Table 1.
Future research priorities and potential techniques to address these research avenues.
| topic | specific research | potential methods |
|---|---|---|
| diving physiology and responses | mechanics of lung collapse | hyperbaric pressure chamber work with small marine mammals |
| kinetics of N2 uptake and distribution | respiratory gas analysis and blood and tissue measurement, aided by techniques such as Van Slyke, mass spectrometry and gas chromatography | |
| gas dynamics at the alveolar boundary | alveolar and arterial gas sensors | |
| soft-tissue changes (alveolar collapse) and shunting of blood | medical imaging (ultrasound, CT and MRI); potential use of polarized gas as more successful contrast agent | |
| passive (pressure-induced) changes to the circulatory system with lung compression? | rubberized casts of the circulatory system at ambient and elevated pressures | |
| perfusion patterns in terms of vascular anatomy and pathology | conventional or CT angiography | |
| changes in blood flow distribution during diving | use of a radioactive isotope of inert gas (e.g. Xe127 or Xe133) with small external gamma ray sensors on the body surface | |
| diving behaviour and bubble incidence | ||
| comparison of bubble incidence with diving behaviour | consistent, replicable protocols for strandings nationally and internationally | |
| detection of bubbles and measurement of local blood flow | intra-vascular ultrasound catheter | |
| measurement of extravascular bubbles from free-swimming animals | development of dual-frequency ultrasound incorporated into attached bio-logging tag | |
| bubble incidence in other high-stress situations including novel anthropogenic or natural threats | physiological monitoring during novel stimulation in shallow and deep divers | |
| bubble avoidance, tolerance, | bubble gas composition | gas sampling |
| effects and pathophysiology | are bubbles more likely to occur and be fatal in certain tissues? | distribution of bubbles in stranded cadavers |
| how do bubbles cause sub-lethal harm? is this via an immune response? | effect of bubbles on in vitro cell cultures; cellular and molecular differences between marine and terrestrial mammals in terms of reaction to bubbles |