Deep-sea exploration

It’s a world few will ever see, but it holds ancient knowledge, remarkable biodiversity and plays a critical role in the health of our ocean, our climate, and our future. They also sequenced the DNA of the fish to compare them to other snailfishes and position the new species within an evolutionary context. The deep ocean is defined as the sea and seabed below 200m because this is where light fades. It makes up 90% of the Earth’s marine environment and is the largest biome (community of plants and animals living together in a particular climate) on the planet (DSCC, n.d.).

Open Ocean Zones

The family are named for shallow-living relatives that stick to rocks via a disk on their belly, curling up like a snail. The discovery of these three snailfishes, new to science, demonstrates how understudied the deep-sea ecosystems remain and the high biodiversity of the deep ocean, Earth’s largest habitat. Resource hunters will want to exploit the mineral rich black smokers in the future. Other reasons for the protection of these ecosystems are the increasing dive tourism, the deep sea fisheries and the increasing interest of scientists in hydrothermal vents. In the protection framework of the hydrothermal vents the WWF called the act a “gift to the earth”, a necessary global action of future environmental protection. The small island republic has followed this request and has protected their black smokers.

• Giant Kraken pulling ships into the depths and huge whales large enough for monks to prey on were common misconceptions of the deep sea and its inhabitants.
• In this way, many jellyfish, but also some species of fish, squid, and other deep-sea fauna can emit a blue, green, or in some cases even red light.
• Natural light does not penetrate the deep ocean, with the exception of the upper parts of the mesopelagic.
• Industrial fishing now covers 55% of the ocean area (Kroodsma et al., 2018).
• They discovered hot vents, regions where water with more than 350°C streams out of the ocean floor and provides habitat for organisms such as bacteria and tubeworms, at 2.500 m depth close to the Galapagos Islands.

WHY THE DEEP OCEAN IS IMPORTANT

They use this feature to attract males, but also (and especially) prey species. For much of the deep ocean, food rains down from above in the form of marine snow. The term ‘marine snow’ is used for all sorts of things in the ocean that start at the top or middle layers of water and slowly drift to the seafloor. This mostly includes waste, such as dead and decomposing animals, poop, silt and other organic items washed into the sea from land. A cold seep is a place on the ocean floor where fluids and gases trapped deep in the earth percolate up to the seafloor.
This, as in the case of the viper fish, gives them a sinister appearance. At a depth Deep Sea of 10,000 metres, up to a tonne of weight rests on every square centimetre of a living creature. The deep-sea is virtually inaccessible to humans and therefore largely unexplored. We even know more about the surface of the moon than about life in the dark expanses of the oceans. Pictures of deep-sea inhabitants provide us a glimpse of a fascinating world.

MBARI researchers discover remarkable new swimming sea slug in the deep sea

Still, the deep-sea remains one of the least explored regions on planet Earth.47 Pressures even in the mesopelagic become too great for traditional exploration methods, demanding alternative approaches for deep-sea research. Baited camera stations, small crewed submersibles, and ROVs (remotely operated vehicles) are three methods utilized to explore the ocean’s depths. Because of the difficulty and cost of exploring this zone, current knowledge is limited. Pressure increases at approximately one atmosphere for every 10 meters meaning that some areas of the deep sea can reach pressures of above 1,000 atmospheres. Natural light does not penetrate the deep ocean, with the exception of the upper parts of the mesopelagic. Except for the areas close to the hydrothermal vents, this energy comes from organic material drifting down from the photic zone.
Many theories on the purpose of bioluminescence have been put forward, but it is still not fully understood. Scientists think that light might help species communicate, attract a mate or prey, or deter predators. Many deep-sea organisms have developed very large rudimentary eyes to maximize their ability to see this chemical light, like some of the shrimp collected in our rock dredges. A siphonophore, these animals are made up of multiple units, each specialized for a function like swimming, feeding, or reproduction. This “modular” construction allows some siphonophores to grow very large, over 100 feet in the deep ocean.

• However, less than one percent of the seafloor has been examined in detail – e.g. with regard to the fauna living there.
• This leads to a molecular change that generates energy in the form of light.
• Scientists have now discovered other layers and “nodules” of pure methane hydrate.
• The fish caught at 9,006 m below the ocean surface was given the name Abyssobrotula galathea.
• For instance, on the continental shelf, microorganisms play a major role in sustainable storage of carbon produced by phytoplankton, but are also filters for methane formed by this fossilized matter.
• Other fragile ecosystems, such as the seamounts or the species rich deep sea coral reefs for example, should, following the Azoran example, be placed under protection very soon.
• Researchers found between 350 and 500 different species of sea stars, sea cucumbers, sponges, anemones and crabs in a region off the coast of Peru at 4,100 m depth.

THE DEEP SEA : A KEY PLAYER TO BE PROTECTED FOR CLIMATE AND ECOSYSTEMS

Submarines had been used in the past, however in 1930 the two Americans William Beebe and Otis Barton were the first to see the deep sea with their own eyes. Enclosed in a cold steel ball (the bathysphere) they were lowered to 427,8 m by a rope – deeper than anyone had previously been. “Shrimp and jellyfish drifted past us like flakes of unknown snowstorms” is how Beebe described the first impressions of the deep sea.

Technologies for Exploring the Deep

Due to the methodological difficulties and the technological requirements it will, however, probably be years, if not decades, until the industrial extraction of gas hydrates becomes possible. The Porcupine Abyssal Plain deep sea region in the North-western Atlantic (-48° 50’ N, 16° 30’ W, at depths of about 4,850 m), in which British and European studies are being conducted. The increased ship traffic and the use of steam engines led to a steady widening of the spectrum of ocean expeditions in the early years of the 20th century. The first expeditions into the ice were made to look for ice-free passageways. After the Titanic sank the German physicist Alexander Behm developed the echo sounder in 1912, through which one could now measure the ocean depth via wave refraction.

This means the “deep” is the part of our ocean that is dark, cold, food-poor, subject to intense pressure, and typically deeper than 200 meters. Carbon is stored in rocks, the atmosphere, soils and plants – and the ocean. Carbon in phytoplankton is incorporated in marine sediments as the organisms die and sink to the seabed, and then, over millennia, the carbon becomes stored in rocks. The abyssal plains of the seabed are the flattest places on earth – because they are vast accumulations of carbon-rich sediment, sometimes over 5km thick, covering the rock below. Ocean sediments cover 70% of the planet’s surface, forming the substrate for the largest ecosystem on Earth and its largest carbon reservoir (Dutkiewicz et al., 2015). The fishing at the far away deep sea locations is often the only way for fishermen from different waters to make back the money they had to invest in the boats and their equipment.