4.9. Summary
While management of O2 has been the central tenet in understanding
what limits the duration of a dive, our current modelling
effort suggests that deep diving whales permanently live with blood
and tissue PN2 levels that elicit a high incidence rate of DCS in terrestrial
animals. Thus, it is possible that diving mammals may have
to end foraging at times when the N2 levels become too high. The
dive behaviour of Ziphius was different from both Mesoplodon and
Hyperoodon, and resulted in higher predicted tissue and blood N2
levels. While the prevalence of Cuvier’s beaked whales stranding
after naval sonar exercises could be explained by a higher abundance
of this species in the affected areas, our results suggest that
species differences in behaviour and/or physiology may also play a
role.