Capturing a waft of breath from an individual that recently chomped on several pounds or raw fish might not seem like a pleasant idea. But if that individual was a beluga whale, and you were a whale scientist, that captured breath would provide a valuable window into the animal's health. In fact, whale breath analysis may one day help wildlife officials quickly assess the well-being of whales in emergency situations like strandings.
Like other marine mammals, whales must come to the ocean surface to breathe, exhaling and inhaling through their blowhole. Large whales exhale ‘blow clouds’ containing not only a surface layer of seawater, but also carbon dioxide from their lungs and tiny droplets of mucous suspended in vapour. From a distance, whale blow looks like a white plume, and if you’ve ever been whale watching, it's what you scan the horizon for, hoping to point and shout, “Whale!”
Researchers have long wondered what might be learned about whales … from their exhales. Blow sampling is part of a recent trend towards developing techniques that are less invasive than taking blood or tissue samples from animals as a means to determine their health status. Recent efforts aided by advancing techniques in human breathing research have enabled scientists to use blow sampling to examine whale stress hormones, immune function, genetics and the ecosystem of tiny microbes that live in their lungs.
Breath sampling has been previously used on bottlenose dolphins (Tursiops truncatus), humpback whales (Megaptera novaeangliae) and north Atlantic right whales, (Eubalaena glacialis), but its use on belugas (Delphinapterus leucas) is a new development.
Research scientist Dr Tracy Romano at the Mystic Aquarium in Connecticut, along with four colleagues there and elsewhere in the US, examined the hormone cortisol in beluga blow as a measure of the animals' stress levels. The team first developed breath-sampling techniques for whales at the aquarium, where whales were trained with rewards to breathe on command. Then, the technique was tested on non-endangered wild belugas in Bristol Bay, Alaska – a population from which whales were already being captured and released on a periodic basis by researchers for a health status check-up. Researchers tested out different materials, settling on a nylon-type membrane stretched over a pre-cooled petri dish as the best capture medium for the mucousy moisture.
Capturing blow from captive belugas trained to breathe on command is one thing, but sampling breath from a briefly captured and then released wild beluga is quite another, so their work wasn’t without challenges. “There’s lots of splashing” in the wild, says Romano, making it tricky to prevent dilution of the blow samples by seawater. To prevent splash contamination, the researchers developed a plastic gasket just the right size to cover the area immediately around the blowhole, while the blow collection plate was held in place to capture a few exhales. The researchers found that just like in humans, some whales breathe more deeply than others.
Romano suggests that with a little creative thinking and further testing, beluga blow sampling may one day be performed without capturing whales at all. That would be extremely useful in monitoring the health of endangered wild beluga populations like those in Alaska’s Cook Inlet and Canada’s St. Lawrence Estuary, which face a variety of threats including industrial pollution, climate change and noise.
Blow sampling means that sometimes, fishy bad breath can be good breath … as a promising new tool for conservation science.
Top header image: Jason Pier, Flickr
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