This year’s consistent cold temperatures have caused many bays and inlets to freeze over. Looking across expanses of ice, it’s easy to lose sight of the fact that there is water underneath it. And in that water, there are still plants and animals that are somehow able to survive the frigid temperatures. This is impressive for any creature and somehow more believable when you think of those creatures that are able to stay under the water all of the time. This is not the case, however, for all of the animals that persist in Maine’s coastal waters throughout the winter.

What if you have to somehow get through that ice to get back up to the surface to breathe? That’s the case for marine mammals. Along our coast, these animals don’t have to go too far to find open water. But in other parts of the world, that is not the case. As someone who is slightly claustrophobic, the idea of having to search for a tiny break in the ice to come up for air is terrifying. Seals, on the other hand, have got it down. They can slow down their metabolism in cold water to hold their breath for an incredible period of time, making it possible to survive at length before they find another one of these breathing holes.

This is something I have known about for a while, having led whale watching trips in San Diego years ago and learning a lot about marine mammals in the process. But what I learned recently, thanks to a phone call from my friend’s son who was working on a school project, is that, in addition to a seal’s amazing ability to hold its breath, is another odd but endearing adaptation: its nostrils. If you have a device nearby, you should check out this very short video: youtube.com/watch?v=mRmqq7OgK.

If you think about jumping into the water, it’s common to hold your nose or at least blow out through your nose so that water doesn’t go up it and into your airway. Seals don’t have to do this. They have a built-in valve that they can close off simply by using their nostril muscles. When these muscles are relaxed, their nostrils can open up quite widely to inhale. Then, they can quickly shut tight so that, when they reenter the water, it doesn’t rush in.

The other benefit to this open-and-shut nostril design is that it is very efficient in allowing a large amount of air to be exhaled and inhaled in a short period of time. If you’ve been out shoveling on a particularly cold day this winter and been breathing hard, you might have had the unpleasant experience of your warm, exhaled air freezing your scarf to your face. Because we humans have to take many breaths in and out, we are letting go of a lot of moisture and heat with every breath. Our nostrils also serve as a chilly pipeline into our bodies, letting in that cold air even when we are not actively breathing through our noses.

If only we could pull a seal’s trick and shut our nostrils up tight, we might be warmer and have less frosty faces. This is the idea behind certain types of face masks that help retain moisture when you are outside. It also is the same idea as some of the masks used during the COVID-19 pandemic to block air from being exchanged between the wearer and the outside environment. This is yet another amazing example of one of my favorite concepts — biomimicry. Biomimicry describes how human designs are inspired by those in nature. There are myriad fascinating examples of this. Thank you to my friend’s son for introducing me to this one and for making me look enviously at a seal’s nostrils and its resulting ability to thrive through the winter (mostly) under the ice.

Susan Olcott is the director of strategic partnerships at Maine Coast Fishermen’s Association.