Whale sets deep-dive record for mammals
Scientists used satellite tags to track Cuvier's beaked whales as they dove to depths of up to 9,816 feet and held their breath for more than two hours.
Cuvier's beaked whales are no ordinary sea drivers. According to a new study, they could be the most extreme breath-holding divers in the ocean.
In a paper titled "First Long-Term Behavioral Records from Cuvier’s Beaked Whales (Ziphius cavirostris) Reveal Record-Breaking Dives" published in the journal PLOS ONE, researchers who carried out the study reported that they used "satellite-linked tags to record the diving behavior and locations of eight Ziphius off the Southern California coast for periods up to three months" between 2010 and 2012.
The 3,732 hours of dive data included dives to 9,816 feet and lasting 137.5 minutes, both new mammalian dive records, say researchers.
"One key adaptation that seems to allow beaked whales to dive more deeply than other species is a dramatic reduction in air spaces within their bodies," Erin Falcone a research biologist with the Cascadia Research Collective in Washington State which led the research project told the BBC.
"It is the presence of air spaces within the body that would crush a human at a fraction of the depths these whales can dive. Reduction in air spaces not only makes them more 'crush resistant', but also likely serves to reduce the uptake of dissolved gases into their tissues – which can lead to decompression sickness or 'the bends'."
Unlike other similar divers such as elephant seals and sperm whales, Cuvier's beaked whales need much less recovery time when they come to the surface between dives – an average of less than two minutes according to a press release.
"It's remarkable to imagine these social, warm-blooded mammals actively pursuing prey in the darkness at such astounding depths, literally miles away from their most basic physiological need: air," said Gregory Schorr from Cascadia Research Collective and an author on the study.
A part of the study was conducted at the Southern California Anti-Submarine Warfare Range to test how whales respond to MFA sonars, which are associated with whale strandings. The relationship between sonar and stranding, however, is poorly understood.
"The area where we conducted our study is one of the most heavily used sonar training areas in the world, and when we began working there we were shocked to find as many Cuvier's beaked whales as we did, given that they seem so sensitive to this type of disturbance elsewhere," Dr. Falcone told BBC.