafrost‐free fens, except for the specific frost heave and collapse features associated with permafrost dynamics. Permafrost aggradation and degradation is ascribed to regional climatic, local autogenic and other factors. Particularly the very recent palsa development can be assessed in terms of climatic changes as inferred from meteorological data and surface hydrological changes related to construction of the railroad. The results indicate that cold years with limited snowfall as well as altered drainage patterns associated with infrastructure development may have contributed to the recent palsa formation.

Holocene Pollen Records and Peatland Development, Northeastern Manitoba*

Peatlands cover extensive parts of northeastern Manitoba that have low relief and impermeable substrates, with peat thicknesses varying between 25 and 400 cm. Peat reserves average 1.5 x 106 m3/km2. Fens, forested plateau bogs, and polygonal plateau bogs are the prevalent peatland types. The thickest peat deposits consist of Sphagnum bogs that developed on glaciolacustrine or marine silt. Thinner deposits are composed of fen peat, or bog peat developed on sandy till. There is a positive relationship between peat thickness and time since postglacial emergence of the land. Also, recently emerged areas are dominated by fen peat, whereas bog peat is more prevalent on older surfaces. Pollen analysis of peat cores show that spruce trees have been abundant in the region south of Churchill for the past 6300 years. Local changes in peat type and accumulation rate occurred as bog and fen habitats changed, probably in response to changes in water table induced by aggradation and degradation of permafrost. Other taxa typical of boreal forest occupied suitable habitats similar to today, with bog and fen habitats increasing as paludification continued through time.

THE KO ZONE: A NEW MODEL FOR PGE Cu Ni MINERALIZATION IN THE MARGINAL ZONE OF THE FOX RIVER SILL, NORTHERN MANITOBA, CANADA

The Fox River Sill is a Paleoproterozoic intrusion that extends for most of the length of the >250 km long Fox River Belt in northeastern Manitoba, Canada. Previous exploration for platinum-group elements (PGE) mineralization in the sill delineated an interval several hundred meters thick of weakly and sporadically mineralized ultramafic and mafic rocks occurring in the upper part of the sill (Upper Central Layered Zone). We describe a second mineralized interval, the KO Zone, near the base of the sill (Marginal Zone). Maximum metal contents obtained to date from the KO Zone are 2.1% Cu, 0.9% Ni and 5.5 g/t combined Pd + Pt + Au. The Marginal Zone comprises the Basal Contact Unit, which is variably contaminated and contains gabbro, melagabbro and lherzolite, overlain by two cyclic units (Cyclic Unit 1, and Cyclic Unit 2) that grade from lherzolite at their base through melagabbro, gabbro, leucogabbro and, locally, anorthosite. The KO Zone occurs at the contact between Cyclic Units 1 and 2 and locally contains disseminated, Cu-, Ni- and PGE-rich sulfide mineralization. The KO Zone features a discontinuous, coarse-grained actinolite-bearing olivine websterite unit, and an overlying medium-grained lherzolite that locally hosts irregularly shaped varitextured gabbro pods. The basal contact of the KO Zone is undulatory and scalloped, with sulfides being concentrated in trough structures. The mineralization is interpreted to have formed in a two-stage process. (1) Early deposition of immiscible magmatic sulfides at the base of Cyclic Unit 2. (2) Upgrading of PGE tenors of the sulfides by interaction with upward migrating, PGE- and volatile-rich intercumulus melt derived from the underlying Cyclic Unit 1.

Age at acquisition of Helicobacter pylori in a pediatric Canadian First Nations population.

Few data exist regarding the epidemiology of Helicobacter pylori infections in aboriginal, including the First Nations (Indian) or Inuit (Eskimo) populations of North America. We have previously found 95% of the adults in Wasagamack, a First Nations community in Northeastern Manitoba, Canada, are seropositive for H. pylori. We aimed to determine the age at acquisition of H. pylori among the children of this community, and if any association existed with stool occult blood or demographic factors. We prospectively enrolled children resident in the Wasagamack First Nation in August 1999. A demographic questionnaire was administered. Stool was collected, frozen and batch analyzed by enzyme-linked immunosorbent assay (ELISA) for H. pylori antigen and for the presence of occult blood. Questionnaire data were analyzed and correlated with the presence or absence of H. pylori. 163 (47%) of the estimated 350 children aged 6 weeks to 12 years, resident in the community were enrolled. Stool was positive for H. pylori in 92 (56%). By the second year of life 67% were positive for H. pylori. The youngest to test positive was 6 weeks old. There was no correlation of a positive H. pylori status with gender, presence of pets, serum Hgb, or stool occult blood. Forty-three percent of H. pylori positive and 24% of H. pylori negative children were < 50th percentile for height (p = 0.024). Positive H. pylori status was associated with the use of indoor pail toileting (86/143) compared with outhouse toileting (6/20) (p = 0.01). In a community with widespread H. pylori infection, overcrowded housing and primitive toileting, H. pylori is acquired as early as 6 weeks of age, and by the second year of life 67% of children test positive for H. pylori.

Incidence of fetal alcohol syndrome in northeastern Manitoba.

The incidence of fetal alcohol syndrome (FAS) in northeastern Manitoba was investigated by examining all 745 live births occurring in Thompson General Hospital in 1994. Birth records were screened with criteria designed to capture all potential FAS cases. Cases were then eliminated if follow-up records indicated the child was not developmentally delayed or no longer had the small head or body size identified at birth. Cases still meeting criteria were personally examined. Five cases of FAS were identified among the 46% of eligible children screened at age 2, roughly an incidence of 7.2/1,000. However, because only 46% of the high risk cases were personally examined, incidence could be as high as 14.8/1,000. Only 1/5 FAS cases had been identified prior to our investigation. The results indicate the incidence of FAS in northeastern Manitoba is very high and that much greater effort needs to be made in its prevention and early detection.

Incidence of Fetal Alcohol Syndrome in Northeastern Manitoba

Incidence of Fetal Alcohol Syndrome in Northeastern Manitoba

Defining the Pen Islands Caribou Herd of southern Hudson Bay

In this paper, we describe the Pen Islands Herd of caribou, the largest aggregation of caribou in Ontario (it also occupies a portion of northeastern Manitoba). Photographic counts showed the herd had a minimum population of 2300 in 1979, 4660 in 1986, 7424 in 1987 and 10 798 in 1994. Throughout the 1980s, the Pen Islands caribou exhibited population behaviour similar to migratory barren-ground caribou herds, although morphology suggests they are woodland caribou or possibly a mixture of subspecies. The herd had well-defined traditional tundra calving grounds, formed nursery groups and large mobile post-calving aggregations, and migrated over 400 km between tundra summer habitats and boreal forest winter habitats. Its migration took it into three Canadian jurisdictions (Ontario, Manitoba, Northwest Territories) and it was important to residents of both Manitoba and Ontario. It is clear that the herd should be managed as a migratory herd and the critical importance of both the coastal and variable large winter ranges should be noted in ensuring the herd's habitat needs are secure.

Code Switching and Language Leveling: Use of Multiple Codes in a Severn Ojibwe Community

Introduction. The northernmost dialect of Ojibwe, often designated Severn Ojibwe by scholars,1 is spoken in some seventeen northwestern Ontario and northeastern Manitoba villages situated along the drainage system of the Severn and Winisk rivers. This dialect has long been an enigma to historians and linguists. Linguistically, Severn Ojibwe differs in a number of important lexical, phonological, and grammatical respects from its closest Ojibwe neighbor, the Northwestern dialect (following the terminology of Rhodes and Todd 1981), spoken directly to the south. To the north, east, and west of the Severn area lie several dialects of another Algonquian language, Cree. Many of the features that distinguish Severn from other Ojibwe dialects are quite similar to Cree, though these same features often show the clear reflexes of Ojibwe phonological development which indicate that they cannot be recent borrowings from Cree.2 Close scrutiny of the codes used in the Severn Ojibwe community of Lynx Lake, one of the remote and seemingly isolated village located in this broad expanse of the subarctic taiga, provides a great deal of information about social relationships among the Severn people, Cree populations, and the Euro-Canadian matrix culture. Within this community of some three hundred people, one finds two subdialects of Severn Ojibwe, three dialects of Cree (Swampy, Plains, and Moose), and at least two varieties of English regularly employed as linguistic resources. Most code-switching research has involved groups living in industrialized societies where two or more speech communities exhibit extensive, daily contact. In the majority of these studies, the languages involved are

Ecological zonation during the carbonate transgression of a late Ordovician rocky shore (Northeastern Manitoba, Hudson Bay, Canada)

Late Ordovician (Ashgillian) carbonates belonging to the Port Nelson Formation transgress a resistant rocky shore near Churchill, Manitoba on the southwest flank of the Hudson Bay Basin in Canada. Examples of ancient rocky shores are very rare and this locality offers the first opportunity to document extensive offshore biological zonation with spatial reference to a well defined shoreline. Five biofacies zones are parallel to a 350 m-long shoreface carved into the Precambrian Churchill Quartzite. Eroded boulders of the dark quartzite blanket the shoreface and clast size is observed to decrease dramatically up section through 4.5 m of tan-colored carbonates. From an onshore to offshore position, the ecological zones include (1) boulder-encrusting favositid corals and a related high-energy fauna, (2) a shell pavement dominated by the inarticulate brahciopod Monomerella, (3) large, free-standing tabulate corals including Palaeophyllum, Calapoecia, and Catenipora, (4) tunneled trace fossils including chondritid, thalassinoid, and less common vertical “volcano” burrows, and (5) surface Cruziana burrows associated with rare, large isotelid (asaphacean) trilobites. Siphuncular debris from aminocerid cephalopods abundantly scattered through zones 2–3, provides data on current orientation consistent with long-shore drift. A wide field of ripple marks preserved near the top of the stratigraphic sequence confirms that wave trains advanced shoreward at an indirect angle of about 45°. Although currents deflected by natural groin fields may have swept coarse clastics more seaward at some spots than others, the biological zones are remarkably linear and persistent. The Churchill site is a comparatively simple case of landward migration by shore-parallel biofacies primarily controlled by factors related to water depth and distance from shore. This interpretation does not preclude the possibility that more random facies patterns may have existed in protected embayments or along more irregularly cliffed sectors of the ancient Churchill coast.

Rubidium–strontium ages of Archean and Proterozoic rocks in the Nejanilini and Great Island domains, Churchill Province, northern Manitoba, Canada

Rubidium–strontium whole-rock ages are reported from the Nejanilini – Great Island area in northeastern Manitoba. This area is part of an extensive zone of Archean basement that was metamorphosed and intruded by granitic magma during the Proterozoic; it extends into Saskatchewan and southern District of Keewatin, Northwest Tertitories. An age of 2577 ± 42 Ma (1σ error) for the extensive Nejanilini granulite massif (Nejanilini domain), considered one of the oldest rock units in the area, is interpreted as a minimum age for late Archean granulite-facies metamorphism. A minimum age of 2052 ± 41 Ma (initial ratio 0.7150) for quartz–feldspar porphyry that intrudes the Seal River volcanic suite constrains the age of these volcanics and could represent a partially reset Archean age. Early Proterozoic quartzite and metagreywacke of the Great Island Group unconformably overlies the quartz–feldspar porphyry. These metasedimentary rocks, which are probably correlative with the Daly Lake Group (Saskatchewan) or the Hurwitz Group (southern District of Keewatin), give an age of 1885 ± 85 Ma, with an initial ratio of 0.7093. The age records the time of closure of the Rb–Sr isotopic system subsequent to early Proterozoic metamorphism. The age and initial ratio are consistent with published results for other, possibly correlative, metasedimentary rocks in this zone. Modelling the Rb–Sr isotopic data constrains the time of sedimentation to between ca. 2100 and 2000 Ma ago. Syn- to late-kinematic, early Proterozoic granite to granodiorite batholiths, which intruded metasedimentary rocks of the Great Island Group, may largely be the product of melting of Archean basement, based on field evidence and high initial 87Sr/86Sr ratios. The Caribou Lake porphyritic quartz monzonite gives an age of 1795 ± 35 Ma, with an initial 87Sr/86Sr ratio of 0.7084. High initial ratios seem to typify early Proterozoic granitic rocks in this remobilized craton.

Nautiloid debris oriented by long‐shore currents along a late Ordovician‐early Silurian rocky shore

Siphuncular fragments from arminocerid cephalopods are abundant along 350 m of a well defined rocky shore of late Ordovician or early Silurian age exposed near Churchill in northeastern Manitoba, Canada. The paleoshore is composed of the Precambrian Churchill Quartzite, which is dramatically abutted by carbonate strata gently dipping north beneath Hudson Bay. At one end of the exposure, a former sea stack or sea arch extends prominently outward for 15 m perpendicular to the otherwise linear paleoshore. Probably it acted as a natural groin with some influence on local currents and waves. The orientations of 189 siphuncular fragments were recorded and found to be dominantly perpendicular to the trend of the ancient shore. They are far more cylindrical in shape than conical, and are interpreted to have been rolled to their final resting place pushed by long-shore currents. Concentration of nearly 80% of the fragments towards one end of the shore is consistent with transport by long-shore currents. Ripple marks preserved at a different stratigraphic level form a 45-degree angle to the trend of the paleoshore, providing additional evidence that wave trains must have set up long-shore currents from time to time.