marlene evans - Academia.edu (original) (raw)

Papers by marlene evans

Zooplankton surveillance cruises were conducted in April, May, June, and July in Lake Huron inclu... more Zooplankton surveillance cruises were conducted in April, May, June, and July in Lake Huron including the North Channel and Georgian Bay. Eleven (May) to 30 (July) stations were investigated during each cruise. Zooplankton standing stocks were characteristic of those of the more oligotrophic or meso- oligotrophic regions of the Great Lakes. Crustacean standing stocks were low, ranging from a May cruise mean of 14,000/m to a July high of 75>60Vm • The community was numerically dominated by Cyclops bi cuspidatus thomasi , Pi aptomus ashlandi , P. mi nutus , and P. s i ci 1 i s , while Bosmi na longi rostr i s , Daphnia galeata mendotae, P. retrocurva , and Eubosmi na coregoni were abundant July species. Species considered indicators of eutrophic waters were rare ( Cyclops vernal is , Eurytemora af f i ni s , Mesocyclops edax, Chydorus sphaer icus ) or not detected ( Pi aptomus s ici loides , Alona spp., Paphni a pulex ) . Rotifer standing stocks also were indicative of oligotrophic to meso- oligotrophic conditions, with abundances ranging from 4,5^1/m in June to l*+>993/m in July. A spring assemblage of Notholca squamula and Synchaeta spp. was succeeded by a July assemblage of Conochi lus unicorni s , Kel 1 icott i a longi spi na , and Keratel 1 a cochlear i s cochlear i s . Species considered indicators of eutrophic waters were rare ( F i 1 i ni a , Ploesoma , Tr i chocerca ) or not detected ( Brach ionus , Euchal ani s ) . Crustaceans were the numerically dominant zooplankton in Lake Huron. This dominance was even larger when standing stock was expressed in terms of dry weight. In general, rotifers accounted for less than 1% of the zooplankton biomass. The dominance of the Lake Huron zooplankton community by crustaceans, particularly copepods, is related to life history strategies of these organisms and their apparent capability to withstand periods of stress. For Lake Huron zooplankton, a probable major physiological stress is food limitation. in the oligotrophic waters of Lake Huron, crustaceans, particularly copepods, dominate even in summer months. Adaptive strategies are discussed and their implications applied to the results of various analyses investigating the statistical relationship between phys i cal -chemi cal factors and zooplankton taxa abundances. In general, rotifer abundances were 1 v more often significantly related to phys i cal -chemi cal parameters while crustacean abundances were more often i ntercorrelated with crustacean zooplankton. Results of statistical analyses (correlation, principal components) provide information on water quality status as estimated from zooplankton population characteristics: such analyses included consideration of the physical-chemical properties of the upper water column at each zooplankton station. in addition, a phytoplankton:zoopl ankton carbon ratio was used to infer relative grazing pressure. I OOcMOOOaOOOOr^-HOcoo-HOvOOOOCMO-HCOOOvOOOvOr^oOcM Or*. OOOOOOOOf^OC30r>.OOOOOOOOOOOOOOO-HOcNOr«!o OO cm ~< co «jH«josromo^oiOHONOCftONONOvOHN<oooooN^cMN -HONcn en cm *3-o * co -* oo m -h «* n cmw o *c n <^o> *-* o oo v> cm -< co -* - ct« OOinoooco«^r^vor^.ooo*eM*3"cocMOv«oeo*ooooo«-*in»3 , tn-«d , o OO oo^Hooo-nooommooooocooo-ir^ooooo^-cn-^-^cy^o do CM CM -* O O CM O -« Hf0N^0\00^OCA0000^-<O00HinoOHOOvON00(MOO oo* so n m m n cm -H^^u-> cmvOvo on vo vo r^co oo cmcm ~* co -i _« a* r»* 3 OOOOOOOO-HO00r^OCMOOO-*OC7\v0\0OOOOOCMC0O-4VOO OO OOOOOOOOOOr>.rN.OOOOO-HOv£3N4DC7\OOOOOOOOOONO OO CO OO*-HOOOOOcMOcMa%Ov0O-HO00O-Ha\stOOOOOr^î

Research Square (Research Square), Apr 18, 2023

Chlorpyrifos (CPY), a widely used organothiophosphate insecticide, has been proposed for listing ... more Chlorpyrifos (CPY), a widely used organothiophosphate insecticide, has been proposed for listing on Annex A of the Stockholm Convention on Persistent Organic Pollutants. While CPY has been widely measured in Arctic air and seawater, information on bioaccumulation of CPY in aquatic food webs in the Arctic is very limited. This study presents results of additional monitoring data on CPY in sh and marine mammal samples from the Canadian Arctic/sub-Arctic based on ongoing studies under Canada's Northern Contaminants Program. The majority of the CPY data was from samples collected from 2011 to 2021 and analysed using USEPA Method 1699, involving quanti cation by high resolution mass spectrometry. The available dataset showed low detection frequencies of CPY ranging from zero in arctic grayling (Thymallus arcticus) to 52% in arctic cod (Boreogadus saida). To enable statistical analysis the non-detects were substituted with ½ the detection limit (½ DL) based on the assumption that the non-detects were not zero and previous studies showing CPY was consistently detected in water and air in the Canadian Arctic. Largest geometric mean CPY concentrations were found in lake white sh (Coregonus clupeaformis) muscle (0.56 ng/g wet wt) while burbot (Lota lota) liver had the highest maximum concentration (8.2 ng/g). Log 10 CPY concentrations (with ½ DL substitution) were signi cantly correlated with % lipid and length in lake trout (Salvelinus namaycush) muscle and with % lipid in burbot liver. Geomean concentrations in ringed seal (Pusa hispida) blubber from 8 communities ranged from 0.005 to 0.605 ng/g and showed no geo-spatial trends. Overall, the results indicate widespread but very low level contamination of Arctic sh and seals by CPY.

Environmental Research Letters, Nov 21, 2017

The mining and processing of the Athabasca oil sands (Alberta, Canada) has been occurring for dec... more 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 region. Early mining operations (during the 1970s and 1980s) led to elevated V and Pb inputs to lakes located <50 km from mining operations. Subsequent improvements to mining and upgrading technologies since the 1980s have reduced V and Pb loading to near background levels at many sites. In contrast, Hg deposition increased by a factor of ∼3 to all 20 lakes over the 20th century, reflecting global-scale patterns in atmospheric Hg emissions. Base cation deposition (from fugitive dust emissions) has not measurably impacted regional lake sediments. Instead, results from a principal components analysis suggest that the presence of carbonate bedrock underlying lakes located close to development appears to exert a first-order control over lake sediment base cation concentrations and overall lake sediment geochemical composition. Trace element concentrations generally did not exceed Canadian sediment quality guidelines, and no spatial or temporal trends were observed in the frequency of guideline exceedence. Our results demonstrate that early mining efforts had an even greater impact on trace element cycling than has been appreciated previously, placing recent monitoring efforts in a critical long-term context.

Science of The Total Environment, 2019

Environmental toxicology and chemistry, Jan 19, 2018

The United Nations' Sustainable Development Goals have been established to end poverty, prote... more The United Nations' Sustainable Development Goals have been established to end poverty, protect the planet, and ensure prosperity for all. Delivery of the Sustainable Development Goals will require a healthy and productive environment. An understanding of the impacts of chemicals which can negatively impact environmental health is therefore essential to the delivery of the Sustainable Development Goals. However, current research on and regulation of chemicals in the environment tend to take a simplistic view and do not account for the complexity of the real world, which inhibits the way we manage chemicals. There is therefore an urgent need for a step change in the way we study and communicate the impacts and control of chemicals in the natural environment. To do this requires the major research questions to be identified so that resources are focused on questions that really matter. We present the findings of a horizon-scanning exercise to identify research priorities of the Eu...

Ecosystems, 2022

Fish consumption advisories for mercury (Hg) are common in rivers, highlighting connections betwe... more 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 fish is not well understood. Here we present a continuum of concentrations and yields of total mercury (THg) and methylmercury (MeHg) from small tributary systems draining diverse western Canadian headwater landscapes through to major transboundary rivers. We associate these downstream patterns with THg concentrations in tissues of resident fish in major rivers. Mean concentrations and yields of unfiltered THg from over 80 monitored tributaries and major rivers were highly variable in space ranging from 0.28 to 120 ng L−1 and 0.39 to 170 µg ha−1 d−1, respectively. Using spatial data and a hierarchical cluster analysis, we identified three br...

Science of The Total Environment

Science of The Total Environment, 2019

Ecotoxicology, 2020

Aerial insectivorous birds such as swallows have been the steepest declining groups of birds in N... more Aerial insectivorous birds such as swallows have been the steepest declining groups of birds in North America over the last 50 years but whether such declines are linked to contaminants has not been examined. We sampled feathers from five species of swallow at multiple locations to assess total mercury [THg] exposure for adults during the non-breeding season, and for juveniles on the breeding grounds. We assessed Hg exposure to juvenile birds in crop-and grass-dominated landscapes to determine if land-use practices influenced feather [THg]. We assayed feathers for stable isotopes (δ 2 H, δ 13 C, δ 15 N) as proxies for relative habitat use and diet to determine their potential influence on feather [THg]. Feather [THg] was highest in adult bank swallows (Riparia riparia) and purple martins (Progne subis) from Saskatchewan and adult cliff swallows (Petrochelidon pyrrhonota) from western regions, indicating differential exposure to Hg on the non-breeding grounds. Juvenile bank, barn (Hirundo rustica) and tree (Tachycineta bicolor) swallows had lower feather [THg] in crop-dominated landscapes than grass-dominated landscapes in Saskatchewan, potentially resulting from lower use of wetland-derived insects due to wetland drainage and intensive agriculture. Feather [THg] was related to juvenile feather stable isotopes for several species, suggesting complex interactions with diet and environmental factors. Many individuals had feather [THg] values >2 µg/g, a threshold at which deleterious effects may occur. Our findings indicate differential Hg exposure among species of swallow, regions and land-uses and highlight the need for additional research to determine dietary and finer-scale land-use impacts on individual species and populations.

Environmental Forensics, 2019

A saponification extraction method with gas chromatography pseudo-MRM (pMRM) mass spectrometry de... more A saponification extraction method with gas chromatography pseudo-MRM (pMRM) mass spectrometry detection was developed for the determination of 50 total polycyclic aromatic hydrocarbons (TPAH50, a combination of parent and alkylated homologues) in biota. The method was aimed at monitoring and identification of potential TPAH contaminants in bitumen impacted environments. Alkylated PAHs were determined by multi-level, quantitative calibration using parent PAHs. The developed and thoroughly validated method required only one injection for TPAH50 analysis which represents significant saving of time and expensive authentic alkylated standards. The current method was tested with certified reference mussel tissue NIST 1974c and performed well. In a comparison study, the method reached a limit of quantitation (LOQ) for the TPAH50 between 0.1 and 0.2 ng g À1 , while the QuEChERs enhanced matrix removallipid (EMR) kit produced by Agilent showed an LOQ of 5-10 ng g À1. The current method relied on response factors (RF) for the quantitation of alkylated PAHs determined against parent PAHs. These RFs were shown to be stable and consistent over the course of 1 year, during which over 200 routine environmental biota monitoring samples were analyzed. The environmental biota monitoring samples analyzed include muscle, carcass and liver, with an average total PAH50 concentration of 13, 90 and 135 ng g À1 , respectively. Results show significant differences in the distributions of 1 ringed, 2 ringed, 3 ringed, 4 ringed, and 5þ ringed TPAHs between the types of biota samples.

Environmental Pollution, 2019

The Fort McMurray region in northeastern Alberta (Canada) is rich in natural sources of polycycli... more The Fort McMurray region in northeastern Alberta (Canada) is rich in natural sources of polycyclic aromatic compounds (PACs) from exposed bitumen beds; anthropogenic sources are being released with increased oil sands industry expansion. Here we report on investigations of PACs (47 compounds) in three species of forage fish collected during the 2012e2013 Joint Oil Sands Monitoring Program (JOSMP) fish health investigations and compare results with PAC data for sediment and water collected under JOSMP and earlier programs. PAC concentrations in sediments varied three orders in magnitude and were highest at downstream tributary mouths, which flowed through the exposed McMurray Formation, and along reaches of the Athabasca River where the formation was exposed. PAC concentrations in water were less variable but with higher concentrations near exposed bitumen beds. Forage fish exhibited the weakest spatial gradients in SPACs concentration, which averaged 102 ± 32 ng/g in trout-perch from the Athabasca River, 125 ± 22 ng/g in lake chub from the Ells River, and 278 ± 267 ng/g in slimy sculpin from the Steepbank, Firebag, and Dunkirk Rivers. Low-molecular weight compounds, particularly naphthalenes and fluorenes, dominated fish PACs. Phenanthrenes occurred in greater percent composition in fish caught in areas where PAC concentrations in sediments were higher due to the proximity of bitumen sources than in other areas. Dibenzothiophene, a major component of bitumen PAC, was a minor component of fish SPACs. Forage fish PAC concentrations were below fish consumption guidelines established by the European Commission (2011) and for the reopening of the commercial fisheries closed by the Deepwater Horizon oil spill. PAC concentrations in forage fish were similar to concentrations observed in many other studies (fish market surveys, estuaries, and marine waters) and lower than in fish sampled from highly impacted areas (near refineries, harbors, and other industrialized areas).

Transactions of the American Microscopical Society, 1979

... MARLENE S. EVANS, LINDA M. SICKO-GOAD, and MOHAMMED OMAIR Great Lakes Research Division, Univ... more ... MARLENE S. EVANS, LINDA M. SICKO-GOAD, and MOHAMMED OMAIR Great Lakes Research Division, University of Michigan, Ann Arbor, Michigan ... A third, unidentified species was taken by Green (1974) from Hampton Court Long Water (England) where it infested several ...

This study is based on the Priority Substance List 2 (PSL2) assessment of the toxicity of the app... more This study is based on the Priority Substance List 2 (PSL2) assessment of the toxicity of the application of road salt to the aquatic environment. The assessment begins with a review of the PSL2 assessment process, including the formation of an Environment Resource Group (ERG) to conduct this assessment. Road salt is then characterized including its composition, properties, and application rates across Canada. This assessment focuses on the chloride salts. Sodium followed by calcium are the primary chloride salts used in the winter application of road salts. Calcium chloride is used mainly as a summer dust suppressant. Small amounts of potassium and magnesium chloride salts are also used as a winter deicer. Winter road salt is applied most heavily in southern Ontario, Quebec, Nova Scotia, New Brunswick, British Columbia, and the central (Edmonton) area of Alberta. An extensive review of the Canadian and United States literature determined that a relatively small number of studies ha...

The Arctic biome is currently undergoing major modifications with climate change. Arctic freshwat... more The Arctic biome is currently undergoing major modifications with climate change. Arctic freshwater ecosystems, as sentinel ecosystems, can record major climate changes before they affect the entire region. However, to fully evaluate the amplitude of changes in Arctic freshwaters, we need to be able to compare future measurements to baseline data. To date, the food web characteristics of lakes are poorly described in remoter Arctic areas of Canada. Greiner Lake is located in the High-Arctic near Cambridge Bay (Ikalutktutiak) on Victoria Island, Nunavut, Canada, and is an important site for Inuit communities as it has always been known to support high fish biomass. The Lake Greiner watershed also represents a key monitoring site for the recently open Canadian High-Arctic Research Station (CHARS). We provide here a summary of the food web characteristics for Greiner Lake including data on primary producers, littoral and pelagic consumers and apex fish predators. The data were collecte...

WIT Transactions on Ecology and the Environment, 2018

The Governments of Canada and Alberta designed an environmental monitoring plan for the lower Ath... more The Governments of Canada and Alberta designed an environmental monitoring plan for the lower Athabasca River between Fort McMurray and its confluence with Lake Athabasca. This plan, known as the Joint Oil Sands Monitoring Plan (JOSM), included monitoring aquatic ecosystem health with a focus on wild fish in the mainstem of the Athabasca River. The fish health program for JOSM used endpoints developed through Canada's Environmental Effects Monitoring Programs for the pulp and paper and metal mining sectors under Canada's Fisheries Act. Fish can be sensitive to multiple stressors, are critical components of aquatic ecosystems, and have significant social and economic value. The objective of the fish component of the aquatic monitoring program was to provide necessary data and supporting information to address key questions regarding both environmental health of fish populations and fish health issues related to use and consumption. The JOSM mainstem program consisted of large bodied fish health assessments at five stations and small bodied fish health assessments at nine stations on the Athabasca River. The large bodied white sucker were sensitive indicators of fish health in the system as consistent changes in fish health downstream, within the oil sands deposit were documented. These differences were indicative of nutrient enrichment as white sucker had increased condition and increased levels of internal fat stores relative to fish upstream of the oil sands area. The fish biomarker, ethoxyresorufin-O-deethylase activity, was a good indicator of exposure to polycyclic aromatic hydrocarbons and indicated the potential for increased exposure to these compounds downstream of oil sands development. Tiers and triggers are being developed for the program to predict change into the future and to be used in management decisions for further development in the area.

Nature Climate Change, 2020

Climate warming at high latitudes has long been expected to exceed that predicted for tropical an... more Climate warming at high latitudes has long been expected to exceed that predicted for tropical and temperate climes, but recent warming in the Arctic has exceeded even those expectations 1 . The geophysical consequences of this warming are reasonably well established 2 , but the impacts on freshwater fauna are poorly understood. Here we use a large-scale geospatial analysis of the population dynamics of one of the most abundant north temperate freshwater fish species to forecast increased demographic rates, productivity and colonization range in response to IPCC climate warming scenarios. Geospatial lake morphometry data were used to characterize 481,784 lakes in the Canadian Arctic capable of supporting lake trout ( Salvelinus namaycush ) populations. Lake trout productivity in existing habitat is projected to increase by 20% by 2050 due to climate change, but an expanded habitable zone may result in a 29% increase in harvestable biomass. Although many ecosystems are likely to be negatively impacted by climate warming, the phenotypic plasticity of fish will allow a rapid relaxation of the current environmental constraints on growth in the far north, as well as enhanced colonization of bodies of water in which there are few potential competitors. Arctic lakes and their resident fish species are warming rapidly. Geospatial analysis of Canadian Arctic lakes predicts a 20% increase in lake trout productivity by 2050 and a 29% increase in harvestable biomass across an expanded range.

Environmental pollution (Barking, Essex : 1987), Jan 25, 2016

Oil sands activities north of Fort McMurray, Alberta, have intensified in recent years with a con... more Oil sands activities north of Fort McMurray, Alberta, have intensified in recent years with a concomitant debate as to their environmental impacts. The Regional Aquatics Monitoring Program and its successor, the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM), are the primary aquatic programs monitoring this industry. Here we examine sediment data (collected by Ekman grabs) to investigate trends and sources of polycyclic aromatic hydrocarbons (PAHs), supplementing these data with sediment core studies. Total PAH (ΣPAH) concentrations were highest at Shipyard Lake (6038 ± 2679 ng/g) in the development center and lower at Isadore's Lake (1660 ± 777 ng/g) to the north; both lakes are in the Athabasca River Valley and lie below the developments. ΣPAH concentrations were lower (622-930 ng/g) in upland lakes (Kearl, McClelland) located further away from the developments. ΣPAH concentrations increased at Shipyard Lake (2001-2014) and the Ells River mouth (1998-...

Research Square (Research Square), Apr 18, 2023

Environmental Research Letters, Nov 21, 2017

Science of The Total Environment, 2019

Environmental toxicology and chemistry, Jan 19, 2018

Ecosystems, 2022

Science of The Total Environment

Science of The Total Environment, 2019

Ecotoxicology, 2020

Environmental Forensics, 2019

Environmental Pollution, 2019

Transactions of the American Microscopical Society, 1979

WIT Transactions on Ecology and the Environment, 2018

Nature Climate Change, 2020

Environmental pollution (Barking, Essex : 1987), Jan 25, 2016