Sensitivity to hypercapnia and elimination of CO2 following diving in Steller sea lions (Eumetopias jubatus)

  title={Sensitivity to hypercapnia and elimination of CO2 following diving in Steller sea lions (Eumetopias jubatus)},
  author={Carling D. Gerlinsky and David A. S. Rosen and Andrew W. Trites},
  journal={Journal of Comparative Physiology B},
The diving ability of marine mammals is a function of how they use and store oxygen and the physiological control of ventilation, which is in turn dependent on the accumulation of CO2. To assess the influence of CO2 on physiological control of dive behaviour, we tested how increasing levels of inspired CO2 (hypercarbia) and decreasing inspired O2 (hypoxia) affected the diving metabolic rate, submergence times, and dive recovery times (time to replenish O2 stores and eliminate CO2) of freely… 

Physiological constraints and energetic costs of diving behaviour in marine mammals: a review of studies using trained Steller sea lions diving in the open ocean

These studies show that the type of diving, the level of underwater activity, the depth and duration of dives, and the nutritional status and physical condition of the animal affect the cost of diving and foraging and demonstrate that changes in prey abundance and nutritional status cause sea lions to alter the balance between time spent at the surface acquiring oxygen and time at depth acquiring prey.

Ecophysiology of mammals

The breadth of recent research on the ecophysiology of mammals is demonstrated, the research activity of the past 25 years is quantified, and future research needs are considered.

Movements and dive behaviour of a toothfish‐depredating killer and sperm whale

It is hypothesize that energetically and physiologically costly dive behaviour while depredating is driven by intra‐ and inter‐specific competition due to the limited availability of this abundant resource.

Post-dive gas recovery and the transition between metabolic states as physiological limits to diving in Steller sea lions (Eumetopias jubatus)

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High diving metabolism results in a short aerobic dive limit for Steller sea lions (Eumetopias jubatus)

This study is the first to estimate cADL based on direct measures of VO2 and blood oxygen stores for an Otariid and indicates they have a much shorter ADL than previously thought.

Steller sea lions (Eumetopias jubatus) have greater blood volumes, higher diving metabolic rates and a longer aerobic dive limit when nutritionally stressed

It is concluded that there was no negative effect of nutritional stress on the diving ability of sea lions, however, nutritional stress did lower foraging efficiency and require more foraging time to meet energy requirements due to increases in diving metabolic rates and surface recovery times.

Unsteady-state gas exchange and storage in diving marine mammals: the harbor porpoise and gray seal.

Data indicate that it is the readjustment of metabolic RQ and not O(2) stores per se that governs the amount of time an animal must spend ventilating at the surface after a dive.

Respiratory Physiology of Freely Diving Harbor Seals (Phoca vitulina)

Two 2-year-old harbor seals were studied during free diving in a circular tank in which they were forced to come to a one-way valve to breathe, and it is suggested that this represents a behavioral control of respiration which must be considered in evaluating the responsiveness of diving mammals to Pco2, and Po2.

Effects of hypoxia and hypercapnia on aerobic metabolic processes in northern elephant seals.

Inhaled CO2 and progressive hypoxia: ventilatory response in a yearling and a newborn harbor seal.

Breathing pattern, CO2 elimination and the absence of exhaled NO in freely diving Weddell seals

Gas exchange of captive freely diving grey seals (Halichoerus grypus).

This result was unexpected and indicates that these seals are utilising substantial physiological responses to conserve oxygen, even during shallow voluntary diving.