Ocean Deep Is Surprisingly Noisy
Scientists haul up a hydrophone from the bottom of the ocean during the Challenger Deep expedition.
Jeff Milisen, Ocean Art Competition 2015
Winners of the 2015 Ocean Art Underwater Photo Competition were announced this week, and they include images of rarely seen marine life. The contest, in its fifth year, attracted entrants from over 50 countries. Organized by theUnderwater Photography Guide
, Ocean Art 2015 judges were professional underwater photographers, including the guide's publisher, Scott Gietler. The Best of Show image, which also won first place in the "Macro" category, is this photo of a larval stage eel. It was snapped at night in 4,000 feet of water off the coast of Kailua-Kona, Hawaii. Gietler told Discovery News, "These subjects are incredibly difficult to find, focus on, and light -- a true winner." Photographer Jeff Milisen explained that he took the image while "on a blackwater dive with a member of the Roddenberry family (of "Star Trek" fame) watching a parade of underwater aliens drift past when this larval cusk eel swam by. The external stomach helps the developing fish grow as fast as possible by eking every last bit of nutrition from its every meal." Milisen added, "Out of the four divers underwater that day, we had over 1000 blackwater dives under our belt and none of us had ever seen anything like it, whether on earth or boldly going elsewhere!"Half of All Marine Life Lost in Just 40 Years
Francesco Visintin, Ocean Art Competition 2015
Gietler says this is "one of the most unique wide-angle photos we've seen in a long time. The photographer (Francesco Visintin) captured both the jellyfish and Snell's window with impeccable lighting." "Snell's window" is a phenomenon by which an underwater viewer sees everything above the surface through a cone of light. The effect is caused by refraction of light entering water. Of the photo, taken in waters off of Tuscany, Italy, Visintin said, "(A) calm sea and unusually good visibility motivated me to explore this fascinating subject from a photographic standpoint, exploiting the soft light of the early morning and sunset."Photos: Mix Of Species Gain Haven In New Marine Reserve
Lill Haugen, Ocean Art Competition 2015
A North Sea anemone, found deep in the waters of the Oslo Forjd, Norway, was backlit with a strobe to produce this winning shot. Photographer Lill Haugen said that "certain species of red shrimps can be found seeking shelter under this type of large, cold water anemone," which appears to dwarf the diver seen in the background.Best Ocean Animal Photos of 2013
Greg LeCoeur, Ocean Art Competition 2015
A pod of pilot whales was the subject of this portrait image, taken in waters off of Nice, France. Photographer Greg LeCoeur said, "During a sailing day off the shore of the Mediterranean Sea, I spotted a big pod of pilot whales that accepted me in the blue water. They were turning around me in the crystal blue water. It was an amazing experience and a great opportunity to photograph them." Gietler said, "Pilot whales are notoriously shy and difficult to photograph. The sun rays and size of this pod made this portrait a clear winner."Pic of Killer Whale Calf Nursing Is Best Ever, Says NOAA
Steven Kovacs, Ocean Art Competition 2015
Look closely, as this image captures a moment that has only been seen by a handful of people. A female Striated frogfish is shown rising toward the surface of water at Lake Worth Lagoon near Riviera Beach, Florida. Photographer Steven Kovacs pressed his camera's shutter at the exact moment that the female released her egg mass, above a waiting male that later fertilized the eggs. Gietler said, "Frogfish have only been photographed spawning a few times before. Capturing this type of photo takes a lot of patience and many hours in the water."Photos: These Fish Are Oddly Shaped For a Reason
This photo of a pregnant blacktip shark ("ma' o mauri" in Tahitian) was taken during a shark-monitoring project with the French Polynesia Shark Observatory. Photographer Lauric Thiault was to capture images of tiger sharks, but had no luck during two lengthy dives at La Vallée Blanche, Tahiti. At the end of the second dive, Thiault said, "I held my breath, facing the surface and waiting for a shark to come between the sun and me." After a few attempts, this impressive female, surrounded by other sharks, "came right into the frame." Gietler said that French Polynesia is one of the few places in the world where you can see sharks in their natural environment.Photos: These Sharks and Rays Just Got Protected
Simon Chiu, Ocean Art Competition 2015
Winner Simon Chiu took this photo of a filefish camouflaged in coral at Mactan in Cebu, Philippines. Gietler said, "This tiny filefish has evolved to look exactly like the small soft coral polyps that it is hiding in, but it could not help ‘peeking' at the photographer, who captured the essence of underwater cuteness."Photos: Animals that Decorate Themselves
Yen Ngee Koh, Ocean Art Competition 2015
Parental care can be a literal and figurative mouthful for marine life, as this jawfish with a mouth crammed with eggs shows. Photographer Yen Ngee Koh took the photo on a dive at Tulamben in Bali, Indonesia. Koh said, "After some frontal shots, I noticed that more eggs were spilling out on the top left side (of the jawfish's mouth). So I decided to shift more to the left and lowered the angle even more, as low as I could. I'm happy to see that it helped to showcase the mouthful of eggs even more."First Face? Prehistoric Fish Was a Jaw-Dropper
Matthew Sullivan, Ocean Art Competition 2015
Photographer Matthew Sullivan spotted this juvenile wood turtle at a mountain creek near the Bridge Waterfall in Pennsylvania. "These turtles are endangered and finding them is a privilege," Sullivan said. "Getting to photograph her in her aquatic habitat was well worth the effort of lugging all my camera gear up into the mountains.Photos: Sea Turtles From Shell to Surf
Alessandro Raho, Ocean Art Competition 2015
This photo shows a glowing Cerianthus, which is a type of tube anemone. The creature, from Noli, Italy, takes on an otherworldly appearance in the image due to clever use of lighting and camera filters. Gietler explained, "Only certain subjects react to ultraviolet light underwater, and special filters on the camera are needed to truly capture the beauty."Photos: What Glows in the Night
Jack Berthomier, Ocean Art Competition 2015
When a predatory houndfish (also called a crocodile needlefish) nabbed a brassy chub at Ouemo Bay in New Caledonia, photographer Jack Berthomier was there to capture the moment. Berthomier likes to dive and take images in this eco-rich location. The houndfish appears to have taken in more than it could handle, however, as Berthomier never did see the predator successfully manage to swallow the fish. Sadly, the photographer also never saw the houndfish again, and suspects that in this fish-eat-fish world, it too was eaten by an even larger hunter. Houndfish are actually feared by many divers and fishermen because of their large size and ability to inflict puncture wounds with their sharp beaks.Pupil Shape Can Show Who's Predator and Who's Prey
Brian Christiansen, Ocean Art Competition 2015
This majestic image of a dolphin was snapped at Deshaies, Guadeloupe. Photographer Brian Christiansen had been enjoying coffee on a sailboat in this part of the Caribbean when a pod of curious dolphins swam around the craft. Christiansen said, "I dropped everything, grabbed the nearest camera, mask and maybe a fin, and jumped in. The pod seemed like one family group with an obvious matriarch who had a young one." He continued, "The ones I spent the most time with were two adolescents who were nonstop playing with each other and me. The compact camera worked well in this situation because I could easily play with the dolphins until in the right position, and then snap off a few pictures just the way I imagined." Gietler said, "Most people are familiar with a solar eclipse, but this photographer experienced a 'dolphin eclipse.'"Image Shows How Dolphins See People
Roland Bach, Ocean Art Competition 2015
Nudibranchs are soft-bodied marine mollusks, aka sea slugs, known for their bright colors and striking forms. They are so photogenic that an entire category is devoted to them in the Ocean Art contest. Gietler said, "Sea slugs are normally photographed with a macro lens, but this photographer was able to capture a beautiful photo of the animal with stunning sun rays behind by using a wide-angle lens." The image was taken in waters off the north coast of the Balearic island Minorca in the Mediterranean.Sea Squirts, Slugs Among 100 New Marine Animals
Dennis Vandermeersch, Ocean Art Competition 2015
Gietler said, "What happens when you mix an artistic vision with great photography and Photoshop skills? Dancing Manatees, of course." Creator Dennis Vandermeersch came up with the idea in Florida as he "was swimming with these gentle creatures. They were in mating behavior, so it looked like a dance." The shot is actually an artistic composite of multiple images taken in Florida, Belgium and Abu Dhabi, which is the capital of the United Arab Emirates. Vandermeersch, however, said that "imagination shouldn't know any borders or boundaries. Let it run free!"Photos: Make Way for Manatees Month
Seven miles below the surface of the sea, the Challenger Deep is the deepest spot in the Mariana Trench and thus on Earth. The only light is that produced by animals that use photoluminescence; no sunlight can penetrate even close to these waters. Such life as exists is either extremely small, extremely slow-moving, or both.
So the deepest place on Earth could reasonably be assumed to be almost deathly quiet.
And yet, according to new NOAA research, it is not.
That the ocean as a whole is full of sound is not a new observation: from pistol shrimps to Weddell seals, walruses to blue whales, the cracking of icebergs and the rumbling of earthquakes, Nature’s underwater symphony is varied and at times cacophonous. But those harmonies have in recent decades been joined by ships’ propellers, pile driving and the loud booms of seismic air guns searching for oil and gas deposits under the sea bed.
In order to get a better handle on the extent of these new additions, scientists from NOAA and Oregon State University have begun a survey to measure noise in the ocean. As a first step, they wanted to establish a baseline, and to do so, they elected to lower a hydrophone into the Challenger Deep.
The purpose-built hydrophone was crafted from titanium nearly an inch thick to withstand pressures of 16,000 pounds per square inch. It was lowered to the seafloor over a six-hour period from the deck of the US Coast Guard cutter Sequoia; a proprietary anchor system held it in place, and the researchers departed, returning several months later to pick up the recorder, sending an acoustic signal that triggered a release mechanism and allowed the device to rise slowly to the surface.
Expecting to hear very little, they were surprised by what they had captured.
“You would think that the deepest part of the ocean would be one of the quietest places on Earth,” said Robert Dziak, a NOAA research oceanographer and chief project scientist, in a press release.
“Yet there is almost constant noise. The ambient sound field is dominated by the sound of earthquakes, both near and far, as well as distinct moans of baleen whales, and the clamor of a category 4 typhoon that just happened to pass overhead.”
The extent to which marine mammal vocalizations were captured was unexpected. Few whales dive much deeper than about a mile — yet their voices traveled clearly to the bottom of the trench. Yet even at this remote of depths, the hydrophone also picked up sound from ship propellers. Challenger Deep is close to Guam, a regional hub for container shipping with China and the Philippines.
Human-created noise has increased steadily in recent decades and getting these first recordings allows scientists in the future to determine if the noise levels are growing and how this might affect marine animals that use sound to communicate, navigate and feed, such as whales, dolphins and fish.
Researchers plan to return in early 2017, to deploy the hydrophone for a longer period of time and attach a deep-ocean camera.