Ashley Blawas

Duke University | DU · Division of Marine Science and Conservation

While basal metabolic rate (BMR) scales proportionally with body mass (M b), it remains unclear whether the relationship differs between mammals from aquatic and terrestrial habitats. We hypothesized that differences in BMR allom-etry would be reflected in similar differences in scaling of O 2 delivery pathways through the cardiorespiratory system....

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, L O 2 /min) during three phases of diving (descent, bottom, and ascent). For shallow dives (d...

Ocean physics and biology can interact in myriad and complex ways. Eddies, features found at many scales in the ocean, can drive substantial changes in physical and biogeochemical fields with major implications for marine ecosystems. Mesoscale eddies are challenging to model and difficult to observe at sea due to their fine-scale variability yet br...

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 energetic costs derived from breath-by-breath respirometry with measurements of overall dynamic body...

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, and eventual organ failure. While humans are relatively intolerant to ischemic events, other sp...

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 ( f H ) to their immediate physiological needs, a marine mammal can improve its metabolic efficiency and maximize the proportion of tim...

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 the tissues leading to cell death, tissue death, and eventual organ failure. While humans are relatively intolerant to these ischemic events, other species,...

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 ( f H ) in six, adult male bottlenose dolphins ( Tursiops truncatus ) spontaneously breathing at the surface to quantify t...

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. This would be beneficial for O2 storage management, but would also allow ventilation-perfusion matching for selecti...

Video abstract: https://www.youtube.com/watch?v=WxqKniwIVf4 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 kg), and an adult female false kil...

Recent data indicate that approximately 12% of children in the United States are affected by neurodevelopmental disorders, including Attention Deficit Hyperactivity Disorder (ADHD), learning disorders, intellectual disabilities and autism spectrum disorders (ASD). Accumulating evidence implicates a multifactorial etiology for these disorders, with...