The Ciborowski Team
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Affiliation: University of Windsor, Department of Biological Sciences
Principal Investigator: Dr. Jan J.H. Ciborowski
Postdoctoral Fellows: Dr. Katya Kovalenko
Current Graduate Students: Carla Wytrykush (Ph.D
candidate), Ryan Boudens (M.Sc. candidate).
Team Role: The Ciborowski team estimated microbial production and respiration in the field (with the University of Waterloo), evaluating zoobenthic composition and secondary production, determining wetland bathymetry, contributing to macrophyte production estimates (with the University of Alberta), examining emergent aquatic insect trophic transfer to tree swallows (with Saskatchewan), and conducting bioassay studies of oil sands process materials (OSPM) effects on midge larvae. |
Graduate Students and Postdoctoral Fellows
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- Carla Wytrykush (Ph.D. In Progress)
- Started: 2002
- Thesis Title: Diversity and ecosystem processes and properties in wetland communities: the effects of ecosystem stressors and reclamation challenges.
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Project Summary: Decomposition of dead plant material is an integral process providing key nutrients to drive primary productivity in wetlands. How rapidly aquatic plant matter is broken down within a wetland can indicate the potential for productivity and, by extension, the adequate functioning of aquatic ecosystems. In contrast, the sequestration of incompletely decomposed materials ultimately results in organic matter production, potentially supporting the development of fens and bogs. Carla's research examines the effects of four factors on cattail and moss decomposition in constructed and natural wetlands: 1) oil sands process sediments (present/absent); 2) oil sands process water (present/ absent); 3) wetland age (younger vs. older); and 4) sediment organic content (low-unamended/high-amended). Carla predicts that all vegetative material will exhibit exponential decay over time, and that cattail decomposition will be more rapid than moss decomposition. For both types of vegetation, decomposition will be slowed by the presence of oil sands process materials.
Preliminary results suggest OSPM affected wetlands function similarly to natural wetlands in terms of plant decomposition. An important and serendipitous result from this project is the evidence that moss growth can occur in OSPM wetlands. This is useful in terms of the development of bogs and fens in the oil sands reclamation landscape.
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- Ryan Boudens (M.Sc. In Progress, Co-supervised by Dr. Chris Weisener)
- Started: 2012
- Thesis Title:
Chemical and biological responses to gamma irradiation treatment of oil sands
fluid fine tailings
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Project Summary:
Exploitation of the oil sands in northeastern Alberta has created large volumes
of waste materials termed fluid fine tailings (FFT). These materials are stored
in large settling basins to allow adequate separation of the oil sands process
water and the FFT. The separated water in these holding areas is used in onsite
bitumen extraction processing or in some cases allowed to settle before
reclamation into functional wetlands. A major concern is the presence of
naphthenic acids (NA); these are considered toxic and comprise recalcitrant
groups of carboxylic acids naturally released from bitumen during the extraction
process. To date several treatment options have been investigated, ranging from
chemical to biological and photo-catalysis treatments. These treatments are
designed to enhance the degradation process and reduce the potential toxicity of
NAs. A less explored treatment option is gamma irradiation, used to break down
complex, recalcitrant organics in industrial wastewaters and contaminated
groundwater. This treatment has two potential benefits as it can suppress
activity of microbes responsible for greenhouse gas emissions and potentially
can disrupt long chain hydrocarbons in a manner similar to ozonation. My study
will assess the development of chemical REDOX gradients, and kinetic responses
of indigenous microbes inoculated into two gamma treated oil sand waste products
(fresh and aged). My goal is to track differences in chemical gradient structure
and the effects of gamma irradiation as a bacterial stimulus. This research will
contribute to our understanding of the biogeochemical processes of FFT treated
with gamma irradiation to degrade NAs and provide insight into our understanding
of the stability of recalcitrant compounds after gamma irradiation
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- Dr. Katya Kovalenko (Postdoctoral Fellow)
- Completed: 2014
- Title: Modelling carbon dynamics and food web structure to understand restoration of ecosystem functions under different reclamation scenarios.
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Project Summary: My primary research project is on the development and evaluation of biological indicators and predicting community thresholds in response to anthropogenic stress in the Great Lakes (GLEI-2 project). In addition, I continue working on carbon dynamics and food web structure in oil sands reclaimed wetlands (CFRAW project).
My other current projects include meta-analysis of the effects of habitat complexity, new approaches to habitat-specific modeling of predator-prey interactions, and food web effects of invasive aquatic plants. [Katya Kovalenko CV]
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- Katie Williams (M.Sc.)
- completed: 2014
- Thesis Title: Aquatic and Riparian Habitat Use by Emerging Adult Insects in Boreal Fen and Marsh Vegetation
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Project Summary: Habitat selection is an important evolutionary adaptation determining the conditions under which organisms will survive and reproduce. Arthropod assemblages are best predicted by plant community characteristics at the biome level. However, factors attracting riparian insect assemblages to colonize distinct wetland ecosystems remain unclear.
Structurally complex habitats are thought to support greater insect diversity and biomass due to increased niche space, microhabitats, and refugia for prey species. Structural complexity in wetlands arises from the diversity of abiotic characteristics, littoral vegetation, and riparian vegetation. My research assesses how structural complexity in wetland plants, their zonation, and their vertical structure affects community composition and biomass of emergent adult insects in boreal fens and marshes in northeastern Alberta. To determine the use of vertical zonation by emergent insects, sticky traps were placed at 4 heights ranging from ground level to 1.5 m above ground in 20 x 20 m wetland plots containing either fen vegetation and soil or recently colonizing cattail and sedge species (marsh vegetation and soils). Insects settling on Tanglefoot-coated acetate sheets over 72 h at each height in August 2011 and May 2012 were enumerated and identified to family. No significant differences in abundance were found among vertical zones in fen vegetation plots. However, wetland resident insects (those whose larvae use a wetland substrate) tended to be associated with traps in the center of tall, emergent marsh vegetation. No differences in either abundance or community composition were found between fen and marsh vegetation plots; this may reflect the small plot size.
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- Sheeva Nakhaie (M.Sc.)
- Completed: 2013
- Thesis Title:
Species area relationships in avian biodiversity in reclaimed and natural wetlands of north-eastern Alberta – Tests of contrasting hypotheses
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Project Summary:
Wetland habitats are in decline due to changing weather conditions and impacts of human development. They are home to a large variety of avian species including a disproportionate number that are rare or at risk. Many wetland obligate species have shown declines in both range and abundance as critical habitat is lost. Thus, effective wetland conservation is essential. It has been documented that species diversity increases with habitat area; larger wetlands support greater avian diversity as well as individual species abundance. In addition, there may be upper and lower limits where species diversity is independent of wetland size and these limits determine a critical habitat size that should be achieved to sustain avian biodiversity in wetlands. We will perform point counts in reclaimed and natural wetlands in north-eastern Alberta that vary in size to determine trends in avian biodiversity. We hypothesize that at the community level there should be an upper limit to the number of species that a wetland can support regardless of wetland area which should indicate the regional species pool. At the individual species level, noncolonial birds should demonstrate increasing abundance with increasing wetland size. Colonial birds should exhibit minimum species abundance as well as a maximum number of individuals that the wetland can support. These limits are likely determined by additional factors such as vegetation, micro habitats and colonial bird interactions.
Thesis Abstract: Oil sands process water (OSPW) is toxic to many aquatic organisms. The goal of this study is to determine if or how midge (Diptera: Chironomidae) productivity and community assemblages may differ between OSPW and reference wetlands and the effects of OSPW wetland water, naphthenic acids (NA), and salts on chironomid growth and survival. Although chironomids differed in size, abundance, and community composition among wetlands, the differences were not attributable to the presence or absence of OSPW. Community composition varied with respect to wetland-specific water chemistry attributes (e.g., dissolved oxygen). Ten-d Chironomus riparius laboratory bioassays indicated that larvae grew to a smaller size when exposed to OSPW wetland water compared to reference wetland water. When C. riparius was reared for 10 d in water mimicking combinations of salts and NA, survival was significantly negatively correlated with salt and NA concentrations, and there was an antagonistic interaction between the two toxicants.
Thesis Abstract: Elevated concentrations of hydrogen sulfide produced by sulfate-reducing prokaryotes are highly reducing, and can impair function of higher trophic levels inside end-pit lakes in the Alberta oil sands region. Microcosms have previously simulated the microbial community structure of tailing ponds; they are used here as analogues of the sediment-water interface of end-pit lake environments to determine sulfide generation patterns and the behaviour of oxygen. In this study, sulfide generation was positively correlated with depth and biotic activity, with production fluxes of ~2 x 103 nmol cm-3s-1. Oxygen consumption in the tailings is dependent on both biotic and abiotic processes. These results have implications for quantitatively estimating impacts of sulfide production and oxygen availability to biota, in addition to the biogeochemical cycles linked to their functional roles in tailings-affected ecosystems.
Thesis Abstract: Sediment oxygen demand (SOD), nutrient concentrations, and submergent
macrophyte biomass were measured in reference wetlands and oil sands process materialaffected
(OSPM) wetlands in the oil sands region of Alberta. Any or all of these factors
could influence the success of wetland reclamation in this area. Gas flux and SOD
chambers were deployed to determine the biological and chemical components. Nutrient
concentrations were estimated from water and sediment extractions as well as PRS™
probes.
Sediment oxygen demand was slightly higher in OSPM-affected wetlands than in
reference wetlands. Over 85% of SOD was due to chemical processes, likely due to
ammonium oxidation. High SOD could limit benthic respiration and ultimately affect
carbon stores. Reference wetlands had greater submergent macrophyte biomass than
OSPM-affected wetlands but phosphorus concentration could not explain this difference.
This implies that sediment oxygen demand, phosphorus concentration, and submergent
macrophyte biomass are independent of one another among wetland classes.
Thesis Abstract: We measured whether carbon loss in the form of sediment-associated microbial respiration differed between unvegetated sediments of recently constructed oil sands process-affected (OSPM) and reference wetlands. Constituents of OSPM-wetlands (increased salinity, conductivity) were expected to influence respiration, increasing gas (methane and carbon dioxide) flux and sediment oxygen demands (SOD) compared to reference wetlands. However, OSPM-wetlands released 1/10th the methane of reference wetland sediments but did not differ in CO2 ebulition. Sediment oxygen demand (SOD) rates were twofold higher in OSPM than reference wetlands; chemical SOD exceeded biological SOD for both wetland classes (~90% of total SOD). OSPM-wetland sediments, likely have less microbial activity and more chemical oxidation than reference wetlands. Carbon accrual is necessary for reclaiming Alberta boreal wetlands. Low microbial activity may promote carbon sequestration within OSPM-wetlands but high chemical SOD may limit available oxygen for benthos respiration.
Thesis Abstract: Midge larvae possess giant polytene chromosomes. Genes on these chromosomes undergoing transcription are visible as puffs. The nucleolar organizer (NOR), an especially large puff, shrinks when a larva is stressed. Two feeding experiments were conducted to examine how NOR size changes as a function of Chironomus riparius growth. NOR size was linearly related to an individual’s recent growth rate, independent of its body size.
Chironomids were collected from wetlands constructed with oil sands mine water and tailings (OSPM), and reference wetlands to evaluate the utility of the NOR as a field-based measure of larval growth and condition. Small larvae (< 9mm) did not yield sufficient quality preparations. Five karyotypes were identified, revealing cryptic diversity in the wetlands. NOR size was measured in a single karyotype; no measures were obtained from OSPM-affected wetlands. NOR size has potential as a surrogate growth measure that can facilitate estimation of chironomid secondary production.
Thesis Abstract: Constructed wetlands using oil sand process materials are being used by the oil sands mining corporations to reclaim the post-mining landscape. A reciprocal sediment transplant study was conducted to measure effects of sediment, water, plant cover, detritus mass and year to year variation on zoobenthic richness, density and relative abundance. Density did not change between wetlands, but the oil sand process water-affected wetland had lower richness than the reference wetland. Zoobenthic relative abundance was influenced by water type, macrophyte density and amount of accumulated detritus in sediment. Zoobenthos density was significantly positively associated with amount of plant cover and detritus combined. Sediment did not directly influence zoobenthic abundance or richneses. However, its inhibition of plan percent cover caused an indirect effect.
Thesis Abstract: The oil-sands operators of Fort McMurray, Alberta produce six million tonnes of petroleum coke per year. The use of coke to stabilize clay-dominated mine tailings in constructed wetlands is being studied in landscape reclamation. We studied 'in situ' effects of petroleum coke amendments placed in three wetlands constructed with different materials over two years. Coke amendments did not significantly increase concentrations of trace metals in sediment pore waters or associated biota in plots. Growth of resident macrophyte species was not prohibited by coke amendments. Coke plots in a reference wetland contained fewer stress-intolerant invertebrates, than reference plots, likely due to avoidance of coke substrates. Adding peat reduced 'Chara' cover and biomass in the reference wetland, but had no impact on plants or invertebrates in the wetlands with little organic content. Overall, local coke amendment effects were detected in a reference wetland but not in two wetlands constructed with other oil sands process materials.
Thesis Abstract: Carbon sources, microbial community production, and respiration were determined in 9 wetlands in northeastern Alberta subject to oil sands mining. A stable isotope mixing model estimated the proportion of carbon sources (primary production, sediment and petroleum) assimilated by microbes. The proportions of petroleum-derived carbon from oil sands process material (OSPM) affected wetlands ranged from 62-97%. Bacterioplankton production was quantified by monitoring 3 H-leucine incorporation into bacterial proteins. Production and methanogenesis were inhibited by sulphate and/or salinity. Amending wetland sediments with topsoil, a reclamation strategy, did not affect bacterial production, or stimulate decomposition. Unvegetated wetland sediments were small net exporters of C (0.61 mg/m2/d) and do not appear to be on a trajectory to becoming net sinks in these early stages of development. Overall, microbial functional processes in OSPM-affected wetlands are markedly different from processes in reference constructed wetlands of equivalent age and do not correspond to those in a natural wetland.
Undergraduate Student Projects
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- Julia Mockler
- Completed: 2012
- Thesis Title: Aquatic Inverterbrate-macrophyte relationships in boreal wetlands: do macrophyte structures or oil sands processed material constructed wetlands exert a greater effect?
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- Hannah Bagnall
- Completed: 2012
- Thesis Title: Zoobenthic Community Composition Trends in Constructed Boreal Wetlands – Residual Effects of Oil Sands Mining By-Products
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- Paige McDonald
- Completed: 2011
- Thesis Title:
The effects of planting and peat on macroinvertebrate colonization in an oil sands
reclaimed wetland.
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- Julia Springolo
- Completed:
2011
- Thesis Title:
Size really doesn't matter: The Nucleolar Organizer Region of the salivary gland
polytene chromosomes as an estimate of recent growth in Chironomus riparius (Diptera:
Chironomidae) larvae.
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- Melanie Martin
- Completed: 2010
- Thesis Title: The effects of peat, coke and composite tailings on macroinvetebrate species richness and abundance in oil sands constructed wetlands.
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- Karolina Jurkowski
- Completed: 2010
- Thesis Title: Inferring energy sources in constructed wetlands through stable isotope analysis of microbial biofilms.
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- Jennifer Thoms
- Completed: 2009
- Thesis Title: Relating zoobenthic & emergent terrestrial insect production to tree swallow
(Tachycineta bicolor) nestling diet in oil sands wetlands.
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- Kurt Frederick
- Completed: 2008
- Thesis Title: Using biofilms and grazing midges (Diptera: Chironomidae) to determine nitrogen
isotope baseline and enrichment in food webs of constructed wetlands differing in anthropogenic inputs.
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- Nadia Qureshi
- Completed: 2007
- Thesis Title: Microbial carbon production in boreal wetlands affected by oil-sands by-products.
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- Anna Swisterski
- Completed: 2006
- Thesis Title: Macroinvertebrate production & community composition in constructed wetlands.
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