Into the abyss: Scientists explore one of Earth’s deepest ocean trenches

“Telepresence” capability will bring mysteries of The Deep to the computer screen

What lives in the deepest part of the ocean–the abyss?

A team of researchers funded by the National Science Foundation (NSF) will use the world’s only full-ocean-depth, hybrid, remotely-operated vehicle, Nereus, and other advanced technology to find out. They will explore the Kermadec Trench at the bottom of the Pacific Ocean.

The trench, located off New Zealand, is the fifth deepest trench in the world. Its maximum depth is 32,963 feet or 6.24 miles (10,047 meters). It’s also one of the coldest trenches due to the inflow of deep waters from Antarctica.

The 40-day expedition to the Kermadec Trench, which begins on April 12, 2014, kicks off a three-year collaborative effort.

The project, known as the Hadal Ecosystem Studies Project (HADES), will conduct the first systematic study of life in ocean trenches, comparing it to the neighboring abyssal plains–flat areas of the seafloor usually found at depths between 9,843 and 19,685 feet (3,000 and 6,000 meters).

“The proposal to study the deep-sea environment as part of HADES was high-risk, but, we hope, also high-reward,” says David Garrison, program director in NSF’s Division of Ocean Sciences, which funds HADES. “Through this exciting project, we will shine a light into the darkness of Earth’s deep-ocean trenches, discovering surprising results all along the way.”

Among least-explored environments on Earth

A result of extreme pressures in these deep-sea environments and the technical challenges involved in reaching them, ocean trenches remain among the least-explored environments on the planet.

“We know relatively little about life in ocean trenches–the deepest marine habitats on Earth,” says Tim Shank, a biologist at the Woods Hole Oceanographic Institution, one of the participating organizations.

“We didn’t have the technology to do these kinds of detailed studies before. This will be a first-order look at community structure, adaptation and evolution: how life exists in the trenches.”

NSF HADES principal investigators are Shank, Jeff Drazen of the University of Hawaii and Paul Yancey of Whitman College.

Other participating researchers are Malcolm Clark and Ashley Rowden of the National Institute of Water and Atmospheric Research in New Zealand, Henry Ruhl of the National Oceanography Centre at the University of Southampton, Alan Jamieson and Daniel Mayor of the University of Aberdeen and collaborators from the Japan Agency for Marine-Earth Science and Technology, Scripps Institution of Oceanography and the University of Oregon.

Telepresence technology aboard the research vessel Thomas G. Thompson will allow the public to share in the discoveries. Live-streaming Web events from the seafloor will include narration from the science team.

The researchers’ work will also be chronicled in video, still images and blog updates on the expedition website.

How does life exist in a deep-sea trench?

What marine animals live in the Kermadec Trench, and how do they survive the crushing pressures found at that depth–some 15,000 pounds per square inch? These are among the questions the scientists will try to answer.

The biologists plan to conduct research at 15 stations, including sites in shallow water for testing purposes, sites along the trench axis and sites in the abyssal plain.

At each one, they will deploy free-falling, full-ocean-depth, baited imaging landers called Hadal-Landers and “elevators” outfitted with experimental equipment–including respirometers to see how animal metabolism functions, plus water-sampling bottles to investigate microbial activity.

The team will use Nereus, which can remain deployed for up to 12 hours, to collect biological and sediment samples.

Nereus will stream imagery from its video camera to the ship via a fiber-optic filament about the width of human hair.

The expedition will build on earlier studies of the Kermadec Trench by Jamieson and colleagues at the National Institute of Water and Atmospheric Research and the University of Tokyo. Using the Hadal-Lander, they documented new species of animals in the Kermadec and other trenches in the Pacific.

Ocean trenches: home to unique species

Once thought devoid of life, trenches may be home to many unique species. There is growing evidence that food is plentiful there. While it is still unclear why, organic material in the ocean may be transported by currents and deposited into the trenches.

In addition to looking at how food supply varies at different depths, the researchers will investigate the role energy demand and metabolic rates of trench organisms play in animal community structure.

“The energy requirements of hadal animals have never been measured,” says Drazen, who will lead efforts to study distribution of food supply and the energetic demands of the trench organisms.

How animals in the trenches evolved to withstand high pressures is unknown, but Shank’s objective is to compare the genomes of trench animals to piece together how they can survive there.

“The challenge is to determine whether life in the trenches holds novel evolutionary pathways that are distinct from others in the oceans,” he says.

Water pressure, which at depths found in ocean trenches can be up to 1,100 times that at the surface, is known to inhibit the activity of certain proteins.

Yancey will investigate the role that piezolytes–small molecules that protect proteins from pressure–play in the adaptation of trench animals. Piezolytes, which Yancey discovered, may explain previous findings that not all deep-sea proteins are able to withstand high pressures.

“We’re trying to understand how life can function under massive pressures in the hadal zone,” says Yancey. “Pressure might be the primary factor determining which species are able to live in these extreme environments.”

Trenches and climate change

Evidence also suggests that trenches act as carbon sinks, making the research relevant to climate change studies. The V-shaped topography along trench axes funnels resources–including surface-derived organic carbon–downward.

“The bulk of our knowledge of trenches is only from snapshot visits using mostly trawls and camera landers,” Shank says.

“Only detailed systematic studies will reveal the role trenches may play as the final location of where most of the carbon and other chemicals are sequestered in the oceans.”

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5 thoughts on “Into the abyss: Scientists explore one of Earth’s deepest ocean trenches”

  1. It is a fact that there are still millions of new species of animals that have not yet been discovered and that the ocean is one of the most unexplored depths.

    This study will explore some of the depths that humans can not explore, whilst SCUBA diving, and will be able to open our eyes to a new world with new and interesting life forms and species. The study will thus help us understand more about how evolution took place in our oceans, what species are able to survive these depths and high pressures and how these species have evolved to be able to do so.

    This study will also show us and help us understand what the ocean’s role is in the mediating of climate change and what chemicals and substances are currently in our deepest ocean waters.This will again help us to understand what effect our lifestyles have on the ocean and it’s waters.

    I look forward to follow up on this study on the live-streaming videos and see what the researchers find, because I believe that these findings will have an important impact on our lifestyles.

  2. It is a proven fact that we know more about the moon than the depths of our oceans. The abyssal zones are so deep where light can no longer penetrate, extreme temperatures drop and astounding pressure increases. Development in deep sea submersibles and image capturing are increasing the opportunities for marine biologists to observe and uncover the mysteries of the deep ocean realm, such as discovering species thought to be extinct.The Nereus is an innovative technological instrument and it will enable scientists to discover abiotic and biotic life in the Kermadec Trench. By studying the microbial activity, energy and metabolic rates that occur in organisms that reside in the trench, scientists could make discoveries that can give us more knowledge of our planet.

  3. I know that this expedition must be very exciting to everyone in the scientific community since there is so much to discover, so I cannot wait to hear more about the advancements made and the experiments done.
    After viewing the website I found the featured video on “Understanding Deep-Sea Fish” with Thomas Linley the most fascinating thus far, and although most of us (especially me) do not fully understand some of the concepts mentioned in the video, such as what gasses are released by the fish, we cannot wait to hear more about it as soon as more of this information is understood.

  4. It is really awesome to see how much money and time is being put in to see what lurks in the deep blue. The chances of finding new life forms (no matter how strange it may be) is extremely high. Many web sites estimate that only about 5% of the sea’s floor surface has been discovered or observed. This bodes extremely well for the expedition for doing research. The reason for this quantum leap forward is robotics. The technology involved has allowed an unmanned and controlled device to do the searching for us at a safe distance. From all the information gathered one can only imagine the possibilities of new information coming in. This information can help make our systems on the surface more efficient at running. Huge evolutionary advancements can be made with some more insight as to the origin of life as we know it. However the research can also show us to what extent the oceans have been harmed by our actions.

  5. The sheer depth and pressure of the trench must surely hold many new life forms and processes that we do not know about. This expedition has the potential to discover new species and ways of life that can help scientists to better understand the ocean which is relatively unexplored. The volume of research being done from this will hopefully show just how diverse our planet is, from its origins to the present. Hopefully we will have the correct technologies to be able to discover and exploit these unknown life forms.

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