Deadly diving? Physiological and behavioural management of decompression stress in diving mammals
نویسندگان
چکیده
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 multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N(2)) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N(2) tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N(2) loading to management of the N(2) load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.
منابع مشابه
Physiological Monitoring in Diving Mammals
The objective with this study is to develop and calibrate an invasive data logger to measure muscle O2 saturation in large, freely diving whales. We intend to use this data logger to measure muscle O2 saturation and determine how blood flow to muscle is altered during diving. These data will be important to determine if muscle blood flow is reduced during diving, and important to estimate how t...
متن کاملAcute and potentially persistent effects of scuba diving on the blood transcriptome of experienced divers.
During scuba diving, the circulatory system is stressed by an elevated partial pressure of oxygen while the diver is submerged and by decompression-induced gas bubbles on ascent to the surface. This diving-induced stress may trigger decompression illness, but the majority of dives are asymptomatic. In this study we have mapped divers' blood transcriptomes with the aim of identifying genes, biol...
متن کاملDive, food, and exercise effects on blood microparticles in Steller sea lions (Eumetopias jubatus): exploring a biomarker for decompression sickness.
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 investigated whether blood microparticles (MPs, measured as number/μl plasma), which increase in response to decompression stress in terrestrial mammal...
متن کاملThe physiological basis of diving to depth: birds and mammals.
There is wide diversity in the animals that dive to depth and in the distribution of their body oxygen stores. A hallmark of animals diving to depth is a substantial elevation of muscle myoglobin concentration. In deep divers, more than 80% of the oxygen store is in the blood and muscles. How these oxygen stores are managed, particularly within muscle, is unclear. The aerobic endurance of four ...
متن کاملBehaviour and buoyancy regulation in the deepest-diving reptile: the leatherback turtle.
In the face of the physical and physiological challenges of performing breath-hold deep dives, marine vertebrates have evolved different strategies. Although behavioural strategies in marine mammals and seabirds have been investigated in detail, little is known about the deepest-diving reptile - the leatherback turtle (Dermochelys coriacea). Here, we deployed tri-axial accelerometers on female ...
متن کامل