Eastern Manitoba Research Articles

Promoting health and wellness through Indigenous sacred sites, ceremony grounds, and land-based learning: a scoping review

This study analyzes the literature on Indigenous sacred sites within the larger topic areas of land-based education and healing, as per the guidance of Anishinaabe (a group of Indigenous Peoples from the Great Lakes and the Great Plains areas of contemporary Canada and USA) Elders and community leaders in eastern Manitoba, Canada. A scoping review was conducted to identify the size, scope, nature, and key themes of existing research in seven databases, inclusive of gray literature which is a key source for Indigenous organizations. In total, we analyzed 35 articles and documents. The emerging themes included: (1) sacred sites and the promotion of health and wellness; (2) sacred sites as places of knowledge; (3) the desecration and protection of sacred sites; and (4) legal battles between Indigenous Peoples and the state. Recommendations to advance understandings and correct colonially imposed imbalances are discussed, and health and legal implications are outlined.

Leaving no one behind? An equity analysis of the HIV care cascade among a cohort of people living with HIV in Manitoba, Canada

BackgroundManitoba is a central Canadian province with annual rates of new HIV infections consistently higher than the Canadian average. National surveillance statistics and data from the provincial HIV care program suggest that epidemiological heterogeneity exists across Manitoba. New HIV cases are disproportionately reported among females, Indigenous-identifying individuals, and those with a history of injection drug use. Given the heterogeneity in acquisition, it is of interest to understand whether this translates into inequalities in HIV care across Manitoba.MethodsA sample of 703 participants from a clinical cohort of people living with HIV in Manitoba, with data current to the end of 2017, was used to conduct cross-sectional, disaggregated analyses of the HIV care cascade to identify heterogeneity in service coverage and clinical outcomes among different groups receiving HIV care in Manitoba. Equiplots are used to identify and visualize inequalities across the cascade. Exploratory multivariable logistic regression models quantify associations between equity variables (age, sex, geography, ethnicity, immigration status, exposure category) and progression along the cascade. Adjusted odds ratios (AOR) and 95% confidence intervals (95%CI) are reported.ResultsEquity analyses highlight inequalities in engagement in and coverage of HIV-related health services among cohort participants. Equiplots illustrate that the proportion of participants in each cascade step is greater for those who are older, white, non-immigrants, and report no history of injection drug use. Compared to those living in Winnipeg, participants in eastern Manitoba have greater odds of achieving virologic suppression (AOR[95%CI] = 3.8[1.3–11.2]). The odds of Indigenous participants being virologically suppressed is half that of white participants (AOR[95%CI] = 0.5[0.3–0.7]), whereas African/Caribbean/Black participants are significantly less likely than white participants to be in care and retained in care (AOR[95%CI] = 0.3[0.2–0.7] and 0.4[0.2–0.9], respectively).ConclusionsInequalities exist across the cascade for different groups of Manitobans living with HIV; equiplots are an innovative method for visualizing these inequalities. Alongside future research aiming to understand why inequalities exist across the cascade in Manitoba, our equity analyses can generate hypotheses and provide evidence to inform patient-centred care plans that meet the needs of diverse client subgroups and advocate for policy changes that facilitate more equitable HIV care across the province.

Assessment of soil trafficability across the agricultural region of the Canadian Prairies with the gridded climate data set

The frequency of days with poor soil trafficability across the Canadian Prairies was determined from simulated soil moisture at soil polygon level during the growing season (April to September) with the Versatile Soil Moisture Budget (VSMB) model. Each soil polygon had a pre-determined critical soil moisture threshold in the first layer (0–5 cm) to trigger poor trafficability. The assessment of soil trafficability was limited to those polygons with good suitability rating for growing grain crops. For each of May, July and September, the polygon modelled soil moisture values were boot strapped into three percentile categories to reflect the highest risk (25th percentile), average conditions (50th percentile) and better than average conditions (75th percentile) for the entire climate period (1971 to 2000). We found that on average, soils with higher clay content (mostly those from eastern Manitoba, the northern fringes of the agricultural zone coinciding with the boreal forest zone and the Alberta Peace River region) had 5 to 9 days of poor trafficability at seeding time (May). In July, the zone with poor soil trafficability (close to two weeks) expanded northward to the Peace River Region of Alberta, northern Saskatchewan and eastern Manitoba. At harvest time (September), poor soil trafficability (>10days) was concentrated in eastern Manitoba which also had the most days with poor soil trafficability at the start and mid-season months. The wet phase represented by the 75th percentile category showed that 10–14 days of poor trafficability can be expected on soil polygons with heavy textures. There were fewer days (1–4) with poor trafficability during dry years (the 25th percentile binned values). The soil trafficability maps generated from this study are a baseline for comparing trafficability levels under climate change scenarios and for planning agricultural activities.

Parallel evolution of site-specific changes in divergent caribou lineages.

The parallel evolution of phenotypes or traits within or between species provides important insight into the basic mechanisms of evolution. Genetic and genomic advances have allowed investigations into the genetic underpinnings of parallel evolution and the independent evolution of similar traits in sympatric species. Parallel evolution may best be exemplified among species where multiple genetic lineages, descended from a common ancestor, colonized analogous environmental niches, and converged on a genotypic or phenotypic trait. Modern North American caribou (Rangifer tarandus) originated from three ancestral sources separated during the Last Glacial Maximum (LGM): the Beringian–Eurasian lineage (BEL), the North American lineage (NAL), and the High Arctic lineage (HAL). Historical introgression between the NAL and the BEL has been found throughout Ontario and eastern Manitoba. In this study, we first characterized the functional differentiation in the cytochrome‐b (cytB) gene by identifying nonsynonymous changes. Second, the caribou lineages were used as a direct means to assess site‐specific parallel changes among lineages. There was greater functional diversity within the NAL despite the BEL having greater neutral diversity. The patterns of amino acid substitutions occurring within different lineages supported the parallel evolution of cytB amino acid substitutions suggesting different selective pressures among lineages. This study highlights the independent evolution of identical amino acid substitutions within a wide‐ranging mammal species that have diversified from different ancestral haplogroups and where ecological niches can invoke parallel evolution.

Disturbance and chronic levels of cortisol in boreal woodland caribou

ABSTRACTDisturbance by anthropogenic activities may cause chronic (long‐term) stress in wildlife and contribute to population declines. Although declines of boreal woodland caribou (Rangifer tarandus caribou) across Canada have been attributed to anthropogenic disturbance, the physiological stress response of caribou to disturbance is not well understood. As a measure of chronic stress, we assessed cortisol concentrations in guard hair from 89 female caribou between 2009 and 2011 in eastern Manitoba. We compared cortisol concentrations among 5 caribou populations occupying areas with varying levels of disturbance, and estimated home ranges of 55 collared caribou to examine how home range size varied with cortisol concentrations. Within each home range, we quantified disturbance characteristics (roads, transmission lines, cottages, and logged and burned areas) and landscape features (lakes, black spruce [Picea mariana], and jack pine [Pinus banksiana]), and used model selection to determine the combination of disturbance features that best explained variation in caribou cortisol concentrations. Hair cortisol concentrations differed among the 5 caribou populations and increased with decreasing home range size. The proportion of the home range logged in the previous 6–21 years best explained variation in cortisol concentrations. Our results suggest that caribou respond negatively to logging, and caribou occupying the southern extent of their range could be vulnerable to disturbance. Although disturbance affects caribou cortisol concentrations, the consequences of increased cortisol concentrations on caribou survival and reproduction are unknown and need to be examined for effective management of populations. © 2017 The Wildlife Society.

Alternative prey use affects helminth parasite infections in grey wolves.

Predators affect prey populations not only through direct predation, but also by acting as definitive hosts for their parasites and completing parasite life cycles. Understanding the affects of parasitism on prey population dynamics requires knowing how their predators' parasite community is affected by diet and prey availability. Ungulates, such as moose (Alces americanus) and white-tailed deer (Odocoileus virginianus), are often important prey for wolves (Canis lupus), but wolves also consume a variety of alternative prey, including beaver (Castor canadensis) and snowshoe hare (Lepus americanus). The use of alternative prey, which may host different or fewer parasites than ungulates, could potentially reduce overall abundance of ungulate parasites within the ecosystem, benefiting both wolves and ungulate hosts. We examined parasites in wolf carcasses from eastern Manitoba and estimated wolf diet using stable isotope analysis. Taeniidae cestodes were present in most wolves (75%), reflecting a diet primarily comprised of ungulates, but nematodes were unexpectedly rare. Cestode abundance was negatively related to the wolf's δ(13) C value, indicating diet affects parasite abundance. Wolves that consumed a higher proportion of beaver and caribou (Rangifer tarandus), estimated using Bayesian mixing models, had lower cestode abundance, suggesting the use of these alternative prey can reduce parasite loads. Long-term consumption of beavers may lower the abundance of adult parasites in wolves, eventually lowering parasite density in the region and ultimately benefiting ungulates that serve as intermediate hosts. Thus, alternative prey can affect both predator-prey and host-parasite interactions and potentially affect food web dynamics.

A case study of aerosol scavenging in a biomass burning plume over eastern Canada during the 2011 BORTAS field experiment

Abstract. We present measurements of a long-range smoke transport event recorded on 20–21 July 2011 over Halifax, Nova Scotia, Canada, during the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS-B) campaign. Ground-based Fourier transform spectrometers and photometers detected air masses associated with large wildland fires burning in eastern Manitoba and western Ontario. We investigate a plume with high trace gas amounts but low amounts of particles that preceded and overlapped at the Halifax site with a second plume with high trace gas loadings and significant amounts of particulate material. We show that the first plume experienced a meteorological scavenging event, but the second plume had not been similarly scavenged. This points to the necessity to account carefully for the plume history when considering long-range transport since simultaneous or near-simultaneous times of arrival are not necessarily indicative of either similar trajectories or meteorological history. We investigate the origin of the scavenged plume, and the possibility of an aerosol wet deposition event occurring in the plume ~ 24 h prior to the measurements over Halifax. The region of lofting and scavenging is only monitored on an intermittent basis by the present observing network, and thus we must consider many different pieces of evidence in an effort to understand the early dynamics of the plume. Through this discussion we also demonstrate the value of having many simultaneous remote-sensing measurements in order to understand the physical and chemical behaviour of biomass burning plumes.

Quantifying fish avoidance of small acoustic survey vessels in boreal lakes and reservoirs

AbstractMobile hydroacoustic surveys are increasingly used to assess the distribution and abundance of freshwater fish; yet, fish may avoid moving vessels, potentially introducing bias in these assessments. In this study, avoidance in boreal lakes and reservoirs was quantified by developing a simple method based on paired drift:drift (D:D) and drift:motor (D:M) transects. Two systems in eastern Manitoba, Canada were studied: Lac du Bonnet reservoir and Nopiming. Acoustic data were collected using a digital DTX echosounder (BioSonics, Seattle, WA, USA), with a downward facing 200‐kHz split‐beam transducer, deployed from 5.5‐m vessels (Boston Whalers) modified for acoustic research. An avoidance coefficient (Ac) was developed based on comparisons of acoustic fish densities while the vessel moved over the same transects by drifting, and by motoring at survey speeds. Ac did not differ significantly from 1 (no avoidance) at Nopiming (median of 0.81, n = 13), but did at Lac du Bonnet (median of 0.51, n = 31, P < 0.05). Variability in Ac was as high in transect pairs and was unrelated to fish depth (mean 6.9 m at Lac du Bonnet; 13.1 m at Nopiming) or survey speed (up to 3.70 m·s−1, 7 knots). Results indicated that fishes did not dive in the presence of the motoring vessel, nor was avoidance size‐based. We did not detect any evidence of fish attraction to our drifting vessel. Our results suggest that boat avoidance during acoustic surveys of shallow boreal lakes may vary in relatively similar water bodies but can be quantified experimentally.

Chemical ecology of lichens and species composition of cryptogams among three boreal habitats in eastern Manitoba

The Precambrian Shield supports a diversity of cryptogams where environmental conditions predict their distribution. Moisture and light are thought to affect secondary metabolite production in lichens, leading to a hypothesis of chemical communities that may be independent of species assemblages. Hypotheses were that habitats will be characterized by lichen secondary metabolites and that lichen and bryophyte species composition will also distinguish among habitats. Lichens and bryophytes were sampled from six quadrats from each of two sites within each of three habitats (rock faces, rock outcrops, and forest floors). This study showed strong relationships among species assemblages, secondary metabolites, and types of habitat. Species abundance, cover, and species richness also differed among habitats. Individual secondary metabolites could differentiate among three habitats, suggesting that certain metabolites such as usnic and squamatic acids would more likely be found in habitats such as dry exposed rock outcrops than in moist shaded habitats. Individual analyses suggested that some secondary metabolites may serve multiple functions in a habitat, such as triterpenes, while others may have more specific functions, such as salazinic acid, where environmental features may be important for secondary metabolite production. Further investigation of specific metabolites is needed to understand their roles in adaptation.

False rings in jack pine and black spruce trees from eastern Manitoba as indicators of dry summers

False rings (FRs) are a tree-ring anomaly that can be used to better understand tree growth and potentially reconstruct past climatic events. The main objective of this study was to explore the association between FRs and climate, especially drought occurrence. Sampling was conducted in Nopiming Provincial Park. Wood cores were extracted from jack pine ( Pinus banksiana Lamb.) in five stands and from co-occurring black spruce ( Picea mariana (Mill.) BSP) in three of these stands. After cross-dating, earlywood, latewood, and total ring width were measured on all cores. All FRs were identified, and their position within a tree ring was determined. Both species showed similar radial growth and FR patterns. Jack pine and to a lesser extent black spruce both showed abundant FRs in the juvenile period. Springs with cool and snowy conditions and summers with severe drought were associated with a higher frequency of FRs. These anomalies could be formed partly in response to timing of the start of the growing season and to conditions during that growing season that lead to interruption and subsequent resumption of normal growth. Jack pine radial growth was found to be more sensitive to precipitation, whereas that of black spruce was more sensitive to temperature.

Alkali Element Uptake in Otoliths: A Link Between the Environment and Otolith Microchemistry

Otoliths taken from fish in the vicinity of rare element pegmatites in eastern Manitoba, Canada, were analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and found to contain lithium, sodium, rubidium, cesium, and strontium at levels ranging from a few ppm to a few 10s of ppm. In some otoliths, the concentrations varied in correspondence to the annular structure of the otoliths, suggesting a periodicity to their incorporation. This is the first reported detection and resolution of periodic signals of Rb and Cs in otoliths. The correspondence between the elements in the otoliths and surrounding rocks suggests there can be a strong link between the microchemistry of a fish's otoliths and its environment particularly where there are distinctive rock types. These elements may serve as natural markers in certain environments and may be used to characterize and monitor lacustrine environments over a period of time.

Races of Puccinia graminis on wheat, barley, and oat in Canada, in 2002 and 2003

Annual surveys of stem rust [Puccinia graminis] are conducted on cereals in Canada to provide information on virulence dynamics in the pathogen population. Wheat, barley, and oat samples were collected in Manitoba, Saskatchewan, Alberta, and Ontario in 2002 and 2003. Stem rust was absent on commercial wheat cultivars in either year. In 2002, stem rust on commercial barley cultivars ranged from trace to 7% severity in Manitoba and, in 2003, was at trace levels across the prairie region. In 2002, stem rust on commercial oat cultivars was heaviest (5%–50% severity) in eastern Manitoba and progressively diminished to trace levels in eastern Saskatchewan. In 2003, stem rust on oat was at trace levels across the prairie region. Eleven races of Puccinia graminis f. sp. tritici were found in trap plots of susceptible wheat, 8 on commercial barley, and 14 on wild barley. The predominant races on wheat and wild barley were RCRSK, QCCJN, and RCCJN in 2002, and QFCSR and QFCSH in 2003. The predominant races on commercial barley were QCCJ- and RCCJ-types, which are virulent against resistance gene Rpg1. Eight races of Puccinia graminis f. sp. avenae were found on commercial oat, and seven on wild oat. The predominant races on commercial oat were NA67 and NA29 (63.4% and 14.4%) in 2002, and NA67 and NA76 (77.8% and 10.4%) in 2003. NA67 and NA29 were also predominant on wild oat in 2002 (43.2% and 24.9%) and in 2003 (53.8% and 22.7%). Race NA28, which is virulent to resistance gene Pg-a and last reported in 1997, was found at two locations in Manitoba in 2003.

Physiologic specialization of Puccinia graminis on wheat, barley, and oat in Canada in 2001

Stem rust is an important disease of cereal crops that is primarily controlled in Canada through cultivar resistance. Annual stem rust surveys are conducted to provide early detection of novel races with virulence to currently grown cultivars and to identify changes in virulence frequency in the pathogen population. Stem rust samples were collected in Manitoba, eastern Saskatchewan, Ontario, and British Columbia in 2001. Stem rust was not found on cultivated wheat, but was found on commercial barley and oat fields in eastern Manitoba (trace to 20% severity) and in western Manitoba and eastern Saskatchewan (<5% severity). Some late-planted oat fields in the Red River Valley region of Manitoba had moderate to heavy (5%–40% severity) stem rust infection. Eight races of Puccinia graminis f. sp. tritici were found on wheat, seven on cultivated barley, and nine on wild barley. The predominant races on wheat and wild barley were RCRSK, QFCSR, and QCCJN. The predominant races on cultivated barley were QCCJN and RCCJN, which could threaten barley production. Eight races of Puccinia graminis f. sp. avenae were found on cultivated oat and five on wild oat. NA67 and NA29 were the predominant races on cultivated (57.6% and 15.8%) and wild (41.6% and 29.6%) oat, while NA76 increased to 14.4% on cultivated oat in 2001. NA67 and NA76 are virulent on all currently grown Canadian oat cultivars. A new race (NA77) avirulent to most oat cultivars was detected in Manitoba in 2001.

Valuing aboriginal artifacts: a combined revealed-stated preference approach

This paper examines the value of unique aboriginal cultural resources using joint revealed-stated preference methods. Our methodology exploits knowledge of previous choices from both the revealed and stated preference data to account for state dependence. We also incorporate procedures to address correlation among the data sources. The empirical application involves the discovery of aboriginal rock paintings along wilderness canoe routes in eastern Manitoba, Canada. A 4-year study of wilderness recreation trips included an SP experiment in which canoeists were asked if they would change their site choices in response to the presence of two types of rock paintings: a “pristine” painting and another spoiled by vandals. Mean welfare measures for the presence of “pristine” paintings at two canoe routes were about $61 and $77 per trip, respectively. Vandalized pictographs are worth considerably less.

Backcountry recreationists' valuation of forest and park management features in wilderness parks of the western Canadian Shield

The economic value of four forest ecosystems, fire-damaged forests, cut blocks, and several park management features was estimated for backcountry recreationists, primarily canoeists, in Nopiming Provincial Park in eastern Manitoba. The analysis was conducted using the travel cost random utility model. It revealed that the forest ecosystems associated with jack pine (Pinusbanksiana Lamb.) and white spruce (Piceaglauca (Moench) Voss) were valued by recreationists. On the other hand, the analysis predicted that recreationists would pay to avoid black spruce (Piceamariana (Mill.) BSP) and aspen (Populustremuloides Michx.) ecosystems, fire-damaged forests, portages, and cottages. The results provide weak statistical evidence that cut blocks that are not in the line of site of recreationists provide positive benefits. While park management variables play a role in determining recreation values, the ages and types of forests located at recreation sites are more important. These findings support a major role for fire in determining recreation economic benefit flows from forests in the Canadian Shield.

Wood moisture content variation in white spruce defoliated by spruce budworm

Mature and over mature white spruce [Picea glauca (Moench) Voss] repeatedly defoliated by spruce budworm (Choristoneura fumiferana Clem.) in eastern Manitoba, were investigated for variation in moisture content (MC) which is known to influence pulping quality. In the fall of 1991, 100 trees in the Abitibi-Price Inc. Forest Management Licence area were selected randomly in two size classes and four defoliation classes. Heartwood and sapwood MC (% dry weight) was measured in 5-cm thick disks cut at 2.5 to 5.0 m intervals for small and large trees, respectively. Living trees with more sapwood than heartwood had a mean MC of 117%, and those with more heartwood than sapwood had a mean MC of 77%. Both of these groups contained sufficient overall moisture (&gt; 45%) for pulping. The repeated defoliation did not affect the overall MC in live trees. Mean MC of trees killed by spruce budworm defoliation was 42% but this level varied with diameter and height above ground: &gt; 45% in stems greater than 36 cm diameter inside bark, 30–60% in sections 17–36 cm, and &lt; 45% in sections less than 17 cm. A minimum DBH of 30 cm is suggested as a criterion for accepting dead trees. Key words: insect defoliation impact, wood moisture content, sapwood, heartwood, dead tree fibre, Manitoba

Archean and Proterozoic tectono-magmatic activity along the southern margin of the Superior Province in northwestern Iowa, United States

A Precambrian igneous body of ultramafic and mafic rocks, named the Otter Creek layered igneous complex, occurs within the basement of northwestern Iowa, United States. It is marked by a circular magnetic anomaly, one of several that lie north and west of an inferred suture between the Archean Superior Province and Early Proterozoic juvenile crust. Sm–Nd whole-rock analyses for several rock types from the Otter Creek complex yield an isochron age of 2890 ± 90 Ma, with an εNd(t) of −0.9 ± 2.4. A block of older banded iron formation, itself intruded by lamprophyre dikes, is contained within the layered sequence. The iron formation – lamprophyre block has undergone high-temperature metamorphism followed by a retrograde event. A quartz monzodiorite gneiss, with a U–Pb age of 2523 ± 5 Ma, occurs near the layered complex, but the contact relations are not known. The layered series is overlain by Proterozoic keratophyre with a U–Pb age of 1782 ± 10 Ma. These felsic pyroclastic rocks are extremely depleted in K, Rb, Ba, and Cs. Our data are consistent with Archean greenstone-belt formation, including chemical sedimentation followed by mafic–ultramafic magmatism at approximately 2.9 Ga, followed by two later episodes of magmatism, one at approximately 2.5 Ga and the other at approximately 1.78 Ga. The Otter Creek complex is the first Archean greenstone reported south of the Great Lakes Tectonic Zone (GLTZ); its 2.9 Ga age is older than those reported for the granite–greenstone rocks north of the GLTZ. The southern portion of the Superior Province thus appears to have formed later, and in a different tectonic environment, than the high-grade gneisses of the Minnesota River Valley, but before the bulk of the granite–greenstone rocks exposed in northern Minnesota, Ontario, and eastern Manitoba.

Individual and group behaviour of pastured cattle in response to attack by biting flies

In 1983 and 1984 the impact of biting flies on the behaviour of pastured heifers was determined for two herds of cattle in eastern Manitoba. One herd received a whole-body spray of cypermethrin (0.1% active ingredient) per animal every 14 days and the other was an untreated control herd. Horse flies (predominantly Hybomitra spp.) were the most bothersome to the heifers, with peak numbers of flies mostly occurring between 11:00 and 15:00. Horse flies and mosquitoes (Aedes spp.) caused an increase in individual avoidance responses of the animals, including head tosses, foot stomps, ear flicks, and tail switches. In 1983, the numbers of tail switches and foot stomps were significantly higher in the control herd, and in 1984, the numbers of head tosses were significantly higher in the treated herd. The formation of grazing lines and bunching were the most prevalent herd responses to biting fly attack. Stampeding was observed only under the most extreme mosquito pressure. Using canonical discriminant analysis on behaviour data, significant differences were identified in behaviour before and after July 10, 1984. Similarly, animals treated with cypermethrin displayed significantly fewer behavioural responses to biting fly attack than nontreated animals.

Affinities of Skeletal Material from the Winnipeg River System

Over the past ten years, a series ofburials {n= 1 0) have been salvaged from the banks of the Winnipeg River in eastern Manitoba. These come from the Slave Falls, River Mouth, and Whaley sites. Although direct artifact associations are sparse, nearby sites contain artifacts from the Middle to Late Woodland and the contact periods. Comparative canonical analysis of the crania suggests that they can all be assigned to the Saulteauxlndians (Ojibwa). It is suggested that the Winnipeg River sites, both with human remains and without, reflect the activities of the Saulteaux before and during the active period of the historic sites of Fort au bas de Ia Riviere and Fort Alexander

Iodine dispersion and effects on groundwater chemistry following a release to a peat bog, Manitoba, Canada

The migration and behaviour of I was investigated in a sphagnum bog on the Precambrian Shield in eastern Manitoba, Canada. A 6 M solution of KI was released at the base of the bog to stimulate a pulse discharge of contaminated groundwater from a fracture in the granitic rock. A network of piezometer tubes was used to monitor the dispersion of the I and the groundwater chemistry over 1 year. Cores of peat were also taken for analysis to supplement the groundwater data and to investigate the sorption of I. The introduced I dispersed 2 m horizontally and 1 m vertically within a month. After this, the system stabilized and further migration was insignificant. The pattern of I dispersion indicated that the bog hydrology was very complex with flow directions changing substantially with depth. The groundwater concentrations of the major cations rose in response to the mass action effect of K displacing them from reaction sites in the peat. Humic materials in the groundwater decreased in size after the KI release and returned to their pre-release conformation one month later. The geometric mean soil distribution coefficient value, K d , for I in the bog was 1.36l/kg, but it was strongly related to pore water concentration. Thus, a single K d value was insufficient for describing the system. Clearly, good groundwater chemistry, sorption and hydrological data are necessary for meaningful modelling of contaminant transport in bogs.