Karsten Liber's research while affiliated with University of Saskatchewan and other places

Publications (143)

Article
Selenium (Se) is an essential micronutrient with a narrow toxicity range known to bioaccumulate in aquatic food webs. Selenium uptake and trophic transfer at the base of aquatic food chains represent a great source of uncertainty for Se risk assessment. The goal of this study was to investigate Se distribution in water and sediment, and its subsequ...
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Full-text available
There is an increasing trend in the use of real‐time sensor technology to remotely monitor aquatic ecosystems. Commercially available probes, however, are currently not able to measure aqueous selenium (Se) concentrations. Because of the well‐described bioaccumulation potential and associated toxicity of Se in oviparous vertebrates, it is crucial t...
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There is increasing interest in using autonomous sensor technology to monitor aquatic ecosystems in real‐time and for using such monitoring data to perform better ecological risk assessments. Here, sensor units were deployed at seven locations in McClean Lake in northern Saskatchewan, receiving diluted uranium milling effluent to track effluent dis...
Article
Selenium (Se) is an environmental contaminant of global concern that can cause adverse effects in fish at elevated levels. Fish gut microbiome play essential roles in gastrointestinal function and host health and can be perturbed by environmental contaminants, including metals and metalloids. Here, an in-situ Se exposure of female finescale dace (P...
Article
Selenium (Se) is a contaminant of concern in Canada mainly due to its teratogenic effects on fish and birds. However, few studies have assessed the effects of Se on invertebrates in a field setting. The objective of this experiment was to assess potential community‐level impacts of Se additions on zooplankton and benthic macroinvertebrates in a bor...
Article
Anodonta woodiana is a globally distributed freshwater bivalve, which is a unique bioindicator in the “Freshwater Mussel Watch” project. Numerous countries have used A. woodiana for biomonitoring the aqueous cadmium (Cd) contamination. However, the bioaccumulation and distribution characteristics of environmentally relevant Cd concentrations in the...
Article
Selenium (Se) is both an essential micronutrient and a contaminant of concern that is of particular interest in mining-influenced waterbodies in Canada. The objective of this research was to characterize the trophic dynamics of selenium along a gradient of exposure concentrations in a Canadian boreal lake ecosystem. From June 20 to August 22, 2018,...
Article
Neonicotinoids are neuroactive insecticides commonly detected in freshwater ecosystems. Recent studies have indicated that these compounds are markedly toxic to Chironomidae, a widespread family of ecologically important aquatic insects. However, despite their sensitivity, the pharmacological mechanisms driving neon-icotinoid toxicity have yet to b...
Article
Vanadium (V) could present a risk for aquatic organisms from the Alberta oil sands region, if present in high concentrations. An industry pilot project has used petroleum coke (PC) as a sorbent to remove organic toxicants from oil sands process-affected water (OSPW), but it also caused V to leach from PC into the OSPW, reaching concentrations of up...
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Objective: Humans consume low quantities of cadmium (Cd), a non-nutritive and potentially toxic heavy metal, primarily via the dietary intake of grains. A trial experiment was conducted to investigate physiological and developmental differences in Cd content in four flax cultivars ('AC Emerson', 'Flanders', 'CDC Bethune', and 'AC McDuff') as part...
Article
Multiple Linear Regression (MLR) modelling has been successfully used to predict how water chemistry variables influence cationic metals’ toxicity to aquatic organisms, but no MLR model exists for vanadium (V). Recent research has indicated that an increase in pH (from 6 to 9), or high concentrations of sodium (473 mg Na+/L), increase V toxicity to...
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Permanent reclamation of tailings generated by surface mining in the Canadian oil sands may be achieved through the creation of end pit lakes (EPLs) in which tailings are stored in mined-out pits and capped with water. However, these tailings contain high concentrations of dissolved organics, metals, and salts, and thus surface water quality of EPL...
Article
Acute (96 h) toxicities of five systemic insecticides (chlorantraniliprole, cyantraniliprole, flupyradifurone, flubendiamide, and sulfoxaflor) were tested on larval Chironomus dilutus and compared to the neonicotinoid, imidacloprid. Three insecticides were less acutely toxic than imidacloprid (2.5 ‐ 25 times lower). However, chlorantraniliprole and...
Article
Agricultural pest control products are a major cause of degradation of water quality and biodiversity loss worldwide. In the Canadian Prairie Pothole Region, the landscape is characterized by millions of ecologically important wetlands, but also large farm sizes and high agrochemical use. Despite the region's agricultural intensity, the spatial ext...
Article
Selenium (Se) is a contaminant of concern in many aquatic ecosystems due to its narrow range between essentiality and toxicity in oviparous (yolk-bearing) vertebrates. The objective of the present study was to determine the effects of Se, experimentally added to in situ limnocorrals as selenite, on invertebrate communities and fathead minnow (Pimep...
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Full-text available
Selenium (Se) is an essential trace element of concern that is known to contaminate aquatic ecosystems as a consequence of releases from anthropogenic activities. Selenium is of particular toxicological concern for egg-laying vertebrates as they bioaccumulate Se through the diet and deposit excess Se to embryo-offspring via maternal transfer, a pro...
Article
Selenium (Se) enrichment has been demonstrated to vary by several orders of magnitude among species of planktonic algae. This is a substantial source of uncertainty when modelling Se biodynamics in aquatic systems. In addition, Se bioconcentration data are largely lacking for periphytic species of algae, and for multi-species periphyton biofilms, a...
Article
Threats to wetland water quality and aquatic insect secondary production in agricultural landscapes are multifaceted and are known to vary spatially and temporally. We designed this study with the aim to disentangle the effects of multiple stressors on emerging aquatic insects from wetlands impacted by intensive agricultural practices and receiving...
Article
Alberta's oil sands petroleum coke (PC) generation has in recent years surpassed 10 million tonnes. Petroleum coke has been proposed as an industrial-scale sorbent to reduce concentrations of organic chemicals in oil sands process-affected water (OSPW). However, PC contains up to 1000 mg of vanadium (V) per kg of PC, and during the treatment it lea...
Article
Human activities have increased the release of selenium (Se) to aquatic environments, but information about the trophic transfer dynamics of Se in Canadian boreal lake systems is limited. In the present study, Se was added as selenite to limnocorrals (2 m diameter, 3000 L in situ enclosures) in a boreal lake in northwestern Ontario to reach nominal...
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Mercury (Hg) in wildlife remains of great concern, especially for apex piscivores. Despite this, exposure information from many species in many areas is lacking, so that management decisions are hampered. Here we examine Hg concentrations in fur, liver, and kidney tissues from river otters ( Lontra canadensis (Schreber, 1777)) ( n = 203) to quantif...
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Seasonal aquatic insect emergence represents a critical subsidy link between aquatic and terrestrial ecosystems. Early and late instar larvae developing in wetlands near neonicotinoid‐treated cropland are at risk of chronic insecticide exposure. An in situ wetland limnocorral experiment compared emergent insect community responses to imidacloprid,...
Article
Widespread agricultural use of neonicotinoid insecticides has resulted in frequent detection of mixtures of these compounds in global surface waters. Recent evidence suggests that neonicotinoid mixtures can elicit synergistic toxicity in aquatic insects under acute exposure conditions, however this has not been validated for longer exposures more c...
Article
Assessment of uranium (U)-contaminated sediment is often hindered by the inability to accurately account for the physicochemical properties of sediment that modify U bioavailability. The goal of this research was to determine whether sediment-associated U bioavailability could be predicted over a wide range of conditions and sediment properties usi...
Article
In order to identify suitable pioneer plant species for future revegetation of coal gob piles, a field survey was conducted to assess the success of different revegetation species and their influence on soil development nine years after initial planting on a reclaimed coal gob pile in the Yangquan mining area of Shanxi province, China. Data were an...
Article
Extensive agricultural use of neonicotinoid insecticide products has resulted in the presence of neonicotinoid mixtures in surface waters worldwide. Although many aquatic insect species are known to be sensitive to neonicotinoids, the impact of neonicotinoid mixtures is poorly understood. In the present study, the cumulative toxicity of binary and...
Article
Elevated vanadium (V) concentrations in oil sands coke, which is produced and stored on the site of some major Athabasca Oil Sands companies, could pose a risk to aquatic ecosystems in northern Alberta, Canada, depending on its future storage and utilization. In the present study, V toxicity was determined in reconstituted Athabasca River water to...
Article
A major source of uncertainty in predicting selenium (Se) distribution in aquatic food webs lies in the enrichment factor (EF), the ratio of Se bioconcentration in primary producers and microorganisms relative to the concentration of Se in the surrounding water. It has been well demonstrated that EFs can vary dramatically among individual algal tax...
Article
Vanadium (V) is an abundant trace metal present in bitumen from the Athabasca Oil Sands (AOS) region in Alberta, Canada. The upgrading of bitumen can result in the production of large volumes of a carbonaceous material referred to as petroleum coke that contains V at elevated levels compared to the native bitumen. Previous studies have shown that c...
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Aside from a companion investigation to this study, there are currently no peer-reviewed phosphorus (P) release rate data for northern North American (i.e., Canadian) reservoirs. Using Lake Diefenbaker, Saskatchewan, Canada as a case study, we tested the effect of variation in overlying water DO conditions on the P release rates from sediment cores...
Article
To better understand the risks and benefits of eating wild-harvested fish from the Northwest Territories, Canada, levels of total mercury (HgT) and selenium (Se) and composition of omega-3 fatty acid (n-3 FA) were measured in muscle tissue of fish harvested from lakes in the Dehcho Region, Northwest Territories, Canada. Average HgT levels ranged fr...
Article
Uranium (U) can enter aquatic environments from natural and anthropogenic processes, accumulating in sediments to concentrations that could, if bioavailable, adversely affect benthic organisms. To better predict the sorption and mobility of U in aquatic ecosystems, we investigated the sediment-solution partition coefficients (Kd) of U for nine unco...
Conference Paper
The consumption of fish, often rich in essential nutrients, promotes health in humans; however, methylmercury, a contaminant in fish, may pose health risks. To better understand these risks and benefits, total mercury (HgT), selenium (Se) content, and omega-3 fatty acid (n-3 FA) composition within the muscle tissues of fish from three lakes in the...
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Non-target aquatic insects are susceptible to chronic neonicotinoid insecticide exposure during the early stages of development from repeated run-off events and prolonged persistence of these chemicals. Investigations on the chronic toxicity of neonicotinoids to aquatic invertebrates have been limited to a few species, under different laboratory co...
Article
The partitioning of metals between dissolved and solid phases directly affects metal bioavailability to benthic invertebrates and is influenced by metal-binding properties of sediment phases. Little research has been done examining the effects of sediment properties on the bioavailability of uranium (U) to freshwater benthic invertebrates. In the p...
Article
Soil quality is defined here as the capacity of soil to have biological function, to sustain plant and animal production, to maintain or enhance water and air quality and to support human health and habitation. There are different soil quality assessment models based on diverse methods and data, but none of the models can fully meet all purposes. T...
Conference Paper
The consumption of fish, often rich in essential nutrients like omega-3 fatty acids (n-3 FAs) and selenium (Se), can promote health in human populations. However, methylmercury (MeHg), a common contaminant in fish, can pose potential health risks. To better understand the risks and benefits of eating fish, total mercury (HgT) and selenium (Se) cont...
Article
Lake Diefenbaker (Saskatchewan, Canada) is a large reservoir in the southern Canadian Prairies. However, limited monitoring data were available to assess long-term trends in environmental quality. Therefore, a paleolimnological study was conducted to investigate temporal trends in the trophic status of the reservoir. Sediment cores were collected a...
Article
Narrow river-valley reservoirs are typically spatially heterogeneous. Little is known about how (a) water quality and algal community composition change longitudinally along a reservoir and (b) how algal composition and production change as a reservoir ages. To address these unknowns, multiple sediment cores were collected from mid-channel location...
Article
Previous research and observations by area residents suggested that the frequency of algal blooms in the Qu'Appelle arm of Lake Diefenbaker, Saskatchewan, Canada, has been increasing over time. However, limited historical data were available to assess long-term trends in the overall reservoir. Narrow river-valley reservoirs, such as Lake Diefenbake...
Article
It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metal...
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Increasingly, our global water storage is contained in large reservoirs that retain nutrients. Given the value of reservoirs to ecosystem services, it is important to know the risks associated with the mobilization of legacy phosphorus (P) from sediments. From 2011 to 2013, Lake Diefenbaker was a significant sink for P retaining 91% of the external...
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There is an up-coming global surge in dam construction. River damming impacts nutrient cycling in watersheds through transformation and retention in the reservoirs. The bioavailability of silicon (Si) relative to nitrogen (N) and phosphorus (P) concentrations, in combination with light environment, controls diatom growth and therefore influences ph...
Article
As a result of long-term metal mining and metallurgical activities, the sediment of Ross Lake (Flin Flin, MB, Canada) is highly contaminated with metals and other elements. Although it is likely that effluents were discharged into Ross Lake as early as the late 1920 s, lake biophysical data were not collected until 1973, more than four decades afte...
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Endocrine-disrupting chemicals (EDCs) in municipal effluents directly affect the sexual development and reproductive success of fishes, but indirect effects on invertebrate prey or fish predators through reduced predation or prey availability, respectively, are unknown. At the Experimental Lakes Area in northwestern Ontario, Canada, a long-term, wh...
Article
For the past decade, considerable research has been conducted at a series of small lakes receiving treated liquid effluent containing elevated selenium (Se) from the Key Lake uranium milling operation in northern Saskatchewan, Canada. Several studies related to this site, including field collections of water, sediment, and biota (biofilm/periphyton...
Article
An in situ caging study was conducted downstream of a metal mine in northern Canada to determine the significance of surface water vs. sediment exposure on selenium (Se) bioaccumulation in the benthic invertebrate Chironomus dilutus. Laboratory-reared C. dilutus larvae were exposed to either site-specific whole-sediment and surface water or surface...
Article
The toxicity of oil sands process affected waters (OSPW) from the Athabasca Oil Sands (AOS) in northern Alberta, Canada, is related to a relatively persistent group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a complex mixture of carboxylic acids, with a general formula Cn H2n+Z O2 , where n indicates the carbon...
Article
To date, the majority of empirical approaches used to derive sediment quality values (SQVs) have focused on metal concentrations in sediment associated with adverse effects on benthic invertebrate communities. Here, we propose the no-effect (NE) approach. This SQV derivation methodology uses metal concentrations in sediment associated with unaffect...
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Boreal wetlands play an important role in global carbon balance. However, their ecosystem function is threatened by direct anthropogenic disturbance and climate change. Oil sands surface mining in the boreal regions of Western Canada denudes tracts of land of organic materials, leaves large areas in need of reclamation, and generates considerable q...
Article
The ability to construct or reclaim functional peat-based wetlands as a replacement for those lost to development activity is uncertain. Oil sands development in northern Alberta, Canada will ultimately result in the removal of over 85 km2 of peat-based wetlands. To examine potential replacement of these lost peatlands we compared four treatments a...
Article
Oil sands process-affected waters (OSPWs) produced during the extraction of bitumen at the Athabasca Oil Sands (AOS) located in northeastern Alberta, Canada, are toxic to many aquatic organisms. Much of this toxicity is related to a group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a natural component of bitumen...
Article
Elemental selenium (Se) is generally considered to be biologically inert due to its insolubility in water. It is a common form of Se in sediment near uranium mining and milling operations in northern Saskatchewan, Canada. Nanosized particles of many materials exhibit different properties compared with their bulk phases, in some cases posing health...
Article
A lake system in northern Saskatchewan receiving treated metal mine and mill effluent contains elevated levels of selenium (Se). An important step in the trophic transfer of Se is the bioaccumulation of Se by benthic invertebrates, especially primary consumers serving as a food source for higher trophic level organisms. Chironomids, ubiquitous comp...
Article
Effective detoxification of oil sands process-affected water (OSPW) is one issue associated with bitumen extraction in the Alberta oil sands. It has been suggested that reclamation ponds can be used to passively treat OSPW, potentially allowing for its safe return to the environment. In this study, OSPW was sampled in two batches (A and B) from the...
Article
Water soluble organic compounds (OCs), including naphthenic acids (NAs), are potentially toxic constituents of oil sands process-affected water (OSPW) that is generated during extraction of bitumen from Alberta oil sands. Ozonation can decrease concentrations of OCs in OSPW. However, effects of ozonated-OSPW on multicellular organisms are unknown....
Article
In a previous study it was shown that pH significantly influences the release of metals from oil sands coke, particularly Ni and V which were identified as the cause of coke leachate toxicity. Coke comes in contact with oil sands process water (OSPW) during its transport to and long term storage in reclamation landscapes. However, the influence of...
Article
Preliminary results are presented for a comprehensive inter-disciplinary study on Lake Diefenbaker initiated by the Global Institute for Water Security to understand the physical and biogeochemical processes affecting water quality under climate change and their policy implications. Lake Diefenbaker is a large reservoir (surface area ~500km2 and Zm...
Article
A previous study found that coke leachates (CL) collected from oil sands field sites were acutely toxic to Ceriodaphnia dubia; however, the cause of toxicity was not known. Therefore, the purpose of this study was to generate CL in the laboratory to evaluate the toxicity response of C. dubia and perform chronic toxicity identification evaluation (T...
Article
The objective of the present study was to describe the uptake and elimination kinetics of selenium (Se) administered in the forms of selenate, selenite, and selenomethionine (seleno-DL-methionine) in different life stages of the midge Chironomus dilutus, and to determine the relationship between Se bioavailability and Se speciation using X-ray abso...
Article
Coagulation/flocculation (CF) by use of alum and cationic polymer polyDADMAC, was performed as a pretreatment for remediation of oil sands process-affected water (OSPW). Various factors were investigated and the process was optimized to improve efficiency of removal of organic carbon and turbidity. Destabilization of the particles occurred through...
Article
Coagulation-flocculation was used as a pretreatment for oil sands process affected waters. The main objectives were to remove the suspended and colloidal particles and organic compounds. Aluminum sulfate, ferric sulfate, and ferric chloride were applied as the coagulant. Synthetic organic polymers were also used as flocculants. The results indicate...
Article
This research evaluated the dominant exposure pathways with regard to the bioaccumulation and trophic transfer of selenium (Se) in caged small-bodied fish inhabiting the receiving waters of a uranium-processing mill in northern Saskatchewan, Canada. A 21-day cage study was conducted using wild naïve lake chub (Couesius plumbeus) collected from a re...