An eagle is perilously close to death. What would you do?

Whether or not to intervene is a wildlife photographer's dilemma.

It was the end of a day of diving off Vancouver, British Columbia, where wildlife photographer and marine biologist Paul Nicklen and his two assistants were conducting an ecological survey. They were heading back to shore in a 16-foot aluminum boat when they came across a bald eagle struggling in the water—and being dive-bombed by other eagles.

It isn't uncommon for eagles to get into disputes over food and territory, sometimes ending up in air-to-air combat and, as it did here, one bird's watery crash landing. As Nicklen and his team watched, the eagle started getting swept out to sea in the strong current and became a target for the other birds. It was getting "more and more tired and was going to die soon enough," he says. Knowing they were still about a mile and a half away from shore, the team was faced with the decision of whether or not to intervene.

"I have a practical view when it comes to the natural rhythm of life," Nicklen says. "If it's ever a predator situation, no matter how gut-wrenching [think, watching a male polar bear attack a cub], you stay out of the way."

In photography, as in life, it's never a good idea to interfere with wildlife—the well-being of the animal and the ecosystem it inhabits comes first and foremost. So when Nicklen is confronted with one of these situations, he makes a case-by-case assessment.

The decision to save the eagle was an emotional, gut reaction, he says. Seeing no real gain or disruption to the ecosystem should the bird be left to drown, he discussed it with his team, knowing they all needed to be on the same page. They agreed without hesitation.

Getting the eagle into the boat was no easy feat—they have incredible power in their talons and beaks. Luckily, once Nicklen's assistant pulled it out of the water and got it into the boat, it relaxed for the rest of the ride.

And as a coda to the story, right after rescuing the eagle, Nicklen and his team heard reports of a missing woman coming over the radio. Her empty kayak had been spotted, but she was nowhere to be found. They launched one of their drones and found her walking on the beach, safe and sound.

All in a day's work.

See more photographs from National Geographic photographers in the field on @Nat Geo Instagram.