Deep sea creature

The term deep sea creature refers to organisms that live below the photic zone of the ocean. These creatures must survive in extremely harsh conditions, such as hundreds of bars of pressure, small amounts of oxygen, very little food, no sunlight, and constant, extreme cold. Most creatures have to depend on food floating down from above.

These creatures live in very demanding environments, such as the abyssal or hadal zones, which, being thousands of meters below the surface, are almost completely devoid of light. The water is between 3 and 10 degrees Celsius and has low oxygen levels. Due to the depth, the pressure is between 20 and 1,000 bars. Creatures that live hundreds or even thousands of meters deep in the ocean have adapted to the high pressure, lack of light, and other factors.

Anoplogaster cornuta 2
Common fangtooth, Anoplogaster cornuta

Barometric pressure

These animals have evolved to survive the extreme pressure of the sub-photic zones. The pressure increases by about one bar every ten meters. To cope with the pressure, many fish are rather small. These creatures have also eliminated all excess cavities that would collapse under the pressure, such as swim bladders.[1]

Lack of light

The lack of light requires creatures to have special adaptations to find food, avoid predators, and find mates. Most animals have very large eyes with retinas constructed mainly of rods, which increases sensitivity. Many animals have also developed large feelers to replace peripheral vision. To be able to reproduce, many of these fish have evolved to be hermaphroditic, eliminating the need to find a mate. Many creatures have also developed a very strong sense of smell to detect the chemicals released by mates.

Lack of resources

Bathynomus giganteus
A giant isopod (Bathynomus giganteus)

At this depth, there is not enough light for photosynthesis to occur and not enough oxygen to support animals with a high metabolism. To survive, creatures have slower metabolisms which require less oxygen; they can live for long periods without food. Most food either comes from organic material that falls from above or from eating other creatures that have derived their food through the process of chemosynthesis (the process of changing chemical energy into food energy). Because of the sparse distributions of creatures, there is always at least some oxygen and food. Also, instead of using energy to search for food, these creatures use particular adaptations to ambush prey.

Hypoxic environment

Creatures that live in the sub-abyss require adaptations to cope with the naturally low oxygen levels.

Deep-sea gigantism

Humpback anglerfish
Humpback anglerfish: Melanocetus johnsonii

The term deep-sea gigantism describes an effect that living at such depths has on some creatures' sizes, especially relative to the size of relatives that live in different environments. These creatures are generally many times bigger than their counterparts. The giant isopod (related to the common pill bug) exemplifies this. To date, scientists have only been able to explain deep-sea gigantism in the case of the giant tube worm. Scientists believe these creatures are much larger than shallower-water tube worms because they live on hydrothermal vents that expel huge amounts of resources. They believe that, since the creatures don't have to expend energy regulating body temperature and have a smaller need for activity, they can allocate more resources to bodily processes.

There are also cases of deep-sea creatures being abnormally small, such as the lantern shark, which fits in an adult human's palm. [2]

Bioluminescence

Nur04512
Smaller cousins of giant tube worms feeding at a hydrothermal vent

Bioluminescence is the ability of an organism to create light through chemical reactions. Creatures use bioluminescence in many ways: to light their way, attract prey, or seduce a mate. Many underwater animals are bioluminescent—from the viper fish to the various species of flashlight fish, named for their light.[3] Some creatures, such as the angler fish, have a concentration of photophores in a small limb that protrudes from their bodies, which they use as a lure to catch curious fish. Bioluminescence can also confuse enemies. The chemical process of bioluminescence requires at least two chemicals: the light producing chemical called luciferin and the reaction causing chemical called luciferase.[4] The luciferase catalyzes the oxidation of the luciferin causing light and resulting in an inactive oxyluciferin. Fresh luciferin must be brought in through the diet or through internal synthesis.[4]

Chemosynthesis

Since, at such deep levels, there is little to no sunlight, photosynthesis is not a possible means of energy production, leaving some creatures with the quandary of how to produce food for themselves. For the giant tube worm, this answer comes in the form of bacteria. These bacteria are capable of chemosynthesis and live inside the giant tube worm, which lives on hydrothermal vents. These vents spew forth very large amounts of chemicals, which these bacteria can transform into energy. These bacteria can also grow free of a host and create mats of bacteria on the sea floor around hydrothermal vents, where they serve as food for other creatures. Bacteria are a key energy source in the food chain. This source of energy creates large populations in areas around hydrothermal vents, which provides scientists with an easy stop for research. Organisms can also use chemosynthesis to attract prey or to attract a mate. [5]

Deep sea research

ALVIN submersible
Alvin in 1978, a year after first exploring hydrothermal vents.

Humans have explored less than 3% of the ocean floor, and dozens of new species of deep sea creatures are discovered with every dive. The submarine DSV Alvin—owned by the US Navy and operated by the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Massachusetts—exemplifies the type of craft used to explore deep water. This 16 ton submarine can withstand extreme pressure and is easily manoeuvrable despite its weight and size.

The extreme difference in pressure between the sea floor and the surface makes the creature's survival on the surface near impossible; this makes in-depth research difficult because most useful information can only be found while the creatures are alive. Recent developments have allowed scientists to look at these creatures more closely, and for a longer time. A marine biologist, Jeffery Drazen, has explored a solution, a pressurized fish trap. This captures a deep-water creature, and adjusts its internal pressure slowly to surface level as the creature is brought to the surface, in the hope that the creature can adjust.[6]

Another scientific team, from the Universite Pierre et Marie Curie, has developed a capture device known as the PERISCOP, which maintains water pressure as it surfaces, thus keeping the samples in a pressurized environment during the ascent. This permits close study on the surface without any pressure disturbances affecting the sample.[7]

In popular culture

  • The BBC's Blue Planet features deep sea creatures, highlighting their peculiar attributes.

See also

Notes

  1. ^ The Deep Sea at MarineBio.org - Ocean biology, Marine life, Sea creatures, Marine conservation
  2. ^ Video: 12ft Crabs, Walking Fish and Mini Sharks: Deep Sea Creatures - Science - WeShow (US Edition)
  3. ^ Monterey Bay Aquarium: Online Field Guide
  4. ^ a b BL Web: Chemistry
  5. ^ Chemosynthesis
  6. ^ New Trap May Take Deep-Sea Fish Safely Out of the Dark
  7. ^ Lever, Anna-Marie (31 July 2008). "Live fish caught at record depth". BBC News. Retrieved 18 February 2011.

External links

Abyss Box

The Abyss Box is a vessel containing 16 litres (3.5 imp gal; 4.2 US gal) of water at the very high pressure of 18 megapascal to simulate the natural underwater environment of hadal fauna living at about 1,800 metres (5,900 ft) below the surface. It is on display at Oceanopolis aquarium in Brest, France. It was designed by French researcher Bruce Shillito from Pierre and Marie Curie University in Paris.All the equipment maintaining the extreme pressure inside the Abyss Box weighs 600 kilograms (1,300 lb). The device will keep deep-dwelling creatures alive so they can be studied, especially regarding their adaptability to warmer ocean temperatures. Currently the Abyss Box houses only common species of deep sea creatures including a deep sea crab, Bythograea thermydron and a deep sea prawn, Pandalus borealis, which are some of the hardier species with a higher survival rate in depressurized environments.

Aquatic ecosystem

An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems.

Aquatic toxicology

Aquatic toxicology is the study of the effects of manufactured chemicals and other anthropogenic and natural materials and activities on aquatic organisms at various levels of organization, from subcellular through individual organisms to communities and ecosystems. Aquatic toxicology is a multidisciplinary field which integrates toxicology, aquatic ecology and aquatic chemistry.This field of study includes freshwater, marine water and sediment environments. Common tests include standardized acute and chronic toxicity tests lasting 24–96 hours (acute test) to 7 days or more (chronic tests). These tests measure endpoints such as survival, growth, reproduction, that are measured at each concentration in a gradient, along with a control test. Typically using selected organisms with ecologically relevant sensitivity to toxicants and a well-established literature background. These organisms can be easily acquired or cultured in lab and are easy to handle.

Benthos

Benthos is the community of organisms that live on, in, or near the seabed, river, lake, or stream bottom, also known as the benthic zone. This community lives in or near marine or freshwater sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.

Many organisms adapted to deep-water pressure cannot survive in the upperparts of the water column. The pressure difference can be very significant (approximately one atmosphere for each 10 metres of water depth).Because light is absorbed before it can reach deep ocean-water, the energy source for deep benthic ecosystems is often organic matter from higher up in the water column that drifts down to the depths. This dead and decaying matter sustains the benthic food chain; most organisms in the benthic zone are scavengers or detritivores.

The term benthos, coined by Haeckel in 1891, comes from the Greek noun βένθος "depth of the sea". Benthos is used in freshwater biology to refer to organisms at the bottom of freshwater bodies of water, such as lakes, rivers, and streams. There is also a redundant synonym, benthon.

Bioluminescence

Bioluminescence is the production and emission of light by a living organism. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria and terrestrial invertebrates such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic organisms such as Vibrio bacteria; in others, it is autogenic, produced by the animals themselves.

In a general sense, the principal chemical reaction in bioluminescence involves some light-emitting molecule and an enzyme, generally called the luciferin and the luciferase, respectively. Because these are generic names, the luciferins and luciferases are often distinguished by including the species or group, i.e. Firefly luciferin. In all characterized cases, the enzyme catalyzes the oxidation of the luciferin.

In some species, the luciferase requires other cofactors, such as calcium or magnesium ions, and sometimes also the energy-carrying molecule adenosine triphosphate (ATP). In evolution, luciferins vary little: one in particular, coelenterazine, is found in eleven different animal (phyla), though in some of these, the animals obtain it through their diet. Conversely, luciferases vary widely between different species, and consequently bioluminescence has arisen over forty times in evolutionary history.

Both Aristotle and Pliny the Elder mentioned that damp wood sometimes gives off a glow and many centuries later Robert Boyle showed that oxygen was involved in the process, both in wood and in glow-worms. It was not until the late nineteenth century that bioluminescence was properly investigated. The phenomenon is widely distributed among animal groups, especially in marine environments where dinoflagellates cause phosphorescence in the surface layers of water. On land it occurs in fungi, bacteria and some groups of invertebrates, including insects.

The uses of bioluminescence by animals include counter-illumination camouflage, mimicry of other animals, for example to lure prey, and signalling to other individuals of the same species, such as to attract mates. In the laboratory, luciferase-based systems are used in genetic engineering and for biomedical research. Other researchers are investigating the possibility of using bioluminescent systems for street and decorative lighting, and a bioluminescent plant has been created.

Call of the Mastodon

Call of the Mastodon is a compilation of early recordings of the metal band Mastodon. It was released on February 7, 2006, by Relapse Records.

The album contains alternate re-ordered versions of all the songs from their early EPs Lifesblood and Slick Leg. It also includes the track "Call of the Mastodon", which previously only appeared on their demo release 9 Song Demo. The Japanese release contains a bonus live version of "Where Strides the Behemoth" from their debut album Remission.

This was their final release on Relapse; they subsequently signed to Warner Music.

In a documentary on the making of Crack the Skye, guitarist/vocalist Brent Hinds referred to Call of the Mastodon as their first studio album. This sentiment was also echoed by Bill Kelliher when he appeared on Loudwire's 'Wikipedia: Fact or Fiction'.

Floodplain restoration

Floodplain restoration is the process of fully or partially restoring a river's floodplain to its original conditions before having been affected by the construction of levees (dikes) and the draining of wetlands and marshes.

The objectives of restoring floodplains include the reduction of the incidence of floods, the provision of habitats for aquatic species, the improvement of water quality and the increased recharge of groundwater.

GIS and aquatic science

Geographic Information Systems (GIS) has become an integral part of aquatic science and limnology. Water by its very nature is dynamic. Features associated with water are thus ever-changing. To be able to keep up with these changes, technological advancements have given scientists methods to enhance all aspects of scientific investigation, from satellite tracking of wildlife to computer mapping of habitats. Agencies like the US Geological Survey, US Fish and Wildlife Service as well as other federal and state agencies are utilizing GIS to aid in their conservation efforts.

GIS is being used in multiple fields of aquatic science from limnology, hydrology, aquatic botany, stream ecology, oceanography and marine biology. Applications include using satellite imagery to identify, monitor and mitigate habitat loss. Imagery can also show the condition of inaccessible areas. Scientists can track movements and develop a strategy to locate locations of concern. GIS can be used to track invasive species, endangered species, and population changes.

One of the advantages of the system is the availability for the information to be shared and updated at any time through the use of web-based data collection.

Lake ecosystem

A lake ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions.Lake ecosystems are a prime example of lentic ecosystems. Lentic refers to stationary or relatively still water, from the Latin lentus, which means sluggish. Lentic waters range from ponds to lakes to wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams. Together, these two fields form the more general study area of freshwater or aquatic ecology.

Lentic systems are diverse, ranging from a small, temporary rainwater pool a few inches deep to Lake Baikal, which has a maximum depth of 1642 m. The general distinction between pools/ponds and lakes is vague, but Brown states that ponds and pools have their entire bottom surfaces exposed to light, while lakes do not. In addition, some lakes become seasonally stratified (discussed in more detail below.) Ponds and pools have two regions: the pelagic open water zone, and the benthic zone, which comprises the bottom and shore regions. Since lakes have deep bottom regions not exposed to light, these systems have an additional zone, the profundal. These three areas can have very different abiotic conditions and, hence, host species that are specifically adapted to live there.

Limnology

Limnology ( lim-NOL-ə-jee; from Greek λίμνη, limne, "lake" and λόγος, logos, "knowledge"), is the study of inland aquatic ecosystems.

The study of limnology includes aspects of the biological, chemical, physical, and geological characteristics and functions of inland waters (running and standing waters, fresh and saline, natural or man-made). This includes the study of lakes, reservoirs, ponds, rivers, springs, streams, wetlands, and groundwater. A more recent sub-discipline of limnology, termed landscape limnology, studies, manages, and seeks to conserve these ecosystems using a landscape perspective, by explicitly examining connections between an aquatic ecosystem and its watershed. Recently, the need to understand global inland waters as part of the Earth System created a sub-discipline called global limnology. This approach considers processes in inland waters on a global scale, like the role of inland aquatic ecosystems in global biogeochemical cycles.Limnology is closely related to aquatic ecology and hydrobiology, which study aquatic organisms and their interactions with the abiotic (non-living) environment. While limnology has substantial overlap with freshwater-focused disciplines (e.g., freshwater biology), it also includes the study of inland salt lakes.

List of watershed topics

This list embraces topographical watersheds and drainage basins and other topics focused on them.

Matthew Cable

Matthew Joseph Cable is a fictional character appearing in DC Comics' Swamp Thing series. Introduced in Swamp Thing (Volume 1) #1 in November 1972, he died and was later resurrected as Dream's raven in Neil Gaiman's rendition of The Sandman.

Matt Cable is played by Henderson Wade in the television series based on the comic book series of the same name for the DC streaming service.

Particle (ecology)

In marine and freshwater ecology, a particle is a small object. Particles can remain in suspension in the ocean or freshwater. However, they eventually settle (rate determined by Stokes' law) and accumulate as sediment. Some can enter the atmosphere through wave action where they can act as cloud condensation nuclei (CCN). Many organisms filter particles out of the water with unique filtration mechanisms (filter feeders). Particles are often associated with high loads of toxins which attach to the surface. As these toxins are passed up the food chain they accumulate in fatty tissue and become increasingly concentrated in predators (see bioaccumulation). Very little is known about the dynamics of particles, especially when they are re-suspended by dredging. They can remain floating in the water and drift over long distances. The decomposition of some particles by bacteria consumes a lot of oxygen and can cause the water to become hypoxic.

Photic zone

The photic zone, euphotic zone (Greek for "well lit": εὖ "well" + φῶς "light"), or sunlight (or sunlit) zone is the uppermost layer of water in a lake or ocean that is exposed to intense sunlight. It corresponds roughly to the layer above the compensation point, i.e. depth where the rate of carbon dioxide uptake, or equivalently, the rate of photosynthetic oxygen production, is equal to the rate of carbon dioxide production, equivalent to the rate of respiratory oxygen consumption, i.e. the depth where net carbon dioxide assimilation is zero.

It extends from the surface down to a depth where light intensity falls to one percent of that at the surface, called the euphotic depth. Accordingly, its thickness depends on the extent of light attenuation in the water column. Typical euphotic depths vary from only a few centimetres in highly turbid eutrophic lakes, to around 200 meters in the open ocean. It also varies with seasonal changes in turbidity.

Since the photic zone is where almost all of the photosynthesis occurs, the depth of the photic zone is generally proportional to the level of primary production that occurs in that area of the ocean. About 90% of all marine life lives in the photic zone. A small amount of primary production is generated deep in the abyssal zone around the hydrothermal vents which exist along some mid-oceanic ridges.

The zone which extends from the base of the euphotic zone to about 200 metres is sometimes called the disphotic zone. While there is some light, it is insufficient for photosynthesis, or at least insufficient for photosynthesis at a rate greater than respiration. The euphotic zone together with the disphotic zone coincides with the epipelagic zone. The bottommost zone, below the euphotic zone, is called the aphotic zone. Most deep ocean waters belong to this zone.

The transparency of the water, which determines the depth of the photic zone, is measured simply with a Secchi disk. It may also be measured with a photometer lowered into the water.

Ramsar Convention

The Ramsar Convention on Wetlands of International Importance especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of wetlands. It is also known as the Convention on Wetlands. It is named after the city of Ramsar in Iran, where the Convention was signed in 1971.

Every three years, representatives of the Contracting Parties meet as the Conference of the Contracting Parties (COP), the policy-making organ of the Convention which adopts decisions (Resolutions and Recommendations) to administer the work of the Convention and improve the way in which the Parties are able to implement its objectives. COP12 was held in Punta del Este, Uruguay, in 2015. COP13 was held in Dubai, United Arab Emirates, in October 2018.

Ramsar site

A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention.The Convention on Wetlands, known as the Ramsar Convention, is an intergovernmental environmental treaty established in 1971 by UNESCO, which came into force in 1975. It provides for national action and international cooperation regarding the conservation of wetlands, and wise sustainable use of their resources.Ramsar identifies wetlands of international importance, especially those providing waterfowl habitat.

As of 2016, there were 2,231 Ramsar sites, protecting 214,936,005 hectares (531,118,440 acres), and 169 national governments are currently participating.

Sustainable gardening

Sustainable gardening includes the more specific sustainable landscapes, sustainable landscape design, sustainable landscaping, sustainable landscape architecture, resulting in sustainable sites. It comprises a disparate group of horticultural interests that can share the aims and objectives associated with the international post-1980s sustainable development and sustainability programs developed to address the fact that humans are now using natural biophysical resources faster than they can be replenished by nature.Included within this compass are those home gardeners, and members of the landscape and nursery industries, and municipal authorities, that integrate environmental, social, and economic factors to create a more sustainable future.

Organic gardening and the use of native plants are integral to sustainable gardening.

The Workhorse Chronicles

"The Workhorse Chronicles" is a DVD release by American progressive metal band Mastodon released on February 21, 2006 through Relapse Records and marks the band's final release through the company, before signing up to Warner Bros. Records.

The DVD is divided into 3 sections. The first is a documentary that traces the process of band's formation and also provides information about previous bands of individual members.

The second section consists of live performances recorded from year 2000 to 2005 including rare footage of the band in their initial form as a five-piece through to sold-out clubs worldwide. There are 28 recorded live performances in total.

The third section is a selection of music videos. It features the band's first 3 music videos: "March Of The Fire Ants", "Blood and Thunder", and "Iron Tusk". The video for "Seabeast" is not included on this release, even though it had been made at the time; the DVD went into pressing before it could to be included. The DVD was originally going to contain alternate videos for some songs (including "Battle At Sea" and "Seabeast") that focused entirely upon drummer Brann Dailor. However, for some unknown reason these "Drum-cam" videos were not included on the DVD.

Tracks 7-10 appears on their compilation album, Call of the Mastodon

Tracks 11-15 on their EP Lifesblood and "Call of the Mastodon"

Tracks 16-25 on their debut album, Remission

Tracks 26-33 on their second album, Leviathan

Aquatic ecosystems

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.