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...

Heart rate and dive behaviour were monitored in double-crested cormorants (Phalacrocorax auritus) during shallow (1 m) and deep diving (12 m), after breathing different gas mixtures, to investigate the role of depth and the accompanying changes in blood gas levels in cardiac and behavioural control during voluntary diving. Pre-dive heart rate in both shallow- and deep-diving birds was approxima...

Breath-hold diving induces, in marine mammals, a reduction of cardiac output due to a decrease of both heart rate and stroke volume. Cardiovascular changes in humans during breath-hold diving are only partially known due to the technical difficulty of studying fully immersed subjects. Recently, a submersible echocardiograph has been developed, allowing a feasible assessment of cardiac anatomy a...

Elevated arterial Pco(2) (hypercapnia) has a major effect on central nervous system oxygen toxicity in diving with a closed-circuit breathing apparatus. The purpose of the present study was to follow up the ability of divers to detect CO(2) and to determine the CO(2) retention trait after 1 year of active oxygen diving with closed-circuit apparatus. Ventilatory and perceptual responses to varia...

INTRODUCTION Need for recommendations on respiratory aspects of fitness to dive Diving has long been performed for commercial and military purposes but it has undergone a dramatic increase in popularity as a leisure pursuit over the past 30 years. It is estimated that, in the United Kingdom, 100 000 individuals participate in diving activities. In addition, diving technology has evolved rapidly...

BACKGROUND Among the most widespread seabirds in the world, shearwaters of the genus Puffinus are also some of the deepest diving members of the Procellariiformes. Maximum diving depths are known for several Puffinus species, but dive depths or diving behaviour have never been recorded for great shearwaters (P. gravis), the largest member of this genus. This study reports the first high samplin...

Many phocid seals are expert divers that remain submerged longer than expected based on estimates of oxygen storage and utilization. This discrepancy is most likely due to an overestimation of diving metabolic rate. During diving, a selective redistribution of blood flow occurs, which may result in reduced metabolism in the hypoperfused tissues and a possible decline in whole-body metabolism to...

As an illustration, consider the following two-step adsorption cycle to purify helium diving gas. Helium diving gas is principally a mixture of oxygen and helium, when the diving chambers are depressurised, the contaminated gas will consist mainly of carbon dioxide, oxygen and helium. Traditionally this waste gas has been thrown away. The PSA cycle described below is a method of purifying this ...

Diving is believed to be very costly in cormorants (Phalacrocoracidae) when compared with other avian divers because of their poor insulation and less-efficient foot propulsion. It was therefore suggested that cormorants might employ a behavioural strategy to reduce daily energy expenditure by minimizing the amount of time spent in water. However, European shags (Phalacrocorax aristotelis) have...

In Poland, the new regulation of the Ministry of Health on Occupational Health for Underwater Works (dated 2007) pursuant to the Act on Underwater Works (dated 2003) has just been published. It is dedicated for commercial, non-military purposes. It defines health requirements for commercial divers and candidates for divers, medical assessment guide with a list of specific medical tests done on ...