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  1. Article ; Online: Watershed characteristics and chemical properties govern methyl mercury concentrations within headwater streams of boreal forests in Ontario, Canada.

    Harrow-Lyle, Tyler J / Lam, Wai Ying / Emilson, Erik J S / Mackereth, Robert W / Mitchell, Carl P J / Melles, Stephanie J

    Journal of environmental management

    2023  Volume 345, Page(s) 118526

    Abstract: Methyl mercury (MeHg) concentrations in boreal headwater streams are influenced by complex natural processes and disturbances such as forestry management. Understanding drivers of MeHg within boreal streams in Ontario, Canada, is of particular interest ... ...

    Abstract Methyl mercury (MeHg) concentrations in boreal headwater streams are influenced by complex natural processes and disturbances such as forestry management. Understanding drivers of MeHg within boreal streams in Ontario, Canada, is of particular interest as there are legacy MeHg concerns. However, models accounting for the complexity of underlying processes have not yet been developed. We assessed how catchment characteristics and stream water chemistry influence MeHg concentrations within 19 watersheds of the Dryden - Wabigoon Forest in Ontario, Canada, using a structural equation modelling (SEM) approach. Despite the study area encompassing a large variation of boreal forest watersheds in the Canadian Shield, our SEM had substantial explanatory power across the region (χ
    MeSH term(s) Mercury/chemistry ; Ontario ; Taiga ; Forests ; Water ; Water Pollutants, Chemical/chemistry ; Environmental Monitoring
    Chemical Substances Mercury (FXS1BY2PGL) ; dimethyl mercury (C60TQU15XY) ; Water (059QF0KO0R) ; Water Pollutants, Chemical
    Language English
    Publishing date 2023-07-05
    Publishing country England
    Document type Journal Article
    ZDB-ID 184882-3
    ISSN 1095-8630 ; 0301-4797
    ISSN (online) 1095-8630
    ISSN 0301-4797
    DOI 10.1016/j.jenvman.2023.118526
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  2. Article ; Online: Watershed characteristics and chemical properties govern methyl mercury concentrations within headwater streams of boreal forests in Ontario, Canada

    Harrow-Lyle, Tyler J. / Lam, Wai Ying / Emilson, Erik J.S. / Mackereth, Robert W. / Mitchell, Carl P.J. / Melles, Stephanie J.

    Elsevier Ltd Journal of Environmental Management. 2023 Nov., v. 345 p.118526-

    2023  

    Abstract: Methyl mercury (MeHg) concentrations in boreal headwater streams are influenced by complex natural processes and disturbances such as forestry management. Understanding drivers of MeHg within boreal streams in Ontario, Canada, is of particular interest ... ...

    Abstract Methyl mercury (MeHg) concentrations in boreal headwater streams are influenced by complex natural processes and disturbances such as forestry management. Understanding drivers of MeHg within boreal streams in Ontario, Canada, is of particular interest as there are legacy MeHg concerns. However, models accounting for the complexity of underlying processes have not yet been developed. We assessed how catchment characteristics and stream water chemistry influence MeHg concentrations within 19 watersheds of the Dryden – Wabigoon Forest in Ontario, Canada, using a structural equation modelling (SEM) approach. Despite the study area encompassing a large variation of boreal forest watersheds in the Canadian Shield, our SEM had substantial explanatory power across the region (χ²₅₁ = 45.37, p-value = 0.70, R² = 0.75). Nitrate concentrations (p-value <0.001), water temperature (p-value = 0.002), and the latent watershed characteristic (p-value <0.001) had a positive influence on MeHg concentrations once variable interactions were accounted. Due to the inherent strengths of applying an SEM approach, we describe two plausible pathways driving MeHg concentrations: 1) indirect effect of forest-derived nutrients increases in-situ MeHg production in Dryden – Wabigoon Forest streams, and 2) direct supply of MeHg from inundated soils following consistent precipitation and inundation events (i.e., fill, sit, and spill).
    Keywords Canadian Shield ; boreal forests ; environmental management ; equations ; forest management ; hydrochemistry ; methylmercury compounds ; nitrates ; streams ; water ; water temperature ; watersheds ; Ontario ; Methyl mercury ; Watershed ; Stream ; Dissolved organic carbon ; Nutrients ; Structural equation modelling
    Language English
    Dates of publication 2023-11
    Publishing place Elsevier Ltd
    Document type Article ; Online
    ZDB-ID 184882-3
    ISSN 1095-8630 ; 0301-4797
    ISSN (online) 1095-8630
    ISSN 0301-4797
    DOI 10.1016/j.jenvman.2023.118526
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  3. Article: Pollen sleuthing for terrestrial plant surveys: Locating plant populations by exploiting pollen movement

    Campbell, Lesley G. / Melles, Stephanie J. / Vaz, Eric / Parker, Rebecca J. / Burgess, Kevin S.

    Applications in plant sciences. 2018 Jan., v. 6, no. 1

    2018  

    Abstract: PREMISE OF THE STUDY: We present an innovative technique for sampling, identifying, and locating plant populations that release pollen, without extensive ground surveys. This method (1) samples pollen at random locations within the target species’ ... ...

    Abstract PREMISE OF THE STUDY: We present an innovative technique for sampling, identifying, and locating plant populations that release pollen, without extensive ground surveys. This method (1) samples pollen at random locations within the target species’ habitat, (2) detects species’ presence using morphological pollen analysis, and (3) uses kriging to predict likely locations of populations to focus future search efforts. METHODS: To demonstrate, we applied the pollen sleuthing system to search for artificially constructed populations of Brassica rapa in an old field. Population size varied from 0–100 flowers labeled with artificial pollen (paint pellets). After characterizing the landscape, we pan‐trapped 2762 potential insect vectors from random locations across the field and washed particulate matter from their bodies to assess artificial pollen abundance with a microscope. RESULTS: Population size greatly influenced artificial pollen detection success; following random pollen trap sampling and interpolation, ground surveys would be best focused on identified areas with high pollen density and low variation in pollen density. Sampling sites most successfully detected artificial pollen when they were located at higher elevations, near showy flowering plants that were not grasses. DISCUSSION: Detection of nascent populations using the proposed system is possible but accuracy will depend on local environmental factors (e.g., wind, elevation). Conservation and invasive species control programs may be improved by using this approach.
    Keywords Brassica rapa ; habitats ; invasive species ; kriging ; landscapes ; particulates ; pollen ; pollen analysis ; pollen flow ; population size ; spore traps ; wind
    Language English
    Dates of publication 2018-01
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 2699923-7
    ISSN 2168-0450
    ISSN 2168-0450
    DOI 10.1002/aps3.1020
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  4. Article: Spatiotemporal Variations in Mercury Bioaccumulation at Fine and Broad Scales for Two Freshwater Sport Fishes

    Thomas, Shyam M / Bhavsar, Satyendra P / Melles, Stephanie J

    Water. 2018 Nov. 11, v. 10, no. 11

    2018  

    Abstract: Bioaccumulation of mercury in sport fish is a complex process that varies in space and time. Both large-scale climatic as well as fine-scale environmental factors are drivers of these space-time variations. In this study, we avail a long-running ... ...

    Abstract Bioaccumulation of mercury in sport fish is a complex process that varies in space and time. Both large-scale climatic as well as fine-scale environmental factors are drivers of these space-time variations. In this study, we avail a long-running monitoring program from Ontario, Canada to better understand spatiotemporal variations in fish mercury bioaccumulation at two distinct scales. Focusing on two common large-bodied sport fishes (Walleye and Northern Pike), the data were analyzed at fine- and broad-scales, where fine-scale implies variations in bioaccumulation at waterbody- and year-level and broad-scale captures variations across 3 latitudinal zones (~5° each) and eight time periods (~5-year each). A series of linear mixed-effects models (LMEMs) were employed to capture the spatial, temporal and spatiotemporal variations in mercury bioaccumulation. Fine-scale models were overall better fit than broad-scale models suggesting environmental factors operating at the waterbody-level and annual climatic conditions matter most. Moreover, for both scales, the space time interaction explained most of the variation. The random slopes from the best-fitting broad-scale model were used to define a bioaccumulation index that captures trends within a climate change context. The broad-scale trends suggests of multiple and potentially conflicting climate-driven mechanisms. Interestingly, broad-scale temporal trends showed contrasting bioaccumulation patterns—increasing in Northern Pike and decreasing in Walleye, thus suggesting species-specific ecological differences also matter. Overall, by taking a scale-specific approach, the study highlights the overwhelming influence of fine-scale variations and their interactions on mercury bioaccumulation; while at broad-scale the mercury bioaccumulation trends are summarized within a climate change context.
    Keywords bioaccumulation ; climate change ; climatic factors ; data analysis ; Esox lucius ; fish ; game fish ; mercury ; models ; monitoring ; spatial variation ; surface water ; temporal variation ; Ontario
    Language English
    Dates of publication 2018-1111
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    ZDB-ID 2521238-2
    ISSN 2073-4441
    ISSN 2073-4441
    DOI 10.3390/w10111625
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  5. Article ; Online: Climate and landscape conditions indirectly affect fish mercury levels by altering lake water chemistry and fish size.

    Thomas, Shyam M / Melles, Stephanie J / Mackereth, Robert W / Tunney, Tyler D / Chu, Cindy / Oswald, Claire J / Bhavsar, Satyendra P / Johnston, Thomas A

    Environmental research

    2020  Volume 188, Page(s) 109750

    Abstract: Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as ... ...

    Abstract Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as individual fish biology and water chemistry at the lake-scale, whereas, climate, and land-use/land-cover conditions within lake catchments can be influential at relatively larger scales. Nevertheless, unravelling the intricate network of pathways that govern how lake-scale and large-scale factors interact to affect mercury levels in fish remains an important scientific challenge. Using structural equation models (SEMs) and multiple long-term databases we identified direct and indirect effects of lake-scale and larger-scale factors on mercury levels in Walleye and Northern Pike - two species that are valued in inland fisheries. At the lake-level, the most parsimonious path models contained direct effects of fish weight, DOC, and pH, as well as an indirect effect of DOC on fish mercury levels via fish weight. Interestingly, lakeshed-, climate-, and full-path models that combine the effects of both lakeshed and climate revealed indirect effects of surrounding landscape conditions and latitude via DOC, pH, and fish weight but no direct effects on fish mercury levels. These results are generally consistent across species and lakes, except for some differences between stratified and non-stratified lakes. Our findings imply that understanding climate and land-use driven alterations of water chemistry and fish biology will be critical to predicting and mitigating fish mercury bioaccumulation in the future.
    MeSH term(s) Animals ; Ecosystem ; Environmental Monitoring ; Fishes ; Humans ; Lakes ; Mercury/analysis ; Mercury/toxicity ; Water Pollutants, Chemical/analysis ; Water Pollutants, Chemical/toxicity
    Chemical Substances Water Pollutants, Chemical ; Mercury (FXS1BY2PGL)
    Language English
    Publishing date 2020-06-01
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 205699-9
    ISSN 1096-0953 ; 0013-9351
    ISSN (online) 1096-0953
    ISSN 0013-9351
    DOI 10.1016/j.envres.2020.109750
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  6. Article: Pollen sleuthing for terrestrial plant surveys: Locating plant populations by exploiting pollen movement.

    Campbell, Lesley G / Melles, Stephanie J / Vaz, Eric / Parker, Rebecca J / Burgess, Kevin S

    Applications in plant sciences

    2018  Volume 6, Issue 1, Page(s) e1020

    Abstract: Premise of the study: We present an innovative technique for sampling, identifying, and locating plant populations that release pollen, without extensive ground surveys. This method (1) samples pollen at random locations within the target species' ... ...

    Abstract Premise of the study: We present an innovative technique for sampling, identifying, and locating plant populations that release pollen, without extensive ground surveys. This method (1) samples pollen at random locations within the target species' habitat, (2) detects species' presence using morphological pollen analysis, and (3) uses kriging to predict likely locations of populations to focus future search efforts.
    Methods: To demonstrate, we applied the pollen sleuthing system to search for artificially constructed populations of
    Results: Population size greatly influenced artificial pollen detection success; following random pollen trap sampling and interpolation, ground surveys would be best focused on identified areas with high pollen density and low variation in pollen density. Sampling sites most successfully detected artificial pollen when they were located at higher elevations, near showy flowering plants that were not grasses.
    Discussion: Detection of nascent populations using the proposed system is possible but accuracy will depend on local environmental factors (e.g., wind, elevation). Conservation and invasive species control programs may be improved by using this approach.
    Language English
    Publishing date 2018-02-08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2699923-7
    ISSN 2168-0450
    ISSN 2168-0450
    DOI 10.1002/aps3.1020
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  7. Article: Climate and landscape conditions indirectly affect fish mercury levels by altering lake water chemistry and fish size

    Thomas, Shyam M / Melles, Stephanie J / Mackereth, Robert W / Tunney, Tyler D / Chu, Cindy / Oswald, Claire J / Bhavsar, Satyendra P / Johnston, Thomas A

    Elsevier Inc. Environmental research. 2020 Sept., v. 188

    2020  

    Abstract: Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as ... ...

    Abstract Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as individual fish biology and water chemistry at the lake-scale, whereas, climate, and land-use/land-cover conditions within lake catchments can be influential at relatively larger scales. Nevertheless, unravelling the intricate network of pathways that govern how lake-scale and large-scale factors interact to affect mercury levels in fish remains an important scientific challenge. Using structural equation models (SEMs) and multiple long-term databases we identified direct and indirect effects of lake-scale and larger-scale factors on mercury levels in Walleye and Northern Pike - two species that are valued in inland fisheries. At the lake-level, the most parsimonious path models contained direct effects of fish weight, DOC, and pH, as well as an indirect effect of DOC on fish mercury levels via fish weight. Interestingly, lakeshed-, climate-, and full-path models that combine the effects of both lakeshed and climate revealed indirect effects of surrounding landscape conditions and latitude via DOC, pH, and fish weight but no direct effects on fish mercury levels. These results are generally consistent across species and lakes, except for some differences between stratified and non-stratified lakes. Our findings imply that understanding climate and land-use driven alterations of water chemistry and fish biology will be critical to predicting and mitigating fish mercury bioaccumulation in the future.
    Keywords Esox lucius ; bioaccumulation ; climate ; equations ; fish ; freshwater ; human health ; hydrochemistry ; land use ; land use and land cover maps ; landscapes ; latitude ; mercury ; pH ; pollution ; research
    Language English
    Dates of publication 2020-09
    Publishing place Elsevier Inc.
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 205699-9
    ISSN 1096-0953 ; 0013-9351
    ISSN (online) 1096-0953
    ISSN 0013-9351
    DOI 10.1016/j.envres.2020.109750
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  8. Article: Potential spread of Great Lakes fishes given climate change and proposed dams: an approach using circuit theory to evaluate invasion risk

    Melles, Stephanie J / Chu, Cindy / Alofs, Karen M / Jackson, Donald A

    Landscape ecology. 2015 May, v. 30, no. 5

    2015  

    Abstract: The Great Lakes currently harbour a number of non-native fishes that are thermally limited to the comparatively warm waters of Lake Erie and Lake Ontario. Climate change could facilitate the inland spread of many non-native species as the Great Lakes and ...

    Abstract The Great Lakes currently harbour a number of non-native fishes that are thermally limited to the comparatively warm waters of Lake Erie and Lake Ontario. Climate change could facilitate the inland spread of many non-native species as the Great Lakes and their tributaries warm, putting thousands of inland lakes and streams at risk. We investigated how watershed network configurations, climate change and proposed hydro-power development could influence invasion risk in the Great Lakes Basin. Electric circuit theory was used to model hydrologic accessibility of aquatic ecological networks (i.e., lake, river, and impoundment chains) within tertiary watersheds. Risk of invasion was measured as the product of probability of non-native species spread (hydrologic accessibility) and amount of suitable thermal habitat under an ensemble of air temperature projections. Proposed hydro-power dam sites and their upstream catchments were used to evaluate changes in total risk of invasion given passable, semi-passable, and impassable dams. We show that projected climate change will lead to more coolwater stream and warmwater lake habitat. Overall invasion risk of cool- and warmwater species was highest in southern Ontario and surprisingly in northern watersheds draining into Lake Superior. This risk could be partially mediated by proposed dams if dams reduce connectivity and access to potentially suitable habitat. Our evaluation of mean invasion risk provides a broad-scale comparative tool for management of invasive species control options.
    Keywords air temperature ; basins ; climate change ; electronic circuits ; fish ; habitats ; hydrologic models ; introduced species ; invasive species ; lakes ; risk ; rivers ; streams ; water power ; watersheds ; Lake Erie ; Lake Ontario ; Lake Superior ; Ontario
    Language English
    Dates of publication 2015-05
    Size p. 919-935.
    Publishing place Springer-Verlag
    Document type Article
    ZDB-ID 1027798-5
    ISSN 1572-9761 ; 0921-2973
    ISSN (online) 1572-9761
    ISSN 0921-2973
    DOI 10.1007/s10980-014-0114-z
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  9. Article: Diversity of practitioners publishing in five leading international journals of applied ecology and conservation biology, 1987–2015 relative to global biodiversity hotspots

    Melles, Stephanie J / Scarpone, Christopher / Julien, Adisa / Robertson, Julie / Levieva, Jennifer Bello / Carrier, Courtney / France, Robert / Guvenc, Sabrina / Lam, Wai Ying / Lucas, Michelle / Maglalang, Alexus / McKee, Keira / Okoye, Frances / Morales, Kayla

    Écoscience. 2019 Oct. 2, v. 26, no. 4

    2019  

    Abstract: Between 1987 and 1995, research papers published in five leading journals of applied ecology and conservation biology (AECB) were overwhelmingly produced by American and British authors. A significant proportion of overall variation in research ... ...

    Abstract Between 1987 and 1995, research papers published in five leading journals of applied ecology and conservation biology (AECB) were overwhelmingly produced by American and British authors. A significant proportion of overall variation in research productivity among nations could be explained by differences in gross national product (GNP). Here, we used bibliometric analyses for a comparative assessment to determine if geographical patterns of research changed or remained consistent between the periods, 1987–1995 and 2007–2015. Our results revealed an absence of a marked increase in geographical diversity of research. Imbalances persisted in global research efforts in five leading journals, with research productivity remaining significantly correlated to national differences in wealth. There is a disparity between where scientific research continues to be conducted and where hotspots of biodiversity are known to exist as indicated by our study and several other recent papers. This is an alarming finding as research is needed to establish conservation status, and work by others shows that the level of conservation spending is significantly correlated with mitigating biodiversity loss and improving species at risk status.
    Keywords applied ecology ; biodiversity ; conservation status ; gross national product ; risk ; wildlife management
    Language English
    Dates of publication 2019-1002
    Size p. 323-340.
    Publishing place Taylor & Francis
    Document type Article
    Note NAL-AP-2-clean
    ISSN 2376-7626
    DOI 10.1080/11956860.2019.1645565
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  10. Article ; Online: Current water quality guidelines across North America and Europe do not protect lakes from salinization.

    Hintz, William D / Arnott, Shelley E / Symons, Celia C / Greco, Danielle A / McClymont, Alexandra / Brentrup, Jennifer A / Cañedo-Argüelles, Miguel / Derry, Alison M / Downing, Amy L / Gray, Derek K / Melles, Stephanie J / Relyea, Rick A / Rusak, James A / Searle, Catherine L / Astorg, Louis / Baker, Henry K / Beisner, Beatrix E / Cottingham, Kathryn L / Ersoy, Zeynep /
    Espinosa, Carmen / Franceschini, Jaclyn / Giorgio, Angelina T / Göbeler, Norman / Hassal, Emily / Hébert, Marie-Pier / Huynh, Mercedes / Hylander, Samuel / Jonasen, Kacie L / Kirkwood, Andrea E / Langenheder, Silke / Langvall, Ola / Laudon, Hjalmar / Lind, Lovisa / Lundgren, Maria / Proia, Lorenzo / Schuler, Matthew S / Shurin, Jonathan B / Steiner, Christopher F / Striebel, Maren / Thibodeau, Simon / Urrutia-Cordero, Pablo / Vendrell-Puigmitja, Lidia / Weyhenmeyer, Gesa A

    Proceedings of the National Academy of Sciences of the United States of America

    2022  Volume 119, Issue 9

    Abstract: Human-induced salinization caused by the use of road deicing salts, agricultural practices, mining operations, and climate change is a major threat to the biodiversity and functioning of freshwater ecosystems. Yet, it is unclear if freshwater ecosystems ... ...

    Abstract Human-induced salinization caused by the use of road deicing salts, agricultural practices, mining operations, and climate change is a major threat to the biodiversity and functioning of freshwater ecosystems. Yet, it is unclear if freshwater ecosystems are protected from salinization by current water quality guidelines. Leveraging an experimental network of land-based and in-lake mesocosms across North America and Europe, we tested how salinization-indicated as elevated chloride (Cl
    MeSH term(s) Animals ; Anthropogenic Effects ; Ecosystem ; Europe ; Guidelines as Topic ; Lakes ; North America ; Salinity ; Water Quality ; Zooplankton
    Language English
    Publishing date 2022-02-19
    Publishing country United States
    Document type Journal Article
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2115033119
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