Using an innovative camera, researchers have discovered a deep-sea soft coral garden in Greenland, the first of its kind to have been identified and assessed in Greenlandic waters. This could have implications for the management of deep-sea trawl fisheries that are close to the habitat.
The soft coral garden is located at 1,600 feet below sea level (almost 500 meters), where the pressure is 50 times greater than at the surface. The habitat, delicate and diverse, is full of life with abundant cauliflower corals, feather stars, sponges, anemones, brittle stars, hydrozoans, bryozoans, and other organisms.
The researchers found it using a low-tech rig called a “benthic sled,” which consists of a GoPro camera, lights, and laser pointers, which they set into special pressure-proof cases, mounted on a steel frame and hung from their research vessel. They recorded video at 18 locations and discovered the garden.
“The deep sea is often over-looked in terms of exploration. In fact we have better maps of the surface of Mars, than we do of the deep sea,” said Stephen Long, first author of the study. “The development of a low-cost tool that can withstand deep-sea environments opens up new possibilities for our understanding and management of marine ecosystems.”
The seafloor is a very dark place and that’s why the team needed lights on the rig. The algae that is usually found in corals in shallow waters, giving them their bright colors, can’t survive in the deep sea. But corals can, as well as other organisms that depend on them for shelter. The researchers found over 44,000 individual organisms there.
Surveying the deep sea has so far proved difficult and expensive. This is partly explained by the ocean pressure, which increases by one atmosphere (which is the average atmospheric pressure at sea level) every 10 meters of descent. That’s why surveys in the deep-sea rely on expensive remote operating vehicles and manned submersibles that can tolerate the pressure.
“Given that the ocean is the biggest habitat on earth and the one about which we know the least, we think it is critically important to develop cheap, accessible research tools. These tools can then be used to explore, describe and crucially inform management of these deep-sea resources,” Chris Yesson, co-author, said in a statement.
The discovery is particularly significant as the deep sea is the most poorly known habitat on Earth, despite it covering 65% of the planet. Until very recently, very little was known about Greenland’s deep-sea habitats, their nature, distribution, and how they are impacted by human activities.
Although it’s not that well understood, the deep-sea is crucial to the economy of Greenland. Up to 90% of the exports of the country are owed to fisheries, which is also a crucial source of jobs and food in the country. But the recently found garden and many others could be at risk in the future due to deep-sea mining and bottom trawling.
That’s why the authors call for the garden they discovered to be protected as a Vulnerable Marine Ecosystem under United Nations guidelines. They are also working with the Greenland government and the local fishing industry, who have been receptive to putting protections for the garden in place.
The deep sea, the area of the ocean below 200 meters, could soon become the new frontier of mining activities. Companies and countries are rushing to get the green light to start extracting minerals from cobalt to manganese from the bottom of the sea. ‘Not so fast’, say conservationists.
While they can be found in abundance on land, most mineral deposits are running short as our society is fueling an increasing demand for such resources, especially for green energy technologies and consumer electronics. This has led many to draw their attention to the minerals on the deep sea.
The seafloor contains a wide array of geological resources and supports countless species, many still unknown to science. It is a highly understudied part of the world, hosting an abundance of species uniquely adapted to harsh conditions such as lack of sunlight and high pressure.
This is why conservation and environmental organizations are raising the alarm over the impacts of deep-sea mining, urging caution until the science is more thorough. Meanwhile, companies argue that the risks are low and that there’s no time to waste amid the high demand for minerals. So, what’s the case for deep-sea mining, and what’s the case against it?
What is deep seabed mining?
Deep-sea mining (or deep seabed mining) is, as the name implies, the process of retrieving mineral deposits from the deep seafloor. Generally, this ‘depth’ refers to parts of the ocean over 200 meters deep — an area that covers around 65% of the Earth’s surface.
In addition to rich biodiversity, these areas also include unique geological features such as mountain ranges, plateaus, volcanic peaks, canyons, vast abyssal plains, the world’s deepest trenches — such as the Mariana Trench, which goes down almost 11,000 meters.
“It is the largest biosphere on the planet. It exchanges biomass, nutrients and other elements with the overlying surface waters, it mixes vertically and horizontally and it comprises arguably more habitats than may be found in terrestrial environments,” said Dr. Cindy Van Dover, a deep-sea biologist at Duke University, for ZME Science.
Much has changed in how scientists regard the deep sea. When Van Dover first started work in this field in the early 1980s, the ‘deep-sea’ meant the area where light stopped coming though, about 500 meters in. While no formal definition is universally accepted, 200 m seems to be regarded as the limit now — the boundary at which photosynthesis is no longer possible, and the temperature drops sharply.
Adjectives often associated with the deep sea before the 1980s include inaccessible, remote, pristine, biological desert, adds Van Dover. These are now obsolete.
“We have access (although that access is costly), the deep-ocean is well connected to coastal and surface waters. Chemicals, wastes, plastics, and climate change are all impacting the deep sea. And we know that the diversity of life in the deep sea is rich, and in some places exuberantly abundant – far from the azoic, desert world it was believed to be in the 1800s and on into the 1900s.”
However, although we’ve learned much about this part of the planet, the vast majority of it remains unexplored and understudied, which is why the topic of industrial activities in these areas tend to touch a nerve.
Should we wait, or start mining as soon as possible?
There are some mining projects in shallow waters around the world, mainly for sand, tin, and diamonds. In the 1960s, Marine Diamond Corp. recovered nearly 1 million carats from the coast of Namibia, but not all investments have been successful — and the process is tedious.
There’s also some deep-sea mining being done in territorial waters of some countries, particularly around hydrothermal vents — fissures on the seafloor where geothermally heated water flows and tends to form rich mineral deposits. Papua New Guinea was the first country to approve a permit for the exploration of minerals in the deep seabed, and the world’s first “large-scale” mining of hydrothermal vents mineral deposits was carried out by Japan in August – September 2017.
But deep-sea mining in international waters that don’t belong to a specific country has still not taken off.
So far, thirty 15-year exploration contracts have been granted to assess the size and extent of three different types of mineral deposits in areas totaling more than 1.3 million square kilometers. But actual mining can’t start until countries agree on an international mining code, now under negotiation.
The task of developing this mining code falls International Seabed Authority (ISA), a rather obscure and autonomous United Nations organization that governs seabed mining from its headquarters in Kingston, Jamaica. Every year, delegates from all around the world fly to Kingston for one week and discuss the legislation for this trillion-dollar industry just waiting to boom, with little attention from the media and even environmental organizations.
The ISA had set 2020 as the deadline to adopt a “mining code” that would allow companies to obtain minerals from the bottom of the ocean but given the current state of affairs, meeting that deadline seems highly unlikely.
Biologists and conservationists argue that some of the difficulties to getting the code approved lies on the fact that the ISA has dual responsibilities. When it was established by the UN, the ISA was given two mandates: to protect the international seabed from serious harm, and to develop its resources, ensuring that their exploitation benefits humankind — so what do you do when those mandates clash and start pulling in different directions? If anything, the role that ISA seems to play at this time is not to prevent environmental damage from deep-sea mining, but rather to mitigate it.
Writing the regulations at this time could also encourage the industry to start mining long before there is enough information on how operators can avoid causing serious environmental harm. That’s why many are now calling for a moratorium until all the necessary information is collected.
“We need more time to drill down on the details, more time to do science and learn on the deep oceans and more time for the stakeholders to internalize all the questions,” Andrew Friedman, head of Pew’s Seabed Mining Project. “If the activity starts, we want to have a robust regulatory framework in place.”
The idea of heavy scrutiny is shared by Van Dover, though a moratorium might not be the best approach, she notes.
“While I welcome the public debate about a moratorium on deep-sea mining, I don’t know that a moratorium may be the optimal approach. To me, our goal has to be to ensure that environmental regulations, standards, and guidelines are robust before any mining begins, including being robust with regards to enforcement.”
Environmental aspects of mining applications should be scrutinized for compliance and subject to independent review by deep-sea environmental experts, she says. Mining should not be permitted where there is insufficient data to ensure no serious harm is done to the environment. However, since there are huge knowledge gaps in our understanding, that will preclude all mining activities for a while.
“It will require thoughtful, informed input to the development of regulations, standards, and guidelines by Member States of and Observers to the ISA, by deep-sea ecologists, scientists, and environmental experts, and by all other stakeholders to ensure that the environmental regulations are robust,” Van Dover adds.
Who wants to explore the deep sea?
Given the lucrative potential of deep sea mining, several countries and companies have already expressed interest.
All countries have the right and opportunity to mine the deep sea and the eventual royalties obtained from the activity will have to be divided equally among all of them. But as the rules aren’t in place yet countries are only on an exploratory phase in international waters.
A group of corporate enterprises, state-owned companies and several governments have been allocated with contracts to explore the deep sea. Each company has to be sponsored by a country, so they are both responsible for any eventual problems.
The list includes China, France, Germany, India, Japan, South Korea, Russia, and the Interoceanmetal Joint Organisation (a consortium of Bulgaria, Cuba, the Czech Republic, Poland, the Russian Federation, and Slovakia). Small island states such as the Cook Islands, Kiribati, Nauru, Singapore, and Tonga are also part of the list. Given the massive rising demand for precious metals in the world, many are closely following developments in this field.
Make no mistake, though — this isn’t some localized interest by which some countries are looking to supplement their natural resources. This is possibly the nascent moment of the largest mining operation in human history.
What minerals does the industry want?
The most common targets are nickel, copper, cobalt, manganese, zinc, silver, and gold. The exploration currently under place is focused on three types of mineral deposits: polymetallic nodules (lying on the seafloor), polymetallic sulfides (which form near hydrothermal vents), and cobalt-rich ferromanganese crusts that cover seamounts.
Once found, such minerals will be used to supplement in-demand electronic products and energy storage such as smartphones, laptops, solar panels, wind turbines, and electric vehicles. Terrestrial supplies are becoming harder and less profitable to extract while demand for minerals continues to grow. Companies argue that deep-sea mining provides a source of reliable, clean, and ethically sourced minerals.
“We are now at the age of metals. We need a lot of them to move into the fourth industrial revolution, which will be based on renewable energy,” said Dr. Gregory Stone, Chief Ocean Scientist at Deep Green. “We need to get the metals from somewhere and obtaining them from the deep sea is an elegant solution.”
Seabed formations will be scooped, dredged, or severed by gigantic machines weighing more than a blue whale. The deposits would be piped up to a ship through several kilometers of tubing and processed at sea, where waste material would be pumped back into the water.
ROV (remotely operated underwater vehicles) have also progressed greatly in recent years, becoming not only more capable and robust, but also cheaper — promising to usher in a new age of undersea exploration.
What effects could it have on the ocean?
Environmental organizations and researchers claim these activities will affect the seabed, the water column above it, and the surrounding area. The scraping of the ocean floor to extract the nodules could destroy deep-sea habitats of octopuses, sponges and other species.
Mining of the vents, which harbor massive animal communities at densities that make them one of the most productive ecosystems on Earth, is likely to stir up sediment that could smother some animals and dramatically affect the habitats of others. Other species adapted to the lack of sunlight and high pressure of deep water, could be affected by the noise and pollution, and the list of potential threats goes far and long.
“Many uncertainties remain as to the impact of this mining but widespread habitat loss will be inevitable, albeit in an environment where the faunas are often sparse,” wrote Van Dover and colleagues in a paper in 2018. “A precautionary approach will be needed with many areas set aside for protection and regional plans put in place before mining begins.”
Environmental organizations are also scrutinizing the climate implications of allowing companies to dig minerals used to make lithium-ion batteries. “Deep-sea mining could even make climate change worse by releasing carbon stored in deep-sea sediments or disrupting the processes which help deliver carbon to those sediments,” Greenpeace argued in a report.
Scientists are also concerned that not enough is known about these species or ecosystems to establish an adequate baseline from which to protect them or monitor the impact of mining. But for the industry, that shouldn’t be the case. DeepGreen said the activity should start as soon as the rules are approved.
“Everybody is in new territory, that’s why this new industry is exciting. Nobody did this type of mining before. ISA will have to get the code ready, and then we’ll do our environmental assessment against that code,” said Dr. Stone. “It will be the least invasive way of getting metals on the planet.”
We once thought the deep sea was uninhabitable but now we know that is not the case. There is an abundance of biodiversity in the deep sea, and the ecological services it provides is invaluable — not only for ocean dwellers, but for humans as well.
In between the fragile ISA mandate, the growing pressure for more mineral resources, and the environmental uncertainty, deep sea mining promises to be a contentious topic for decades to come.
Whether it will bring a revolution for mineral resources or devastate the subsurface environment, the effects will be powerful and long-lasting.
“The deep sea remains a difficult place to study and in my opinion will be impossible to “fix” if we “break” it,” Van Dover concludes.
Australia is no stranger to bizarre and unique creatures, and nor are its coastlines. During an expedition that explored the deep sea off the continent’s coast, researchers have discovered over 30 new marine species. Among them was a siphonophore that measures nearly 150 feet (45 meters) in length. This is the longest creature that scientists have ever found.
The spire-like creature is actually made up of multiple smaller clones that are joined together, acting in unison as a single long string no thicker than a broomstick. If you were to pull and straighten this string, it would be the size of an 11-story building, twice as long as a blue whale.
This particular siphonophore, part of the genus Apolemia, was caught on film off Western Australia’s Nigaloo coast by researchers affiliated with the Western Australian Museum onboard the Schmidt Ocean Institute‘s (SOI) research vessel Falkor.
Usually, siphonophores are about 20 centimeters to a meter in size, but researchers have never seen anything this large before. The creature also employs a unique hunting strategy, coiling itself into a spiral in order to attack and catch prey.
Siphonophores, just like jellyfish, feed by dangling their stinging tentacles in the water. Sometimes, unsuspecting prey like small fish and crustaceans get stung and become paralyzed once they pass through the curtain of tentacles.
“There is so much we don’t know about the deep sea, and there are countless species never before seen,” SOI co-founder Wendy Schmidt said in the press release. “Our planet is deeply interconnected – what happens in the deep sea impacts life on land–and vice versa. This research is vital to advance our understanding of that connection – and the importance of protecting these fragile ecosystems. The Ningaloo Canyons are just one of many vast underwater wonders we are about to discover that can help us better understand our planet.”
Besides this impressive UFO-like creature, the researchers discovered dozens of other new candidate species around the Gascoyne Coast bioregion. It might, however, take many months — perhaps years given the current coronavirus situation — before they verify and formally described these new species.
The shark inhabits the depths of the Pacific and sports an exceptionally large nose.
Etmopterus lailae is a member of the Lanternshark family, living more than 300 meters (1000 feet beneath the surface). Image credits: Stephen Kajiura, Florida Atlantic University.
A light in the darkness
If you go deep enough, underwater life starts to become really bizarre. Where light just barely goes through (or doesn’t at all), pressure starts to mount up, and temperatures drop significantly, creatures have adapted in complex and often strange ways. Eyes can grow very large to capture what little light comes through, or decay completely and abandon any hope of visibility. Membranes and proteins start to develop specific structures to cope with the pressure, and because food is so scarce in the absence of all photosynthesis, fascinating feeding mechanisms have emerged. Among these adaptations, bioluminescence plays a special role.
Bioluminescence is any production and emission of light by a living organism. In the deep oceans, every bit of light can make a difference, and bioluminescence can help in a number of ways. It can serve as a headlight (the so-called photophores of lantern fish), to lure unsuspecting prey (for the anglerfish), or even to attract sexual partners. The oceans are vast and very dark, so that can be a daunting task. Some creatures such as sea cucumbers even use bioluminescence as a “burglar alarm” — whenever they’re attacked by a predator, they light up to attract an even bigger predator to take care of the threat.They can even spray glow-in-the-dark mucus on the predator so that the “police” can find it later.
This newly discovered shark, Etmopterus lailae, is also bioluminescent, but that’s hardly the most remarkable thing about it.
A nose for sharks
Image credits: Stephen M. Kajiura, Florida Atlantic University.
Weighing less than 1 kg (two pounds) and measuring less than 30 centimeters (1 foot), the shark is still a sight to behold. Found in the Pacific Ocean off the coast of Hawaii’s northwestern islands, it looks more like a fairy tale monster than a shark, but that’s to be expected for such a deep dwelling predator.
The shark was discovered 17 years ago, but it took a really long time to properly identify it. At first, Stephen M. Kajiura, the study author thought it wasn’t a new species. When he submitted the findings to a journal, a reviewer told them the shark is not what they think it is. This came as quite a shock — a thrilling one, as Kajiura himself notes.
“There are only about 450 known species of sharks worldwide and you don’t come across a new species all that often. A large part of biodiversity is still unknown, so for us to stumble upon a tiny, new species of shark in a gigantic ocean is really thrilling,” Kajiura said in a university press release.
“The unique features and characteristics of this new species really sets it apart from the other Lanternsharks,” said Kajiura. “For one thing, it has a strange head shape and an unusually large and bulgy snout where its nostrils and olfactory organs are located. These creatures are living in a deep sea environment with almost no light so they need to have a big sniffer to find food.”
Analyzing and characterizing the shark required diligent categorization and thorough comparisons with other museum specimens. The species also features unusual flank markings that go forward and backward on their bellies, as well as fewer teeth than other sharks.
It’s not clear why this shark is bioluminescent, though the team has some ideas. Most likely, this is how the shark lures in shrimp or other prey and recognizes its mates — as in, to be sure it’s mating with the right species.
This is just the tip of the iceberg, and there’s certainly much more to discover about this species and others like it, but that’s hard to do for obvious reasons. Since 60% of the planet is covered by water more than a mile deep, that makes the deep sea the largest habitat on Earth. It’s also the most unexplored. No doubt, many surprises still await to be discovered. This particular shark, unfortunately for him, is now hosted at the Bernice P. Bishop Museum in Hawaii.
Journal Reference: David A. Ebert, Yannis P. Papastamatious, Stephen M. Kajiura, Bradley M. Wetherbee — Etmopterus lailae sp. nov., a new lanternshark (Squaliformes: Etmopteridae) from the Northwestern Hawaiian Islands. DOI: http://dx.doi.org/10.11646/zootaxa.4237.2.10
An international team of scientists has returned from a deep sea research voyage, finding several intriguing species including what seems to be a fish without a face.
Typhlonus nasus, collected east of Jervis Bay, New South Wales, May 2017. Image credits: Dianne J. Bray / Museum Victoria.
A fish has no face
The voyage, called Sampling the Abyss, was organized and carried out by Museums Victoria and the Commonwealth Scientific and Industrial Research Organization (CSIRO). The mission was settling into a normal rhythm when they found a bizarre-looking fish which seemed to have no face. They pulled it up from 4,000 meters — it was unfortunate for the fish, but the team was thrilled.
“Everyone was amazed,” writes Dianne Bray from Museums Victoria. “We fishos thought we’d hit the jackpot, especially as we had no idea what it was. Tissue samples were taken (for genetic analyses) and images were emailed to experts who work on weird abyssal fishes. We even conjured up possible new scientific names!”
After looking through several collections of publications, John Pogonoski, of CSIRO’s Australian National Fish Collection, found something similar. As it turns out, the fish had been described before, in the 80s: a cusk eel, with a name to match: Typhlonus nasus. In Greek, typhlos (= blind) and onos (= hake) — so a blind hake! Cusk eels, as it turns out, are not even eel. So it was not a new species, though a pretty rare one to find.
Abraliopsis – a species of squid found on the trip. Image credits: Dianne J. Bray / Museum Victoria.
Although rare, the fish is spread across a wide geographical range, known to be from the Arabian Sea, Indonesia, Papua New Guinea, Japan, and Hawaii. Interestingly, the first time this fish was discovered was in 1874, when the Voyage of HMS Challenger(link is external), the world’s first round the world oceanographic expedition, recovered one from a depth of 2440 fathoms nearby Australia. In case you’re wondering, a fatho is a unit of length equal to six feet (1.8 metres). I know, the Imperial System confuses me too.
An illustration of one of the syntypes (similar type specimens upon which the description and name of a new species is based) of Typhlonus nasus. Image: Günther (1887) Rept Sci. Res. HMS Challenger 22(57): Pl. 25. License: Public Domain.
More than 100 years later, a chubbier and somewhat happier-looking Faceless Cusk. Image: John Pogonoski, CSIRO Australian National Fish Collection.
Also, despite its appearance, the fish does have a face; it even has eyes! It’s just hidden.
“Although very little is known about this strange fish without a face, it does have eyes – which are apparently visible well beneath the skin in smaller specimens. I doubt they’d be of much use though, so we’ve decided to call it the Faceless Cusk,” Bray added.
For all we know about other planets and even other galaxies, there’s still much to learn about our very own planet – especially its oceans. The oceans are teeming with life of which we know nothing or very little about; now, Florida researchers have discovered a new species of angler fish that dwells 1 km below sea level (3200 ft).
Please welcome the new anglerfish, Lasiognathus regan. (Photo courtesy of Theodore Pietsch, University of Washington)
“Every time we go out on a deep-sea research excursion there’s a good chance we’ll see something we’ve never seen before — the life at these depths is really amazing,” said Tracey Sutton, a deep-sea life expert who was involved in the study.
Indeed, it seems like every deep sea expedition comes up with something new.
“As a researcher, the one thing I know is that there’s so much more we can learn about our oceans,” said Tracey Sutton, an oceanographer at NSU . “Every time we go out on a deep-sea research excursion there’s a good chance we’ll see something we’ve never seen before — the life at these depths is really amazing.”
Anglerfish are spectacular, dangerously-looking abyssal fish. Their distinctive characteristic is a fleshy growth from their heads which acts as a lure for their prey. This latest discovery looks a bit like a hunchback, with a large, strange looking mouth and an even stranger zig-zagging fishing pole coming out of its head.
“This fish dangles the appendage until an unsuspecting fish swims up thinking they found a meal, only to quickly learn that they are, in fact, a meal themselves,” the marine researchers from Nova Southeastern University in Fort Lauderdale, Florida, said in a statement.
Three female fish were discovered – they were named Lasiognathus regan and will reside at the University of Washington.
Exploration Vessel (E/V) Nautilus is a 64-meter research vessel currently operated by dr. Robert Ballard, the discovered of Titanic’s shipwreck. Now, Hercules’ camera spotted an extremely elusive deep sea creature – a siphonophore.
The siphonophore an order of the Hydrozoa, a class of marine animals belonging to the phylum Cnidaria, which also includes jellyfish. Although a siphonophore appears to be a single organism much like a jellyfish, each specimen is actually a colony composed of many individual animals, specialized to serve a specific function. In fact, most individuals (called zooids) are so specialized that they can’t survive on their own. Most colonies are long, thin, transparent pelagic floaters. Some siphonophores superficially resemble jellyfish. The best known species is the dangerous Portuguese man o’ war (Physalia physalis).
Siphonophores are truly remarkable creatures, unique in the animal kingdom.
For the first time, researchers have taken a look at the life that thrives in one of the deepest spots in the ocean. They investigated the New Hebrides trench, located just West of Vanuatu, and revealed that cusk eels and crustaceans teem more than 7,000m (23,000ft) down. They used cameras fitted on an unmanned lander to film the deep-sea creatures.
The fact that this is happening at a depth of 7 kilometers simply blows my mind.
Marine biologists were surprised to see that life in this trench significantly differed from other regions of the deep that had been studied – painting a good picture of just how spectacular and interesting this extreme biodiversity really is.
“We’re starting to find out that what happens at one trench doesn’t necessarily represent what happens in all the trenches,” said Dr Alan Jamieson, from Oceanlab at the University of Aberdeen, UK, who carried out the expedition with the National Institute of Water and Atmospheric Research in New Zealand.
The 30 day expedition was largely successful showing large, grey cusk eels up to 1 meter long, chopping on the bait, as well as large, bright red prawns scrabbling around on the sandy seabed which reaches 7.200 meters in its deepest point. They also spotted eel pouts, arrow-tooth eels and thousands of smaller crustaceans – some of which were unfortunate enough to be captured and taken back to the surface.
There are over 30 deep trenches across the world, most of them in the Pacific Ocean, due to its very intense tectonics. Until this expedition, the New Hebrides Trench (which is also some 1.500 km away from New Zealand) has been relatively unstudied – from a biological point of view. When compared to other, apparently similar areas, the differences are major.
Dr Jamieson said:
“The surprising thing was that there was a complete and utter lack of one of the most common deep sea fish we would expect to see. Anywhere else around the Pacific Rim, around the trenches we’ve looked at, you see a lot of grenadiers – they are quite a conspicuous part of the deep-sea community. But when we went to the New Hebrides trench, we didn’t see a single one.
“But what we did see was a fish called the cusk eel. These turn up elsewhere but in very, very low numbers. But around the New Hebrides trench, these – and the prawns – were all that we saw.”
They also reported a rather surprising absence of a certain snailfish, a small pink fish commonly found throughout the world’s trenches. They believe the differences lie in the absence of a major nutrient source in the New Hebrides Trench.
“If you look at the New Hebrides trench, and where it is geographically, it lies under very unproductive waters – there is not a lot happening at the surface of the tropical waters,” said Dr Jamieson. It seems the cusk eels are specialists in very low food environments, whereas the grenadiers require a greater source of food.”
This expedition is part of a larger wave to explore the very depths of the planetary ocean, which can go even 11 km deep, in the Mariana Trench. Almost all of this has been carried out using landers or other unmanned vehicles, but in 2012 Hollywood movie director James Cameron made a record-breaking dive to the deepest place in the ocean – the Mariana trench. He described it as an alien place, devoid of life. This is the situation not so much because of the depth, but rather because it is so far from the continental shelf, which means that very few nutrients drift into it. However, researchers have shown that while it may be devoid of macroscopic life, microscopic life still thrives – even in this fantastically extreme environment.
Many deep sea animals, such as the infamous anglerfish, use parts of their bodies as decoys, to attract unsuspecting prey. Now, researchers have found that a certain squid can do this as well – its tentacle tips flap and flutter as if swimming on their own. Biologists believe that the mesmerizing movement of the tentacles lures small shrimp and other animals to approach within reach of the squid.
Most squids have eight tentacles which act as ‘arms’, and two longer tentacles which they use for feeding. The tips of the tentacles are often broader and armed with suckers or hooks – used for preying. Deep sea squid Grimalditeuthis bonplandi, named after the reigning family of Monaco, seems to employ a different strategy. A slow, almost lazy swimmer, with a gelatinous body and long, fragile tentacles, it is the only known squid which doesn’t have suckers, hooks, or photophores (glowing spots).
Until a few years ago, nobody had ever seen a living G. bonplandi, except for those captured in thrawling nets. However, using video from underwater robots known as remotely operated vehicles (ROVs), the authors of the recent paper were able to study how these squids act in their natural habitat, 1-2 km below the surface.
As you can see from the video, when the ROV first approached, the squids were just hanging around in the water, with their eight arms spread and its two feeding tentacles just dangling below. What intrigued biologists was not that they didn’t move on their own, but that the tip of their tentacles (clubs, as they are often called) were propelled by fluttering and flapping motions of thin, fin-like membranes. The clubs basically appeared to be swimming on their own, while the tentacles were just trailing behind. Instead of acting like most squids, G. bonplandi sends its clubs swimming away from its body, dragging the tentacles behind. Also, when threatened, instead of retracting its tentacles as most squids would do, it first coils both the tentacles and clubs and hides them within its arms before swimming away.
What all these motions do is give the message that the clubs are in fact smaller animals, swimming on their own, independent from the rest of the body. But what’s interesting is that these clubs don’t glow – which of course, makes them invisible at the depths where the squid is living. But researchers have proposed other mechanisms through which it could attract prey: one possibility is that it can disturb glowing microscopic organisms in the surrounding water, also creating sound and turbulence in the water, which can be detected by their prey. Such vibrations might mimic the vibrations used by prey animals to attract mates. But sadly, the team hasn’t been able to actually see the squid capture its prey – until then, we can’t really know for sure.
Either way, this is just another remarkable case of what you can discover indirectly, with insufficient information, and the improbable adaptation strategies animals can implement in order to survive.
Journal Reference: H. J. T. Hoving, L. D. Zeidberg, M. C. Benfield, S. L. Bush, B. H. Robison, M. Vecchione. First in situ observations of the deep-sea squid Grimalditeuthis bonplandi reveal unique use of tentacles. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1769): 20131463 DOI: 10.1098/rspb.2013.1463
I recently came across this TED presentation, and I can honestly say it is one of the most amazing things I have ever seen – it totally rocked my world! It shows some truly amazing things happening in deep water regions, and even in shallow waters. I’ll quit my rambling now and just let you watch the video – I guarantee you’ll love it!