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Sascha Usenko - One of the best experts on this subject based on the ideXlab platform.
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eighty years of chemical exposure profiles of persistent organic pollutants reconstructed through baleen whale Earplugs
Science of The Total Environment, 2020Co-Authors: Zach C Winfield, Stephen J Trumble, Farzaneh Mansouri, Charles W Potter, Richard Sabin, Sascha UsenkoAbstract:Abstract Despite decades of effort, significant knowledge gaps still exist regarding the global transport and distribution of persistent organic pollutants (POPs) in marine ecosystems, especially for periods prior to the 1970s. Furthermore, for long-lived marine mammals such as baleen whales, POPs impacts on early developmental (first years of life), as well as lifetime exposure profiles for periods of use and phase-out, are not well characterized. Recently, analytical techniques capable of reconstructing lifetime (i.e., birth to death; ~6 mos. resolution) chemical exposure profiles in baleen whale Earplugs have been developed. Earplugs represent a unique opportunity to examine the spatiotemporal trends of POPs in the marine ecosystem. Baleen whale Earplugs were collected from six whales (one blue whale (Balaenoptera musculus) and five fin whales (Balaenoptera physalus)), including four from archived collections and two from recent strandings. Lifespans for some of these individuals date back to the 1930s and provide insight into early periods of POP use. POP concentrations (reported in ng g–1 dry wt.) were determined in laminae (n = 35) and were combined with age estimates and calendar year to reconstruct lifetime POP exposure profiles and lifetime bioaccumulation rates. Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) were found to be the most dominant POPs (spanning the past 80 y), were detected as early as the 1930s and were ubiquitous in the North Pacific and Atlantic Oceans. Lifetime bioaccumulation rates determined using baleen whale Earplugs were 56 times higher in the North Pacific as compared to the North Atlantic. This suggest baleen whales from the North Pacific may be to be exposed to increased levels of POPs.
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hormone comparison between right and left baleen whale Earplugs
Conservation Physiology, 2020Co-Authors: Danielle D Crain, Sascha Usenko, Amanda Thomas, Farzaneh Mansouri, Charles W Potter, Stephen J TrumbleAbstract:Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left Earplugs from the same individual were compared for two reasons: (i) to determine whether right and left Earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left Earplugs to control for individuals' naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left Earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left Earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left Earplugs are no different from zero. The results of this study reveal that both right and left Earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale Earplugs.
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baleen whale cortisol levels reveal a physiological response to 20th century whaling
Nature Communications, 2018Co-Authors: Stephen J Trumble, Danielle D Crain, Farzaneh Mansouri, Charles W Potter, Zach C Winfield, Richard Sabin, Stephanie A Norman, Christine M Gabriele, Sascha UsenkoAbstract:One of the most important challenges researchers and managers confront in conservation ecology is predicting a population’s response to sub-lethal stressors. Such predictions have been particularly elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale Earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970–2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
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selective pressurized liquid extraction of pesticides polychlorinated biphenyls and polybrominated diphenyl ethers in a whale Earplug earwax a novel method for analyzing organic contaminants in lipid rich matrices
Journal of Chromatography A, 2013Co-Authors: Eleanor M Robinson, Stephen J Trumble, Bikram Subedi, Rebel Sanders, Sascha UsenkoAbstract:Abstract Lipid-rich matrices are often sinks for lipophilic contaminants, such as pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Typically methods for contaminant extraction and cleanup for lipid-rich matrices require multiple cleanup steps; however, a selective pressurized liquid extraction (SPLE) technique requiring no additional cleanup has been developed for the simultaneous extraction and cleanup of whale earwax (cerumen; a lipid-rich matrix). Whale earwax accumulates in select whale species over their lifetime to form wax Earplugs. Typically used as an aging technique in cetaceans, layers or laminae that comprise the Earplug are thought to be associated with annual or semiannual migration and feeding patterns. Whale Earplugs (earwax) represent a unique matrix capable of recording and archiving whales’ lifetime contaminant profiles. This study reports the first analytical method developed for identifying and quantifying lipophilic persistent organic pollutants (POPs) in a whale Earplug including organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). The analytical method was developed using SPLE to extract contaminants from ∼0.25 to 0.5 g aliquots of each lamina of sectioned Earplug. The SPLE was optimized for cleanup adsorbents (basic alumina, silica gel, and Florisil ® ), adsorbent to sample ratio, and adsorbent order. In the optimized SPLE method, the earwax homogenate was placed within the extraction cell on top of basic alumina (5 g), silica gel (15 g), and Florisil ® (10 g) and the target analytes were extracted from the homogenate using 1:1 (v/v) dichloromethane:hexane. POPs were analyzed using gas chromatography–mass spectrometry with electron capture negative ionization and electron impact ionization. The average percent recoveries for the POPs were 91% (±6% relative standard deviation), while limits of detection and quantification ranged from 0.00057 to 0.96 ng g −1 and 0.0017 to 2.9 ng g −1 , respectively. Pesticides, PCBs, and PBDEs, were measured in a single blue whale ( Balaenoptera musculus ) cerumen lamina at concentrations ranging from 0.11 to 150 ng g −1 .
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Blue whale Earplug reveals lifetime contaminant exposure and hormone profiles
Proceedings of the National Academy of Sciences, 2013Co-Authors: Stephen J Trumble, M. Berman-kowalewski, E M Robinson, C. W. Potter, Sascha UsenkoAbstract:Lifetime contaminant and hormonal profiles have been reconstructed for an individual male blue whale (Balaenoptera musculus, Linnaeus 1758) using the Earplug as a natural aging matrix that is also capable of archiving and preserving lipophilic compounds. These unprecedented lifetime profiles (i.e., birth to death) were reconstructed with a 6-mo resolution for a wide range of analytes including cortisol (stress hormone), testosterone (developmental hormone), organic contaminants (e.g., pesticides and flame retardants), and mercury. Cortisol lifetime profiles revealed a doubling of cortisol levels over baseline. Testosterone profiles suggest this male blue whale reached sexual maturity at approximately 10 y of age, which corresponds well with and improves on previous estimates. Early periods of the reconstructed contaminant profiles for pesticides (such as dichlorodiphenyltrichloroethanes and chlordanes), polychlorinated biphenyls, and polybrominated diphenyl ethers demonstrate significant maternal transfer occurred at 0-12 mo. The total lifetime organic contaminant burden measured between the Earplug (sum of contaminants in laminae layers) and blubber samples from the same organism were similar. Total mercury profiles revealed reduced maternal transfer and two distinct pulse events compared with organic contaminants. The use of a whale Earplug to reconstruct lifetime chemical profiles will allow for a more comprehensive examination of stress, development, and contaminant exposure, as well as improve the assessment of contaminant use/emission, environmental noise, ship traffic, and climate change on these important marine sentinels.
Stephen J Trumble - One of the best experts on this subject based on the ideXlab platform.
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evidence of multi decadal behavior and ecosystem level changes revealed by reconstructed lifetime stable isotope profiles of baleen whale Earplugs
Science of The Total Environment, 2021Co-Authors: Farzaneh Mansouri, Danielle D Crain, Charles W Potter, Zach C Winfield, Richard Sabin, Brooke Morris, Patrick Charapata, Amanda S Hering, James M Fulton, Stephen J TrumbleAbstract:Abstract Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale Earplugs from three different species (N = 6 Earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of Earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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eighty years of chemical exposure profiles of persistent organic pollutants reconstructed through baleen whale Earplugs
Science of The Total Environment, 2020Co-Authors: Zach C Winfield, Stephen J Trumble, Farzaneh Mansouri, Charles W Potter, Richard Sabin, Sascha UsenkoAbstract:Abstract Despite decades of effort, significant knowledge gaps still exist regarding the global transport and distribution of persistent organic pollutants (POPs) in marine ecosystems, especially for periods prior to the 1970s. Furthermore, for long-lived marine mammals such as baleen whales, POPs impacts on early developmental (first years of life), as well as lifetime exposure profiles for periods of use and phase-out, are not well characterized. Recently, analytical techniques capable of reconstructing lifetime (i.e., birth to death; ~6 mos. resolution) chemical exposure profiles in baleen whale Earplugs have been developed. Earplugs represent a unique opportunity to examine the spatiotemporal trends of POPs in the marine ecosystem. Baleen whale Earplugs were collected from six whales (one blue whale (Balaenoptera musculus) and five fin whales (Balaenoptera physalus)), including four from archived collections and two from recent strandings. Lifespans for some of these individuals date back to the 1930s and provide insight into early periods of POP use. POP concentrations (reported in ng g–1 dry wt.) were determined in laminae (n = 35) and were combined with age estimates and calendar year to reconstruct lifetime POP exposure profiles and lifetime bioaccumulation rates. Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) were found to be the most dominant POPs (spanning the past 80 y), were detected as early as the 1930s and were ubiquitous in the North Pacific and Atlantic Oceans. Lifetime bioaccumulation rates determined using baleen whale Earplugs were 56 times higher in the North Pacific as compared to the North Atlantic. This suggest baleen whales from the North Pacific may be to be exposed to increased levels of POPs.
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hormone comparison between right and left baleen whale Earplugs
Conservation Physiology, 2020Co-Authors: Danielle D Crain, Sascha Usenko, Amanda Thomas, Farzaneh Mansouri, Charles W Potter, Stephen J TrumbleAbstract:Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left Earplugs from the same individual were compared for two reasons: (i) to determine whether right and left Earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left Earplugs to control for individuals' naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left Earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left Earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left Earplugs are no different from zero. The results of this study reveal that both right and left Earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale Earplugs.
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baleen whale cortisol levels reveal a physiological response to 20th century whaling
Nature Communications, 2018Co-Authors: Stephen J Trumble, Danielle D Crain, Farzaneh Mansouri, Charles W Potter, Zach C Winfield, Richard Sabin, Stephanie A Norman, Christine M Gabriele, Sascha UsenkoAbstract:One of the most important challenges researchers and managers confront in conservation ecology is predicting a population’s response to sub-lethal stressors. Such predictions have been particularly elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale Earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970–2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
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selective pressurized liquid extraction of pesticides polychlorinated biphenyls and polybrominated diphenyl ethers in a whale Earplug earwax a novel method for analyzing organic contaminants in lipid rich matrices
Journal of Chromatography A, 2013Co-Authors: Eleanor M Robinson, Stephen J Trumble, Bikram Subedi, Rebel Sanders, Sascha UsenkoAbstract:Abstract Lipid-rich matrices are often sinks for lipophilic contaminants, such as pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Typically methods for contaminant extraction and cleanup for lipid-rich matrices require multiple cleanup steps; however, a selective pressurized liquid extraction (SPLE) technique requiring no additional cleanup has been developed for the simultaneous extraction and cleanup of whale earwax (cerumen; a lipid-rich matrix). Whale earwax accumulates in select whale species over their lifetime to form wax Earplugs. Typically used as an aging technique in cetaceans, layers or laminae that comprise the Earplug are thought to be associated with annual or semiannual migration and feeding patterns. Whale Earplugs (earwax) represent a unique matrix capable of recording and archiving whales’ lifetime contaminant profiles. This study reports the first analytical method developed for identifying and quantifying lipophilic persistent organic pollutants (POPs) in a whale Earplug including organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). The analytical method was developed using SPLE to extract contaminants from ∼0.25 to 0.5 g aliquots of each lamina of sectioned Earplug. The SPLE was optimized for cleanup adsorbents (basic alumina, silica gel, and Florisil ® ), adsorbent to sample ratio, and adsorbent order. In the optimized SPLE method, the earwax homogenate was placed within the extraction cell on top of basic alumina (5 g), silica gel (15 g), and Florisil ® (10 g) and the target analytes were extracted from the homogenate using 1:1 (v/v) dichloromethane:hexane. POPs were analyzed using gas chromatography–mass spectrometry with electron capture negative ionization and electron impact ionization. The average percent recoveries for the POPs were 91% (±6% relative standard deviation), while limits of detection and quantification ranged from 0.00057 to 0.96 ng g −1 and 0.0017 to 2.9 ng g −1 , respectively. Pesticides, PCBs, and PBDEs, were measured in a single blue whale ( Balaenoptera musculus ) cerumen lamina at concentrations ranging from 0.11 to 150 ng g −1 .
Frederic Laville - One of the best experts on this subject based on the ideXlab platform.
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three dimensional finite element modeling of the human external ear simulation study of the bone conduction occlusion effecta
Journal of the Acoustical Society of America, 2014Co-Authors: Martin Brummund, Franck Sgard, Yvan Petit, Frederic LavilleAbstract:A linear three-dimensional (3D) elasto-acoustic finite element model was used to simulate the occlusion effect following mechanical vibration at the mastoid process. The ear canal and the surrounding soft and bony tissues were reconstructed using images of a female cadaver head (Visible Human Project®). The geometrical model was coupled to a 3D Earplug model and imported into comsol Multiphysics (COMSOL®, Sweden). The software was used to solve for the sound pressure at the eardrum. Finite element modeling of the human external ear and of the occlusion effect has several qualities that can complement existing measuring and modeling techniques. First, geometrically complex structures such as the external ear can be reconstructed. Second, various material behavioral laws and complex loading can be accounted for. Last, 3D analyses of external ear substructures are possible allowing for the computation of a broad range of acoustic indicators. The model simulates consistent occlusion effects (e.g., insertion depth variability). Comparison with an experimental dataset, kindly provided by Stenfelt and Reinfeldt [Int. J. Audiol. 46, 595-608 (2007)], further demonstrates the model's accuracy. Power balances were used to analyze occlusion effect differences obtained for a silicone Earplug and to examine the increase in sound energy when the ear canal is occluded (e.g., high-pass filter removal).
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influence of the external ear tissue domains on the sound attenuation of an Earplug predicted by a finite element model
Journal of the Acoustical Society of America, 2013Co-Authors: Guilhem Viallet, Franck Sgard, Frederic LavilleAbstract:Earplugs are a widespread solution to prevent the problem of hearing loss in the workplace environment, but they do not always perform as desired. Using a model of the ear canal occluded by an Earplug could be helpful to perform sensitivity analyses (geometry and materials of the Earplug) and to better understand the role of the Earplug. The human external ear is a complex system made up of different tissues with a 3D geometry. In practice, it is reduced to a 2D cylindrical geometry for the acoustical tests fixtures. The purpose of this study is to compare the insertion loss predicted by a 3D complex finite element model of the ear canal surrounded by different tissue domains (skin, soft tissue, and bone) and occluded by a silicon Earplug versus a 2D axisymmetric model of the same system. In both models, some investigations are made in order to verify if the models could be simplified by replacing the tissue domains by mechanical impedances. These investigations are made to reduce the complexity of the mo...
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measurement of hearing protection devices performance in the workplace during full shift working operations
Annals of Occupational Hygiene, 2012Co-Authors: Hugues Nelisse, Jeremie Voix, Marcandre Gaudreau, Jerome Boutin, Frederic LavilleAbstract:Objectives: The effectiveness of hearing protection devices (HPDs), when used in workplace conditions, has been shown over the years to be usually lower than the labeled values obtained under well-controlled laboratory conditions. Causes for such discrepancies have been listed and discussed by many authors. This study is an attempt to understand the issues in greater details and quantify some of these factors by looking at the performance of hearing protectors as a function of time during full work shift conditions. Methods: A non-invasive field microphone in the real ear (F-MIRE)-based method has been developed for measuring the effectiveness of different HPDs as a function of time in the workplace. Details of the test procedures, the equipment used, and the post-processing operations are presented and discussed. The methodology was developed in such a way that a complete time and frequency representation are possible. The system was used on a total of 24 workers in eight different companies. Work shifts of up to 9-h long were recorded. Various types of earmuffs and one type of molded Earplugs were tested. Results: Attenuation data reported as a function of time showed, for most workers tested, considerable fluctuations over entire work shift periods. Parts of these fluctuations are attributed to variations in the low-frequency content in the noise (in particular for earmuffs) as well as poor insertion and/or fitting of Earplugs. Lower performances than laboratory-based ones were once again observed for most cases tested but also, important left and right ear differences were obtained for many individuals. When reported as a function of frequency, the attenuation results suggested that the few approximations used to relate the measurements to subjective real-ear-attenuation-at-threshold (REAT) data were realistic. Conclusions: The use of individualized attenuation data and performance ratings for HPDs as well as a good knowledge of the ambient noise in the workplace are key ingredients when evaluating the performance of hearing protectors in field conditions.
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a simplified axi symmetric finite element model of the human outer ear to determine the Earplug induced auditory occlusion effect
Journal of the Acoustical Society of America, 2011Co-Authors: Martin Brummund, Franck Sgard, Yvan Petit, Frederic LavilleAbstract:Earplugs are a frequently used short-term solution for hearing conservation in the workplace environment. Due to limited auditory comfort, however, workers often only wear them for short periods of time and become prone to hearing loss. An important source of discomfort is the auditory occlusion effect, which expresses itself through the distortion of the wearer's voice and the amplification of physiological noises upon Earplug insertion. Simplified numerical modeling can help to better assess and design Earplugs, because it requires few system resources and is simpler in terms of numerical and experimental implementation than an equivalent complex model. This work describes a novel coupled linear elasto-acoustic two dimensional finite element (FE) model of the human outer ear. The model comprises the auditory canal as well as the bony, cartilaginous, and skin tissues whose material parameters were approximated using literature findings. The outlined model can compute the transfer functions between the so...
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subjective quantification of Earplug occlusion effect using external acoustical excitation of the mouth cavity
Journal of the Acoustical Society of America, 2010Co-Authors: Cecile Le Cocq, Frederic Laville, Christian GargourAbstract:Occlusion of the ear canal by hearing aids or hearing protectors often results in an occlusion effect, which creates a discomfort to wearers in that it changes their perception of their own voice. As no account was found in the literature on the quantification of this subjective voice occlusion effect, an experimental method is proposed based on the use of an artificial sound source emitting within the subject’s mouth to replace his own voice. A block diagram is constructed to identify the different internal sound path components involved in the perception of one’s own voice and is used to show that the subjective voice occlusion effect is the weighted energy summation of two components. The first component, the voice air and body conduction occlusion effect for which data is obtained from the experiments reported in the present paper, constitute the lower limit of the subjective voice occlusion effect. The second component, the voice body conduction occlusion effect for which data is available in the lit...
Farzaneh Mansouri - One of the best experts on this subject based on the ideXlab platform.
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evidence of multi decadal behavior and ecosystem level changes revealed by reconstructed lifetime stable isotope profiles of baleen whale Earplugs
Science of The Total Environment, 2021Co-Authors: Farzaneh Mansouri, Danielle D Crain, Charles W Potter, Zach C Winfield, Richard Sabin, Brooke Morris, Patrick Charapata, Amanda S Hering, James M Fulton, Stephen J TrumbleAbstract:Abstract Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale Earplugs from three different species (N = 6 Earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of Earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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eighty years of chemical exposure profiles of persistent organic pollutants reconstructed through baleen whale Earplugs
Science of The Total Environment, 2020Co-Authors: Zach C Winfield, Stephen J Trumble, Farzaneh Mansouri, Charles W Potter, Richard Sabin, Sascha UsenkoAbstract:Abstract Despite decades of effort, significant knowledge gaps still exist regarding the global transport and distribution of persistent organic pollutants (POPs) in marine ecosystems, especially for periods prior to the 1970s. Furthermore, for long-lived marine mammals such as baleen whales, POPs impacts on early developmental (first years of life), as well as lifetime exposure profiles for periods of use and phase-out, are not well characterized. Recently, analytical techniques capable of reconstructing lifetime (i.e., birth to death; ~6 mos. resolution) chemical exposure profiles in baleen whale Earplugs have been developed. Earplugs represent a unique opportunity to examine the spatiotemporal trends of POPs in the marine ecosystem. Baleen whale Earplugs were collected from six whales (one blue whale (Balaenoptera musculus) and five fin whales (Balaenoptera physalus)), including four from archived collections and two from recent strandings. Lifespans for some of these individuals date back to the 1930s and provide insight into early periods of POP use. POP concentrations (reported in ng g–1 dry wt.) were determined in laminae (n = 35) and were combined with age estimates and calendar year to reconstruct lifetime POP exposure profiles and lifetime bioaccumulation rates. Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) were found to be the most dominant POPs (spanning the past 80 y), were detected as early as the 1930s and were ubiquitous in the North Pacific and Atlantic Oceans. Lifetime bioaccumulation rates determined using baleen whale Earplugs were 56 times higher in the North Pacific as compared to the North Atlantic. This suggest baleen whales from the North Pacific may be to be exposed to increased levels of POPs.
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hormone comparison between right and left baleen whale Earplugs
Conservation Physiology, 2020Co-Authors: Danielle D Crain, Sascha Usenko, Amanda Thomas, Farzaneh Mansouri, Charles W Potter, Stephen J TrumbleAbstract:Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left Earplugs from the same individual were compared for two reasons: (i) to determine whether right and left Earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left Earplugs to control for individuals' naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left Earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left Earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left Earplugs are no different from zero. The results of this study reveal that both right and left Earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale Earplugs.
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baleen whale cortisol levels reveal a physiological response to 20th century whaling
Nature Communications, 2018Co-Authors: Stephen J Trumble, Danielle D Crain, Farzaneh Mansouri, Charles W Potter, Zach C Winfield, Richard Sabin, Stephanie A Norman, Christine M Gabriele, Sascha UsenkoAbstract:One of the most important challenges researchers and managers confront in conservation ecology is predicting a population’s response to sub-lethal stressors. Such predictions have been particularly elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale Earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970–2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
Danielle D Crain - One of the best experts on this subject based on the ideXlab platform.
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evidence of multi decadal behavior and ecosystem level changes revealed by reconstructed lifetime stable isotope profiles of baleen whale Earplugs
Science of The Total Environment, 2021Co-Authors: Farzaneh Mansouri, Danielle D Crain, Charles W Potter, Zach C Winfield, Richard Sabin, Brooke Morris, Patrick Charapata, Amanda S Hering, James M Fulton, Stephen J TrumbleAbstract:Abstract Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale Earplugs from three different species (N = 6 Earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of Earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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hormone comparison between right and left baleen whale Earplugs
Conservation Physiology, 2020Co-Authors: Danielle D Crain, Sascha Usenko, Amanda Thomas, Farzaneh Mansouri, Charles W Potter, Stephen J TrumbleAbstract:Marine animals experience additional stressors as humans continue to industrialize the oceans and as the climate continues to rapidly change. To examine how the environment or humans impact animal stress, many researchers analyse hormones from biological matrices. Scientists have begun to examine hormones in continuously growing biological matrices, such as baleen whale earwax plugs, baleen and pinniped vibrissae. Few of these studies have determined if the hormones in these tissues across the body of the organism are interchangeable. Here, hormone values in the right and left Earplugs from the same individual were compared for two reasons: (i) to determine whether right and left Earplug hormone values can be used interchangeably and (ii) to assess methods of standardizing hormones in right and left Earplugs to control for individuals' naturally varying hormone expressions. We analysed how absolute, baseline-corrected and Z-score normalized hormones performed in reaching these goals. Absolute hormones in the right and left Earplugs displayed a positive relationship, while using Z-score normalization was necessary to standardize the variance in hormone expression. After Z-score normalization, it was possible to show that the 95% confidence intervals of the differences in corresponding lamina of the right and left Earplugs include zero for both cortisol and progesterone. This indicates that the hormones in corresponding lamina of right and left Earplugs are no different from zero. The results of this study reveal that both right and left Earplugs from the same baleen whale can be used in hormone analyses after Z-score normalization. This study also shows the importance of Z-score normalization to interpretation of results and methodologies associated with analysing long-term trends using whale Earplugs.
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baleen whale cortisol levels reveal a physiological response to 20th century whaling
Nature Communications, 2018Co-Authors: Stephen J Trumble, Danielle D Crain, Farzaneh Mansouri, Charles W Potter, Zach C Winfield, Richard Sabin, Stephanie A Norman, Christine M Gabriele, Sascha UsenkoAbstract:One of the most important challenges researchers and managers confront in conservation ecology is predicting a population’s response to sub-lethal stressors. Such predictions have been particularly elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale Earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970–2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
