According to a paper published in Nature Communications, dolphins and seals might be pushing the boundaries of their aquatic life. The study observed dolphins and Weddell seals during their deepest dives and found that both have a surprisingly high frequency of heart arrhythmias. The normal dive rate in sea creatures involves a marked cut in heart rate as well as other physiological changes to conserve limited oxygen reserves while the air-breathing animals are under water. How the sea animals cope up with the exertion that is needed to follow up prey at depth is unclear.
The new study says that conflicting signals to the heart may lead to cardiac arrhythmias according to leading author of the study Terrie Williams who is also a professor of ecology as well as evolutionary biology at UC Santa Cruz.