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Articles 1 - 11 of 11

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Assessment Of Hazard Metrics For Predicting Field Benthic Invertebrate Toxicity In The Detroit River, Ontario, Canada, Kerry N. Mcphedren, Alice Grigicak-Mannnion, Gord Paterson, Briggs Tedd, Jan J.H. Ciborowski, G. Douglass Haffner, Ken G. Drouillard Mar 2016

Assessment Of Hazard Metrics For Predicting Field Benthic Invertebrate Toxicity In The Detroit River, Ontario, Canada, Kerry N. Mcphedren, Alice Grigicak-Mannnion, Gord Paterson, Briggs Tedd, Jan J.H. Ciborowski, G. Douglass Haffner, Ken G. Drouillard

Great Lakes Institute for Environmental Research Publications

Numerical sediment quality guidelines (SQGs) are frequently used to interpret site specific sediment chemistry and predict potential toxicity to benthic communities. These SQGs are useful for a screening line of evidence (LOE) that can be combined with other LOEs in a full weight of evidence (WOE) assessment of impacted sites. Three common multi-chemical hazard quotient methods (PEC-Qavg, PEC-Qmet and PEC-Qsum) and a novel (Hazard Score; HZD) approach were used in conjunction with a consensus based set of SQGs to evaluate the ability of different scoring metrics to predict the biological effects of sediment contamination under …


Identification, Enumeration And Diversity Of Nitrifying Planktonic Archaea And Bacteria In Trophic End Members Of The Laurentian Great Lakes, Maitreyee Mukherjee, Anirban Ray, Anton F. Post, Robert Michael Mckay, George S. Bullerjahn Feb 2016

Identification, Enumeration And Diversity Of Nitrifying Planktonic Archaea And Bacteria In Trophic End Members Of The Laurentian Great Lakes, Maitreyee Mukherjee, Anirban Ray, Anton F. Post, Robert Michael Mckay, George S. Bullerjahn

Great Lakes Institute for Environmental Research Publications

Oligotrophic Lake Superior and mesotrophic Lake Erie are trophic end members of the hydrologically connected Laurentian Great Lakes system, and as such exhibit different profiles of dissolved nitrogen species. Nitrification in Lake Superior has led to increasing nitrate concentrations over the past century, as opposed to Erie, where nitrate inventories have declined due to denitrification. In this study, we examined the abundance and diversity of nitrifying microbes involved in the oxidation of ammonia to nitrite, and nitrite to nitrate. By in situ hybridization methods, we enumerated the major planktonic ammonia oxidizing bacteria (AOB) and archaea (AOA) during a July 2011 …


Latitudinal Variation In Ecological Opportunity And Intraspecific Competition Indicates Differences In Niche Variability And Diet Specialization Of Arctic Marine Predators, David J. Yurkowski, Steven Ferguson, Emily S. Choy, Lisa L. Loseto, Tanya M. Brown, Derek Cg Muir, Christina Ad Semeniuk, Aaron T. Fisk Jan 2016

Latitudinal Variation In Ecological Opportunity And Intraspecific Competition Indicates Differences In Niche Variability And Diet Specialization Of Arctic Marine Predators, David J. Yurkowski, Steven Ferguson, Emily S. Choy, Lisa L. Loseto, Tanya M. Brown, Derek Cg Muir, Christina Ad Semeniuk, Aaron T. Fisk

Great Lakes Institute for Environmental Research Publications

Individual specialization (IS), where individuals within populations irrespective of age, sex, and body size are either specialized or generalized in terms of resource use, has implications on ecological niches and food web structure. Niche size and degree of IS of near-top trophic-level marine predators have been little studied in polar regions or with latitude. We quantified the largescale latitudinal variation of population- and individual-level niche size and IS in ringed seals (Pusa hispida) and beluga whales (Delphinapterus leucas) using stable carbon and nitrogen isotope analysis on 379 paired ringed seal liver and muscle samples and 124 paired beluga skin and …


Is It Appropriate To Composite Fish Samples For Mercury Trend Monitoring And Consumption Advisories?, Ken G. Drouillard, Nilima Gandhi, Satyendra P. Bhavsar, Sarah B. Gewurtz, George B. Arhonditsis, Steve Petro Jan 2016

Is It Appropriate To Composite Fish Samples For Mercury Trend Monitoring And Consumption Advisories?, Ken G. Drouillard, Nilima Gandhi, Satyendra P. Bhavsar, Sarah B. Gewurtz, George B. Arhonditsis, Steve Petro

Great Lakes Institute for Environmental Research Publications

Monitoring mercury levels in fish can be costly because variation by space, time, and fish type/size needs to be captured. Here, we explored if compositing fish samples to decrease analytical costs would reduce the effectiveness of the monitoring objectives. Six compositing methods were evaluated by applying them to an existing extensive dataset and examining their performance in reproducing the fish consumption advisories and temporal trends. The methods resulted in varying amount (average 34-72%) of reductions in samples, but all (except one) reproduced advisories very well (96-97% of the advisories did not change or were one category more restrictive compared to …


Employing Individual Measures Of Baseline Glucocorticoids As Population-Level Conservation Biomarkers: Considering Within-Individual Variation In A Breeding Passerine, Christine L. Madliger, Oliver P. Love Jan 2016

Employing Individual Measures Of Baseline Glucocorticoids As Population-Level Conservation Biomarkers: Considering Within-Individual Variation In A Breeding Passerine, Christine L. Madliger, Oliver P. Love

Great Lakes Institute for Environmental Research Publications

Labile physiological variables, such as stress hormones [i.e. glucocorticoids (GCs)], allow individuals to react to perturbations in their environment and may therefore reflect the effect of disturbances or positive conservation initiatives in advance of population-level demographic measures. Although the application of GCs as conservation biomarkers has been of extensive interest, few studies have explicitly investigated whether baseline GC concentrations respond to disturbances consistently across individuals. However, confirmation of consistent responses is of paramount importance to assessing the ease of use of GCs in natural systems and to making valid interpretations regarding population-level change (or lack of change) in GC concentrations. …


Temporal Overlap And Repeatability Of Feather Corticosterone Levels: Practical Considerations For Use As A Biomarker, Christopher M. Harris, Christine L. Madliger, Oliver P. Love Jan 2016

Temporal Overlap And Repeatability Of Feather Corticosterone Levels: Practical Considerations For Use As A Biomarker, Christopher M. Harris, Christine L. Madliger, Oliver P. Love

Great Lakes Institute for Environmental Research Publications

The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows (Tachycineta bicolor) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared …


Fullfact: An R Package For The Analysis Of Genetic And Maternal Variance Components From Full Factorial Mating Designs, Aimee Lee S. Houde, Trevor E. Pitcher Jan 2016

Fullfact: An R Package For The Analysis Of Genetic And Maternal Variance Components From Full Factorial Mating Designs, Aimee Lee S. Houde, Trevor E. Pitcher

Great Lakes Institute for Environmental Research Publications

Full factorial breeding designs are useful for quantifying the amount of additive genetic, nonadditive genetic, and maternal variance that explain phenotypic traits. Such variance estimates are important for examining evolutionary potential. Traditionally, full factorial mating designs have been analyzed using a two-way analysis of variance, which may produce negative variance values and is not suited for unbalanced designs. Mixed-effects models do not produce negative variance values and are suited for unbalanced designs. However, extracting the variance components, calculating significance values, and estimating confidence intervals and/or power values for the components are not straightforward using traditional analytic methods. We introduce fullfact …


Quantitative Biomonitoring In The Detroit River Using Elliptio Complanata: Verification Of Steady State Correction Factors And Temporal Trends Of Pcbs In Water Between 1998-2015, Ken G. Drouillard, Mark Cook, Todd A. Leadley, Paul Drca, Ted Briggs, G Douglas Haffner Jan 2016

Quantitative Biomonitoring In The Detroit River Using Elliptio Complanata: Verification Of Steady State Correction Factors And Temporal Trends Of Pcbs In Water Between 1998-2015, Ken G. Drouillard, Mark Cook, Todd A. Leadley, Paul Drca, Ted Briggs, G Douglas Haffner

Great Lakes Institute for Environmental Research Publications

Quantitative biomonitoring methods were applied to determine PCB concentrations in water from the Detroit River over a 17 year period. During 2014, mussels were deployed for and extended duration (21-364 d) and time dependent PCB concentrations were fit to a bioaccumulation model to estimate elimination coefficients (ktot) and provide site specific calibration of mussel toxicokinetics. The site specific calibration and different ktot versus KOW relationships from the literature were used to correct for steady state. ∑PCB concentrations in water were not significantly dependent on the ktot values used indicating that individual variation exceeds error contributed …


Determination Of Pcb Elimination Coefficients In Round Goby And Tubenose Goby, Xin Sun, Tim B. Johnson, Ken G. Drouillard Jan 2016

Determination Of Pcb Elimination Coefficients In Round Goby And Tubenose Goby, Xin Sun, Tim B. Johnson, Ken G. Drouillard

Great Lakes Institute for Environmental Research Publications

Whole-body elimination coefficients of polychlorinated biphenyls (PCBs) were determined in two Great Lakes invasive fish species, round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus semilunaris). Elimination rates were determined for a set of model PCB congeners (n=12 congeners) dosed to fish by intraperitoneal injection and allowed to depurate at a temperature of 21.4oC for 90 d. Eight PCBs (PCB 6, 13, 21, 57, 62, 68, 89, 112 and 125) exhibited significant elimination by round goby and had corresponding half lives ranging from 13 to 39.8 d. For tubenose goby, four congeners (PCBs 21, 58, …


Determination Of The Gut Retention Of Plastic Microbeads And Microfibers In Goldfish 1 (Carassius Auratus), Stefan Grigorakis, Sherri A. Mason, Ken G. Drouillard Jan 2016

Determination Of The Gut Retention Of Plastic Microbeads And Microfibers In Goldfish 1 (Carassius Auratus), Stefan Grigorakis, Sherri A. Mason, Ken G. Drouillard

Great Lakes Institute for Environmental Research Publications

Microplastics are ubiquitous pollutants in aquatic habitats and commonly found in the gut contents of fish yet relatively little is known about the retention of these particles by fish. In this study, goldfish were fed a commercial fish food pellet amended with 50 particles of one of two microplastics types, microbeads and microfibers. Microbeads were obtained from a commercial facial cleanser while microfibers were obtained from washed synthetic textile. Following consumption of the amended pellet, fish were allowed to feed to satiation on non-amended food followed by fasting for periods ranging from 1.5 h to 6 days. Fish sacrificed at …


Global Solutions To Regional Problems: Collecting Global Expertise To Address The Problem Of Harmful Cyanobacterial Blooms. A Lake Erie Case Study, George S. Bullerjahn, Robert M. Mckay, Timothy W. Davis, David B. Baker, Gregory L. Boyer, Lesley V. D'Anglada, Gregory J. Doucette, Jeff C. Ho, Elena G. Irwin, Catherine L. Kling, Raphael M. Kudela, Rainer Kurmayer, Anna M. Michalak, Joseph D. Ortiz, Timothy G. Otten, Hans W. Paerl, Boqiang Qin, Brent L. Sohngen Jan 2016

Global Solutions To Regional Problems: Collecting Global Expertise To Address The Problem Of Harmful Cyanobacterial Blooms. A Lake Erie Case Study, George S. Bullerjahn, Robert M. Mckay, Timothy W. Davis, David B. Baker, Gregory L. Boyer, Lesley V. D'Anglada, Gregory J. Doucette, Jeff C. Ho, Elena G. Irwin, Catherine L. Kling, Raphael M. Kudela, Rainer Kurmayer, Anna M. Michalak, Joseph D. Ortiz, Timothy G. Otten, Hans W. Paerl, Boqiang Qin, Brent L. Sohngen

Great Lakes Institute for Environmental Research Publications

In early August 2014, the municipality of Toledo, OH (USA) issued a ‘do not drink’ advisory on their water supply directly affecting over 400,000 residential customers and hundreds of businesses (Wilson, 2014). This order was attributable to levels of microcystin, a potent liver toxin, which rose to 2.5 μg L−1 in finished drinking water. The Toledo crisis afforded an opportunity to bring together scientists from around the world to share ideas regarding factors that contribute to bloom formation and toxigenicity, bloom and toxin detection as well as prevention and remediation of bloom events. These discussions took place at an NSF- …