Before he became Dr. Alex Mustard, award winning underwater photographer and marine biologist, young Alex was avid snorkeler — to the point where his family joked that he always returned from vacations with a tanned back and a pasty white front. One day, after much begging for an underwater camera, his family finally gave in and bought him one. And so, at nine years old, his underwater photography career began.

Since then, he has seen things that most of us can only dream about, and the incredible images he has captured give us a peek into the otherworldly beauty of what lies beneath the ocean’s surface. So in honor of World Oceans Day, we sat down with him to learn a bit about what it takes to get the right shot — while luring sharks toward his lens, swimming in live volcanoes and exploring shipwrecks.

What’s your absolute favorite thing about underwater photography?

If I had to pick one thing, it’s that underwater I can move freely in three dimensions. This means I can approach my subjects from whatever angle I choose, selecting the best viewpoint for a photograph. Imagine how different photography on land would be if everyone could fly — that’s what we have underwater.

Barracuda Swirl by Alexander Mustard - Wildlife Photographer of the Year 2014 Awards
“Successful photos of schools of fish are all about togetherness. I am always on the lookout for organised — not messy — schools, ideally forming pleasing shapes. But I couldn’t believe my luck with this school of barracuda swirled into a 6 right in front of my camera. The formation only lasted a second, but with a camera you can preserve it forever.”
What are some of the challenges you encounter as an underwater photographer?

Water. It sounds like a flippant answer but actually almost all the challenges of underwater photography come from the water itself. First of all, electronic cameras and seawater are not best friends and the smallest leak in an underwater housing instantly transforms an expensive and sophisticated camera into a paperweight. Second, light does not pass easily through water, and this means that almost all underwater photographs are taken within touching-distance of the subject. So there’s the challenge — but also the fun — of getting so close to subjects. Finally, as humans we cannot stay underwater indefinitely, and therefore underwater photography is always done under time pressure.

Pygmy Seahorse (Hippocampus denise) Misool, Raja Ampat by Alex Mustard
“It’s hard to believe pygmy seahorses exist. They are not only one of the tiniest fish in the sea, but so specialised is their adaptation to their home that most species remained undiscovered until the last decade. Photographers often try and photograph them in as much high magnification and detail as possible. But here I choose to compose the picture with the seahorse small in the frame, communicating its diminutive (1cm) stature.”
For those of us who have never gone diving, can you describe what it feels like?

Diving is a very addictive sport and, like many activities, means very different things to different folks. Some only dive in shallow, warm and bright conditions, where the sea is benign and welcoming. Buoyed by the water, you are weightless. You are free of the trappings and contact from the world above. It is a relaxing, even meditative experience. But the underwater world also offers much more challenging diving experiences that require many years of training to even attempt.

Silfra Fissure Thingvellir Iceland Diving by Alex Mustard
“This photo is taken in the crack in the earth’s crust between the American tectonic plate (left) and the Eurasian tectonic plate (right) in Iceland. The crack is filled with glacial melt water, only just above freezing but crystal clear and pure enough to drink. It is very dark in the Silfra canyon, so I waited until the middle of the day to take this shot, when the low sun is perfectly aligned to illuminate both sides of the canyon.”
What is a typical expedition like (if there is such a thing as a “typical” expedition)?

Actually, all expeditions are quite similar. The rules and limitations of diving and boats mean that there are far more similarities than differences between exploring the Maldives and Vancouver Island. I put a lot of planning into every trip. Like on land, most wildlife events underwater have seasons and it is important to study these. The big difference underwater is the monthly cycle of tides that affects just about everything. Most marine life is totally tuned in to the cycle – and if you go at the wrong time of the month, you won’t hit the peak of the action. Diving conditions also vary greatly with the tidal cycle, which determines the strength of the currents.

All my pre-dive rituals involve checking my camera. You can’t change a lens underwater, but you also can’t take off a lens cap or change a battery. So it’s doubly important that you check everything and then check it again before you dive.

Wreck of the Kittiwake, Grand Cayman by Alex Mustard
“Shipwrecks are one of the most exciting underwater subjects especially when the water is clear enough to truly show their scale. I planned this composition in black and white, framing the wreck against the light to exploit the large areas of shadow and smaller highlight details in the image. Just as I had everything set up, the school of fish swam into frame.”
An understanding of lighting is so important in photography. Can you talk about how light behaves differently underwater? How do you have to adjust?

It’s hard to sum this up in just a few sentences. After all, I’ve just filled a whole book, Underwater Photography Masterclass, with this very subject. Light does not pass easily through water. It is both absorbed and scattered. Like a foggy day, scattering stops us from seeing the detail in the subject. Absorption actually affects different colors of light to different degrees. All the warm light is absorbed almost straight away, leaving a completely blue world.

This means that just about every underwater picture must be taken with flash to restore the color and from a very close distance to capture all the detail in the subject. Most underwater shots involve balancing the light from our flashguns with the ambient light underwater. This is a challenge, but also where much of the art of underwater photography is.

Night Moves by Alex Mustard, Wildlife Photographer of the Year 2013 Awards
“A long exposure showing the blurred trails left behind by predatory fish (bar jacks) as they hunt plankton and smaller fish attracted close to a coral reef at night. This artistic and experimental image was intended to show this behaviour in a more abstract way, with the long exposure rendering the fish like swirling phantoms against the inky, black sea. On the right you can see the outline of one fish as it stops to feed, its trail showing how it swooped down across the frame to catch its prey. Around the central reef sponge you can even see the trails of the smaller fish and zooplankton that the jacks were hunting.”
What do you think your role is as an underwater photographer? Historian? Conservationist? Photojournalist? Or just pure photographer?

I guess it varies between all of them. Each location, each story is different, and that brings out different aspects of what you do. The greatest reward in being a photographer is seeing your work being used and inspiring others — especially when your work generates interest in the projects and causes that are important to you. And this can be maritime history, natural history, conservation and more. But in all cases, your images need strong graphic qualities to draw people into the story.

Throughout the time you’ve been photographing the sea, have you seen the underwater landscape change?

Yes and no. Yes, in so many places the heavy hand of mankind is very obvious. The big creatures go first. There are so many places called “shark reef” that no longer have any sharks. Fishing is to blame for that. Some species grow fast and produce thousands of eggs. These make good fisheries. Other species, like sharks, grow slowly and give birth to a few babies. You fish them out and they are gone.

Large-scale objects like wrecks often have a positive effect. There is a lack of hard seabed for life to attach to and they are quickly colonized by life. They also provide a refuge from fishing. Smaller pollution, particularly plastics, are really problematic for the oceans. We produce 300 million tons of plastic every year and it does not go away. The Great Pacific garbage patch, made up of floating plastics, covers an area of ocean between 2 and 6 times the size of Italy. And this plastic gets into the marine food chain, our food chain. This is very sad.

But there are good stories too. Areas that have been properly conserved and protected are like oases of life. Big creatures are common and the life is rich. These protected areas benefit the surrounding sea as eggs and youngsters spill out, even helping fisheries be more productive. In those places it’s possible to see places that are even richer than I remember from the old days – because we were already fishing the oceans intensively when I started diving.

Coral Spawn Cayman Islands - Underwater Photography by Alex Mustard
“Corals spend most of the year doing a very convincing impression of a rock. They only spawn for a few seconds all year and it happens late at night. It is not an easy sight to spot and tougher still to photograph. I had been studying coral spawning in the Cayman Islands for more than a decade and it was this knowledge that made this photo possible. I had to know what coral would spawn and when, so that I could set up my off-camera strobe to illuminate the scene.”

World Oceans Day aims not only to celebrate the beauty of the ocean, but also to raise awareness about the environmental issues that threaten the ocean’s health. So today, share your shots of the ocean — above or below the surface — on PicsArt photo editor with the hashtag #WorldOceansDay!

All photos by Alex Mustard.