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https://www.readbyqxmd.com/read/28695252/oil-spills-and-marine-mammals-in-british-columbia-canada-development-and-application-of-a-risk-based-conceptual-framework
#1
Adrianne L Jarvela Rosenberger, Misty MacDuffee, Andrew G J Rosenberger, Peter S Ross
Marine mammals are inherently vulnerable to oil spills. We developed a conceptual framework to evaluate the impacts of potential oil exposure on marine mammals and applied it to 21 species inhabiting coastal British Columbia (BC), Canada. Oil spill vulnerability was determined by examining both the likelihood of species-specific (individual) oil exposure and the consequent likelihood of population-level effects. Oil exposure pathways, ecology, and physiological characteristics were first used to assign species-specific vulnerability rankings...
July 2017: Archives of Environmental Contamination and Toxicology
https://www.readbyqxmd.com/read/28666015/first-longitudinal-study-of-seal-feeding-killer-whales-orcinus-orca-in-norwegian-coastal-waters
#2
Eve Jourdain, Dag Vongraven, Anna Bisther, Richard Karoliussen
Killer whales (Orcinus orca) have been documented preying on either fish or marine mammals in several regions, suggesting that this odontocete species has the ability to specialize on different types of prey. Off Norway, killer whales have been shown to rely on the Atlantic herring (Clupea harengus) as a main prey resource. Infrequent observations have revealed seals as an additional component of their diet, yet the extent of predation on marine mammals has remained largely unknown. Here, we present the findings of 29 years of photographic and observational data on seal-feeding killer whale groups identified in Norwegian coastal waters...
2017: PloS One
https://www.readbyqxmd.com/read/28662095/population-growth-is-limited-by-nutritional-impacts-on-pregnancy-success-in-endangered-southern-resident-killer-whales-orcinus-orca
#3
Samuel K Wasser, Jessica I Lundin, Katherine Ayres, Elizabeth Seely, Deborah Giles, Kenneth Balcomb, Jennifer Hempelmann, Kim Parsons, Rebecca Booth
The Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females in the population. Lack of prey, increased toxins and vessel disturbance have been listed as potential causes of the whale's decline, but partitioning these pressures has been difficult. We validated and applied temporal measures of progesterone and testosterone metabolites to assess occurrence, stage and health of pregnancy from genotyped killer whale feces collected using detection dogs...
2017: PloS One
https://www.readbyqxmd.com/read/28554115/blubber-depth-distribution-and-bioaccumulation-of-pcbs-and-organochlorine-pesticides-in-arctic-invading-killer-whales
#4
Sara Pedro, Conor Boba, Rune Dietz, Christian Sonne, Aqqalu Rosing-Asvid, Martin Hansen, Anthony Provatas, Melissa A McKinney
Sightings of killer whales (Orcinus orca) in Greenland have increased in recent years, coincident with sea ice loss. These killer whales are likely from fish-feeding North Atlantic populations, but may have access to marine mammal prey in Greenlandic waters, which could lead to increased exposures to biomagnifying contaminants. Most studies on polychlorinated biphenyl (PCB) and organochlorine (OC) contaminants in killer whales have used biopsies which may not be representative of contaminant concentrations through the entire blubber depth...
May 26, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28487524/vertebral-bone-microarchitecture-and-osteocyte-characteristics-of-three-toothed-whale-species-with-varying-diving-behaviour
#5
Tim Rolvien, Michael Hahn, Ursula Siebert, Klaus Püschel, Hans-Joachim Wilke, Björn Busse, Michael Amling, Ralf Oheim
Although vertebral bone microarchitecture has been studied in various tetrapods, limited quantitative data are available on the structural and compositional changes of vertebrae in marine mammals. Whales exhibit exceptional swimming and diving behaviour, and they may not be immune to diving-associated bone pathologies. Lumbar vertebral bodies were analysed in three toothed whale species: the sperm whale (Physeter macrocephalus), orca (Orcinus orca) and harbour porpoise (Phocoena phocoena). The bone volume fraction (BV/TV) did not scale with body size, although the trabeculae were thicker, fewer in number and further apart in larger whale species than in the other two species...
May 9, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28464669/killer-whale-orcinus-orca-behavioral-audiograms
#6
Brian K Branstetter, Judy St Leger, Doug Acton, John Stewart, Dorian Houser, James J Finneran, Keith Jenkins
Killer whales (Orcinus orca) are one of the most cosmopolitan marine mammal species with potential widespread exposure to anthropogenic noise impacts. Previous audiometric data on this species were from two adult females [Szymanski, Bain, Kiehl, Pennington, Wong, and Henry (1999). J. Acoust. Soc. Am. 108, 1322-1326] and one sub-adult male [Hall and Johnson (1972). J. Acoust. Soc. Am. 51, 515-517] with apparent high-frequency hearing loss. All three killer whales had best sensitivity between 15 and 20 kHz, with thresholds lower than any odontocete tested to date, suggesting this species might be particularly sensitive to acoustic disturbance...
April 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28273531/a-rapid-analytical-method-to-quantify-complex-organohalogen-contaminant-mixtures-in-large-samples-of-high-lipid-mammalian-tissues
#7
Jean-Pierre Desforges, Igor Eulaers, Luke Periard, Christian Sonne, Rune Dietz, Robert J Letcher
In vitro investigations of the health impact of individual chemical compounds have traditionally been used in risk assessments. However, humans and wildlife are exposed to a plethora of potentially harmful chemicals, including organohalogen contaminants (OHCs). An alternative exposure approach to individual or simple mixtures of synthetic OHCs is to isolate the complex mixture present in free-ranging wildlife, often non-destructively sampled from lipid rich adipose. High concentration stock volumes required for in vitro investigations do, however, pose a great analytical challenge to extract sufficient amounts of complex OHC cocktails...
June 2017: Chemosphere
https://www.readbyqxmd.com/read/28239473/fine-scale-foraging-movements-by-fish-eating-killer-whales-orcinus-orca-relate-to-the-vertical-distributions-and-escape-responses-of-salmonid-prey-oncorhynchus-spp
#8
Brianna M Wright, John K B Ford, Graeme M Ellis, Volker B Deecke, Ari Daniel Shapiro, Brian C Battaile, Andrew W Trites
BACKGROUND: We sought to quantitatively describe the fine-scale foraging behavior of northern resident killer whales (Orcinus orca), a population of fish-eating killer whales that feeds almost exclusively on Pacific salmon (Oncorhynchus spp.). To reconstruct the underwater movements of these specialist predators, we deployed 34 biologging Dtags on 32 individuals and collected high-resolution, three-dimensional accelerometry and acoustic data. We used the resulting dive paths to compare killer whale foraging behavior to the distributions of different salmonid prey species...
2017: Movement Ecology
https://www.readbyqxmd.com/read/28126344/characterization-and-longitudinal-monitoring-of-serum-androgens-and-glucocorticoids-during-normal-pregnancy-in-the-killer-whale-orcinus-orca
#9
Todd R Robeck, Karen J Steinman, Justine K O'Brien
The secretory patterns of testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA), cortisol (C), and corticosterone (Co) were characterized throughout 28 normal pregnancies until two-months post-partum in eleven killer whales. Effects of fetal sex, dam parity or age, and season were evaluated across either day post-conception (DPC), stage of pregnancy (PRE, EARLY, MID, LATE, POST) or indexed month post-conception (IMPC) using a mixed model linear regression with animal ID and pregnancy number as the random variables...
January 23, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/27923044/killer-whale-orcinus-orca-predation-on-beaked-whales-mesoplodon-spp-in-the-bremer-sub-basin-western-australia
#10
Rebecca Wellard, Keith Lightbody, Leila Fouda, Michelle Blewitt, David Riggs, Christine Erbe
Observations of killer whales (Orcinus orca) feeding on the remains of beaked whales have been previously documented; however, to date, there has been no published account of killer whales actively preying upon beaked whales. This article describes the first field observations of killer whales interacting with, hunting and preying upon beaked whales (Mesoplodon spp.) on four separate occasions during 2014, 2015 and 2016 in the Bremer Sub-Basin, off the south coast of Western Australia.
2016: PloS One
https://www.readbyqxmd.com/read/27870149/development-of-sociality-and-emergence-of-independence-in-a-killer-whale-orcinus-orca-calf-from-birth-to-36-months
#11
Sara Guarino, Heather M Hill, Julie Sigman
Dolphin calves spend most of their time swimming with their mother immediately after birth. As they mature, the calves become increasingly independent, and begin to interact more often with other calves, juveniles, and sub-adults. For bottlenose dolphin calves, sociality is related to maternal behaviors. Unfortunately, much less is known about the development of sociality and emergence of independence for killer whale calves. The purpose of this study was to examine the developmental changes in social behaviors and solitary activities of a killer whale calf across a 36-month period...
January 2017: Zoo Biology
https://www.readbyqxmd.com/read/27770983/conservation-status-of-killer-whales-orcinus-orca-in-the-strait-of-gibraltar
#12
REVIEW
R Esteban, P Verborgh, P Gauffier, D Alarcón, J M Salazar-Sierra, J Giménez, A D Foote, R de Stephanis
Killer whales (Orcinus orca) in the Mediterranean Sea are currently restricted to the Strait of Gibraltar and surrounding waters. Thirty-nine individuals were present in 2011, with a well-differentiated social structure, organized into five pods. Killer whale occurrence in the Strait is apparently related to the migration of their main prey, Atlantic bluefin tuna (Thunnus thynnus). In spring, whale distribution was restricted to shallow waters off the western coast of the Strait where all pods were observed actively hunting tuna...
2016: Advances in Marine Biology
https://www.readbyqxmd.com/read/27770981/marine-mammals-in-the-mediterranean-sea-an-overview
#13
G Notarbartolo di Sciara
Despite being a small part of the world's oceans, the Mediterranean Sea hosts a diverse marine mammal fauna, with a total of 28 different species known to occur, or to have occurred, in the region. Species currently recognised as regular in the Mediterranean-the Mediterranean monk seal (Monachus monachus) and 11 cetaceans (fin whale, Balaenoptera physalus; sperm whale, Physeter macrocephalus; Cuvier's beaked whale, Ziphius cavirostris; short-beaked common dolphin, Delphinus delphis; long-finned pilot whale, Globicephala melas; Risso's dolphin, Grampus griseus; killer whale, Orcinus orca; striped dolphin, Stenella coeruleoalba; rough-toothed dolphin, Steno bredanensis; common bottlenose dolphin, Tursiops truncatus; harbour porpoise, Phocoena phocoena relicta) have adapted well to the region's environmental conditions, but their coexistence with humans is problematic...
2016: Advances in Marine Biology
https://www.readbyqxmd.com/read/27636553/androgen-and-glucocorticoid-production-in-the-male-killer-whale-orcinus-orca-influence-of-age-maturity-and-environmental-factors
#14
J K O'Brien, K J Steinman, G A Fetter, T R Robeck
Circulating concentrations of testosterone and its precursor androstenedione, as well as dehydroepiandrosterone (DHEA) and the adrenal hormones cortisol and corticosterone were measured at monthly intervals in 14 male killer whales (Orcinus orca) aged 0.8-38 years. Analyses were performed for examination of the relationships of age, sexual maturation status (STATUS), season, and environmental temperature (monthly air ambient temperature, A-TEMP) with hormone production using a mixed effects linear regression model with animal ID as the random variable...
January 2017: Andrology
https://www.readbyqxmd.com/read/27547372/dietary-habits-of-polar-bears-in-foxe-basin-canada-possible-evidence-of-a-trophic-regime-shift-mediated-by-a-new-top-predator
#15
Melissa P Galicia, Gregory W Thiemann, Markus G Dyck, Steven H Ferguson, Jeff W Higdon
Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability...
August 2016: Ecology and Evolution
https://www.readbyqxmd.com/read/27536700/comparative-in-silico-study-of-sex-determining-region-y-sry-protein-sequences-involved-in-sex-determining
#16
Masoume Vakili Azghandi, Mohammadreza Nasiri, Ali Shamsa, Mohsen Jalali, Mohammad Mahdi Shariati
BACKGROUND: The SRY gene (SRY) provides instructions for making a transcription factor called the sex-determining region Y protein. The sex-determining region Y protein causes a fetus to develop as a male. In this study, SRY of 15 spices included of human, chimpanzee, dog, pig, rat, cattle, buffalo, goat, sheep, horse, zebra, frog, urial, dolphin and killer whale were used for determine of bioinformatic differences. METHODS: Nucleotide sequences of SRY were retrieved from the NCBI databank...
April 2016: Reports of Biochemistry & Molecular Biology
https://www.readbyqxmd.com/read/27401258/characterization-and-longitudinal-monitoring-of-serum-progestagens-and-estrogens-during-normal-pregnancy-in-the-killer-whale-orcinus-orca
#17
Todd R Robeck, Karen J Steinman, Justine K O'Brien
The secretory patterns of progestagens and estrogens were characterized throughout 28 normal pregnancies until two month post-partum in eleven killer whales. HPLC analysis of serum from different reproductive stages (luteal phase, EARLY, MID, and LATE pregnancy) identified three major immunoreactive progestagen peaks; progesterone (P4), 5α-pregnane-3,20-dione (5α-DHP) and pregnanediol, with 5α-DHP approximately half of that for P4 in the luteal phase, and EARLY, but approximately 2/3 of P4 during MID and LATE pregnancy...
September 15, 2016: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/27385756/the-significance-of-respiration-timing-in-the-energetics-estimates-of-free-ranging-killer-whales-orcinus-orca
#18
Marjoleine M H Roos, Gi-Mick Wu, Patrick J O Miller
Respiration rate has been used as an indicator of metabolic rate and associated cost of transport (COT) of free-ranging cetaceans, discounting potential respiration-by-respiration variation in O2 uptake. To investigate the influence of respiration timing on O2 uptake, we developed a dynamic model of O2 exchange and storage. Individual respiration events were revealed from kinematic data from 10 adult Norwegian herring-feeding killer whales (Orcinus orca) recorded with high-resolution tags (DTAGs). We compared fixed O2 uptake per respiration models with O2 uptake per respiration estimated through a simple 'broken-stick' O2-uptake function, in which O2 uptake was assumed to be the maximum possible O2 uptake when stores are depleted or maximum total body O2 store minus existing O2 store when stores are close to saturated...
July 1, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27269787/longitudinal-evaluation-of-leukocyte-transcripts-in-killer-whales-orcinus-orca
#19
Tatjana Sitt, Lizabeth Bowen, Chia-Shan Lee, Myra T Blanchard, James McBain, Christopher Dold, Jeffrey L Stott
Early identification of illness and/or presence of environmental and/or social stressors in free-ranging and domestic cetaceans is a priority for marine mammal health care professionals. Incorporation of leukocyte gene transcript analysis into the diagnostic tool kit has the potential to augment classical diagnostics based upon ease of sample storage and shipment, inducible nature and well-defined roles of transcription and associated downstream actions. Development of biomarkers that could serve to identify "insults" and potentially differentiate disease etiology would be of great diagnostic value...
July 2016: Veterinary Immunology and Immunopathology
https://www.readbyqxmd.com/read/27229472/separating-underwater-ambient-noise-from-flow-noise-recorded-on-stereo-acoustic-tags-attached-to-marine-mammals
#20
Alexander M von Benda-Beckmann, Paul J Wensveen, Filipa I P Samarra, S Peter Beerens, Patrick J O Miller
Sound-recording acoustic tags attached to marine animals are commonly used in behavioural studies. Measuring ambient noise is of interest to efforts to understand responses of marine mammals to anthropogenic underwater sound, or to assess their communication space. Noise of water flowing around the tag reflects the speed of the animal, but hinders ambient noise measurement. Here, we describe a correlation-based method for stereo acoustic tags to separate the relative contributions of flow and ambient noise...
August 1, 2016: Journal of Experimental Biology
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