Conservation photographer Paul Nicklen has spent more than two decades documenting the ice and wildlife in some of the most inhospitable places on Earth — the Arctic and the Antarctic.

It's a risky business: Nicklen often finds himself immersed in frigid waters, just a camera's length away from deadly predators. Once, in Antarctica, he came face-to-face with a 1,000-pound leopard seal: "She opened up her mouth and her head is twice as big as a grizzly bear, and I am starring down her throat," he says.

Nicklen adds that his utmost concern is for the well-being of the animals he encounters. "I want to get close, but I also never want to harass an animal," he says. "What you learn about these animals is how communicative they are, how intelligent they are, how social they are, how forgiving they are."

On how he's come to ignore his gut in dangerous situations

When it comes to working with these big predators ... your, sort of, innate fear mechanisms are telling you not to do it. So you're always ignoring your gut. And when you ignore your gut all the time, at some point you don't know where that benchmark is anymore. ... You're always stepping into this gray area and you're stepping over the line, and so now I've learned ... when my gut's really screaming at me, to slow down and be smart. I start to back up a little bit and just spend more quality time analyzing, thinking, watching and then ... moving on with it if it seems like the right decision. ...

I think I get so caught up in how important these stories are and how my images have to have that three-dimensional feel to them, to really bring people into the issues I care about, and I think I just get so focused sometimes on getting those images.

I'm not really scared of death, I just want my death to be cool, and I guess being speared by a narwhal would be a pretty cool way to go.

Paul Nicklen, conservation photographer

On not being afraid of dying doing his work

I'm not really scared of death, I just want my death to be cool, and I guess being speared by a narwhal would be a pretty cool way to go. ... I think if I'm out there pushing and trying to push the limits to come back with something amazing to connect the world to what I love, then sure.

On a memorable interaction with a leopard seal

This leopard seal stayed with me for four days straight. And every time I would show up on the water, she'd be there to greet me. She would follow me back to the sailboat at night. Once she established her dominance, she completely relaxed, and then she disappeared and I thought the encounter was over.

Then she showed up a few minutes later with a penguin in her mouth. She had just caught a penguin chick — she was holding it by the feet — and the penguin is flapping, trying to get away from her. And she would sort of line it up with me, and when it was lined up perfectly with me she would let it go, and it would swim off, she caught it, she did this over and over.

And I realized at that moment that she was trying to feed me a live penguin. And I think she realized quickly in this encounter that I was not capable of catching a live, moving, swimming penguin, and so she brought me another penguin. She did all these different attempts to feed me live penguins. And at one point ... there's a photo of her looking dejected, sort of disappointed in me that I'm so useless that I'm unable to catch or accept one of her gifts, so then she started to bring me dead penguins, and at one point I had five penguins floating around my head. ...

Further on in the encounter ... she got so tired of me being unable to accept one of her penguins that she grabbed it and she flipped it on top of my head.

On falling in love with the leopard seal

I definitely fell in love with this seal. It's embarrassing to admit this to you. ... I'd fall asleep at night with tears coming down my cheeks. ... I was just so grateful, just to spend your life out with animals and to be fighting to get yourself into a situation where you can try and get close, where you can try and even get within 100 meters of something.

And all of a sudden here's a top predator, and not only are you getting to see it, it's interacting with you; it's trying to force-feed you penguins, it's trying to take care of you. It's a very very humbling thing. ... Just to flop yourself into its world and for it to spend that much time and energy trying to figure out who you are and to interact with you. ... I think that's why I get emotional, because we had such a connection.

On what happens to the polar bears when the sea ice melts

In the last 20 years, to have the scientists talking about how we're reaching the lowest extent of ice we've ever had, a place like Svalbard, Norway historically has been covered by sea ice year-round. In the last 20 to 30 years that ice has been just in a few fjords, and then now in the last few years there's been no ice at all around Svalbard. There's been a little strip down on the east side.

And when there's no ice that means bears basically do not have that platform to catch seals, and that's their main food source. They might eat a little bit of seaweed ... they might get the odd bird egg or the odd bird, but that's not giving them any nutritional value.

Essentially, bears are designed to go on land for long periods of time. They can be on land for two months and not eat a meal. But they're not designed to go four or five or six months on land without eating any food, and that's where we're starting to find emaciated bears, dead bears. ...

I've never had a scary moment with a polar bear, and people come to me like, "Isn't that the only animal that actively pursues humans for food?" And I just see this powerful, but very fragile, vulnerable species that is so at the mercy of its ecosystem. And it's sort of the one species that I really use to drive home that connection to how important this icy ecosystem is. I want people to realize that ice is like the soil in the garden — without ice the polar regions cannot exist.

Radio producers Amy Salit and Thea Chaloner and Web producers Bridget Bentz, Molly Seavy-Nesper and Beth Novey contributed to this story.

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