Colin A Cooke

Alberta Environment and Parks · Environmental Monitoring and Science

On October 31, 2013, a catastrophic release of approximately 670,000m3 of coal process water occurred as the result of the failure of the wall of a post-processing settling pond at the Obed Mountain Mine near Hinton, Alberta. A highly turbid plume entered the Athabasca River approximately 20km from the mine, markedly altering the chemical compositi...

Human activities over the last several centuries have transferred vast quantities of mercury (Hg) from deep geologic stores to actively-cycling earth-surface reservoirs, increasing atmospheric Hg deposition worldwide. Understanding the magnitude and fate of these releases is critical to predicting how rates of atmospheric Hg deposition will respond...

Both cinnabar (HgS) and metallic mercury (Hg(0)) were important resources throughout Andean prehistory. Cinnabar was used for millennia to make vermillion, a red pigment that was highly valued in pre-Hispanic Peru; metallic Hg(0) has been used since the mid-16th century to conduct mercury amalgamation, an efficient process of extracting precious me...

Peatlands are a key component of the global carbon cycle. Chronologies of peatland initiation are typically based on compiled basal peat radiocarbon (14C) dates and frequency histograms of binned calibrated age ranges. However, such compilations are problematic because poor quality 14C dates are commonly included and because frequency histograms of...

We present unambiguous records of preindustrial atmospheric mercury (Hg) pollution, derived from lake-sediment cores collected near Huancavelica, Peru, the largest Hg deposit in the New World. Intensive Hg mining first began ca. 1400 BC, predating the emergence of complex Andean societies, and signifying that the region served as a locus for early...

Climate change is driving the loss of alpine glaciers globally, yet investigations about the water quality of rivers stemming from them are few. Here we provide an overview assessment of a biogeochemical data set containing 200+ parameters that we collected between 2019 and 2021 from the headwaters of three such rivers (Sunwapta‐Athabasca, North Sa...

The Canada-Alberta Oil Sands Monitoring (OSM) Program began long-term surface water quality monitoring on the lower Athabasca River in 2012. Sampling of low level, bio-accumulative polycyclic aromatic compounds (PACs) targeted a suite of parent and alkylated compounds in the Athabasca River (AR) mainstem using semi-permeable membrane devices (SPMDs...

Mercury concentrations and yields in the Yukon River are the highest of the world’s six largest panarctic drainages. Permafrost thaw has been implicated as the main driver of these high values. Alternative sources include mercury released from glacial melt and erosion, atmospheric mercury pollution, or surface mining. To determine the summer source...

Lake sediment serves as a natural archive of historical biological information. The use of sedimentary DNA (sedDNA), a form of environmental DNA (eDNA) shed by aquatic organisms and preserved in sediment, has been instrumental in reconstructing past faunal composition in aquatic communities. However, the low abundance of fish sedDNA and the often h...

Abundant reserves of metals and oil have spurred large-scale mining developments across northwestern Canada during the past 80 years. Historically, the associated emissions footprint of hazardous metal(loid)s has been difficult to identify, in part, because monitoring records are too short and sparse to have characterized their natural concentratio...

Polycyclic aromatic compounds (PACs) threaten the health of aquatic ecosystems. In northeastern Alberta, Canada, decades of oil sands mining and upgrading activities have increased PAC delivery into freshwaters. This PAC pollution adds to natural inputs from river erosion of bitumen-bearing McMurray Formation outcrops and wildfire inputs. Quantifyi...

Significance Understanding Intertropical Convergence Zone (ITCZ) responses to external forcing is critical for predicting climate change in a warming world. We analyzed paleoclimate records of precipitation change in the neotropics and climate model simulations that span the preindustrial last millennium to assess ITCZ behavior on multicentury time...

Fish consumption advisories for mercury (Hg) are common in rivers, highlighting connections between landscape sources of Hg and downstream fluvial ecosystems. Though watershed conditions can influence concentrations of Hg in smaller streams, how Hg changes downstream through larger rivers and how these changes associate with Hg concentrations in fi...

Permafrost degradation has been implicated as a dominant control on riverine mercury fluxes in arctic watersheds. However, the importance of permafrost thaw on fluxes of mercury, methylmercury, and trace metals such as lead—relative to other geomorphic and hydroclimatic controls—remains unclear. To investigate these competing controls, we conducted...

Lead and mercury have long histories of anthropogenic use and release to the environment extending into preindustrial times. Yet, the timing, magnitude, and persistence of preindustrial emissions remain enigmatic, especially for mercury. Here, we quantify tropical lead and mercury deposition over the past ∼3000 years using a well-dated sediment cor...

Mercury (Hg) is a pollutant of concern across Canada and transboundary anthropogenic Hg sources presently account for over 95% of national anthropogenic Hg deposition. This study applies novel statistical analyses of 82 high-resolution dated lake sediment cores collected from 19 regions across Canada, including nearby point sources and in remote re...

Most bitumen in the Alberta oil sands (Canada) is extracted by thermal in-situ recovery. Despite the widespread use of in-situ bitumen extraction, little information is available on the release of petroleum hydrocarbons by this method to adjacent land and water. Here we analyzed the composition and abundance of parent and alkylated polycyclic aroma...

Fugitive dust associated with surface mining activities is one of the principal vectors for transport of airborne contaminants in Canada's Athabasca oil sands region (AOSR). Effective environmental management requires quantitative identification of the sources of this dust. Using natural abundance radiocarbon (Δ14C) and dual (δ13C, δ2H) compound-sp...

Chlorophyll is frequently used as a proxy for autochthonous production in lakes. This use of chlorophyll concentrations in sediments to infer historical changes in lake primary production relies heavily on the assumption that preservation is sufficient to reflect the productivity in a meaningful way. In this study, we use a series of freeze cores f...

The application of statistical modeling is still infrequent in mercury research in peat, despite the ongoing debate on the weight of the diverse factors (climate, peat decomposition, vegetation changes, etc.) that may affect mercury accumulation. One of the few exceptions is the Hg record of Pinheiro mire (souheast Brazil). Previous studies on this...

Trace elements can accumulate in aquatic foodwebs, becoming potentially hazardous to wildlife and human health. While many studies have examined mercury dynamics in freshwater environments, evidence for the bioaccumulative potential of other trace elements (e.g., arsenic) is conflicting. Trace element concentrations found in surface water of the Re...

Bioaccumulation of mercury in freshwater fish is a complex process driven by environmental and biological factors. In this study, we assessed mercury in fish from four tributaries to the Red Deer River, Alberta, Canada, which are characterized by high surface water mercury concentrations. We used carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotopes to...

Wildfires can have severe and lasting impacts on the water quality of aquatic ecosystems. However, our understanding of these impacts is founded primarily from studies of small watersheds with well-connected runoff regimes. Despite the predominance of large, low-relief rivers across the fire-prone Boreal forest, it is unclear to what extent and dur...

We present a high-resolution record of Late Glacial and Early Holocene mercury (Hg) accumulation within the sediments of Laguna de Los Anteojos, a small headwater alpine lake in Venezuela. Our sediment core spans the Older Dryas (OD) and Younger Dryas (YD) climate reversals, providing new insight into the effects of abrupt climatic transitions on a...

Environmental archives offer an opportunity to reconstruct temporal trends in atmospheric Hg deposition at various timescales. Lake sediment and peat have been the most widely used archives; however, new records from ice, tree rings, and the measurement of Hg stable isotopes, are offering new insights into past Hg cycling. Preindustrial Hg depositi...

Bitumen mining and upgrading in northeastern Alberta, Canada, releases toxic pollutants into the atmosphere, including mercury (Hg) and methylmercury (MeHg). This Hg and MeHg is then deposited to the surrounding landscape; however, the fate of these contaminants remains unknown. Here, we compare snowpack chemistry to high-frequency measurements of...

The extraction and upgrading of bitumen have been identified as sources of enhanced atmospheric deposition of pollutant elements to ecosystems in the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada. Bitumen extraction became increasingly efficient and oil prices surged in the 1990’s, resulting in rapid expansion and increased producti...

Ombrotrophic peat underlain by permafrost has been used to reconstruct past atmospheric mercury (Hg) deposition (e.g., Bathurst Island and Inuvik, Canada; Abisko/Stordalen valley, Sweden). Here, we analyze a core collected from a rapidly-aggrading, raised peat bog near Dawson City, Yukon, Canada, to reconstruct natural and anthropogenic Hg depositi...

Plain Language Summary Wildfires release large amounts of toxic pollutants like heavy metals and polycyclic aromatic hydrocarbons. So far, it remains unknown if and how long these pollutants stay in local houses after a fire. We collected house dust samples from 64 houses in Fort McMurray (Alberta, Canada), where a wildfire forced the evacuation of...

Increased delivery of mercury to ecosystems is a common consequence of industrialization, including in the Athabasca Oil Sands Region (AOSR) of Canada. Atmospheric mercury deposition has been studied previously in the AOSR; however, less is known about the impact of regional industry on toxic methylmercury (MeHg) concentrations in lake ecosystems....

The rise in mercury concentrations in lake sediment deposited over the last ~150 years is widely recognized to have resulted from human activity. However, few studies in the Great Lakes region have used lake sediment to reconstruct atmospheric mercury deposition on millennial timescales. Here we present a 9,000-year mercury record from sediment in...

In 2011, the Governments of Canada and Alberta designed a monitoring plan for surface water quality and quantity, air quality and biodiversity of the lower Athabasca River between Fort McMurray and its confluence with Lake Athabasca. The plan, known as the Joint Oil Sands Monitoring Plan (JOSM), included monitoring water quality in the main stem of...

Executive Summary In 2011, the Governments of Canada and Alberta designed a monitoring plan for surface waterquality and quantity, air quality and biodiversity of the lower Athabasca River between Fort Mc-Murray and its confluence with Lake Athabasca. The purpose of this report is to answer the following key questions identified in the Joint Oil Sa...

The mining and processing of the Athabasca oil sands (Alberta, Canada) has been occurring for decades; however, a lack of consistent regional monitoring has obscured the long-term environmental impact. Here, we present sediment core results to reconstruct spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands...

Erosion is important in the transport of heavy metals from terrestrial to fluvial environments. In this study, we investigated riverine heavy metal (Cd, Cu, Hg and Pb) dynamics in the Red Deer River (RDR) watershed at sites upstream (n=2) and downstream (n=7) of the Alberta badlands, an area of naturally high erosion. At sites draining the badlands...

Our LAQ paper concluded that cinnabar pigment found by archaeologists in northern Peru was produced at Huancavelica in south-central Peru. In contrast, Bruhns and her colleagues suggest the mines near Azogues in southern Ecuador were an important cinnabar source for prehispanic Ecuador and Peru. In their commentary, they introduce new historic and...

Freshwaters in the Athabasca Oil Sands Region (AOSR) are vulnerable to the atmospheric emissions and land disturbances caused by the local oil sands industry; however, they are also affected by climate change. Recent observations of increases in aquatic primary production near the main development area have prompted questions about the principal dr...

Estimated spatial extent of nutrient deposition. Estimated spatial extent (km2) of interpolated spring-time snowpack loadings (mg/g2) of dissolved inorganic nitrogen (DIN) 1978, DIN 2014, total nitrogen (TN) 2014, soluble reactive phosphorus (SRP) 2014, total dissolved phosphorus (TDP) 2014, and total phosphorus (TP) 2014 obtained by geostatistical...

Sediment core dating. Downcore profiles of supported (226Ra activity) (blue dashed line) and total 210Pb activity (red circles). Downcore profiles of 137Cs activity (yellow triangles) (± 1 SD), and age-depth models (black and grey circles) for 23 sediment cores (A-W). Black circles represent constant rate of supply (CRS)-inferred dates. Grey circle...

Selected physical and chemical parameters of study lakes. (TIF)

Comparisons of kriging range means and measured means. Kriging means, measured means, and differences between kriged and measured means in each kriging zone for dissolved inorganic nitrogen (DIN) 1978, DIN 2014, total nitrogen (TN) 2014, soluble reactive phosphorus (SRP) 2014, total dissolved phosphorus (TDP) 2014, and total phosphorus (TP) 2014. (...

Correlations between 5-year averaged VRS-chla Z scores and 5-year averaged precipitation data. Results from Pearson correlations between VRS-chla Z scores (averaged over 5-year intervals) from highly and minimally DBT-enriched lakes and annual and seasonal AOSR precipitation (averaged over the same 5-year intervals). (TIF)

5-year averages of VRS-chla Z scores. 5-year average VRS-chla Z scores from (A) minimally and (B) highly DBT-enriched sites. (TIF)

VRS-chla profiles. Downcore VRS-chla concentrations for each site calibrated to include diagenetic processes arranged by DBT enrichment factor. (A) Profiles and breakpoints for highly DBT-enriched lakes suitable for breakpoint analysis (n = 13), (B) profiles and breakpoints for minimally DBT-enriched lakes suitable for breakpoint analysis (n = 5),...

Summary of kriging settings. ArcGIS10 Geostatistical Analyst software settings used to generate deposition maps for dissolved inorganic nitrogen (DIN) 1978, DIN 2014, total nitrogen (TN) 2014, soluble reactive phosphorus (SRP) 2014, total dissolved phosphorus (TDP) 2014, and total phosphorus (TP) 2014. (TIF)

Snowpack sample sites. Maps of sites in the Athabasca Oil Sands Region where snowpack samples were collected in January 1978 and March 2014. (TIF)

5-year averages of mean annual and seasonal temperature and precipitation data. Historical temperature (station no. 3062696) and precipitation (station no. 3062693) data for Fort McMurray obtained from Environment Canada’s Adjusted and Homogenized Canadian Climate Data website (www.ec.gc.ca/dccha-ahccd) dating back to 1916 and 1920, respectively. (...

Lake Names. Names and alternate names for study sites. Asterisks (*) denote names that have been previously used in academic literature. (TIF)

Deposition map of dissolved inorganic nitrogen in 1978 snowpack. Interpolated loads of dissolved inorganic nitrogen (DIN) (mg/m2) to the Athabasca Oil Sands Region in January 1978. (TIF)

For the Western North America Mercury Synthesis, we compiled mercury records from 165 dated sediment cores from 138 natural lakes across western North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and infer...

Cinnabar ore is the source of a bright red pigment (mercury [II] sulfide, HGS), a substance that was highly valued in the Central Andes during prehispanic times. It is traditionally believed to come from Huancavelica in south-central Peru, although some scholars have argued that a prehispanic cinnabar source existed at Azogues near Cuenca in southe...

The evidence presented in this paper is a first effort to contextualize aspects related to the sourcing, production and uses of red paint during the second millennium BC in Northern Peru. The site tested was Gramalote, a fishing settlement of the Peruvian North Coast. The results show that the inhabitants of this settlement had access to a local so...

The tropical Andes are undergoing climate changes that rival those occurring anywhere else on the planet, and are likely to have profound consequences for ecosystems. Paleolimnological investigations of remote mountain lakes can provide details of past environmental change, especially where monitoring data are absent. Here, we reconstruct fossil di...

The consequences of recent warming in the Andes have been dramatic, most iconically visualized by the rapid retreat of tropical mountain glaciers. Of all the ecosystems in the tropical Andes, lakes have received amongst the least research attention. We examined subfossil diatom and chrysophyte assemblages to chronicle recent (past ~150 years) ecolo...

The extraction of mineral resources has been occurring for millennia in both the Old and New Worlds. Lake sediments can archive the environmental legacy of these preindustrial activities, offering an independent method for understanding the magnitude and spatial extent of metal pollution through time. A number of geochemical records of past metal p...

Significance An exceptionally detailed ice core from the high-altitude location of Quelccaya (Peru) contains compelling evidence that the well-known metallurgic activities performed during the Inca Empire (A.D. 1438−1532) had a negligible impact on the South American atmosphere. In contrast, atmospheric emissions of a variety of toxic trace element...

Air temperatures in the tropical Andes have risen at an accelerated rate relative to the global average over recent decades. However, the effects of climate change on Andean lakes, which are vital to sustaining regional biodiversity and serve as an important water resource to local populations, remain largely unknown. Here, we show that recent clim...

Although recent ecological changes are widespread in Arctic lakes, it remains unclear whether they are more strongly associated with climate warming or the deposition of reactive nitrogen (Nr) from anthropogenic sources. We developed a 3500-yr paleolimnological record from the world's northernmost lake to explore this question. Microfossils indicat...

Anthropogenic activities have increased the amount of mercury (Hg) transported atmospherically to the Arctic. At the same time, recent climate warming is altering the limnology of arctic lakes and ponds, including increases in aquatic primary production. It has been hypothesized that climate-driven increases in aquatic production have enhanced Hg s...

a b s t r a c t Few lakes in the Arctic preserve sediments older than Holocene age because of pervasive glacial scour during the last ice age. Here we present sediment diatom and geochemical records from a lake on east-central Baffin Island (CF8, Nunavut, Canada) that captures three successive interglacial periods within the last 200,000 years: a p...

We reconstructed historical trends in mercury (Hg) accumulation over the past ∼ 150 years in nine western Canadian alpine lakes. Recent Hg accumulation rates (fluxes) ranged between ∼ 7 and 75 μg m(-2) yr(-1), which were an average of 1.8 times higher than preindustrial (i.e., pre-1850) fluxes. Increased Hg fluxes in these lakes were less than at l...

The development of the mercury (Hg) amalgamation process in the mid-sixteenth century triggered the onset of large-scale Hg mining in both the Old and New Worlds. However, ancient Hg emissions associated with amalgamation and earlier mining efforts remain poorly constrained. Using a geochemical time-series generated from lake sediments near Cerro R...

Peatlands play an important role in millennial-scale climate change and the C cycle because they are important C sinks as well as a substantial CH4 source. Chronologies of past peatland initiation are typically based on compiled basal peat radiocarbon (14C) dates and frequency histograms of binned calibrated age ranges; results from such compilatio...

Lake sediments are frequently used to reconstruct the rate and magnitude of human impacts on the biogeochemical cycle of mercury (Hg). The vast majority of these studies rely on excess (210)Pb inventories in short cores to temporally constrain recent trends in Hg deposition, revealing an approximately 3-fold increase in Hg deposition since preindus...

Long lacustrine records are rare in glaciated parts of the Arctic, which limits our long-term perspective on current Arctic environmental change. We have recovered an unusual sedimentary record from Lake CF8 on Baffin Island, where repeated overriding advances of the Laurentide Ice Sheet accomplished very little erosion, and lake sediments from suc...

The Arctic is currently undergoing dramatic environmental transformations, but it remains largely unknown how these changes compare with long-term natural variability. Here we present a lake sediment sequence from the Canadian Arctic that records warm periods of the past 200,000 years, including the 20th century. This record provides a perspective...

The geochemical record preserved in lake sediments is a potentially powerful tool in archaeometallurgy. Here, sediments from Llamacocha, a small lake in the central Peruvian Andes, are used to reconstruct a 1400 year legacy of metal extraction from Cerro de Pasco, once the largest silver mine in the world. The earliest evidence for anthropogenic le...

To date, few studies have investigated the environmental legacy associated with industrialization in the South American Andes. Here, we present an environmental archive of industrial pollution from (210)Pb-dated lake cores recovered from Laguna Chipian, located near the Cerro de Pasco metallurgical region and Laguna Pirhuacocha, located near the Mo...

To reconstruct local to regional histories of anthropogenic Pb pollution in the Andes, we measured weakly bound Pb in three lake cores located along a north–south transect through Peru and Bolivia. The flux of Pb to lake sediment can be used as a proxy for smelting intensity because there is both histori-cal and archeological evidence for the use o...

To date, information concerning pre-Colonial metallurgy in South America has largely been limited to the archaeological record of artifacts. Here, we reconstruct a millennium of smelting activity in the Peruvian Andes using the lake-sediment stratigraphy of atmospherically derived metals (Pb, Zn, Cu, Ag, Sb, Bi, and Ti) and lead isotopic ratios (20...

Although arctic lakes rank among the most pristine ecosystems remaining on Earth, widespread paleoecological analyses have revealed rapid recent changes in lake ecology that largely surpass Holocene natural variability and that are generally attributed to climate warming since the end of the Little Ice Age. However, the possibility that climate is...

Although arctic lakes rank among the most pristine ecosystems remaining on Earth, widespread paleoecological analyses have revealed rapid recent changes in lake ecology that largely surpass Holocene natural variability and that are generally attributed to climate warming since the end of the Little Ice Age. However, the possibility that climate is...