Mysterious whales hold their breath in the murky waters of the benthic zone, the ocean’s deepest layer, which famous mainly for invertebrates like sea urchins, worms, and crabs. The activities of beaked whales have long been a mystery to humans. Still, a recent study sheds light on their habits, thanks to discovering two new subpopulations in the Atlantic.
“I almost started bawling when I did the analysis,” says Kerri Smith, a Smithsonian National Museum of Natural History research scholar who studies beaked whales. “I was ecstatic since it was completely new to me. I knew something that no one else in the entire globe knew for about an hour.”
Smith’s current study focused on the carcasses of Sowerby’s beaked whales stranded or caught as bycatch in fisheries and housed in museums and research institutions. Researchers discovered two subpopulations of Sowerby’s beaked whales in the east and west Atlantic by studying compounds found in the whales’ skin, muscle, and bone tissue. The published findings in the journal Frontiers in Conservation Science. They expected to lay the groundwork for a better understanding of these species and future conservation efforts.
Even though beaked whales account for more than 25% of all extant cetaceans, little knowledge about their lifestyles (including dolphins, porpoises, and whales), unlike other creatures that swim close to the beach or on the sea’s surface, Beaked whales prefer deep, offshore seas, making them difficult to locate and follow. Their dark grey or black appearance and their short dorsal fin make them even more difficult to recognize from the water.
Beaked whales come in 23 different species, some of which have never been observed alive and only known from stranded bodies. However, this number might quickly rise or fall. If, as happened recently in Japan, one individual assumed to be only a weird-looking variation of a known species turns out to be an altogether other species after DNA analysis.
Beaked whales spend much of their time in the open ocean’s deepest depths, and we have no idea what they’re doing down there. We know that their bodies have evolved to allow them to stay at these depths for extended periods. Cuvier’s beaked whale holds the mammalian records for both the deepest dive (almost two miles below the surface) and the longest-held breath (137.5 minutes).
“They’re such enormous animals in comparison to humans, and we still know so little about them,” Chris Stinson, a curatorial assistant at the Beaty Biodiversity Museum in Vancouver, says of the beaked whale skulls and skeletons on display. “They’re out in the broad ocean, living in a completely different environment where they surface for a breath and then spend 80% of their time underneath, looking for things with senses we can’t even imagine.”
Some beaked whales like to eat fish from the water’s surface, while others are supposed to be squid specialists in the deep waters, yet others prefer the benthic depths, where they eat fish from the seafloor. At the same time, cetaceans as a whole knowledge to be gregarious animals who live in groups, with little knowledge about the beaked whales’ daily activities.
“Almost everything we know about beaked whales comes from dead bodies because they’re so difficult to examine when they’re alive,” Smith adds. “It’s quite difficult to deduce what they were doing when they were alive in terms of social relations, play, and other activities from dead bodies.”
However, as Smith’s recent research shown, dead bodies can provide a wealth of information.
The researchers looked at carbon and nitrogen levels in the whales’ bodies to learn more about where they lived and fit into the food chain. The type of analysis they performed, known as stable isotope analysis, has the advantages of being quick and low-cost. Because tracking and locating the elusive beaked whales can be difficult and expensive, this makes it an excellent use for them.
The methodology could provide further insight into the secretive whales’ habits and habitat if other components, such as oxygen, hydrogen, and sulfur, are studied in the future. Smith plans to do a genetic study in the future to learn more about the two Sowerby’s beaked whale subpopulations.
Because we know so little about beaked whales, there are currently no conservation or management plans in place. The International Union for Conservation of Nature classifies them as “data poor,” implying insufficient data to assess extinction danger based on distribution and/or population state.
However, studies like Smith’s can help us learn more about these elusive species’ habitats and migration patterns, which could help shape future conservation measures.
“We can’t conserve something we don’t understand,” Smith argues. “We have no idea where these animals are or what environments they are in—a there’s catch-all term for deep offshore shelf waters, but what does it mean? What happened to them? What are the shelves they’re using? Do some people require greater protection than others? We won’t be able to implement truly concrete, meaningful, and actionable programmes until we have answers to those questions.”
