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The Deep SeaThe Oceans / NEXT: Research Tools & Methods »

Over 60% of our planet is covered by water more than a mile

deep. The deep sea is the largest habitat on earth and is largely

unexplored. More people have traveled into space than have traveled

to the deep ocean realm.... - The Blue Planet Seas of Life

Most people familiar with the oceans know about life only in theintertidal zone, where the water meets land, and the epipelagiczone, the upper sunlit zone of the open ocean. Though these zonescontain an abundance of ocean life because sunlight is available forphotosynthesis, they make up only a small fraction of the oceanbiome. In fact, most of the ocean is cold, dark and deep. It isimportant to realize that photosynthesis occurs only down to about100 - 200 m, and sunlight disappears altogether at 1,000 m orless, while the ocean descends to a maximum depth of about11,000 m in the Mariana Trench!

To get an idea of how vast the ocean's depths are, consider that79% of the entire volume of the earth's biosphere consists ofwaters with depths greater than 1,000 m. Until recently, the deep sea was largely unexplored. But advances in deep seasubmersibles and image capturing and sampling technologies are increasing the opportunities for marine biologists to observeand uncover the mysteries of the deep ocean realm.

Deep sea research is vital because this area is such an enormous part of the biosphere . Despite its depth and distance, itis still our backyard in comparison to outer space. And yet, human exploration has revealed more detail about the surface ofthe moon and Mars that it has about the deep sea! Consider that hydrothermal vents and their unique organisms, whichrevolutionized our ideas about energy sources and the adaptability of life, were only discovered in 1977. There may be yetother life-altering discoveries to be found at the bottom of the ocean.

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The oceans are divided into two broad realms; the pelagic and the benthic. Pelagic refers to the open water in whichswimming and floating organisms live. Organisms living there are called the pelagos. From the shallowest to the deepest,biologists divide the pelagic into the epipelagic (less than 200 meters, where there can be photosynthesis), the mesopelagic(200 - 1,000 meters, the "twilight" zone with faint sunlight but no photosynthesis), the bathypelagic (1,000 - 4,000 meters),the abyssopelagic (4,000 - 6,000 meters) and the deepest, the hadopelagic (the deep trenches below 6,000 meters to about11,000 m or 36,000 feet deep). The last three zones have no sunlight at all.

Benthic zones are defined as the bottom sediments and other surfaces of a body of water such as an ocean or a lake.Organisms living in this zone are called benthos. They live in a close relationship with the bottom of the sea, with many ofthem permanently attached to it, some burrowed in it, others swimming just above it. In oceanic environments, benthic habitatsare zoned by depth, generally corresponding to the comparable pelagic zones: the intertidal (where sea meets land, with nopelagic equivalent), the subtidal (the continental shelves, to about 200 m), the bathyal (generally the continental slopes to4,000 m), the abyssal (most of the deep ocean seafloor, 4,000 - 6,000 m), and the hadal (the deep trenches 6,000 to 11,000m).

There are several types of deep benthic surfaces, each having different life forms. First, most of the deep seafloor consists ofmud (very fine sediment particles) or "ooze" (defined as mud with a high percentage of organic remains) due to theaccumulation of pelagic organisms that sink after they die. [Unlike the shoreline, sandy habitats are rarely found in the deepsea because sand particles, created by wave action on coral and rocks at shorelines, are too heavy to be carried by currentsto the deep.] Second, benthic areas too steep for sediment to stick are rocky. Rocky areas are found on the flanks of islands,seamounts, rocky banks, on mid-ocean ridges and their rift valleys, and some parts of continental slopes. At the mid-oceanridges, where magma wells up and pushes seafloor tectonic plates apart, even flat surfaces are rocky because these areasare too geologically new to have accumulated much mud or ooze. Third, in some areas certain chemical reactions produceunique benthic formations. The best known of these formations are the "smoker" chimneys created by hydrothermal vents,

which are described in detail below.

Exploration of these zones has presented a challenge to scientists fordecades and much remains to be discovered. However, advances intechnology are increasingly allowing scientists to learn more about thestrange and mysterious life that exists in this harsh environment. Life inthe deep sea must withstand total darkness (except for non-solar lightsuch as bioluminescence ), extreme cold, and great pressure. To learnmore about deep-sea marine life, sophisticated data collection deviceshave been developed to collect observations and even geological andbiological samples from the deep. First, advances in observationalequipment such as fiber optics that use LED light and low light camerashas increased our understanding of the behaviors and characteristics of

deep sea creatures in their natural habitat. Such equipment may be deployed on permanent subsea stations connected to landby fiber optic cables, or on "lander" devices which drop to the seafloor and which are later retrieved (typically after a radiocommand activates the dropping of ballast so the lander may float up.) Second, remotely operated vehicles (ROVs) have beenused underwater since the 1950s. ROVs are basically unmanned submarine robots with umbilical cables used to transmit databetween the vehicle and researcher for remote operation in areas where diving is constrained by physical hazards. ROVs areoften fitted with video and still cameras as well as with mechanical tools such as mechanical arms for specimen retrieval andmeasurements. Other unmanned submarine robots include AUVs (autonomous undersea vehicles) that operate without acable, and the USA's new Nereus , a hybrid unmanned sub which can switch from ROV to AUV mode and which is currentlythe world's only unmanned submarine capable of reaching the deepest trenches. Third, manned deep sea submersibles arealso used to explore the ocean's depths. Alvin is an American deep sea submersible built in 1964 that has been usedextensively over the past 4 decades to shed light on the black ocean depths. Like ROVs, it has cameras and mechanicalarms. This sub, which carries 3 people (typically a pilot and 2 scientists), has been used for more than 4,000 dives reaching amaximum depth of more than 4,500 m. France, Japan and Russia have similar manned scientific submersibles that canreach somewhat greater depths, while China is currently building one to reach 7,000 m.

The bathyscaphe Trieste at the National Museum of the U.S. Navy in Washington, D.C.

Until 2012, only one manned submarine device has ever reached the bottom of Mariana trench at almost 11,000 m: thebathyscaphe Trieste manned by Jacques Piccard and Don Walsh. During the Trieste's single dive in 1960, its windowsbegan to crack, and it has never been used since. 52 years later, on March 25, 2012 (March 26 local time) , JamesCameron successfully dove in his commissioned one-man sub to the Challenger Deep . Don Walsh was invited to jointhe expedition.

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Physical Characteristics of the Deep Sea

The physical characteristics that deep sea life must contend with to survive are:

1. abiotic (non-living) ones, namely light (or lack thereof), pressure, currents, temperature,oxygen, nutrients and other chemicals; and

2. biotic ones, that is, other organisms that may be potential predators, food, mates,competitors or symbionts.

All these factors have led to fascinating adaptions of deep sea life for sensing, feeding,reproducing, moving, and avoiding being eaten by predators.

Light

The deep sea begins below about 200 m, where sunlight becomes inadequate forphotosynthesis . From there to about 1,000 m, the mesopelagic or "twilight" zone,sunlight continues to decrease until it is gone altogether. This faint light is deep blue incolor because all the other colors of light are absorbed at depth. The deepest ocean waters below 1,000 m are as black asnight as far as sunlight is concerned. And yet, there IS some light. People who dive deep in a submersible (with its lights off)are often mesmerized by an incredible "light show" of floating, swirling, zooming flashes of light. This is bioluminescence , achemical reaction in a microbe or animal body that creates light without heat, and it is very common. And yet, this light is lowcompared to sunlight, so animals here — as well as those in the mesopelagic zone — need special sensory adaptations. Manydeep-sea fish such as the stout blacksmelt have very large eyes to capture what little light exists. Other animals such astripodfishes are essentially blind and instead rely on other, enhanced senses including smell, touch and vibration.

Scientists think bioluminescence has six different functions (not all used by any one species):

1. headlights, such as the forward-facing light organs (called photophores ) of lantern fish;

2. social signals such as unique light patterns for attracting mates;

3. lures to attract curious prey, such as the dangling "fishing lures" of anglerfish;

4. counterillumination, in which rows of photophores on the bellies of many mesopelagic fish produce blue light exactly matchingthe faint sunlight from above (making the fish invisible to predators below them);

5. confusing predators or prey, such as bright flashes that some squid make to stun their prey, and decoys that divert attention,such as the glowing green blobs ejected by green bomber worms ; and

6. "burglar alarms" in which an animal being attacked illuminates its attacker (the "burglar") so that an even bigger predator (the"police") will see the burglar and go after it. Some swimming sea cucumbers even coat their attackers with sticky glowingmucus so the "police" predators can find them many minutes later.

Most bioluminescence is blue, or blue-green, because those are the colors that travel farthest in water. As a result, mostanimals have lost the ability to see red light, since that is the color of sunlight that disappears first with depth. But a fewcreatures, like the dragonfish, have evolved the ability to produce red light. This light, which the dragonfish can see, gives it asecret "sniper" light to shine on prey that do not even know they are being lit up!

Pressure

Considering the volume of water above the deepest parts of the ocean, it's no wonder that hydrostatic pressure is one of themost important environmental factors affecting deep sea life. Pressure increases 1 atmosphere (atm) for each 10 m indepth. The deep sea varies in depth from 200 m to about 11,000 m, therefore pressure ranges from 20 atm to more than1,100 atm. High pressures can cause air pockets, such as in fish swim bladders , to be crushed, but it does not compresswater itself very much. Instead, high pressure distorts complex biomolecules — especially membranes and proteins — uponwhich all life depends. Indeed, many food companies now use high pressure to sterilize their products such as packagedmeats.

Life appears to cope with pressure effects on biomolecules in two ways. First, their membranes and proteins have pressure-resistant structures that work by mechanisms not yet fully understood, but which also mean their biomolecules do not workwell under low pressure in shallow waters. Second, some organisms may use "piezolytes" (from the Greek "piezin" forpressure). These are small organic molecules recently discovered that somehow prevent pressure from distorting largebiomolecules. One of these piezolytes is trimethylamine oxide (TMAO). This molecule is familiar to most people because itgives rise to the fishy smell of marine fish and shrimp. TMAO is found at low levels in shallow marine fish and shrimp thathumans routinely eat, but TMAO levels increase linearly with depth and pressure in other species. Really deep fish, includingsome grenadiers which humans are now fishing, smell much more fishy!

Animals brought from great depth to the surface in nets and submersible sample boxes generally die; in the case of some (butnot most) deep-sea fishes, their gas-filled swim bladder (adapted to resist high pressure) expands to a deadly size. However,the vast majority of deep-sea life has no air pockets that would expand as pressure drops during retrieval. Instead, it is thoughtthat rapid pressure as well as temperature changes kill them because their biomolecules no longer work well (high TMAO doesnot help, as it appears to be too high in deep-sea life for biomolecules to work properly at the surface). Advances in deep seatechnology are now enabling scientists to collect species samples in chambers under pressure so that they reach the surfacefor study in good condition.

Pressure-adapted microbes have been retrieved from trenches down to 11,000 m, and have been found in the laboratory tohave all these adaptations (pressure-resistant biomolecules and piezolytes). However, pressure adaptations have only beenstudied in animals down to about 5,000 m. We do not yet know if the adaptations found at those depths work at greaterdepths down to 11,000 m.

Temperature

Except in polar waters, the difference in temperature between theeuphotic, or sunlit, zone near the surface and the deep sea can be

dramatic because of thermoclines, or the separation of water layers ofdiffering temperatures. In the tropics, for example, a layer of warm waterover 20°C floats on top of the cold, dense deeper water. In most partsof the deep sea, the water temperature is more uniform and constant.With the exception of hydrothermal vent communities where hot wateris emitted into the cold waters, the deep sea temperature remainsbetween about -1 to about +4°C . However, water never freezes inthe deep sea (note that, because of salt, seawater freezes at -1.8°C ). Ifit did somehow freeze, it would just float to the surface as ice! Life in the deep is thought to adapt to this intense cold in thesame ways that shallow marine life does in the polar seas. This is by having "loose" flexible proteins and unsaturatedmembranes which do not stiffen up in the cold. Membranes are made of fats and need to be somewhat flexible to work well,so you may be familiar with this adaptation in your kitchen. Butter, a saturated fat, is very hard in your refrigerator and wouldmake a poor membrane in the cold, while olive oil — an unsaturated fat — is semi-solid and would make a good flexiblemembrane. However, as with pressure, there is a tradeoff: loose membranes and proteins of cold-adapted organisms readilyfall apart at higher temperatures (much as olive oil turns to liquid at room temperature).

Oxygen

The dark, cold waters of much of the deep sea have adequate oxygen. This is because cold water can dissolve more oxygenthan warm water, and the deepest waters generally originate from shallow polar seas. In certain places in the northern andsouthern seas, oxygen-rich waters cool off so much that they become dense enough to sink to the bottom of the sea. Theseso-called thermohaline currents can travel at depth around the globe, and oxygen remains sufficient for life because there isnot enough biomass to use it all up. However, there are also oxygen-poor environments in intermediate zones, whereverthere is no oxygen made by photosynthesis and there are no thermohaline currents. These areas, called oxygen minimumzones , usually lie at depths between 500 - 1,000 m in temperate and tropical regions. Here, animals as well as bacteriathat feed on decaying food particles descending through the water column use oxygen, which can consequently drop to nearzero in some areas. Biologists are still investigating how animals survive under such conditions.

Although most of the deep seafloor has oxygen, there are exceptions in isolated basins with no circulation. Some of thesebasins that have no oxygen are found at the bottom of the Mediterranean Sea . In 2010, scientists investigating these at3,000 m depths made a startling discovery: the first known animals to be living continuously without any oxygen. Theanimals are tiny Loriciferans , members of an animal phylum first discovered in 1983. How they can survive theseconditions is not yet known [see Animals thrive without oxygen at sea bottom ].

Food

Deep sea creatures have evolved some fascinating feeding mechanisms becausefood is scarce in these zones. In the absence of photosynthesis, most food consistsof detritus — the decaying remains of microbes, algae, plants and animals from theupper zones of the ocean — and other organisms in the deep. Scavengers on theseafloor that eat this "rain" of detritus include sea cucumbers (the most commonbenthic animal of the deep), brittle stars (seen in the photo above), and grenadieror rattail fish. The corpses of large animals such as whales that sink to the bottomprovide infrequent but enormous feasts for deep sea animals and are consumed by avariety of species. This includes jawless fish such as hagfish, which burrow intocarcasses, quickly consuming them from the inside out; scavenger sharks; crabs; anda newly discovered group of worms (called Osedax , meaning bone-eater) whichgrow root-like structures into the bone marrow!

Deep-sea pelagic fish such as gulper eels have very large mouths, huge hinged jawsand large and expandable stomachs to engulf and process large quantities of scarcefood. Many deep-sea pelagic fish have extremely long fang-like teeth that pointinward. This ensures that any prey captured has little chance of escape. Somespecies, such as the deep sea anglerfish and the viperfish , are also equipped witha long, thin modified dorsal fin on their heads tipped with a photophore lit with bioluminescence used to lure prey. Many ofthese fish don't expend much energy swimming in search of food; rather they remain in one place and ambush their prey usingclever adaptations such as these lures. Others, such as rattails or grenadiers (pictured below) cruise slowly over the seafloorlistening and smelling for food sources failing from above, which they engulf with their large mouths.

Many mesopelagic and deeper pelagic species also save energy by having watery, gelatinous muscles and other tissues withlow nutritive content. For example, an epipelagic tuna's muscle (the kind you might eat) may be 20% protein. This makes fora strong, fast muscle, but also takes considerable energy to maintain. In contrast, a deep pelagic blacksmelt or viperfish mayhave only 5-8% protein. This means they cannot swim as well as a tuna, but they can achieve a larger body size with muchless maintenance costs.

Some mesopelagic species have adapted to the low food supply (and sometimes to the low oxygen content) in moderate-depth waters with a special behavior called vertical migration . At dusk, millions of lantern fish, shrimp, jellies and othermobile animals migrate to the food-rich surface waters to feed in the darkness of night. Then, presumably to avoid being eatenin daylight, they return to the depths at dawn to digest. Some of the species undergo large pressure and temperature changesduring their daily migrations, but we do not yet know exactly how they cope with those dramatic daily changes.

Since plankton is scarce in the deep sea, filter feeding (the most common mode of feeding in shallow waters) is a difficultway to make a living. Consequently, some deep-sea animals belonging to groups once thought to be exclusively filter feedershave evolved into carnivores! One of these is the carnivorous sea squirt Megalodicopia hians . Sea squirts or tunicates aregenerally harmless filter feeders which draw in microscopic organisms through a siphon tube, but Megalodicopia hians has ahuge jaw-like siphon that can rapidly engulf swimming animals! Another of these is the ping-pong-tree sponge, Chondrocladia

lampadiglobus. Again, the vast majority of sponges draw in microscopic material through tiny pores, but this sponge hastree-like branches with large glass globes covered in Velcro-like sharp spikes that impale swimming prey!

Submarine canyons provide mixed blessings for seafloor life

Other Adaptations of Deep-sea Animals

We've described many of the unique adaptations that animals of the deep-sea have evolved to cope with their harshenvironment. Let's look at some others, not all of which are fully understood.

1. Body Color: This is often used by animals everywhere for camouflage and protection from predators. In the deep sea,animals' bodies are often transparent (such as many jellies and squids), black (such as blacksmelt fish ), or even red (suchas many shrimp and other squids). The absence of red light at these depths keeps them concealed from both predators andprey. Some mesopelagic fish such as hatchetfish have silvery sides that reflect the faint sunlight, making them hard to see.

2. Reproduction: Consider how hard it must be to find a mate in the vast dark depths. For most deep sea species, we do notknow how they achieve this. Earlier we noted that unique light patterns may aid in this. Deep-sea anglerfish may use suchlight patterns as well as scents to find mates, but they also have another interesting reproductive adaptation. Males are tinyin comparison to females and attach themselves to their mate using hooked teeth, establishing a parasitic-like relationship forlife. The blood vessels of the male merges with the female's so that he receives nourishment from her. In exchange, thefemale is provided with a very reliable sperm source, avoiding the problem of having to locate a new mate every breedingcycle.

3. Gigantism: Another possible adaptation that is not fully understood is called deep-sea gigantism . This is the tendency forcertain types of animals to become truly enormous in size. A well-known example is the giant squid, but there are manyothers such as the colossal squid, the giant isopod , the king-of-herrings oarfish (which may be the source of sea-serpentlegends ), and the recently captured giant amphipod from 7,000 m in the Kermadec Trench near New Zealand.While the giant tubeworms of hydrothermal vents (see below) grow well due to abundant energy supplies, the other giganticanimals live in food-poor habitats, and it is not known how they achieve such growth. It may simply be a result of the featurewe examine next: long lives.

4. Long Lives: Many deep-sea organisms, including gigantic but also many smaller ones, have been found to live for decadesor even centuries. Long-lived fishes include rattails or grenadiers and the orange roughy, which are of special concern asthey are targets of deep-sea fisheries . These species reproduce and grow to maturity very slowly, such that populationsmay take decades to recover (if at all) after being overfished. This has happened repeatedly to the orange roughy, a deep-sea fish easily found congregating around seamounts in the southern oceans. Once fisheries have wiped out oneseamount population, they move on to another seamount. [see Rough seas for orange roughy: Popular U.S. fish import injeopardy ]

Also of concern with respect to their long, slow lives are a group of animals once thought to be restricted to warm tropicalwaters: corals. In the last 30 years, numerous cold-water coral species have been found on rocky surfaces throughout thedeep sea. These animal colonies may live for centuries, or — amazingly — even millennia. One deep-sea coral colony offHawaii has been dated at over 4,000 years old, making it older than the Pyramids of Egypt! [see Deep-Sea Corals May BeOldest Living Marine Organism ] Again, these corals are highly vulnerable to fisheries as they are easily destroyed by deep-sea trawl nets , and they may take decades to grow back. [see NOAA's Coral Reef Conservation Program: Threats to Deep-sea Corals for more information]

Science at FMNH – Exploring Unknown Deep Sea Ecosystems

Hydrothermal Vent and Cold Seep Communities

Life in the deep sea is relatively sparse compared to the epipelagic (euphotic) and intertidal zones, with two exciting, andrelatively recently discovered exceptions — hydrothermal vent and cold seep communities.

Hydrothermal Vents

These amazing formations were first discovered in 1976 - 77 during a deep sea expedition with Alvin at a mid-ocean ridge near the Galapagos . At that time, only geologists were aboard, with the goal of directly observing seafloor spreading —the mid-ocean ridges being places where magma welling up underneath pushes two tectonic plates apart, creating a riftvalley between them. Some geologists thought there might be geyser-like hot springs, as found in rift valleys on land (such asin Iceland), while others thought that high pressure would prevent such formations. However no one predicted any interestingbiology. What they found not only revolutionized geology but biology even more so. These dives to depths of about 2,700 mrevealed hot springs of far greater complexity and beauty than anyone had imagined: hot mineral-rich water spewing (likecontinuous geysers) from vents heated by magma , with metal sulfides precipitating in the cold surrounding seawater to formintricate, colorful and often towering chimneys.

Moreover, a completely unexpected community of life was found around these aptly named hydrothermal vents, with not onlyhigh densities of numerous new species, but also a new kind of ecosystem flourishing in the dark that had never beenimagined by scientists — an ecosystem based on toxic gas! The most amazing of the new species was a giant tubeworm,named Riftia . Growing rapidly in dense clusters, these 2-meter-tall worms were found to have no digestive tract. Therevolutionary finding was that they subsist on energy-rich hydrogen sulfide in vent water and generated in the Earth's crust.Hydrogen sulfide (rotten-egg gas) is normally toxic to animals, but these worms avoid the problem in a spectacular manner.They harbor bacteria known as chemoautotrophs (in a large sac replacing a digestive system), which can use the energy inhydrogen sulfide to convert carbon dioxide into sugars, just as plants do using sunlight. The worm's blood picks up anddelivers sulfide, carbon dioxide and oxygen to these bacterial symbionts, which in turn "feed" their hosts with the excesssugars they make (while turning the sulfide into a non-toxic waste product). Thus, the ecosystem was found to run on theEarth's geothermal energy rather than sunlight. Many scientists now think that life on Earth began at such vents over 3billion years ago.

Since those first discoveries near the Galapagos, hydrothermal vent communities have been found at depths ranging fromabout 1,500 m to over 5,000 m [see Expedition to Mid-Cayman Rise Identifies Unusual Variety of Deep Sea Vents ].Most vents are along the mid-ocean ridges, where magma is close to seawater. Other animals with bacterial symbionts have been found, including other species of tubeworms, giant clams and mussels, snails, and shrimp. Undoubtedly many ventcommunities are yet to be found, since many ridge areas have not yet been explored.

The water temperature of vents is much warmer than normal for the deep sea (about 2°C ), reaching as high at 400°C without boiling due to the high pressure. However, nothing can live at such temperatures. The communities of vent life aremostly found between about 8 - 25°C , but may reach perhaps 60°C around some animals such as Pompeii worms(Alvinella) . Though complex life seems not to live at higher temperatures, some archaea have been found living attemperatures of over 120°C !

IMCS Deep Sea Microbiology Lab videos: Black Smoker | Tube Worms | Pompeii Worms | Zoarcid Fish | Crabs

Cold Seeps

After the first vent discoveries, other unexpected high-density deep-sea ecosystems were found. Named cold seeps, these occur atplaces (mostly along continental margins ) where cold methane (which at depths below 500 m forms methane-hydrate "ice"),hydrogen sulfide, and/or oil seep out of sediments to provideabundant energy. By some estimates, there is more energy lockedup in the methane hydrates than in all (other) fossil/hydrocarbonfuels combined. Animals with symbiotic bacteria were found, differentfrom but related to vent species, including tubeworms, clams, andmussels. Some mussels harbor methane-using bacteria instead ofsulfide-using ones, making ecosystems powered by natural gas!

Dense seep communities have also been found around deep brinepools, or "lakes within oceans." These form where salt depositsunder the ocean floor dissolve to form pools of water so dense fromtheir salt content that they do not mix with the overlying seawater.So far a few of these have been found in the Gulf of Mexico and theMediterranean Sea. At the best-studied brine pool (in the Gulf ofMexico: [see Lakes Within Oceans ] high densities of mussels live around the rim, subsisting (using symbionts) on methanegas seeping from the pool. However, no known animal can survive the salt within the pool itself. Various microbes have beenfound in the high salt waters, however.

In 2012, a new deep-sea ecosystem dubbed a "hydrothermal seep" was discovered off Costa Rica. It is a mosaic of vent andseep communities, with many new species. See the news story "Hot Meets Cold at New Deep-Sea Ecosystem " for moreinformation.

ReferencesMarine Biology, an Ecological Approach, J.W. Nybakken, Benjamin Cummings, 1994. Chapter 4: Deep Sea BiologyDive and Discover: Expeditions to the Seafloor - Woods Hole Oceanographic Institution NOAA Ocean Explorer Deep-Sea Biology by Paul Yancey Deep-Sea Biology, J.D. Gage & P.A. Taylor, Cambridge Univ. Press, 1992Deep-Sea Fishes, D.J. Randall & A.P. Farrell, Academic Press, 1997The Ecology of Deep-sea Hydrothermal Vents, C.L. Van Dover, Princeton Univ. Press, 2000The Biology of the Deep Ocean, P. Herring, Oxford Univ. Press, 2001The Silent Deep: The Discovery, Ecology, and Conservation of the Deep Sea, T. Koslow, Univ. Chicago Press, 2009.Deep-Sea Biodiversity: Pattern and Scale by M.A. Rex and R.J. Etter, Harvard Univ. Press, 2010.Lamellibrachia luymesi - Wikipedia

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MLA Citation: "The Deep Sea at MarineBio.org - Ocean biology, Marine life, Sea creatures, Marine conservation...". Dr. Paul Yancey/MarineBio.org.Updated 29 December 2011. Accessed 3 August 2012 <http://marinebio.org/oceans/deep/>.

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I love this website. It's amazing. Yet again, I love biology.<3 -Allysonallyson • 7 months ago

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who is the author of this page?Malbury95 • 5 months ago

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Look for "MLA Citation" under the Feedback? heading below. Best of luck!MarineBio MOD • 5 months ago • parent

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I am writing a research paper and would like to properly cite this webpage. Who is the author(s)

and the date this was written?

Thank you very much for this excellent webpage.

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MLA Citation:

"The Deep Sea at MarineBio.org". Dr. Paul Yancey/MarineBio.org. Updated 29 December 2011.

Accessed 22 February 2012 http://marinebio.org/oceans/de....

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This is a fantastic article, very well written and researched. I am also citing it in a

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Can anything in the deep sea be useful to humans, or are humans affecting the deep sea at all?Curious Student • 3 months ago

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I saw a documentary on deep sea creatures a long time ago and there was a creature that was as

long as a football field. Do you know what this is called? It is completely white and looks like a centipede

and extremely long.

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It was likely a siphonophore, see http://www.siphonophores.org/, http://www.ville-

ge.ch/mhng/hy..., and http://jellieszone.com/siphono... for more information about these fascinating

creatures.

MarineBio MOD • 5 months ago • parent

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• Reply •

this website is amazing, it had all the info I needed to make a power pointAndrew • 6 months ago

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• Reply •

This is totally helping me with my english article that I am making about the possibility of other

intelligent life forms in the ocean. :) Merci!

Danis • 8 months ago

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• Reply •

im making an research paper thanks to your knowledge and cooperation i love sea monster so ive

decided to make a research paper about the new species discovered in this year 2011 thanks again.

jeffrey nolasco • 8 months ago

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• Reply •

We're glad to help... best of luck!MarineBio MOD • 8 months ago • parent

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• Reply •

im doing a project about the possibility of humans able to live in the deep sea and this page

reeaally helped me in finding the info of the biosystem i need ... thank you guys very much!

Edwardt97 • 8 months ago

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• Reply •

Wow! That's really cool! This helped me with my Biology project so . . . THANK YOU! :DNam Rita • 9 months ago

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• Reply •

Wow, it's good to know that their are some people who really want to know what's around us and it

is just amazing to see the life at the bottom of the ocean... so keep up the good work and I hope some day I

will have enough money to be able to go deep in the ocean and see such interesting creatures too!

Joshuaharvey85 • 10 months ago

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Sea Life News :: ScienceDaily

Coral reef thriving in sediment-laden waters Rapid rates of coral reef growth have been identified in sediment-laden marine environments,

conditions previously believed to be detrimental to reef growth. A new study has established

that Middle Reef – part of Australia's iconic Great Barrier Reef – has grown more rapidly than

many other reefs in areas with lower levels of sediment stress.

Identifying dolphins with technology A student-developed computer program simplifies the process of manual photo identification

of bottlenose dolphins and other species.

Amazing deep diving by imperial cormorant bird Researchers recently fitted a South American sea bird called an imperial cormorant with a

small camera, then watched stunned as it became 'superbird' -- diving 150 feet underwater in

40 seconds, feeding on the ocean floor for 80 seconds where it eventually caught a snakelike fish, before returning to the surface 40

seconds later.

Critically endangered whales sing like birds; New recordings hint at rebound The critically endangered bowhead whales sing like birds in the Fram Strait, off the east coast of Greenland, indicating that the whales

might be more populous than previously thought or that they sing a wide repertoire of songs, unlike other whales, biologists have

found.

An avian flu that jumps from birds to mammals is killing New England's baby seals A novel avian influenza virus has acquired the ability to infect aquatic mammals and was responsible for an outbreak of fatal

pneumonia that recently struck harbor seals in New England, according to scientists.

New influenza virus from seals highlights the risks of pandemic flu from animals A new strain of influenza virus found in harbor seals could represent a threat to wildlife and human health, according to scientists.

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A new strain of influenza virus found in harbor seals could represent a threat to wildlife and human health, according to scientists.

Humpback whales staying in Antarctic bays later into autumn Large numbers of humpback whales are remaining in bays along the Western Antarctic Peninsula to feast on krill late into the austral

autumn, long after scientists thought their annual migrations to distant breeding grounds would begin, according to a new study.

Researchers monitor 'red tides' in Chesapeake Bay waters Researchers are monitoring the algal blooms that have been discoloring Chesapeake Bay waters during the last few weeks. These

"red tides" occur in the lower Bay every summer, but have appeared earlier and across a wider area than in years past, likely due to

last winter's warmth and this summer's heat.

Engineers are designing, building mechanical ray Batoid rays, such as stingrays and manta rays, are among nature's most elegant swimmers. They are fast, highly maneuverable,

graceful, energy-efficient, can cruise, bird-like, for long distances in the deep, open ocean, and rest on the sea bottom. Researchers

are trying to emulate the seemingly effortless but powerful swimming motions of rays by engineering their own ray-like machine

modeled on nature. They are designing an "autonomous underwater vehicle" that someday may surpass what nature has provided as

a model. The vehicle has potential commercial and military applications, and could be used for undersea exploration and scientific

research.

Ion selectivity in neuronal signaling channels evolved twice in animals Excitation of neurons depends on the selected influx of certain ions through specific channels. Obviously, these channels were

crucial for the evolution of nervous systems in animals. Scientists have revealed that voltage-gated sodium channels, which are

responsible for neuronal signaling in the nerves of animals, evolved twice in higher and lower animals.

Students discover methane seep ecosystem During a recent oceanographic expedition off San Diego, graduate student researchers discovered convincing evidence of a deep-sea

site where methane is likely seeping out of the seafloor, the first such finding off San Diego County.

Molecular mechanism behind deep-sea bacteria's pressure tolerance A Japanese research team has identified a structural change that confers pressure-resistant properties on a particular protein found

in bacteria.

The fin whale, under more threat in the Mediterranean than thought Until now it was thought that fin whales in the Strait of Gibraltar and the Alboran Sea made up part of the distribution of this species

of whale in the Mediterranean. However, scientists have just discovered that their population has been overestimated by including

specimens from the Atlantic that visit at certain times the western Mediterranean, where the noise generated by human activity affects

their survival.

International regulation curbs illegal trade of caviar Research that used mitochondrial DNA-based testing to compare the extent of fraudulent labeling of black caviar purchased before

and after international protection shows conservation benefits.

A fish friendly facility for the International Space Station While aquariums provide a relaxing pastime for humans on Earth, recreation is not the goal behind the new Aquatic Habitat, or AQH,

aboard the International Space Station. Instead, researchers will use this unique facility to look at how microgravity impacts marine

life.

Tropical plankton invade arctic waters: Researchers see natural cycle, but questions arise on climate change For the first time, scientists have identified tropical and subtropical species of marine protozoa living in the Arctic Ocean. Apparently,

they traveled thousands of miles on Atlantic currents and ended up above Norway with an unusual -- but naturally cyclic -- pulse of

warm water, not as a direct result of overall warming climate, say the researchers. On the other hand: Arctic waters are warming

rapidly, and such pulses are predicted to grow as global climate change causes shifts in long-distance currents.

Superfast evolution in sea stars How quickly can new species arise? In as little as 6,000 years, according to a study of Australian sea stars.

Marine microorganisms hold the key to life on Earth Few people realize that all life on earth evolved from microorganisms in the sea. Microorganisms, or microbes, are those organisms

too small to be observed by the human eye and they are everywhere, often in huge numbers. Just one litre of coastal seawater

contains up to a billion microbes including thousands of different types.

Mangroves: A filter for heavy metals A mangrove is a forest consisting of various species of mangrove trees growing with their bases submerged in water, at the interface

between land and sea. They cover more than three quarters of tropical coastlines, that is to say almost 200,000km². In New

Caledonia, they accounts for almost 80% of the island's western coastline. They act as a buffer zone between the lagoon and the

mountain mining areas, rich in metallic elements (iron, manganese, nickel, chrome and cobalt, nearly all toxic pollutants).

Marine protected areas: what is their impact on fishing? In a context of overfishing of aquatic resources, marine protected areas (MPAs) are tools for protecting biodiversity. These defined

marine areas are subject to preservation measures to save habitats necessary for fish reproduction and juvenile growth. What role do

they have to play in the management of halieutic resources?

Help us continue to share the wonders of the ocean with the world, raise awareness of marine conservation issues and theirsolutions, and support marine conservation scientists and students involved in the marine life sciences. Join the MarineBioConservation Society or make a donation today. We would like to sincerely thank all of our members, donors, and sponsors,we simply could not have achieved what we have without you and we look forward to doing even more.

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