Scholars@Duke
Andreas Fahlman

Andreas Fahlman

Adjunct Associate Professor in the Division of Marine Science and Conservation
Marine Science and Conservation

Selected Publications

Allocation and use of body energy reservoirs in striped dolphins and Blainville's beaked whales: Snowball effect in negative energetic balance

Journal Article Marine Mammal Science · April 1, 2025 Climate change, overfishing, and other anthropogenic activities can negatively impact the energetic balance and body condition of cetaceans. Still, cetaceans must meet their energetic demands for survival, which are more expensive to maintain in the marine ... Full text Cite

Phylogenetic allometric scaling of near basal breathing frequency in terrestrial, semi-aquatic and aquatic mammals.

Journal Article Experimental physiology · April 2025 We measured the BASAL breathing frequency following an overnight fast in adult, non-pregnant/non-lactating, inactive mammals ranging in body mass from 15 to 5520 kg. The data included results from 338 individual animals from 34 species that were divided in ... Full text Cite

Respiratory flow and tidal volume scale with body mass in sea turtles but not breath duration.

Journal Article Comparative biochemistry and physiology. Part A, Molecular & integrative physiology · April 2025 The ventilatory capacity of sea turtles is an important factor in their diving ability because they spend most of their time submerged. However, there is limited information on the relationship between the ventilatory capacity and body mass of sea turtles. ... Full text Cite

In-water electrical impedance tomography: EIT and the sea.

Journal Article Physiological measurement · March 2025 Objective.Electrical impedance tomography (EIT) has shown the ability to provide clinically useful functional information on ventilation in humans and other land mammals. We are motivated to use EIT with sea mammals and human divers, since EIT could ... Full text Cite

Spirometry as a diagnostic tool to assess respiratory health in beached bottlenose dolphins Tursiops spp.

Journal Article Diseases of aquatic organisms · March 2025 In this study, we used a dataset including 42 individual bottlenose dolphins (Tursiops spp.) to determine the reliability of lung function testing as a method for assessing respiratory health. Each dolphin was trained to beach voluntarily, allowing researc ... Full text Cite

Respiratory reference values for bottlenose dolphins (Tursiops spp.) and its importance for conservation

Journal Article Marine Mammal Science · January 1, 2025 Respiratory disease is one of the main causes for morbidity and mortality in cetaceans, which highlights the importance of understanding normal lung function and how it may impede homeostasis, and diving capacity. In addition, the use of breathing frequenc ... Full text Cite

The role of cognition as a factor regulating the diving responses of animals, including humans.

Journal Article The Journal of experimental biology · October 2024 The dive response involves three main components - breath holding, reduced heart rate and increased peripheral vasoconstriction - and is ubiquitous during forced dives in air-breathing vertebrates; however, numerous studies in free-diving animals have show ... Full text Cite

Breathing patterns and associated cardiovascular changes in intermittently breathing animals: (Partially) correcting a semantic quagmire.

Journal Article Experimental physiology · July 2024 Many animal species do not breathe in a continuous, rhythmic fashion, but rather display a variety of breathing patterns characterized by prolonged periods between breaths (inter-breath intervals), during which the heart continues to beat. Examples of inte ... Full text Cite

Cardiorespiratory adaptations in small cetaceans and marine mammals.

Journal Article Experimental physiology · March 2024 The dive response, or the 'master switch of life', is probably the most studied physiological trait in marine mammals and is thought to conserve the available O2 for the heart and brain. Although generally thought to be an autonomic reflex, seve ... Full text Cite

Effects of feeding and habitat on resting metabolic rates of the Pacific walrus

Journal Article Marine Mammal Science · January 1, 2024 Arctic marine mammals live in a rapidly changing environment due to the amplified effects of global warming. Pacific walruses (Odobenus rosmarus divergens) have responded to declines in Arctic sea-ice extent by increasingly hauling out on land farther from ... Full text Cite

Resting metabolic rate and lung function in fasted and fed rough-toothed dolphins, Steno bredanensis

Journal Article Marine Mammal Science · January 1, 2024 We measured resting metabolic rate (RMR), tidal volume (VT), breathing frequency (fR), respiratory flow, and end-expired gases in rough-toothed dolphins (Steno bredanensis) housed in managed care after an overnight fast and 1–2 hr following a meal. The mea ... Full text Cite

First evidence of microplastic inhalation among free-ranging small cetaceans.

Journal Article PloS one · January 2024 Plastic is a ubiquitous environmental contaminant, resulting in widespread exposure across terrestrial and marine spaces. In the environment, plastics can degrade into microparticles where exposure has been documented in a variety of fauna at all trophic l ... Full text Cite

Deep diving by offshore bottlenose dolphins (Tursiops spp.)

Journal Article Marine Mammal Science · October 2023 AbstractWe used satellite‐linked tags to evaluate dive behavior in offshore bottlenose dolphins (Tursiops spp.) near the island of Bermuda. The data provide evidence that bottlenose dolphins commo ... Full text Cite

Surface and diving metabolic rates, and dynamic aerobic dive limits (dADL) in near- and off-shore bottlenose dolphins, Tursiops spp., indicate that deep diving is energetically cheap

Journal Article Marine Mammal Science · July 1, 2023 High-resolution dive depth and acceleration recordings from nearshore (Sarasota Bay, dive depth < 30 m), and offshore (Bermuda) bottlenose dolphins (Tursiops spp.) were used to estimate the diving metabolic rate (DMR) and the locomotor metabolic rate (LMR, ... Full text Cite

Evaluating feasibility of functional near-infrared spectroscopy in dolphins.

Journal Article Journal of biomedical optics · July 2023 SignificanceUsing functional near-infrared spectroscopy (fNIRS) in bottlenose dolphins (Tursiops truncatus) could help to understand how echolocating animals perceive their environment and how they focus on specific auditory objects, such a ... Full text Cite

Allometric scaling of metabolic rate and cardiorespiratory variables in aquatic and terrestrial mammals.

Journal Article Physiol Rep · June 2023 While basal metabolic rate (BMR) scales proportionally with body mass (Mb ), it remains unclear whether the relationship differs between mammals from aquatic and terrestrial habitats. We hypothesized that differences in BMR allometry would be reflected in ... Full text Link to item Cite

New insights into risk variables associated with gas embolism in loggerhead sea turtles (Caretta caretta) caught in trawls and gillnets.

Journal Article Conservation physiology · January 2023 Tissue and blood gas embolism (GE) associated with fisheries bycatch are likely a widespread, yet underestimated, cause of sea turtle mortality. Here, we evaluated risk factors associated with tissue and blood GE in loggerhead turtles caught incidentally b ... Full text Cite

UNDER PRESSURE

Chapter · January 1, 2023 This chapter questions how marine mammals cope with the huge pressures they face at depth. For some species, these can be pressures of over 200 atm at 2000 m depths. It examines the gas laws relating to pressure and particularly the inverse relationship be ... Full text Cite

Cardiorespiratory coupling in the bottlenose dolphin (Tursiops truncatus).

Journal Article Frontiers in physiology · January 2023 Introduction: The bottlenose dolphin (Tursiops truncatus) is an intermittent breather, where the breath begins with an exhalation followed by inhalation and an extended inter-breath interval ranging from 10 to 40 s. Breathing has been shown t ... Full text Cite

Studying dolphin physiology

Chapter · January 1, 2023 How do mammals manage to live underwater? To us their environment presents many challenges: it is often cold, conductive, viscous, murky, saline, high pressured, and most critically—devoid of air. Aquatic mammals therefore need various physiological adapta ... Full text Cite

Human impacts on dolphins: Physiological effects and conservation

Chapter · January 1, 2023 In this chapter, we describe aspects of the growing pressure on coastal and inshore common bottlenose dolphins (Tursiops truncatus, hereafter referred to as dolphins) as human use of these marine environments increases. While the ultimate outcomes of many ... Full text Cite

Diving physiology in dolphins and human

Chapter · January 1, 2023 During diving, the body is exposed to a number of environmental stressors that result in physiological responses. Many of these responses are common across both humans and dolphins. One of the best known is the dive response, historically referred to as th ... Full text Cite

The Physiology of Dolphins

Book · January 1, 2023 The Physiology of Dolphins is a robust, up-to-date reference. It provides a collection of review chapters from leaders in the field of dolphin ecophysiology, making it essential for instructors, researchers, and graduate students interested in the physiolo ... Full text Cite

Genetic and molecular adaptations

Chapter · January 1, 2023 Dolphins and other marine mammals possess unique adaptations that allow them to thrive in aquatic environments. While many physiological and anatomical adaptations play a clear role in marine mammal phenotypes, less is known about how genetic and molecular ... Full text Cite

Respiratory physiology in the dolphin and other whales

Chapter · January 1, 2023 Bottlenose dolphins, like all mammals, depend on the respiratory system to bring oxygen into the body and remove the carbon dioxide produced by aerobic metabolism. In marine mammals, such as dolphins, that divide their time at the surface exchanging gases ... Full text Cite

Dynamic body acceleration as a proxy to predict the cost of locomotion in bottlenose dolphins.

Journal Article The Journal of experimental biology · February 2022 Estimates of the energetic costs of locomotion (COL) at different activity levels are necessary to answer fundamental eco-physiological questions and to understand the impacts of anthropogenic disturbance to marine mammals. We combined estimates of energet ... Full text Cite

Key questions in marine mammal bioenergetics.

Journal Article Conservation physiology · January 2022 Bioenergetic approaches are increasingly used to understand how marine mammal populations could be affected by a changing and disturbed aquatic environment. There remain considerable gaps in our knowledge of marine mammal bioenergetics, which hinder the ap ... Full text Cite

Light Propagation through Dolphin Blubber: Towards Marine Mammal NIRS

Conference Optics InfoBase Conference Papers · January 1, 2022 Non-invasive long-term acquisition devices of physiological data in marine mammals are sparse. NIRS could fill this gap. Optical properties of dolphin tissue are measured and used in finite element models to optimize NIRS tag properties. ... Cite

Subsurface swimming and stationary diving are metabolically cheap in adult Pacific walruses (Odobenus rosmarus divergens).

Journal Article The Journal of experimental biology · December 2021 Walruses rely on sea-ice to efficiently forage and rest between diving bouts while maintaining proximity to prime foraging habitat. Recent declines in summer sea ice have resulted in walruses hauling out on land where they have to travel farther to access ... Full text Cite

Scaling of heart rate with breathing frequency and body mass in cetaceans.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · August 2021 Plasticity in the cardiac function of a marine mammal facilitates rapid adjustments to the contrasting metabolic demands of breathing at the surface and diving during an extended apnea. By matching their heart rate (fH) to their immediate ... Full text Cite

Introduction to the theme issue: Measuring physiology in free-living animals.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · August 2021 By describing where animals go, biologging technologies (i.e. animal attached logging of biological variables with small electronic devices) have been used to document the remarkable athletic feats of wild animals since the 1940s. The rapid developm ... Full text Cite

What is physiologging? Introduction to the theme issue, part 2.

Journal Article Philosophical transactions of the Royal Society of London. Series B, Biological sciences · August 2021 The physiological mechanisms by which animals regulate energy expenditure, respond to stimuli and stressors, and maintain homeostasis at the tissue, organ and whole organism levels can be described by 'physiologging'-that is, the use of onboard miniature e ... Full text Cite

RESPIRATORY CHANGES IN STRANDED BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS).

Journal Article Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians · April 2021 Lung function (breath duration, respiratory flow [V̇], and tidal volume [VT]), and end-expiratory O2 were measured in 19 adult bottlenose dolphins (Tursiops spp.) while at rest in water or beached for up to 10 min. ... Full text Cite

How Do Marine Mammals Manage and Usually Avoid Gas Emboli Formation and Gas Embolic Pathology? Critical Clues From Studies of Wild Dolphins

Journal Article Frontiers in Marine Science · February 5, 2021 Decompression theory has been mainly based on studies on terrestrial mammals, and may not translate well to marine mammals. However, evidence that marine mammals experience gas bubbles during diving is growing, causing concern that these bubbles may cause ... Full text Cite

Myoglobin Concentration and Oxygen Stores in Different Functional Muscle Groups from Three Small Cetacean Species.

Journal Article Animals : an open access journal from MDPI · February 2021 Compared with terrestrial mammals, marine mammals possess increased muscle myoglobin concentrations (Mb concentration, g Mb · 100g-1 muscle), enhancing their onboard oxygen (O2) stores and their aerobic dive limit. Although myoglobin ... Full text Cite

Lung function assessment in the Pacific walrus (Odobenus rosmarus divergens) while resting on land and submerged in water.

Journal Article The Journal of experimental biology · January 2021 In the present study, we examined lung function in healthy resting adult (born in 2003) Pacific walruses (Odobenus rosmarus divergens) by measuring respiratory flow ([Formula: see text]) using a custom-made pneumotachometer. Three female walruses (6 ... Full text Cite

Respiratory sinus arrhythmia and submersion bradycardia in bottlenose dolphins (Tursiops truncatus).

Journal Article The Journal of experimental biology · January 2021 Among the many factors that influence the cardiovascular adjustments of marine mammals is the act of respiration at the surface, which facilitates rapid gas exchange and tissue re-perfusion between dives. We measured heart rate (fH) in si ... Full text Cite

An integrated comparative physiology and molecular approach pinpoints mediators of breath-hold capacity in dolphins

Journal Article · 2021 Ischemic events, such as ischemic heart disease and ischemic stroke, are the number one cause of death globally. Ischemia prevents blood, carrying essential nutrients and oxygen, from reaching tissues and organ systems, leading to cell and tissue death, an ... Full text Cite

The New Era of Physio-Logging and Their Grand Challenges.

Journal Article Frontiers in physiology · January 2021 Full text Cite

Activity of loggerhead turtles during the U-shaped dive: Insights using angular velocity metrics

Journal Article Endangered Species Research · January 1, 2021 Understanding the behavioural ecology of endangered taxa can inform conservation strategies. The activity budgets of the loggerhead turtle Caretta caretta are still poorly understood because many tracking methods show only horizontal displacement and ignor ... Full text Cite

A Baseline Model For Estimating the Risk of Gas Embolism in Sea Turtles During Routine Dives.

Journal Article Frontiers in physiology · January 2021 Sea turtles, like other air-breathing diving vertebrates, commonly experience significant gas embolism (GE) when incidentally caught at depth in fishing gear and brought to the surface. To better understand why sea turtles develop GE, we built a mathematic ... Full text Cite

An integrated comparative physiology and molecular approach pinpoints mediators of breath-hold capacity in dolphins.

Journal Article Evol Med Public Health · 2021 BACKGROUND AND OBJECTIVES: Ischemic events, such as ischemic heart disease and stroke, are the number one cause of death globally. Ischemia prevents blood, carrying essential nutrients and oxygen, from reaching tissues, leading to cell and tissue death, an ... Full text Link to item Cite

Near-Infrared Spectroscopy as a Tool for Marine Mammal Research and Care.

Journal Article Frontiers in physiology · January 2021 Developments in wearable human medical and sports health trackers has offered new solutions to challenges encountered by eco-physiologists attempting to measure physiological attributes in freely moving animals. Near-infrared spectroscopy (NIRS) is one suc ... Full text Cite

Cardiorespiratory coupling in cetaceans; a physiological strategy to improve gas exchange?

Journal Article The Journal of experimental biology · September 2020 In the current study we used transthoracic echocardiography to measure stroke volume (SV), heart rate (fH) and cardiac output (CO) in adult bottlenose dolphins (Tursiops truncatus), a male beluga whale calf [Delphinapterus leuca ... Full text Cite

Extreme diving in mammals: first estimates of behavioural aerobic dive limits in Cuvier's beaked whales.

Journal Article The Journal of experimental biology · September 2020 We analysed 3680 dives from 23 satellite-linked tags deployed on Cuvier's beaked whales to assess the relationship between long duration dives and inter-deep dive intervals and to estimate aerobic dive limit (ADL). The median duration of presumed foraging ... Full text Open Access Cite

Response to: The metabolic cost of whistling is low but measurable in dolphins.

Journal Article The Journal of experimental biology · June 2020 Full text Cite

Improving estimates of diving lung volume in air-breathing marine vertebrates.

Journal Article The Journal of experimental biology · June 2020 The air volume in the respiratory system of marine tetrapods provides a store of O2 to fuel aerobic metabolism during dives; however, it can also be a liability, as the associated N2 can increase the risk of decompression sickness. In ... Full text Cite

An "orientation sphere" visualization for examining animal head movements.

Journal Article Ecology and evolution · May 2020 Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.Animal heads often move during specific behav ... Full text Cite

Hyperbaric tracheobronchial compression in cetaceans and pinnipeds.

Journal Article The Journal of experimental biology · March 2020 Assessment of the compressibility of marine mammal airways at depth is crucial to understanding vital physiological processes such as gas exchange during diving. Very few studies have directly assessed changes in cetacean and pinniped tracheobronchial shap ... Full text Cite

Pulmonary function testing as a diagnostic tool to assess respiratory health in bottlenose dolphins Tursiops truncatus.

Journal Article Diseases of aquatic organisms · February 2020 Pulmonary function testing was performed in 3 bottlenose dolphins Tursiops truncatus (1 female and 2 males) under managed care during a 2 yr period to assess whether these data provide diagnostic information about respiratory health. Pulmonary radiographs ... Full text Cite

Behavioral Biomarkers for Animal Health: A Case Study Using Animal-Attached Technology on Loggerhead Turtles

Journal Article Frontiers in Ecology and Evolution · January 21, 2020 Vertebrates are recognized as sentient beings. Consequently, urgent priority is now being given to understanding the needs and maximizing the welfare of animals under human care. The general health of animals is most commonly determined by physiological in ... Full text Cite

Estimates for energy expenditure in free-living animals using acceleration proxies: A reappraisal.

Journal Article The Journal of animal ecology · January 2020 It is fundamentally important for many animal ecologists to quantify the costs of animal activities, although it is not straightforward to do so. The recording of triaxial acceleration by animal-attached devices has been proposed as a way forward for this, ... Full text Cite

Whistling is metabolically cheap for communicating bottlenose dolphins (Tursiops truncatus).

Journal Article The Journal of experimental biology · January 2020 Toothed whales depend on sound for communication and foraging, making them potentially vulnerable to acoustic masking from increasing anthropogenic noise. Masking effects may be ameliorated by higher amplitudes or rates of calling, but such acoustic compen ... Full text Cite

Pulmonary function and resting metabolic rates in California sea lions (Zalophus californianus) on land and in water

Journal Article Aquatic Mammals · January 1, 2020 Respiratory flow, expired O2, and CO2 were measured during voluntary participation while spontaneously breathing in 13 confirmed healthy, male California sea lions (Zalophus californianus; body mass [Mb] range: 49 to 130 kg). Expiratory and inspiratory flo ... Full text Cite

Comparative Respiratory Physiology in Cetaceans.

Journal Article Frontiers in physiology · January 2020 In the current study, we used breath-by-breath respirometry to evaluate respiratory physiology under voluntary control in a male beluga calf [Delphinapterus leucas, body mass range (Mb): 151-175 kg], an adult female (estimated ... Full text Cite

Response to: The metabolic cost of whistling is low but measurable in dolphins

Journal Article JOURNAL OF EXPERIMENTAL BIOLOGY · 2020 Cite

Conditioned Variation in Heart Rate During Static Breath-Holds in the Bottlenose Dolphin (Tursiops truncatus).

Journal Article Frontiers in physiology · January 2020 Previous reports suggested the existence of direct somatic motor control over heart rate (fH) responses during diving in some marine mammals, as the result of a cognitive and/or learning process rather than being a reflexive response. Th ... Full text Cite

Respiratory sinus arrhythmia and submersion bradycardia in bottlenose dolphins (Tursiops truncatus).

Journal Article The Journal of experimental biology · January 2020 Among the many factors that influence the cardiovascular adjustments of marine mammals is the act of respiration at the surface, which facilitates rapid gas exchange and tissue re-perfusion between dives. We measured heart rate (fH) in six, adult male bott ... Full text Cite

Cardiorespiratory coupling in cetaceans; a physiological strategy to improve gas exchange?

Journal Article The Journal of experimental biology · January 2020 In the current study we used transthoracic echocardiography to measure stroke volume (SV), heart rate (fH), and cardiac output (CO) in adult bottlenose dolphins (Tursiops truncatus), a male beluga calf (Delphinapterus leucas, body mass [Mb] range: 151-175 ... Full text Cite

Lung function assessment in the Pacific walrus (Odobenus rosmarus divergens) while resting on land and submerged in water.

Journal Article The Journal of experimental biology · January 2020 In the present study, we examined lung function in healthy resting adult (born in 2003) Pacific walruses (Odobenus rosmarus divergens) by measuring respiratory flow (V̇) using a custom-made pneumotachometer. Three female walruses (670 - 1025 kg) voluntarily ... Full text Cite

Wearable multifunctional printed graphene sensors

Journal Article npj Flexible Electronics · December 1, 2019 The outstanding properties of graphene have initiated myriads of research and development; yet, its economic impact is hampered by the difficulties encountered in production and practical application. Recently discovered laser-induced graphene is generated ... Full text Cite

Re-evaluating the significance of the dive response during voluntary surface apneas in the bottlenose dolphin, Tursiops truncatus.

Journal Article Scientific reports · June 2019 The dive response is well documented for marine mammals, and includes a significant reduction in heart rate (fH) during submersion as compared while breathing at the surface. In the current study we assessed the influence of the Respiratory Sinu ... Full text Cite

Ventilation and gas exchange before and after voluntary static surface breath-holds in clinically healthy bottlenose dolphins, Tursiops truncatus.

Journal Article The Journal of experimental biology · March 2019 We measured respiratory flow (V̇), breathing frequency (fR), tidal volume (VT), breath duration and end-expired O2 content in bottlenose dolphins (Tursiops truncatus) before and after static surfa ... Full text Cite

Characterizing respiratory capacity in belugas (Delphinapterus leucas).

Journal Article Respiratory physiology & neurobiology · February 2019 We measured respiratory flow, breath duration, and calculated tidal volume (VT) in nine belugas (Delphinapterus leucas, mean measured body mass: 628 ± 151 kg, n = 5) housed in managed care facilities. Both spontaneous (resting at station) and tr ... Full text Cite

Diving behavior and fine-scale kinematics of free-ranging Risso's dolphins foraging in shallow and deep-water habitats

Journal Article Frontiers in Ecology and Evolution · January 1, 2019 Air-breathing marine predators must balance the conflicting demands of oxygen conservation during breath-hold and the cost of diving and locomotion to capture prey. However, it remains poorly understood how predators modulate foraging performance when feed ... Full text Cite

Advances in research on the impacts of anti-submarine sonar on beaked whales.

Journal Article Proceedings. Biological sciences · January 2019 Mass stranding events (MSEs) of beaked whales (BWs) were extremely rare prior to the 1960s but increased markedly after the development of naval mid-frequency active sonar (MFAS). The temporal and spatial associations between atypical BW MSEs and naval exe ... Full text Cite

Implanted Nanosensors in Marine Organisms for Physiological Biologging: Design, Feasibility, and Species Variability.

Journal Article ACS sensors · January 2019 In recent decades, biologists have sought to tag animals with various sensors to study aspects of their behavior otherwise inaccessible from controlled laboratory experiments. Despite this, chemical information, both environmental and physiological, remain ... Full text Cite

Using Respiratory Sinus Arrhythmia to Estimate Inspired Tidal Volume in the Bottlenose Dolphin (Tursiops truncatus).

Journal Article Frontiers in physiology · January 2019 Man-made environmental change may have significant impact on apex predators, like marine mammals. Thus, it is important to assess the physiological boundaries for survival in these species, and assess how climate change may affect foraging efficiency and t ... Full text Cite

Swimming energy economy in bottlenose dolphins under variable drag loading

Journal Article Frontiers in Marine Science · December 11, 2018 Instrumenting animals with tags contributes additional resistive forces (weight, buoyancy, lift, and drag) that may result in increased energetic costs; however, additional metabolic expense can be moderated by adjusting behavior to maintain power output. ... Full text Cite

Deciphering function of the pulmonary arterial sphincters in loggerhead sea turtles (Caretta caretta).

Journal Article The Journal of experimental biology · December 2018 To provide new insight into the pathophysiological mechanisms underlying gas emboli (GE) in bycaught loggerhead sea turtles (Caretta caretta), we investigated the vasoactive characteristics of the pulmonary and systemic arteries, and the lung parenc ... Full text Cite

Pulmonary ventilation-perfusion mismatch: a novel hypothesis for how diving vertebrates may avoid the bends.

Journal Article Proceedings. Biological sciences · April 2018 Hydrostatic lung compression in diving marine mammals, with collapsing alveoli blocking gas exchange at depth, has been the main theoretical basis for limiting N2 uptake and avoiding gas emboli (GE) as they ascend. However, studies of beached an ... Full text Cite

Resting Metabolic Rate and Lung Function in Wild Offshore Common Bottlenose Dolphins, Tursiops truncatus, Near Bermuda.

Journal Article Frontiers in physiology · January 2018 Diving mammals have evolved a suite of physiological adaptations to manage respiratory gases during extended breath-hold dives. To test the hypothesis that offshore bottlenose dolphins have evolved physiological adaptations to improve their ability for ext ... Full text Cite

Modeling Tissue and Blood Gas Kinetics in Coastal and Offshore Common Bottlenose Dolphins, Tursiops truncatus.

Journal Article Frontiers in physiology · January 2018 Bottlenose dolphins (Tursiops truncatus) are highly versatile breath-holding predators that have adapted to a wide range of foraging niches from rivers and coastal ecosystems to deep-water oceanic habitats. Considerable research has been done to und ... Full text Cite

Field energetics and lung function in wild bottlenose dolphins, Tursiops truncatus, in Sarasota Bay Florida.

Journal Article Royal Society open science · January 2018 We measured respiratory flow rates, and expired O2 in 32 (2-34 years, body mass [Mb] range: 73-291 kg) common bottlenose dolphins (Tursiops truncatus) during voluntary breaths on land or in water (between 2014 and 2017). ... Full text Cite

Impact of gas emboli and hyperbaric treatment on respiratory function of loggerhead sea turtles (Caretta caretta).

Journal Article Conservation physiology · January 2018 Fisheries interactions are the most serious threats for sea turtle populations. Despite the existence of some rescue centres providing post-traumatic care and rehabilitation, adequate treatment is hampered by the lack of understanding of the problems incur ... Full text Cite

Defining risk variables causing gas embolism in loggerhead sea turtles (Caretta caretta) caught in trawls and gillnets.

Journal Article Scientific reports · June 2017 Incidental capture, or 'bycatch' in fishing gear is a major global threat to sea turtle populations. A recent study showed that underwater entrapment in fishing gear followed by rapid decompression may cause gas bubble formation within the blood stream (em ... Full text Cite

Respiratory function and mechanics in pinnipeds and cetaceans.

Journal Article The Journal of experimental biology · May 2017 In this Review, we focus on the functional properties of the respiratory system of pinnipeds and cetaceans, and briefly summarize the underlying anatomy; in doing so, we provide an overview of what is currently known about their respiratory physiology and ... Full text Cite

Allometric scaling of decompression sickness risk in terrestrial mammals; cardiac output explains risk of decompression sickness.

Journal Article Scientific reports · February 2017 A probabilistic model was used to predict decompression sickness (DCS) outcome in pig (70 and 20 kg), hamster (100 g), rat (220 g) and mouse (20 g) following air saturation dives. The data set included 179 pig, 200 hamster, 360 rat, and 224 mouse exposures ... Full text Cite

Updating a gas dynamics model using estimates for California sea lions (Zalophus californianus).

Journal Article Respiratory physiology & neurobiology · December 2016 Theoretical models are used to predict how breath-hold diving vertebrates manage O2, CO2, and N2 while underwater. One recent gas dynamics model used available lung and tracheal compliance data from various species. As vari ... Full text Cite

Dive, food, and exercise effects on blood microparticles in Steller sea lions (Eumetopias jubatus): exploring a biomarker for decompression sickness.

Journal Article American journal of physiology. Regulatory, integrative and comparative physiology · April 2016 Recent studies of stranded marine mammals indicate that exposure to underwater military sonar may induce pathophysiological responses consistent with decompression sickness (DCS). However, DCS has been difficult to diagnose in marine mammals. We investigat ... Full text Cite

Estimating energetics in cetaceans from respiratory frequency: why we need to understand physiology.

Journal Article Biology open · April 2016 The accurate estimation of field metabolic rates (FMR) in wild animals is a key component of bioenergetic models, and is important for understanding the routine limitations for survival as well as individual responses to disturbances or environmental chang ... Full text Cite

INTRAPERITONEAL DEXTROSE ADMINISTRATION AS AN ALTERNATIVE EMERGENCY TREATMENT FOR HYPOGLYCEMIC YEARLING CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS).

Journal Article Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians · March 2016 The Marine Mammal Center (TMMC) cares for malnourished California sea lion (CSL) (Zalophus californianus) pups and yearlings every year. Hypoglycemia is a common consequence of malnutrition in young CSLs. Administering dextrose during a hypoglycemic crisis ... Full text Cite

Corrigendum: Respiratory Function in Voluntary Participating Patagonia Sea Lions (Otaria flavescens) in Sternal Recumbency.

Journal Article Frontiers in physiology · January 2016 [This corrects the article on p. 528 in vol. 7, PMID: 27899896.]. ... Full text Cite

Respiratory Function in Voluntary Participating Patagonia Sea Lions (Otaria flavescens) in Sternal Recumbency.

Journal Article Frontiers in physiology · January 2016 We measured esophageal pressures (n = 4), respiratory flow rates (n = 5), and expired O2 and CO2 (n = 4) in five adult Patagonia sea lions (Otaria flavescens, body mass range 94.3-286.0 kg) during voluntary ... Full text Cite

Pressure regulation

Chapter · 2016 Cite

Evaluating cardiac physiology through echocardiography in bottlenose dolphins: using stroke volume and cardiac output to estimate systolic left ventricular function during rest and following exercise.

Journal Article The Journal of experimental biology · November 2015 Heart-rate (fH) changes during diving and exercise are well documented for marine mammals, but changes in stroke volume (SV) and cardiac output (CO) are much less known. We hypothesized that both SV and CO are also modified following intense exercise. Usin ... Full text Cite

Lung mechanics and pulmonary function testing in cetaceans.

Journal Article The Journal of experimental biology · July 2015 We measured esophageal pressures, respiratory flow rates, and expired O2 and CO2 in six adult bottlenose dolphins (Tursiops truncatus) during voluntary breaths and maximal (chuff) respiratory efforts. The data were used to estimate the dynamic specific lun ... Full text Cite

Phosphatidylcholine composition of pulmonary surfactant from terrestrial and marine diving mammals.

Journal Article Respiratory physiology & neurobiology · June 2015 Marine mammals are repeatedly exposed to elevated extra-thoracic pressure and alveolar collapse during diving and readily experience alveolar expansion upon inhalation - a unique capability as compared to terrestrial mammals. How marine mammal lungs overco ... Full text Cite

The degradation of proteins in pinniped skeletal muscle: viability of post-mortem tissue in physiological research.

Journal Article Conservation physiology · January 2015 As marine divers, pinnipeds have a high capacity for exercise at depth while holding their breath. With finite access to oxygen, these species need to be capable of extended aerobic exercise and conservation of energy. Pinnipeds must deal with common physi ... Full text Cite

Pressure regulation

Chapter · January 1, 2015 However, they still have to cope with changes in pressure many times per day, and rapidly and repeatedly recruit their alveoli each time they surface. How do they avoid other problems associated with pressure, such as atelectasis, the “bends” or decompress ... Full text Cite

Bottlenose dolphins modify behavior to reduce metabolic effect of tag attachment.

Journal Article The Journal of experimental biology · December 2014 Attaching bio-telemetry or -logging devices ('tags') to marine animals for research and monitoring adds drag to streamlined bodies, thus affecting posture, swimming gaits and energy balance. These costs have never been measured in free-swimming cetaceans. ... Full text Cite

Drag, but not buoyancy, affects swim speed in captive Steller sea lions.

Journal Article Biology open · April 2014 Swimming at an optimal speed is critical for breath-hold divers seeking to maximize the time they can spend foraging underwater. Theoretical studies have predicted that the optimal swim speed for an animal while transiting to and from depth is independent ... Full text Cite

A comparative analysis of marine mammal tracheas.

Journal Article The Journal of experimental biology · April 2014 In 1940, Scholander suggested that stiffened upper airways remained open and received air from highly compressible alveoli during marine mammal diving. There are few data available on the structural and functional adaptations of the marine mammal respirato ... Full text Cite

Man's place among the diving mammals

Journal Article Human Evolution · January 1, 2014 A theory was forwarded in 1960 that humans significantly deviate in anatomy, physiology and behavior from their closest relatives, the great apes, and instead resemble diving mammals, as a result of a period of selective pressure to enter the water (Hardy, ... Cite

Inflation and deflation pressure-volume loops in anesthetized pinnipeds confirms compliant chest and lungs.

Journal Article Frontiers in physiology · January 2014 We examined structural properties of the marine mammal respiratory system, and tested Scholander's hypothesis that the chest is highly compliant by measuring the mechanical properties of the respiratory system in five species of pinniped under anesthesia ( ... Full text Cite

Ontogenetic changes in skeletal muscle fiber type, fiber diameter and myoglobin concentration in the Northern elephant seal (Mirounga angustirostris).

Journal Article Frontiers in physiology · January 2014 Northern elephant seals (Mirounga angustirostris) (NES) are known to be deep, long-duration divers and to sustain long-repeated patterns of breath-hold, or apnea. Some phocid dives remain within the bounds of aerobic metabolism, accompanied by physiologica ... Full text Cite

How man-made interference might cause gas bubble emboli in deep diving whales.

Journal Article Frontiers in physiology · January 2014 Recent cetacean mass strandings in close temporal and spatial association with sonar activity has raised the concern that anthropogenic sound may harm breath-hold diving marine mammals. Necropsy results of the stranded whales have shown evidence of bubbles ... Full text Cite

Significance of Muscle Fiber Type in Biopsied Elephant Seals

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · January 1, 2014 Link to item Cite

Lung mechanics in live cetaceans

Conference INTEGRATIVE AND COMPARATIVE BIOLOGY · January 1, 2014 Link to item Cite

Behavioral impacts of disentanglement of a right whale under sedation and the energetic cost of entanglement

Journal Article Marine Mammal Science · January 1, 2014 Protracted entanglement in fishing gear often leads to emaciation through reduced mobility and foraging ability, and energy budget depletion from the added drag of towing gear for months or years. We examined changes in kinematics of a tagged entangled Nor ... Full text Cite

Activity as a proxy to estimate metabolic rate and to partition the metabolic cost of diving vs. breathing in pre- and post-fasted Steller sea lions

Journal Article Aquatic Biology · April 30, 2013 Three Steller sea lions Eumetopias jubatus, trained to dive voluntarily to depths ranging from 10 to 50 m, were used to determine whether the relationship between activity and metabolic rate during a diving interval (MRDI, dive + surface interval) was affe ... Full text Cite

Gas Bubble Disease in the Brain of a Living California Sea Lion (Zalophus californianus).

Journal Article Frontiers in physiology · January 2013 A yearling California sea lion (Zalophus californianus) was admitted into rehabilitation with signs of cerebellar pathology. Diagnostic imaging that included radiography and magnetic resonance imaging (MRI) demonstrated space-occupying lesions predominantl ... Full text Cite

Bubbles in live-stranded dolphins.

Journal Article Proceedings. Biological sciences · April 2012 Bubbles in supersaturated tissues and blood occur in beaked whales stranded near sonar exercises, and post-mortem in dolphins bycaught at depth and then hauled to the surface. To evaluate live dolphins for bubbles, liver, kidneys, eyes and blubber-muscle i ... Full text Cite

Deadly diving? Physiological and behavioural management of decompression stress in diving mammals.

Journal Article Proceedings. Biological sciences · March 2012 Decompression sickness (DCS; 'the bends') is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to m ... Full text Cite

Changes in dive behavior during naval sonar exposure in killer whales, long-finned pilot whales, and sperm whales.

Journal Article Frontiers in physiology · January 2012 Anthropogenic underwater sound in the environment might potentially affect the behavior of marine mammals enough to have an impact on their reproduction and survival. Diving behavior of four killer whales (Orcinus orca), seven long-finned pilot whales (Glo ... Full text Cite

Estimated Tissue and Blood N(2) Levels and Risk of Decompression Sickness in Deep-, Intermediate-, and Shallow-Diving Toothed Whales during Exposure to Naval Sonar.

Journal Article Frontiers in physiology · January 2012 Naval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue N(2) gas bubbles. Increased tissue and blood N(2) levels, and thereby increased risk of decompression sickness (DCS), is thought to result from chang ... Full text Cite

The use of Diagnostic Imaging for Identifying Abnormal Gas Accumulations in Cetaceans and Pinnipeds.

Journal Article Frontiers in physiology · January 2012 Recent dogma suggested that marine mammals are not at risk of decompression sickness due to a number of evolutionary adaptations. Several proposed adaptations exist. Lung compression and alveolar collapse that terminate gas-exchange before a depth is reach ... Full text Cite

Static inflation and deflation pressure-volume curves from excised lungs of marine mammals.

Journal Article The Journal of experimental biology · November 2011 Excised lungs from eight marine mammal species [harp seal (Pagophilus groenlandicus), harbor seal (Phoca vitulina), gray seal (Halichoerus grypush), Atlantic white-sided dolphin (Lagenorhynchus acutus), common dolphin (Delphinus delphis), Risso's dolphin ( ... Full text Cite

Hyperbaric computed tomographic measurement of lung compression in seals and dolphins.

Journal Article The Journal of experimental biology · July 2011 Lung compression of vertebrates as they dive poses anatomical and physiological challenges. There has been little direct observation of this. A harbor and a gray seal, a common dolphin and a harbor porpoise were each imaged post mortem under pressure using ... Full text Cite

The genetic component of the forced diving bradycardia response in mammals.

Journal Article Frontiers in physiology · January 2011 We contrasted the forced diving bradycardia between two genetically similar (inbred) rat strains (Fischer and Buffalo), compared to that of outbred rats (Wistar). The animals were habituated to forced diving for 4 weeks. Each animal was then tested during ... Full text Cite

Changes in the foraging dive behaviour and energetics of king penguins through summer and autumn: A month by month analysis

Journal Article Marine Ecology Progress Series · March 11, 2010 King penguins Aptenodytes patagonicus are known to change their diving behaviour in response to changes in both prey location and their breeding status through the early stages of the breeding cycle (austral summer and autumn). However, little information ... Full text Cite

Fasting affects the surface and diving metabolic rates of steller sea lions Eumetopias jubatus

Journal Article Aquatic Biology · December 1, 2009 Changes in metabolic rates were measured in 3 captive female Steller sea lions Eumetopias jubatus that experienced fasts during summer and winter. We measured metabolic rates (via O2 consumption) before (MRs, surface) and after (DMR, dive + surface interva ... Full text Cite

Decompression sickness in breath-hold divers: a review.

Journal Article Journal of sports sciences · December 2009 Although it has been generally assumed that the risk of decompression sickness is virtually zero during a single breath-hold dive in humans, repeated dives may result in a cumulative increase in the tissue and blood nitrogen tension. Many species of marine ... Full text Cite

Could beaked whales get the bends? Effect of diving behaviour and physiology on modelled gas exchange for three species: Ziphius cavirostris, Mesoplodon densirostris and Hyperoodon ampullatus.

Journal Article Respiratory physiology & neurobiology · July 2009 A mathematical model, based on current knowledge of gas exchange and physiology of marine mammals, was used to predict blood and tissue tension N2 (P(N2)) using field data from three beaked whale species: northern bottlenose whales, Cuvier's beaked whales, ... Full text Cite

Estimating the effect of lung collapse and pulmonary shunt on gas exchange during breath-hold diving: the Scholander and Kooyman legacy.

Journal Article Respiratory physiology & neurobiology · January 2009 We developed a mathematical model to investigate the effect of lung compression and collapse (pulmonary shunt) on the uptake and removal of O(2), CO(2) and N(2) in blood and tissue of breath-hold diving mammals. We investigated the consequences of pressure ... Full text Cite

How Do Marine Mammals Avoid DCS?

Conference FUTURE OF DIVING:100 YEARS OF HALANE AND BEYOND · January 1, 2009 Link to item Cite

Discussion: Diving Researcher Recruitment

Conference FUTURE OF DIVING:100 YEARS OF HALANE AND BEYOND · January 1, 2009 Link to item Cite

Discussion: Decompression Physiology and Methodology

Conference FUTURE OF DIVING:100 YEARS OF HALANE AND BEYOND · January 1, 2009 Link to item Cite

Buoyancy does not affect diving metabolism during shallow dives in steller sea lions Eumetopias jubatus

Journal Article Aquatic Biology · December 1, 2008 Changes in buoyancy due to seasonal or abnormal changes in body composition are thought to significantly affect the energy budget of marine mammals through changes in diving costs. We assessed how changes in body composition might alter the foraging effici ... Full text Cite

Activity and diving metabolism correlate in Steller sea lion Eumetopias jubatus

Journal Article Aquatic Biology · December 1, 2008 Three Steller sea lions Eumetopias jubatus were trained to participate in free-swimming, open-ocean experiments designed to determine if activity can be used to estimate the energetic cost of finding prey at depth. Sea lions were trained to dive to fixed d ... Full text Cite

Modeling the marine resources consumed in raising a king penguin chick: an energetics approach.

Journal Article Physiological and biochemical zoology : PBZ · November 2008 Accurate estimates of penguin energetics would represent an important contribution to our understanding of the trophodynamics of the Southern Ocean ecosystem and our ability to predict effects of environmental change on these species. We used the heart rat ... Full text Cite

Metabolic costs of foraging and the management of O2 and CO2 stores in Steller sea lions.

Journal Article The Journal of experimental biology · November 2008 The metabolic costs of foraging and the management of O2 and CO2 stores during breath-hold diving was investigated in three female Steller sea lions (Eumetopias jubatus) trained to dive between 10 and 50 m (N=1142 dives). Each trial consisted of two to eig ... Full text Cite

Recovery from swimming-induced hypothermia in king penguins: effects of nutritional condition.

Journal Article Physiological and biochemical zoology : PBZ · July 2008 We investigated changes in the rate of oxygen consumption (V O2) and body temperature of wild king penguins (Aptenodytes patagonicus) in different nutritional conditions during recovery after exposure to cold water. Over time, birds undertook an identical ... Full text Cite

Tracheal compression delays alveolar collapse during deep diving in marine mammals.

Journal Article Respiratory physiology & neurobiology · May 2008 Marine mammals have very compliant alveoli and stiff upper airways; an adaptation that allows air to move from the alveoli into the upper airways, during breath-hold diving. Alveolar collapse is thought occur between 30 and 100 m and studies that have atte ... Full text Cite

The pressure to understand the mechanism of lung compression and its effect on lung function.

Journal Article Journal of applied physiology (Bethesda, Md. : 1985) · April 2008 Full text Cite

Pharmacological interventions to decompression sickness in rats: comparison of five agents.

Journal Article Aviation, space, and environmental medicine · January 2008 IntroductionThis research investigated whether decompression sickness (DCS) risk or severity could be reduced using drug interventions that are easier to implement and equal to or more efficacious than recompression therapy.MethodsUsing a ... Full text Cite

Behavioral and physiological significance of minimum resting metabolic rate in king penguins.

Journal Article Physiological and biochemical zoology : PBZ · January 2008 Because fasting king penguins (Aptenodytes patagonicus) need to conserve energy, it is possible that they exhibit particularly low metabolic rates during periods of rest. We investigated the behavioral and physiological aspects of periods of minimum metabo ... Full text Cite

To what extent might N2 limit dive performance in king penguins?

Journal Article The Journal of experimental biology · October 2007 A mathematical model was used to explore if elevated levels of N2, and risk of decompression sickness (DCS), could limit dive performance (duration and depth) in king penguins (Aptenodytes patagonicus). The model allowed prediction of blood and tissue (cen ... Full text Cite

Fine-scale analyses of diving energetics in king penguins Aptenodytes patagonicus: How behaviour affects costs of a foraging dive

Journal Article Marine Ecology Progress Series · August 23, 2007 Heart rate data loggers were implanted into king penguins Aptenodytes patagonicus undertaking foraging trips at sea during three austral summers. Data were obtained from a total of 20 king penguins. Our aim was to investigate variations in mean heart rate ... Full text Cite

Onshore energetics in penguins: theory, estimation and ecological implications.

Journal Article Comparative biochemistry and physiology. Part A, Molecular & integrative physiology · August 2007 Penguins are known to have high pedestrian locomotory costs in comparison to other cursorial birds, but the ecological consequences of this difference have received limited attention. Here we present a method for the accurate estimation of onshore energeti ... Full text Cite

7.P2. King penguins modulate their behaviour such that energy costs of foraging dives do not increase as winter approaches

Conference Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology · August 2007 Full text Cite

Laboratory studies in wildlife conservation: The case of the Steller sea lion

Conference Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology · April 2007 Full text Cite

King penguins as bio-indicators? Variations in the behaviours and energetic costs of foraging dives

Conference Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology · April 2007 Full text Cite

Changes in dive profiles as an indicator of feeding success in king and Adélie penguins

Conference Deep-Sea Research Part II: Topical Studies in Oceanography · February 1, 2007 Determining when and how deep avian divers feed remains a challenge despite technical advances. Systems that record oesophageal temperature are able to determine rate of prey ingestion with a high level of accuracy but technical problems still remain to be ... Full text Cite

How accurately can we estimate energetic costs in a marine top predator, the king penguin?

Journal Article Zoology (Jena, Germany) · January 2007 King penguins (Aptenodytes patagonicus) are one of the greatest consumers of marine resources. However, while their influence on the marine ecosystem is likely to be significant, only an accurate knowledge of their energy demands will indicate their true f ... Full text Cite

Deep diving mammals: Dive behavior and circulatory adjustments contribute to bends avoidance.

Journal Article Respiratory physiology & neurobiology · August 2006 A mathematical model was created that predicted blood and tissue N(2) tension (P(N2)) during breath-hold diving. Measured muscle P(N2) from the bottlenose dolphin after diving repeatedly to 100 m (Tursiops truncatus [Ridgway and Howard, 1979, Science, 4423 ... Full text Cite

Nitrogen load in rats exposed to 8 ATA from 10-35 degrees C does not influence decompression sickness risk.

Journal Article Aviation, space, and environmental medicine · August 2006 IntroductionEnvironmental temperature is commonly thought to modulate decompression sickness (DCS) risk, but the literature is mixed regarding which conditions elicit the greatest risk. If temperature is a risk factor, then managing thermal exposu ... Cite

Dehydration effects on the risk of severe decompression sickness in a swine model.

Journal Article Aviation, space, and environmental medicine · February 2006 BackgroundSeveral physiological factors have been suspected of affecting the risk of decompression sickness (DCS), but few have been thoroughly studied during controlled conditions. Dehydration is a potential factor that could increase the risk of ... Cite

Metabolism and thermoregulation during fasting in king penguins, Aptenodytes patagonicus, in air and water.

Journal Article American journal of physiology. Regulatory, integrative and comparative physiology · September 2005 We measured oxygen consumption rate (Vo(2)) and body temperatures in 10 king penguins in air and water. Vo(2) was measured during rest and at submaximal and maximal exercise before (fed) and after (fasted) an average fasting duration of 14.4 +/- 2.3 days ( ... Full text Cite

The acute hypoxic ventilatory response: testing the adaptive significance in human populations.

Journal Article Comparative biochemistry and physiology. Part A, Molecular & integrative physiology · March 2005 The acute Hypoxic Ventilatory Response (HVR) is an important component of human hypoxia tolerance, hence presumably physiological adaptation to high altitude. We measured the isocapnic HVR (L min(-1) %(-1)) in two genetically divergent low altitude souther ... Full text Cite

Measurement reliability of highly variable physiological responses to experimentally-manipulated gas fractions.

Journal Article Physiological measurement · October 2004 Ventilatory and cardiac responses to changing inhaled gas fractions are notoriously variable within individuals. Such variation can confound clinical diagnoses and hypotheses about human adaptation. In this study we use a cardiac (HHR) and a ventilatory (H ... Full text Cite

Heart rate and energetics of free-ranging king penguins (Aptenodytes patagonicus).

Journal Article The Journal of experimental biology · October 2004 The main objective of this study was to determine heart rate (fh) and the energetic costs of specific behaviours of king penguins while ashore and while foraging at sea during their breeding period. In particular, an estimate was made of the energetic cost ... Full text Cite

Effect of fasting on the VO2-fh relationship in king penguins, Aptenodytes patagonicus.

Journal Article American journal of physiology. Regulatory, integrative and comparative physiology · October 2004 King penguins (Aptenodytes patagonicus) may fast for up to 30 days during their breeding period. As such extended fasting may affect the relationship between the rate of O(2) consumption (Vo(2)) and heart rate (f(H)), five male king penguins were exercised ... Full text Cite

Treatment of decompression sickness in swine with intravenous perfluorocarbon emulsion.

Journal Article Aviation, space, and environmental medicine · April 2004 BackgroundWe examined an adjunctive treatment for severe decompression sickness (DCS) to be used when hyperbaric treatment is delayed or unavailable.HypothesisIt has been hypothesized that intravenous perfluorocarbon (PFC) emulsion combin ... Cite

Treatment of Decompression Sickness in Swine with Intravenous Perfluorocarbon Emulsion

Journal Article Aviation Space and Environmental Medicine · April 1, 2004 Background: We examined an adjunctive treatment for severe decompression sickness (DCS) to be used when hyperbaric treatment is delayed or unavailable. Hypothesis: It has been hypothesized that intravenous perfluorocarbon (PFC) emulsion combined with 100% ... Cite

Probabilistic modelling for estimating gas kinetics and decompression sickness risk in pigs during H2 biochemical decompression.

Journal Article Bulletin of mathematical biology · July 2003 We modelled the kinetics of H2 flux during gas uptake and elimination in conscious pigs exposed to hyperbaric H2. The model used a physiological description of gas flux fitted to the observed decompression sickness (DCS) incidence in two groups of pigs: un ... Full text Cite

Patterns of respiration in diving penguins: is the last gasp an inspired tactic?

Journal Article The Journal of experimental biology · May 2003 Humboldt penguins Spheniscus humboldti in captivity and free-living Magellanic penguins S. magellanicus were fitted with loggers to determine beak angles during breathing. The Humboldt penguins were also fitted with masks for determining rates of air flow ... Full text Cite

Prophylactic high dose methylprednisolone fails to treat severe decompression sickness in swine.

Journal Article Aviation, space, and environmental medicine · January 2003 IntroductionControlled decompression from saturation conditions is not always an option, particularly in a disabled submarine scenario. Hypothesis Prophylactic high dose methylprednisolone (MP) would improve outcome in severe cases of decompressio ... Cite

A simple breathing circuit to maintain isocapnia during measurements of the hypoxic ventilatory response.

Journal Article Respiratory physiology & neurobiology · November 2002 We report the development and testing of a simple breathing circuit that maintains isocapnia in human subjects during hypoxic hyperpnea. In addition, the circuit permits rapid switching between two gas mixtures with different partial pressures of oxygen. E ... Full text Cite

Modulation of decompression sickness risk in pigs with caffeine during H(2) biochemical decompression.

Journal Article Journal of applied physiology (Bethesda, Md. : 1985) · November 2002 In H(2) biochemical decompression, H(2)-metabolizing intestinal microbes remove gas stored in tissues of animals breathing hyperbaric H(2), thereby reducing decompression sickness (DCS) risk. We hypothesized that increasing intestinal perfusion in pigs wou ... Full text Cite

On the likelihood of decompression sickness during H(2) biochemical decompression in pigs.

Journal Article Journal of applied physiology (Bethesda, Md. : 1985) · December 2001 A probabilistic model was used to predict decompression sickness (DCS) outcome in pigs during exposures to hyperbaric H(2) to quantify the effects of H(2) biochemical decompression, a process in which metabolism of H(2) by intestinal microbes facilitates d ... Full text Cite

Increasing activity of H(2)-metabolizing microbes lowers decompression sickness risk in pigs during H(2) dives.

Journal Article Journal of applied physiology (Bethesda, Md. : 1985) · December 2001 The risk of decompression sickness (DCS) was modulated by varying the biochemical activity used to eliminate some of the hydrogen (H(2)) stored in the tissues of pigs (19.4 +/- 0.2 kg) during hyperbaric exposures to H(2). Treated pigs (n = 16) received int ... Full text Cite

Decompression sickness risk reduced by native intestinal flora in pigs after H2 dives.

Journal Article Undersea & hyperbaric medicine : journal of the Undersea and Hyperbaric Medical Society, Inc · January 2001 Decompression sickness (DCS) risk following a simulated dive in H2 was lower in pigs with a native intestinal flora that metabolized H2. Pigs (n = 27; 19.4 +/- 0.2 kg body mass) were placed in a chamber that was pressurized to 22.2-25.5 atm (absolute; 2.2- ... Cite

Calorimetry and respirometry in guinea pigs in hydrox and heliox at 10-60 atm.

Journal Article Pflugers Archiv : European journal of physiology · October 2000 We used direct calorimetry and respirometry to measure the total rate of heat loss (Qsigma) and of oxygen consumption (VO2) in guinea pigs in 1-atm (0.1 MPa) air and at 10-60 atm in either heliox (98% He, 2% O2) or hydrox (98% H2, 2% O2). Our objective was ... Full text Cite

Natural history of severe decompression sickness after rapid ascent from air saturation in a porcine model.

Journal Article Journal of applied physiology (Bethesda, Md. : 1985) · August 2000 We developed a swine model to describe the untreated natural history of severe decompression sickness (DCS) after direct ascent from saturation conditions. In a recompression chamber, neutered male Yorkshire swine were pressurized to a predetermined depth ... Full text Cite

Gene up-regulation in heart during mammalian hibernation.

Journal Article Cryobiology · June 2000 A cDNA library prepared from heart of hibernating golden-mantled ground squirrels, Spermophilus lateralis, was differentially screened to clone genes that were up-regulated during hibernation. Two differentially expressed clones were found after three roun ... Full text Cite