Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada

MacLeod, Josef; Keller, Wendel; Paterson, Andrew M.; Dyer, Richard D.; Gunn, John M.

doi:10.4081/jlimnol.2016.1553

Cited by 5 publications

(3 citation statements)

References 26 publications

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“…The ADB is a large and remote watershed that spans two distinct ecozones in northern Ontario; the watershed begins with deep headwater lakes on the thinly soiled, igneous, Boreal shield and transitions into shallower lakes and the main-stem Attawapiskat River on the peatland-dominated Hudson Bay Lowlands that are underlain by glaciofluvial deposits, sedimentary limestones and dolostones. Lakes on the Shield have distinctly forested riparian areas and notably different water chemistry (e.g., higher total phosphorus and alkalinity) when compared to Lowland lakes and river sites, where riparian areas are wetland-dominated . A total of 27 lakes (18 in the Boreal Shield, 9 in the Lowlands) and 20 river sites were sampled; all of these sites were in the ADB, with the exception of four Lowland lakes that were in the Albany drainage basin, on the south side of the ADB (Figure ).…”

Section: Methodsmentioning

confidence: 99%

“…Lakes on the Shield have distinctly forested riparian areas and notably different water chemistry (e.g., higher total phosphorus and alkalinity) when compared to Lowland lakes and river sites, where riparian areas are wetland-dominated. 24 A total of 27 lakes (18 in the Boreal Shield, 9 in the Lowlands) and 20 river sites were sampled; all of these sites were in the ADB, with the exception of four Lowland lakes that were in the Albany drainage basin, on the south side of the ADB (Figure 1). River sites were selected and sampled by the Ontario Ministry of the Environment and Climate Change (OMOECC) as part of their Far North monitoring program.…”

Section: Introductionmentioning

confidence: 99%

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Optical Properties of Dissolved Organic Matter and Their Relation to Mercury Concentrations in Water and Biota Across a Remote Freshwater Drainage Basin

Lescord

Emilson

Johnston

et al. 2018

Environ. Sci. Technol.

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Dissolved organic matter (DOM) includes an array of carbon-based compounds that vary in size and structure and have complex interactions with mercury (Hg) cycling in aquatic systems. While many studies have examined the relationship between dissolved organic carbon concentrations ([DOC]) and methyl Hg bioaccumulation, few studies have considered the effects of DOM composition (e.g., protein-content, aromaticity). The goal of this study was to explore the relationships between total and methyl [Hg] in water, invertebrates, and fish and optically derived measures of DOM composition from 47 lake and river sites across a boreal watershed. Results showed higher aqueous total [Hg] in systems with more aromatic DOM and higher [DOC], potentially due to enhanced transport from upstream or riparian areas. Methyl [Hg] in biota were all positively related to the amount of microbial-based DOM and, in some cases, to the proportions of labile and protein-like DOM. These results suggest that increased Hg bioaccumulation is related to the availability of labile DOM, potentially due to enhanced Hg methylation. DOM composition explained 68% and 54% more variability in [Hg] in surface waters and large-bodied fish, respectively, than [DOC] alone. These results show that optical measures of DOM characteristics are a valuable tool for understanding DOM-Hg biogeochemistry.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Optical Properties of Dissolved Organic Matter and Their Relation to Mercury Concentrations in Water and Biota Across a Remote Freshwater Drainage Basin

Lescord

Emilson

Johnston

et al. 2018

Environ. Sci. Technol.

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“…Whereas previous studies have investigated the impact of nutrient limitation on eDNA degradation in marine ecosystems (Salter, 2018), showing that variability in eDNA levels can be correlated to the microbial metabolic response to limitations in nutrient availability, this phenomenon has not been thoroughly investigated in freshwater systems. The chemical composition of a lake is indicative of the water quality and nutrient availability, both can vary widely between lakes in the same area (MacLeod et al., 2017) and among regions at broader scales (Wagner et al., 2011). Environmental conditions could thus produce inaccurate estimates of species presence, absence, and community composition especially if sampling strategies do not account environmental effects on eDNA degradation.…”

Section: Discussionmentioning

confidence: 99%

Quantifying the effect of water quality on eDNA degradation using microcosm and bioassay experiments

McKnight,

Shafer,

Frost

2024

Environmental DNA

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Environmental DNA (eDNA) is often used to determine the presence and absence of species in a specific environment, be it air, water, or soil. Numerous environmental conditions are known to directly alter the rate at which eDNA degrades, including pH, temperature, and UV‐B light exposure. Beyond these, many limnological parameters have not been thoroughly examined for their ability to modify the degradation rate of eDNA. Here we used 20 mL microcosms with water collected from 12 lakes from the Kawartha Highlands near Peterborough Ontario, Canada, to study the decay rates of dissolved Yellow perch (Perca flavescens) eDNA. We measured and related rates of eDNA loss to multiple water quality parameters: total dissolved phosphorus, total dissolved nitrogen, size‐fractionated carbon, and chlorophyll‐a levels. Bioassays were also conducted to examine the bacterial role in eDNA degradation using three treatments under natural system conditions: non‐filtered, filtered (0.22 μm), and non‐filtered with added phosphorus (50 μg/L). Each microcosm exhibited a unique rate of degradation with eDNA half‐life (C0.5) ranging from 2.5 to 12.9 h. Chlorophyll‐a levels exhibited a positive linear relationship to the rate of degradation, while all other parameters showed no effect. The bioassays showed a general trend of the filtered treatments exhibiting the lowest rate of degradation, followed by the phosphorus treatments with the non‐filtered treatment containing bacteria exhibiting the highest rate of degradation. Overall, water with an increased level of chlorophyll‐a, in conjunction with elevated bacteria (i.e. non‐filtered bioassay) will exhibit a faster overall rate of eDNA degradation. These results show the necessity to individualize eDNA survey plans to the water body of interest and to account for environmental conditions relating to the microbial processing of eDNA.

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Mercury bioaccumulation in relation to changing physicochemical and ecological factors across a large and undisturbed boreal watershed

Lescord

Johnston

Branfireun

et al. 2019

Can. J. Fish. Aquat. Sci.

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Within a drainage basin, the position of a lake or river can greatly affect its limnological and ecological characteristics. These properties influence the cycling of mercury (Hg), a neurotoxic and bioaccumulative metal prevalent in remote northern watersheds. In this study, we examined how 43 physical, chemical, and ecological endpoints change across 58 lake and river sites within an undisturbed boreal watershed in Ontario, Canada, and assessed the influence of these endpoints on aqueous and biotic Hg concentrations ([Hg]). We found that several physicochemical parameters, but few ecological factors, varied in systematic patterns across the watershed. Overall, [Hg] in water and some fish increased in systems with decreasing landscape positions. Aqueous and biotic [Hg] were strongly related to dissolved organic carbon and nutrient concentrations. Biotic [Hg] was lower in higher-nutrient systems, potentially due to biodilution, but higher in systems with more nitrates + nitrites, suggesting an indirect relationship between Hg and nitrogen cycling. This study is the first to assess patterns of [Hg] across an entire intact watershed and provides valuable results for a region anticipating substantial industrial development.

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Scale and watershed features determine lake chemistry patterns across physiographic regions in the far north of Ontario, Canada

Abstract: Changes

Cited by 5 publications

References 26 publications

Optical Properties of Dissolved Organic Matter and Their Relation to Mercury Concentrations in Water and Biota Across a Remote Freshwater Drainage Basin

Optical Properties of Dissolved Organic Matter and Their Relation to Mercury Concentrations in Water and Biota Across a Remote Freshwater Drainage Basin

Quantifying the effect of water quality on eDNA degradation using microcosm and bioassay experiments

Mercury bioaccumulation in relation to changing physicochemical and ecological factors across a large and undisturbed boreal watershed

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