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Hunting, trapping, and fishing are part of an Indigenous lifestyle in subarctic Canada. However, this lifestyle may be a route of exposure to contaminants and may pose a risk for the people who rely on a subsistence diet. Monte Carlo simulations for the chemical concentration of eight game species and one fish species were carried out by randomly sampling 10,000 samples from the contaminant measures for each species. We then calculated a probabilistic non-carcinogenic hazard quotient or carcinogenic risk values to estimate the human health risk of exposure to contaminants. Of the species examined, ducks were of concern for potential carcinogenic risk. There was a modeled probabilistic 95th-percentile risk associated with the consumption of ducks and polybrominated biphenyl (PBB) congener 153 in boys, women, and men (1.09 × 10−6, 1.57 × 10−6, and 2.17 × 10−6, respectively) and, to a lesser extent, with geese and polychlorinated biphenyl (PCB) congener 153 in men (1.19 × 10−6). Contaminant concentration in the intake rate (food consumption) for PBB congener 153 exposure risk was more important than that for PCB congener 153, where intake rate had greater relevance. The consumption of waterfowl may increase the exposure to organohalogens; however, there are health and wellness benefits associated with the harvesting and consumption of subsistence foods that must also be considered. We recommend follow-up species-specific studies focused on ducks to clarify and elucidate the results in the present study. [ABSTRACT FROM AUTHOR]

Indoor concentrations of black carbon (BC) were measured when wood was burned for traditional cultural activities in a study in a Cree community located in subarctic Canada. The study also included an intervention using a propane-fuelled heater to mitigate in situ BC. Mass concentrations of BC were measured in a game-smoking tent for 39 days and in hunting cabins on the west coast of James Bay, Canada, for 8 days. Five-minute averaged BC mass concentration (N = 12,319) data were recorded and assessed using optimised noise-reduction averaging. Mean BC mass concentrations were lower in hunting cabins (mean = 8.25 micrograms per cubic metre (µg m−3)) and higher in the game-smoking tent (mean = 15.46 µg m−3). However, excessive BC peaks were recorded in the game-smoking tent (maximum = 3076.71 µg m−3) when the fire was stoked or loaded. The intervention with the propane heater in a hunting cabin yielded a 90% reduction in measured BC mass concentrations. We do not presume that exposure to BC is of concern in hunting cabins with appropriate wood-burning appliances that are well-sealed and vent outside. In game-smoking tents, we advise that persons take intermittent breaks outside of the tent for fresh air. [ABSTRACT FROM AUTHOR]

Understanding the processes controlling peatland carbon (C) sequestration is critical to anticipate potential changes in the global C cycle in response to climate change. Although identification of these factors may be relatively straightforward on seasonal timescales, at centennial to millennial timescales complexities arise because of interactions between climate, vegetation, hydrology and long-term ecological processes. To better understand the factors controlling long-term C accumulation, Holocene rates of C sequestration were quantified from three pristine ombrotrophic peatlands in boreal Quebec, northeastern Canada (52°N, 75–76°W). Bulk density and loss-on-ignition analyses, combined with radiocarbon dating and age–depth modelling, were used to estimate long-term apparent rates of carbon accumulation. Past changes in vegetation and water-table depth were obtained from plant macrofossil and testate amoeba analysis. Earliest regional peat accumulation started ~7520 cal. BP, with long-term rates of C sequestration varying between 14.9 and 22.6 g/m2 per yr. High C sequestration rates occurred during the mid Holocene when relatively stable Sphagnum section Acutifolia communities were present, while low rates were found during the cooler late Holocene when Cyperaceae and ligneous vegetation were more dominant. However, C sequestration was highly variable among cores, implying that local topography, geomorphology and hydrology, or disturbance factors such as fire, mediate the influence of climate on C accumulation. Reconstructed water-table depths reveal several dry shifts since 3000 cal. BP, suggesting that episodic cold and dry conditions during the late Holocene may have contributed to lower C sequestration rates. Given the intensity of the water-table shifts at these times, we hypothesize that recurrent episodes of frozen subsurface peat might have intensified surface drying. As projected by climate scenarios, anticipated warmer and wetter conditions may lead to greater stability of hummock Sphagna cover and increased C sequestration potential in boreal peatlands. [ABSTRACT FROM PUBLISHER]

The seaweed flora from James Bay, Canada is compared with three contiguous northeastern Canadian Arctic areas (Hudson Bay, Hudson Strait, and the Ellesmere-Baffin Islands area extending northward to the Arctic Ocean). A conspicuous reduction pattern was evident with 131 taxa recorded for the Ellesmere-Baffin Islands area, 106 for Hudson Strait, 81 from Hudson Bay, and 44 in James Bay. The Ellesmere-Baffin Islands area has a more rocky open coastal environment and higher salinities than James Bay, which is more highly sedimented and impacted by hydroelectric development and freshwater discharge. The Ellesmere-Baffin Islands area (∼32-30.5%) has a higher mean number of shared taxa (90.0 ± 18.4 SE) than James Bay (37.6 ± 2.7 SE), while Hudson Strait and Hudson Bay have intermediate values of 78 ± 14.1 SE and 64 ± 9.2 SE, respectively. The combined flora from the four areas consists of 164 taxa, including 49 red, 65 brown, 1 chrysophyte, and 49 green algae. Fifty of these total taxa (31%) were only found in one area, with 25 occurring between Ellesmere Island and Baffin Island, 13 within the Strait proper, and 6 in both Hudson and James Bays. Strong habitat and salinity gradients, as well as the great distances between collection sites and the haphazard nature of collections may have contributed to these restrictive patterns. Cheney's (1977) floristic ratio documents that all four geographies (including their composite flora) have cold water floras. Four new distributional records are documented from James Bay: Chaetomorpha minima, Elachista fucicola, Phyllophora pseudoceranoides, and Spyridia filamentosa. The cryptogenic taxon Spyridia, which has unclear origins, is a warm-water disjunct in the northwestern Atlantic previously known only from one site in Nova Scotia and a few locations in southern Maine/New Hampshire but mostly south of Cape Cod, Massachusetts. A single introduced species (Dumontia contorta from Europe) is recorded from James Bay and the Ellesmere-Baffin Islands area, while none are documented from the other areas. [ABSTRACT FROM AUTHOR]

Ecosystems are complex and difficult to predict and control. Western science-based societies have tended to simplify ecosystems to manage them. Some indigenous and other rural groups who interact closely with a given resource system seem to have developed practices that are adapted to live with complexity. This paper examines how indigenous Cree hunters in James Bay, subarctic Canada, understand and deal with ecological complexity and dynamics, and how their understanding of uncertainty and variability shape subsistence activities. The focus is the Canada goose ( Branta canadensis) hunt which is adaptive to shifts and changes in local and regional conditions. Ecological understandings of Cree hunters allow them to account for and deal with a very large number of variables at multiples scales. The Cree deal with these variables qualitatively, an approach consistent with some scientific ways of dealing with complexity, such as adaptive management and fuzzy logic. [ABSTRACT FROM AUTHOR]

Great concern has been raised with respect to the 13 traplines that constitute the traditional territory of the Ouje-Bougoumou Cree located in the James Bay region of northern Quebec, Canada, with respect to mine wastes originating from three local mines. As a result, an “Integrative Risk Assessment” was initiated consisting of three interrelated components: a comprehensive human health study, an assessment of the existing ecological/environmental database, and a land use/potential sites of concern study. In this paper, we document past and present land use in the traditional territory of the Ouje-Bougoumou Cree for 72 heads of households, including 13 tallymen, and use a Geographic Information System (GIS) to layer harvest/hunting and gathering/collecting data over known mining areas and potential sites of concern. In this way, potential receptors of contamination and routes of human exposure were identified. Areas of overlap with respect to land use activity and mining operations were relatively extensive for certain harvesting activities (e.g., beaver, Castor canadensis and various species of game birds), less so for fish harvesting (all species) and water collection, and relatively restrictive for large mammal harvesting and collection of firewood (and other collection activities). Potential receptors of contaminants associated with mining activity (e.g., fish and small mammals) and potential routes of exposure (e.g., ingestion of contaminated game and drinking of contaminated water) were identified. [ABSTRACT FROM AUTHOR]

Fishing is part of the traditional activities of Indigenous people in Canada. However, it is also a route of exposure to methylmercury, a known neurotoxicant, and this is a concern for those who rely on fish as part of their diet. The probable weekly intake (PWI) of methylmercury from six species of fish was calculated for Indigenous community members (N = 1406), grouped by age and sex, and compared to Canadian and international provisional reference doses to assess exposure. Mixed-effects regression models were also used to estimate the input of methylmercury into the blood, and Hazard Quotients (HQ) were used to assess potential effects. Of the species of fish in our study, walleye and lake trout contributed the most to methylmercury intake. There was a positive association between the consumption of walleye and the total blood mercury concentrations of mercury in women and men (R2 A = 0.40 and 0.47, respectively), and to a lesser extent, children. Similar results were observed for the consumption of lake trout. The 95th-percentile HQ for girls (3.16) and boys (3.18) from the consumption of lake trout was relatively high, and to a lesser extent, so was the HQ for walleye and pike. The consumption of some species of fish increases the exposure to methylmercury, however, taking a balanced approach, there are health benefits associated with the consumption of fish that must be considered. To mitigate future exposure to methylmercury, we recommend follow-up blood monitoring and local-geospatial-based assessments. • Consumers of large predatory fish have higher total blood mercury concentrations. • Children should be cautious of consuming too much large and medium predatory fish. • Blood-Hg concentration following fish consumption predicts methylmercury exposure. • Fish consumption is good for health and dependent on seasonal availability. [ABSTRACT FROM AUTHOR]

Exposure to methylmercury is a concern for those who rely on fish as a traditional food in the Eeyou Istchee territory of James Bay, Quebec, Canada, because industrial land uses overlap with community water bodies where fish are harvested. Consequently, this study assessed if traditional practices, particularly fishing, increased the risk of exposure to methylmercury from the consumption of locally harvested fish. We designed a geographic information system (GIS) that included land use and fish methylmercury tissue concentrations to assess clustering of potential hot spots. We also used generalized linear models to assess the association of fish consumption to blood organic-mercury concentrations, and logistic regression models to assess the probability of fish exceeding the safety threshold for methylmercury tissue concentrations in areas of high intensity land use. The GIS demonstrated significant clustered hot spots around regions of hydroelectric and mining land use. Our results also revealed that adult consumption of pike, lake trout and/or walleye, and child consumption of pike or walleye were significantly associated with blood organic-mercury concentrations. Further, large fish harvested in a community with high intensity land use yielded a 77% probability that the fish exceeded the safety threshold. From a human exposure perspective, our study highlights the need for further research on children who consume fish from this region., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)