A researcher hailing from Northern Ireland has uncovered an extraordinary sensory ability that enables marine mammals to become unparalleled divers.
Dr. Chris McKnight from County Antrim has been studying why seals can remain submerged without breathing for extended periods compared to numerous other animal species as part of his research at the University of St Andrews in Scotland.
He discovered that, apart from effectively storing oxygen, they possess a distinctive capability to mentally gauge the levels in their bloodstream to prevent drowning.
"It's tremendously exciting to discover such a crucial element of marine mammal evolution, which plays a vital role in much of their activity—diving," stated Dr. McKnight.
He emphasized that the adaptation was crucial for the development of marine mammals such as seals and walruses, enabling both these creatures and possibly other breath-holding divers—like certain birds and reptiles—to lead lives largely devoid of surface time during underwater excursions.
"Discovering such a crucial element of marine mammal evolution, which plays a vital role in much of their activity—diving—is immensely thrilling," stated Dr. McKnight.
It feels as though it was hiding right beneath our noses all along.
"It may appear straightforward and logical that seals can detect oxygen levels, which aids them in making choices to avoid running out of air and drowning; however, from an evolutionary perspective, this places both the species and their bodily functions among the most distinctively adapted creatures," he explained.
While scientists knew How do mammals manage to remain underwater without breathing for such extended periods? , they were unaware that they were measuring the duration of their dives.
To determine this, six young seals were observed at the university's Sea Mammal Research Unit over nearly a year, examining how they modified their behavior based on varying levels of oxygen availability.
Seals such as Trish and Oisin voluntarily dove into the unit's pool to catch fish while under observation.
The atmospheres they encountered had been modified to change the amounts of oxygen and carbon dioxide.
The length of each dive increased with greater access to oxygen, yet carbon dioxide played no role in this effect.
This demonstrated that the seals are not as sensitive to carbon dioxide as some other species might be.
Dr Joanna Kershaw, one of the report’s authors, commended the skill and commitment of the research group.
She expressed her excitement about working with these incredible creatures and discovering one of the key factors behind their perfect adaptation to their habitat.
