Update: I am joining the faculty of the University of Nevada Reno Natural Resources and Environmental Science Department beginning July 2019. The new lab website is here: www.blaszczaklab.weebly.com
RESEARCH OBJECTIVES:
I am a watershed biogeochemist, ecosystem ecologist, and environmental toxicologist interested in the transport and transformation of materials through watersheds and the streams that drain them. My research interests lie at the interface of biogeochemistry, landscape ecology, hydrology, and toxicology.
The goal of my work is to improve understanding of how carbon, nutrients, and contaminants move through landscapes, undergo biogeochemical transformations, and their ultimate impact on aquatic ecosystem communities and processes.
At the broadest level, I am interested in understanding how aquatic ecosystems will respond to increasing hydroclimatic variability and land use change in the Anthropocene. This interest lead me to focus my dissertation work on some of the most extreme cases of currently altered physical and chemical disturbance regimes -- headwater streams draining urbanized landscapes (see past projects below). In my current work as a postdoctoral research associate, I am investigating how carbon transport and transformation in streams is affected by variation in the residence time of water and hydrologic disturbance.
View my Google Scholar profile for links to my publications or please contact me for a copy of any publication.
The goal of my work is to improve understanding of how carbon, nutrients, and contaminants move through landscapes, undergo biogeochemical transformations, and their ultimate impact on aquatic ecosystem communities and processes.
At the broadest level, I am interested in understanding how aquatic ecosystems will respond to increasing hydroclimatic variability and land use change in the Anthropocene. This interest lead me to focus my dissertation work on some of the most extreme cases of currently altered physical and chemical disturbance regimes -- headwater streams draining urbanized landscapes (see past projects below). In my current work as a postdoctoral research associate, I am investigating how carbon transport and transformation in streams is affected by variation in the residence time of water and hydrologic disturbance.
View my Google Scholar profile for links to my publications or please contact me for a copy of any publication.
CURRENT PROJECTS
|
Monitoring and process-based modeling of carbon transport and transformation in rivers
My research as a postdoctoral research associate at the Flathead Lake Biological Station is primarily focused on modeling hydrologic controls on freshwater metabolism funded through the NSF StreamPulse project. I am also monitoring and modeling the transport and transformation of carbon within streams and rivers around the Flathead Valley, including those found in the Coram Experimental Forest and the Nyack Floodplain of the Middle Fork of the Flathead River. |
|
Patterns and drivers of global riverine hypoxia
Forecasts for hydroclimatic change in the twenty-first century predict greater variability in precipitation across the globe with implications for drought and flood disturbance regimes in riverine ecosystems. Within rivers with excess nutrients from draining intensively managed landscapes, altered flow regimes can increase the mean residence time of water at baseflow. In combination, these changes set up ideal conditions for hypoxia (< 2 mg dissolved oxygen/L) in warmer temperatures. Hypoxia is a stressor on aquatic organisms and can alter biogeochemical cycling and contaminant fate and transport within aquatic ecosystems. We are compiling a database of DO measurements in rivers around the globe (see https://data.streampulse.org/grdo_filedrop) to complement records available in the StreamPulse database, and characterizing the spatial and temporal extent of riverine hypoxia.
Collaborators: Alice Carter, Christopher Dutton, Lluis Gomez-Gener, Nancy Grimm, Judd Harvey, Ashley Helton, Lauren Koenig, Francine Mejia, Matt Cohen
Publication: Blaszczak, J.R., Carter, A., Dutton, C., Gomez-Gener, L., Grimm, N., Harvey, J., Helton, A., Koenig, L., Mejia, F., & M. Cohen. Patterns and drivers of global riverine hypoxia. In preparation.
Forecasts for hydroclimatic change in the twenty-first century predict greater variability in precipitation across the globe with implications for drought and flood disturbance regimes in riverine ecosystems. Within rivers with excess nutrients from draining intensively managed landscapes, altered flow regimes can increase the mean residence time of water at baseflow. In combination, these changes set up ideal conditions for hypoxia (< 2 mg dissolved oxygen/L) in warmer temperatures. Hypoxia is a stressor on aquatic organisms and can alter biogeochemical cycling and contaminant fate and transport within aquatic ecosystems. We are compiling a database of DO measurements in rivers around the globe (see https://data.streampulse.org/grdo_filedrop) to complement records available in the StreamPulse database, and characterizing the spatial and temporal extent of riverine hypoxia.
Collaborators: Alice Carter, Christopher Dutton, Lluis Gomez-Gener, Nancy Grimm, Judd Harvey, Ashley Helton, Lauren Koenig, Francine Mejia, Matt Cohen
Publication: Blaszczak, J.R., Carter, A., Dutton, C., Gomez-Gener, L., Grimm, N., Harvey, J., Helton, A., Koenig, L., Mejia, F., & M. Cohen. Patterns and drivers of global riverine hypoxia. In preparation.
PAST PROJECTS
Microbiome Stress Project
Through the development of a microbial sequencing database (high-throughput sequencing only) using previous published and unpublished studies, we are investigating how natural and anthropogenic stressors shape microbial community structure across multiple types of stressors and environments. We will use this database and the R package 'Phylofactor' to identify microbial taxa specifically sensitive or resistant to a large range of natural and anthropogenic stressors across various habitats (freshwater, saltwater, soil, biofilms, gut, sediments).
Collaborators: Jennifer Rocca, Marie Simonin, Firas Midani, Alex Washburne, and Sean Gibbons
Visit the MBSP website: http://microbiomestressproject.weebly.com/
Publication: Rocca, J.J., Simonin, M.S., Blaszczak, J.R., Ernakovich, J.G., Gibbons, S.M., Midani, F.S, & A.D. Washburne. 2019. Microbiome Stress Project: towards a global meta-analysis of environmental stressors and their effects on microbial communities. DOI: 10.3389/fmicb.2018.03272
Through the development of a microbial sequencing database (high-throughput sequencing only) using previous published and unpublished studies, we are investigating how natural and anthropogenic stressors shape microbial community structure across multiple types of stressors and environments. We will use this database and the R package 'Phylofactor' to identify microbial taxa specifically sensitive or resistant to a large range of natural and anthropogenic stressors across various habitats (freshwater, saltwater, soil, biofilms, gut, sediments).
Collaborators: Jennifer Rocca, Marie Simonin, Firas Midani, Alex Washburne, and Sean Gibbons
Visit the MBSP website: http://microbiomestressproject.weebly.com/
Publication: Rocca, J.J., Simonin, M.S., Blaszczak, J.R., Ernakovich, J.G., Gibbons, S.M., Midani, F.S, & A.D. Washburne. 2019. Microbiome Stress Project: towards a global meta-analysis of environmental stressors and their effects on microbial communities. DOI: 10.3389/fmicb.2018.03272
Do hydrologic disturbances exacerbate or mitigate the effects of contaminants in urban streams?
Frequent flooding due to catchment urbanization tends to reduce the productivity and biomass of biofilms in urban streams, and may alter their ability to assimilate and transform contaminants. Understanding of how the timing of contaminant exposure (i.e. salt, pharmaceuticals, metals) may independently alter the recovery of biofilms between storms is limited. We conducted an artificial stream experiment in which treatment streams underwent a simulated storm. We then dosed streams with a chemical mixture mimicking a highly contaminated stream in Baltimore, MD in a pulse at different stages of biofilm recovery (1, 7, and 14 days post-storm). We are currently investigating biofilm community composition and contaminant bioaccumulation in order to understand changes to whole-stream process rates.
Collaborators: Emily Bernhardt, Jenny Rocca, Emma Rosi-Marshall
This work was carried out at the Cary Institute for Ecosystem Studies in Millbrook, NY and funded by a NSF DDIG grant.
Publications:
Blaszczak, J.R., Rocca, J., Rosi, E.J., & E.S. Bernhardt. Do hydrologic disturbances exacerbate or mitigate the effects of contaminants in urban streams? In preparation.
Frequent flooding due to catchment urbanization tends to reduce the productivity and biomass of biofilms in urban streams, and may alter their ability to assimilate and transform contaminants. Understanding of how the timing of contaminant exposure (i.e. salt, pharmaceuticals, metals) may independently alter the recovery of biofilms between storms is limited. We conducted an artificial stream experiment in which treatment streams underwent a simulated storm. We then dosed streams with a chemical mixture mimicking a highly contaminated stream in Baltimore, MD in a pulse at different stages of biofilm recovery (1, 7, and 14 days post-storm). We are currently investigating biofilm community composition and contaminant bioaccumulation in order to understand changes to whole-stream process rates.
Collaborators: Emily Bernhardt, Jenny Rocca, Emma Rosi-Marshall
This work was carried out at the Cary Institute for Ecosystem Studies in Millbrook, NY and funded by a NSF DDIG grant.
Publications:
Blaszczak, J.R., Rocca, J., Rosi, E.J., & E.S. Bernhardt. Do hydrologic disturbances exacerbate or mitigate the effects of contaminants in urban streams? In preparation.
Urban stream metabolic & dissolved oxygen regimes under multiple stressors
What are the metabolic regimes of urban streams? How does geomorphology mediate the relationship between hydrologic disturbances and metabolism in urban streams?
Collaborators: Emily Bernhardt, Dean Urban, Martin Doyle, Joseph Delesantro
Publication: Blaszczak, J.R., Delesantro, J.M., Urban, D.L., Doyle, M.W., & E.S. Bernhardt. 2018. Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes. Limnology & Oceanography. DOI: 10.1002/lno.11081
Press: Sierra Club
What are the metabolic regimes of urban streams? How does geomorphology mediate the relationship between hydrologic disturbances and metabolism in urban streams?
Collaborators: Emily Bernhardt, Dean Urban, Martin Doyle, Joseph Delesantro
Publication: Blaszczak, J.R., Delesantro, J.M., Urban, D.L., Doyle, M.W., & E.S. Bernhardt. 2018. Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes. Limnology & Oceanography. DOI: 10.1002/lno.11081
Press: Sierra Club
Linking urban landscape connectivity & configuration to the water quality of receiving streams
How does the connectivity and configuration of urban development (surface and subsurface) in small catchments affect nutrient and contaminant loading in urban streams? We are compared 24 first- and second-order catchments in the Piedmont Triangle, NC which spanned the broadest possible range of development characteristics within a 10-36% impervious surface cover range to determine which attributes of urban development best explain the variation we see in urban streamwater chemistry across the landscape.
Collaborators: Emily Bernhardt, Dean Urban, Joseph Delesantro, Megan Fork, Ethan Baruch
Visit our website at www.urbanstreamsrt.com
Publications:
Blaszczak, J.R., Delesantro, J.M., Zhong, Y., Urban, D.L., & E.S. Bernhardt. 2019. Watershed urban development controls on urban streamwater chemistry variability. Biogeochemistry. DOI: 10.1007/s10533-019-00572-7
Baruch, E.M., Voss, K.A., Blaszczak, J.R., Delesantro, J., Urban, D.L., & E.S. Bernhardt. 2018. Not all pavements lead to streams: variation in impervious surface connectivity affects urban stream ecosystems. Freshwater Science. DOI: 10.1086/699014
Fork, M.L., Blaszczak, J.R., Delesantro, J.M., & J.B. Heffernan. 2018. Engineered headwaters can act as sources of dissolved organic matter and nitrogen to urban stream networks. Limnology & Oceanography Letters. DOI: 10.1002/lol2.10066
Press: Duke Forest Newsletter
Urban Homogenization? N cycling and contaminants in urban ponds across the US
How do common urban contaminants affect N cycling in urban pond sediments? As part of a broader Urban Homogenization project, we investigated how conditions in urban aquatic ecosystems affected rates of denitrification in pond sediments. Sediment and water samples were collected during the summer of 2014 from 64 ponds across Durham, NC, Baltimore, MD, Boston, MA, Minneapolis/St. Paul, MN, Miami, FL, Phoenix, AZ, Portland, OR, and Salt Lake City, UT.
Publications:
Blaszczak, J.R., Steele, M.K., Badgley, B.D., Heffernan, J.B., Hobbie, S.E., Morse, J.L., Rivers, E.N., Hall, S.J., Neill, C., Pataki, D., Groffman, P.M., & E.S. Bernhardt. Sediment Chemistry of Urban Stormwater Ponds and Controls on Denitrification. Ecosphere, 9 (6): e02318
Baalousha, M., Yang, Y., Vance, M.E., Coleman, B., McNeal, S., Xu, J., Blaszczak, J.R., Steele, M., Bernhardt, E.S., & M.F. Hochella Jr. 2016. Outdoor urban nanomaterials: the emergence of a new, integrated, and critical field of study. Science of the Total Environment, 557: 740-753
Press Release: Duke University Press Release
Winter streamwater methylmercury peaks in boreal catchments
Which boreal catchment variables best explain observed peaks in winter streamwater methylmercury (MeHg) concentrations? We found different drivers for the spatial versus temporal variation in streamwater MeHg export from paired catchments at the Langtjern long term research site in southern Norway.
This work was done as part of the 2011-2012 Fulbright program at my host institution of the Norwegian Institute for Water Research (NIVA).
Publication:
de Wit, H.A., Granhus, A., Lindholm, M., Kainz, M.J., Lin, Y., Braaten, H.F.V., & J.R. Blaszczak. 2014. Forest harvest effects on mercury in streams and biota in Norwegian boreal catchments. Forest Ecology and Management, 324: 52-63
Which boreal catchment variables best explain observed peaks in winter streamwater methylmercury (MeHg) concentrations? We found different drivers for the spatial versus temporal variation in streamwater MeHg export from paired catchments at the Langtjern long term research site in southern Norway.
This work was done as part of the 2011-2012 Fulbright program at my host institution of the Norwegian Institute for Water Research (NIVA).
Publication:
de Wit, H.A., Granhus, A., Lindholm, M., Kainz, M.J., Lin, Y., Braaten, H.F.V., & J.R. Blaszczak. 2014. Forest harvest effects on mercury in streams and biota in Norwegian boreal catchments. Forest Ecology and Management, 324: 52-63
