Life in Deepests Parts of the Ocean: The Big Questions

"ROVs have given us new insights into deep-sea animals...but many mysteries still remain...," NOAA 

"We've never seen this before," on May 5 LA Times echoed to the World the words of NOAA Experts aboard the Okeanos diving deep into the Mariana Trench. 

Today we all know that life in the deepest parts of the Oceans exists...but very few people actually know that there are thousands of known species and probable thousands of unknown species in these deep ocean environments. 

The Trench environment could be as rich as Global Rainforests or Global Coral Reefs are in biodiversity, energy and global importance. The geological process from tectonics to fuming chimneys could be vital for the health of the planet. 

The role that deep water organisms play in the overall Global Balance of Life on this Planet is completely unknown. 

Would life as we know it today be possibly if the deepest living ocean creatures did not exist? Would things be different if they were not here? One thing is certain they are here and their numbers are growing as we continue to discover them. 

NOAA Okeanos -diving again in the Mariana Trench and The Schmidt Ocean Institute -diving again in the Fiji-Tonga Trench came into the action with a science showdown that took over the World News throughout April 2016. 

In the past month images of a strange Jellyfish unknown to science took over the global media. The photograph was taken by NOAA Okeanos at Mariana Trench. Soon other images of new deep water creatures flooded the web. NOAA was feeding live video from Mariana Trench to the World through Youtube.

Scientists know that global issues are affecting the deepest parts of the Ocean. From climate change to mining to contamination Trench environments and its ecology are changing. This impact brings in a new urge for immediate attention. It is no longer about answering the basic questions such as; Did Life start at the bottom of the ocean but about can we answer the question before the bottom is completely gone? Are we too late to a game that is only but getting started for us? 

45% of the deepest waters of the oceans are Ocean Trenches: Known as the Hadal Zone it is still enigmatic and remains one of the least explored habitats on Earth. 

NOAA recently discovered several new species adding them to the Census of Deep Ocean Life. 

It took long decades -even Centuries for Humankind to understand and prove that life existed at these incredible depths. In 1895 British Expedition HMS Penguin recorded a depth of 9,144 meters in the Kermadec Trench in the Southwest Pacific but it would be hundreds of years from them before life was revealed in the bottom.

From 1895 to 1948 there was absolutely no scientific discovery made or related to Trenches. Knowing that Trenches are linked directly to tectonic activity this is a particularly strange fact. We have learnt more about Trenches in the past three decades than we have in all the history of Mankind. 

In 1989 the Hadal Region Endemic Species Data was published. It showed that of the 600 species which were extracted from the Hadal depths, 56% were endemic -meaning they could only live in those depths and area. But even then we were just scratching the surface of the ecology of Trenches and the vast number of species which live there. 

In 2009 ROV Nereus at the Mariana Trench using a trap lander and baited cameras revealed not only the typical scavenger fish communities of the depths and the accompanying decapods. A total of 813 invertebrates were collected. The Census of Marine Life assures that only polychaete species living below 2000 meters account for more than 3.6 thousand species. Most new to science for the past 200 years. 

NOAA Okeanos and SChmidt Ocean Institute -while two completely separate organizations working in the same area both agree that the depths are rich in life and now that they are tapping into the sediment and going into smaller dimensions in search of microorganism the number is expected to increase dramatically. 

But besides small bacteria and microorganisms what else dwells the depths? Deep corals, holothurians, polychaetes, isopods, anemones, amphipods, isopods, clams, bivalves, deep water fish, snailfish, polychaete, tunicates, jellyfish, mesoplankton, foraminifera, macro and meiofauna, large density of scavenging amphipods -which feed off the dead biological material that reach the depths, massive colonies of vesicomyid clams, bioluminescent creatures, and organisms that breathe in sulphur and turn it into energy. 

Schmidt Ocean Institute expedition to the Fiji-Tonga Trench was kickstarted in April 7 and stretched through the first days of May. 

“Western Pacific back-arc basins are geologically and ecologically unique and the frequency of their tectonic or volcanic events and species are not well documented,” researchers of Schmidt explained. The team actually revisited a site which they studied over 10 years ago, allowing them to take on comparative analysis of species and geological changes. 

"Essentially, what they are doing is they are looking at this hydrothermal vent site that they have been studying for 10 years to see if there are long-term changes to how it is developing," Ms Carlie Wiener Schmidt Ocean Institute communications manager told Fiji Times.

"Unlike other organisms, they do not use light as a source of energy so instead of photosynthesis, they use a process called chemosynthesis,” Ms Wiener told Fiji Times. 

The photosynthetic cycles on Earth are known to be a prime driving force of life on the planet but communities of hydrothermal vent areas are aloop of this cycle because photosynthesis can only be achieved with the presence of light and sun rays do not reach the Hadal Zone. So understanding chemosynthesis -a cycle which instead of light uses energy and chemical elements presents in hydrothermal vents, and its importance in the integral cycle of life and balance in this Planet is of unparalleled importance.  

Schmidt recognized the more urgent need for scientific information demanded directly by a growing mining investment area. They assure that the limited knowledge of the Trench system in the area is meeting an increase demand and interest by the mining sector. Schmidt Ocean Institute Scientists assure that for Conservation to be effective studies need to step up their pace. 

“To date, Papua New Guinea, Fiji, and the Kingdom of Tonga have granted exploration licenses in their territorial waters for industrial mining of polymetallic sulfide deposits around hydrothermal vents,” Schmidt Ocean Institute stated before embarking on the “research vessel Falkor to Fiji to obtain necessary new knowledge”. 

Okeanos of NOAA while diving deep far from Fiji in the Mariana Trench is on a very similar path.  Okeanos focused on the deepwater environments in and around the Commonwealth of the Northern Mariana Islands and the Marianas Trench Marine National Monument.

“The primary expedition goal is to acquire baseline information in deepwater areas to support science and management needs, and to understand the diversity and distribution of deepwater habitats in and around…(these areas), “ NOAA Mission log directs. 

“...10,000 feet deep in the ocean’s midnight zone, a robotic submarine lights and cameras thrust this previously unseen world into prime time. The robot belongs the National Oceanic and Atmospheric Administration’s Okeanos Explorer, which is now several weeks into a nearly three-month expedition to explore the mysterious deep-water areas around the Marianas Trench…”LA Times turned poetic to describe the events which were taking over the media. 

“A key part of the mission is to investigate the unexplored areas of the ocean,” Expedition Manager Kelley Elliott told the LA Times. Okeanos uses ROVs to study environments which they cannot trawl and while at it they provide unique live video stream of the environment and the life in it. 

“A lot of what we’re seeing has never been seen by human eyes before,” deep sea ecologist Diva Amon said by phone from the Okeanos. “That makes us incredibly lucky -and all those viewers who are tuning in very lucky.”  

At Okeanos Scientists also have an eye out for conservation. 

When commenting a live image of the ROV “hovering across a vast garden of corals teeming with colorful shrimp, anemones and stars Elliot explained “Many of the same species of corals are mined to make expensive jewelry, and as a result can become threatened”.

“That colony is several hundreds of years old (up to 4 thousand years old) and I’m not sure we should be making jewelry out of things that old,” Chris Kelley, a UH Manoa biologist watching the dive from one of NOAA’s exploration command centers added.

Hydrothermal vents are also fascinating from a geological view and of great importance in the prevention and early detection of natural disasters. The Trench areas are active tectonic locations where subduction and convection process occur on daily basis, where destruction and generation of crust takes place and where underwater volcanoes and lava fissures exists. These systems lead the way to earthquake, tsunami and related natural disaster generation and epicenter distribution. These elements are also the main reason why so many organisms live there, NOAA explains... 

“In the tectonically active Marianas region, colliding continental plates allow cold seawater to drip down into the Earth’s crust. The mineral-rich water becomes superheated and bubbles out in the form of the black plume. The cold water causes those minerals to harden, building up the tall chimney-like structures of the vent,” Okeanos says.

“How do we know what we know?” Schmidt Ocean Institute asks but does not stop there when it comes to asking questions. 

“How do scientists know so much about animals? How do they know how animals live their lives? What do they eat? What conditions do they like? How do they choose a mate? What is their family history? Finding some of these answers is more straightforward than others,” Schmidt Scientists say.

“Learning how vent fauna live their lives is particularly difficult since the vents we visit are 2-3 km deep. This depth requires the use of remotely operated vehicles ROVs which means we only visit these sites once every few years,” scientists which untapped unique symbiotic relationships happening between several species of the Hadal Zone of the Fiji-Tonga Trench stated..  

Schmidt describes with enthusiasm the symbiotic relationship between vent snails and chemosynthetic bacteria and wonders if snails travel from vent site to vent site. Still they struggle to understand how the larva of snails -which were spawned as a result of an egg and sperm release into the column water actually settle down in a vent site. 

“We don’t know, and we cannot follow these microscopic larvae as they wander about. Their larvae may be able to wander between sites. Similarly, the chemosynthetic bacteria that live within the gills of these snails can live outside the snails for an unknown period of time. Do the symbionts travel between sites or do they stay within site?” the questions keep coming as they study specie after specie, after specie, after specie...and finally the Big Questions come...inevitably.

“Understanding life in extreme environments such as hydrothermal vents could help us understand how and where life might exist in the Universe?” Schmidt Ocean Institute asks. 

Hydrothermal Vents are among the best candidate environments for the Origin of Life itself on Earth. Understanding vent life takes us closer to answering questions about our own beginnings. 

NOAA explains that there are Trench systems distributed through the World. They are part of the Global Trench System. The Mariana Trench where they are diving now is just one of about 30 subduction zones that make up the Hadal Zone. The depths go from 6 thousand meters below surface waters to 11 thousand meters below surface waters. 

Down there life is teeming...restlessly in an action which still has not been deciphered.