Seamounts are exceptionally important to their biome ecologically, but their role in their environment is poorly understood. Because they project out above the surrounding sea floor, they disturb standard water flow, causing eddies and associated hydrological phenomena that ultimately result in water movement in an otherwise still ocean bottom. Currents have been measured at up to 0.9 knots, or 48 centimeters per second. Because of this upwelling seamounts often carry above-average plankton populations, seamounts are thus centers where the fish that feed on them aggregate, in turn falling prey to further predation, making seamounts important biological hotspots. Seamounts provide habitats and spawning grounds for these larger animals, including numerous fish.
Ecological role of seamounts
Seamount
Seamount | Ecological role of seamounts
Seamounts are exceptionally important to their biome ecologically, but their role in their environment is poorly understood. Because they project out above the surrounding sea floor, they disturb standard water flow, causing eddies and associated hydrological phenomena that ultimately result in water movement in an otherwise still ocean bottom. Because they project out above the surrounding sea floor, they disturb standard water flow, causing eddies and associated hydrological phenomena that ultimately result in water movement in an otherwise still ocean bottom Seamounts provide habitats and spawning grounds for these larger animals, including numerous fish. They often carry above-average plankton populations, seamounts are thus centers where the fish that feed on them aggregate, in turn falling prey to further predation, making seamounts important biological hotspots.
what is a chain of underwater mountains called
user
Seamount
assistant
what can you tell about its geographic features?
user
Seamounts can be found in every ocean basin in the world, distributed extremely widely both in space and in age. A seamount is technically defined as an isolated rise in elevation of or more from the surrounding seafloor, and with a limited summit area, of conical form.
assistant
how are these chain of mountains formed?
user
Formed millions of years ago by volcanism, they have since subsided far below sea level. This long chain of islands and seamounts extends thousands of kilometers northwest from the island of Hawaii.
assistant
what can you tell about its structure?
user
Seamounts can form in a wide variety of tectonic settings, resulting in a very diverse structural bank. Seamounts come in a wide variety of structural shapes, from conical to flat-topped to complexly shaped. Some are built very large and very low
assistant
how can you describe its ecological role?
user
Seamounts are exceptionally important to their biome ecologically, but their role in their environment is poorly understood. Because they project out above the surrounding sea floor, they disturb standard water flow, causing eddies and associated hydrological phenomena that ultimately result in water movement in an otherwise still ocean bottom. Currents have been measured at up to 0.9 knots, or 48 centimeters per second. Because of this upwelling seamounts often carry above-average plankton populations, seamounts are thus centers where the fish that feed on them aggregate, in turn falling prey to further predation, making seamounts important biological hotspots. Seamounts provide habitats and spawning grounds for these larger animals, including numerous fish.
Seamount | Ecological role of seamounts
This causes a different type of fauna to exist than on the seafloor, and leads to a theoretically higher degree of endemism. However, recent research especially centered at Davidson Seamount suggests that seamounts may not be especially endemic, and discussions are ongoing on the effect of seamounts on endemicity. They "have", however, been confidently shown to provide a habitat to species that have difficulty surviving elsewhere.
Seamount | Ecological role of seamounts
Some species, including black oreo "(Allocyttus niger)" and blackstripe cardinalfish "(Apogon nigrofasciatus)", have been shown to occur more often on seamounts than anywhere else on the ocean floor. Marine mammals, sharks, tuna, and cephalopods all congregate over seamounts to feed, as well as some species of seabirds when the features are particularly shallow. Seamounts often project upwards into shallower zones more hospitable to sea life, providing habitats for marine species that are not found on or around the surrounding deeper ocean bottom. Because seamounts are isolated from each other they form "undersea islands" creating the same biogeographical interest. As they are formed from volcanic rock, the substrate is much harder than the surrounding sedimentary deep sea floor.
Seamount | Ecological role of seamounts
Studies have indicated that a seamount functions as an "oasis of life," with a higher species count and more biodiversity than the surrounding seafloor. Although previous analysis has stressed the exceptionalism of the seamount habitat, recent biological analysis, much of it centered on Davidson Seamount, has indicated that this does not necessarily translate into a higher endemic percentage. However, it "is" believed that they provide a refuge for rare species that have difficulty surviving elsewhere. There are reasons that seamounts are biologically important. They rise high in the water column, creating complex current patterns that support life on, around, and above the seamount.
Davidson Seamount | Ecology
The surface of the seamount also provides a substrate upon which organisms can attach themselves and grow. This in turn supports the species that feed on them, in turn supporting the whole ecological food web. Scientists have found that seamounts often provide a habitat for endemic species that are not found anywhere else. Davidson Seamount is among the best biologically described seamounts worldwide. Six major expeditions to the volcano have yielded over 60,000 species observations. scientists have observed and recorded 168 species of megafauna on the seamount. Of these, about 7% of the species at Davidson are endemic, meaning they live only at Davidson.
Davidson Seamount | Ecology
There are various habitats and biological communities in the Condor Seamount.
Condor seamount | Habitats
The unique ecological condition of the Great Meteor Seamount is shown by the many endemic copepod and nematode species.
Great Meteor Seamount | Ecology
During one survey, a species of cutthroat eel, believed to be found only near Australia, was identified. Corals, echinoderms, and crustaceans make up a large portion of the creatures found on the seamount. These organisms act as indicator species, identifying potential problems in the ecosystem.
New England Seamounts | Biota
Water temperatures and salinity of the water masses around Tropic Seamount decrease with increasing depth and ripples indicate that strong ocean currents affect the seamount. A number of separate water masses surround the seamount, which originate from regions such as the North Atlantic, the South Atlantic and Antarctica and are stacked over each other. Corals and sponges and more generally sessile fauna cover parts of the eastern and western spurs of Tropic Seamount, forming multicoloured "forests"; among the animals are glass sponges. The bivalve "Rhinoclama teres" and the echinoids "Echinocyamus scaber", "Palaeotropus josephinae", "Peripatagus cinctus" and "Selenocidaris varispina" have been found on this seamount, as are xenophyophorea.
Tropic Seamount | Environment
Vesteris Seamount displays high biological productivity. The summit area of the seamount is densely inhabited by mats and biogenic structures formed by ascidians, bryozoans, polychaetes and sponges; in other sectors of the volcano sponges are accompanied by crinoids. Actinians, brittle stars, hydrozoans, molluscs, radiolarians and starfish are also found, as well as foraminiferal sands. Similar lifeforms are also found on the lower slopes of the seamount. Traces of endolithic fungi have been found in rock samples from the seamount. Life on Vesteris has formed a variety of structures, including hedges, mats, mounds, spurs and thickets, and a dense layer of biogenic sediments and living specimens covers large areas of the upper Vesteris Seamount.
Vesteris Seamount | Biology and climate
Whether there was Holocene activity 5,000–6,000 years ago or present-day hydrothermal activity is unclear. A variety of lifeforms are found both on Vesteris Seamount and within its rocks. Layers of sponges and bryozoans cover the upper parts of the seamount and form structures like mounds. This ecosystem has been compared to coral reefs.
Vesteris Seamount | Introduction
Despite our increasing knowledge on seamounts, there is still very little known about the relationships between their ecosystem functioning and biodiversity, and that of the surrounding areas. This information is vital in order to improve our understanding of connectivity between seamount hotspots and adjacent areas, and HERMIONE research will aim to discover whether seamounts act as centres of speciation (the evolution of new species), or if they play a role as "stepping stones", allowing fauna to colonise and disperse across the oceans.
Hotspot Ecosystem Research and Man's Impact On European Seas | Seamounts
Green Seamount is not very biologically diverse. The only fauna observed at its hydrothermal sites were single-celled, fan-shaped xenophyophores, and some shrimp. Still, marks of biological life were plentiful wherever sediments were or more deep. The xenophyophores in particular were of a type that was found on many of the seamounts in the eastern Pacific region. "Alvin" took two samples, a sponge of the Hexactinellid family and barnacles of the Sessilia order, back to the surface for analysis.
Green Seamount | Biology
palmiformis", the sea snail "Lepetodrilus fucensis", the bristle worm "Amphisamytha galapagensis", and the sea spider "Sericosura verenae".
Axial Seamount | Ecology
After a period of explosive activity near the ocean surface, the eruptions slowly die away. With eruptions becoming infrequent and the seamount losing its ability to maintain itself, the volcano starts to erode. After finally becoming extinct (possibly after a brief rejuvenated period), they are ground back down by the waves. Seamounts are built in a far more dynamic oceanic setting than their land counterparts, resulting in horizontal subsidence as the seamount moves with the tectonic plate towards a subduction zone. Here it is subducted under the plate margin and ultimately destroyed, but it may leave evidence of its passage by carving an indentation into the opposing wall of the subduction trench.
Seamount | Geochemistry and evolution
The hydrothermal vents and seamounts of the Azores ("") are a series of Atlantic seamounts and hydrothermal vents that are part of the Mid-Atlantic Ridge system, giving rise to the archipelago and bathymetric region of the Azores. These geological structures, formed from masses of basalt (typical of mid-ocean regions), are of a geomorphological interest due to their rich deposits of ore. In addition it fosters a rich ecosystem of diverse subaquatic plant and animal life. There are food chains within this environment, for example, that are purely chemosynthetic, and do not need sunlight for photosynthesis.
Hydrothermal vents and seamounts of the Azores | Introduction
The most important feature of the hydrodynamics of the Condor seamount is the presence of a mainstream coming from North, and a pattern of movement with rotation to the right (clockwise) over its Western Ridge. This pattern of movement can capture and retain nutrients and organisms from the outside of the Bank, in the area of 50–60 m above its top. This model can be interrupted by sporadic events of default elimination of movement, which can last up to a few months, encouraging the entry of new materials of the surrounding areas. Thus, the biological productivity of the area may change depending on oceanographic conditions.
Condor seamount | Oceanography
The seamount was discovered in 1958. Anton Dohrn Seamount hosts a diverse ecosystem characterized by reefs formed by cold water corals, sponges and xenophyophorans, which themselves host a number of animals. It has been affected by human fishing operations, however.
Anton Dohrn Seamount | Introduction
Seamounts are underwater mountains that rise from the depths of the ocean, and whose summits can sometimes be found just a few hundred metres below the sea surface. To be classified as a seamount the summit must be 1000 m higher than the surrounding seafloor, and under this definition there are an estimated 1000–2800 seamounts in the Atlantic Ocean and around 60 in the Mediterranean Sea. Seamounts enhance water flow through localised tides, eddies, and upwelling, and these physical processes may enhance primary production. Seamounts may therefore be considered as hotspots of marine life; fauna benefit from the enhanced hydrodynamics and phytoplankton supply, and thrive on the slopes and summits.
Hotspot Ecosystem Research and Man's Impact On European Seas | Seamounts
Like many other seamounts, Cobb Seamount acts as a biological center of diversity, and supports a dense oceanic ecosystem. Relatively convenient access and an interesting biological setting have made the seamount an object of several scientific cruises and dives.
Cobb Seamount | Introduction
There is evidence that seamounts can host concentrations of biologic diversity, each with its own unique local ecosystem; they seem to affect oceanic currents, resulting among other things in local concentration of plankton which in turn attracts species that graze on it, and indeed are probably a significant overall factor in biogeography of the oceans. They also may serve as way stations in the migration of whales and other pelagic species. Despite being poorly studied, they are heavily targeted by commercial fishing, including dredging. In addition they are of interest to potential seabed mining. The overall goal of CenSeam is "to determine the role of seamounts in the biogeography, biodiversity, productivity, and evolution of marine organisms, and to evaluate the effects of human exploitation on seamounts." To this effect, the group organizes and contributes to various research efforts about seamount biodiversity.
Global Census of Marine Life on Seamounts | Introduction
A seamount is a large geologic landform that rises from the ocean floor but that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor to in height. They are defined by oceanographers as independent features that rise to at least above the seafloor, characteristically of conical form. The peaks are often found hundreds to thousands of meters below the surface, and are therefore considered to be within the deep sea. During their evolution over geologic time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface.
Seamount | Introduction
The Condor Seamount was chosen as a study model, for several reasons: is representative of these sub aquatic Azorean ecosystems; their depths cover a good range of different biological communities; its relatively small size allows a thorough sampling of the different habitats; its accessibility facilitates periodic biological sampling campaigns. Since 2008, the Condor Seamount became the target of several scientific campaigns in order to increase the knowledge of their ecosystems and human activities that concern, with a view to their sustainable management, in order to serve as a model for other seamounts. It was an underwater observatory for monitoring and experimental multidisciplinary studies that involve a considerable number of researchers of Portuguese and international institutions.
Condor seamount | Scientific Campaigns
In addition there are long gullies formed either by erosional or volcanic processes, as well as parasitic vents and volcanic ridges.
Tropic Seamount | Local
Marine life also flourishes around seamounts that rise from the depths, where fish and other sea life congregate to spawn and feed.
Marine habitats | Seamounts
Interactions between seamounts and underwater currents, as well as their elevated position in the water, attract plankton, corals, fish, and marine mammals alike. Their aggregational effect has been noted by the commercial fishing industry, and many seamounts support extensive fisheries. There are ongoing concerns on the negative impact of fishing on seamount ecosystems, and well-documented cases of stock decline, for example with the orange roughy ("Hoplostethus atlanticus"). 95% of ecological damage is done by bottom trawling, which scrapes whole ecosystems off seamounts.
Seamount | Introduction
Seamounts can form in a wide variety of tectonic settings, resulting in a very diverse structural bank. Seamounts come in a wide variety of structural shapes, from conical to flat-topped to complexly shaped. Some are built very large and very low, such as Koko Guyot and Detroit Seamount; others are built more steeply, such as Loihi Seamount and Bowie Seamount. Some seamounts also have a carbonate or sediment cap. Many seamounts show signs of intrusive activity, which is likely to lead to inflation, steepening of volcanic slopes, and ultimately, flank collapse. There are also several sub-classes of seamounts. The first are guyots, seamounts with a flat top.
Seamount | Structure
The seamount is elongated in about northeast-south-southwest direction, with ridges radiating from its northern sector and the lower southern sector spreading southwestward like a tongue. This elongation matches the trend of magnetic lineations on the surrounding seafloor, implying that it may be controlled by the surrounding tectonic environment. The submarine slopes of the seamount are quite steep and show two benches at and depth. The seamount has dimensions of on the seafloor. About 15–20 parasitic vents dot the deeper flanks of the seamount and reach height, and small ridges en echelon to Vesteris are found on the southeastern flank. The total volume of the seamount is about .
Vesteris Seamount | Geography and geology
The seamount chain provides a unique habitat for deep sea marine creatures. Coral formations grow on the rocky outcrops, resembling underwater forests that provide shelter for invertebrates and fish. Due to the expense and difficulties of studying the deep ocean, little was known of the creatures that inhabited the New England Seamounts. In fact, before recent expeditions, there was only one known coral species in the entire chain. Since 2000, marine biologists, during various exploratory studies, have caught and classified over 203 species of fish and 214 species of invertebrates on the Bear Seamount. This range of diversity suggests that other seamounts may harbour more unknown macro-organisms.
New England Seamounts | Biota
Decapods, fish including "Lepidion eques", the eel "Synaphobranchus kaupi" and squat lobsters "Munida sp." have also been encountered.
Anton Dohrn Seamount | Ecology
A wide variety of sealife lives on the seamount. Corals dominate in deeper areas and sponges in its shallower parts.
Pioneer Seamount | Biological environment
The Tasmanian Seamounts are an important feature of the south Tasmanian marine environment. While oceans generally contain few nutrients, the presence of seamounts increases the flowing speed of the water current. This effect, created by the topography of the seafloor mountain, clears rocks in the area of sediments and provides food for filter feeders. The swept rocks serve as substrate for sponges and corals to attach to. Among them are some of the longest–living organisms on Earth, reaching an age of "hundreds and possibly thousands of years". The Tasmanian Seamounts in particular are dominated by the stony coral "Solenosmilia variabeles"; these corals provide a roost and living space for benthic mollusks, echinoderms and crustaceans like stone crabs ("Parclamis sp."), squat lobsters ("Munidopsis treis"), and top snails ("Trochidae sp."), thus solidifying the seamounts' ecology.
Tasmanian Seamounts | Ecology
Guyots are also associated with specific lifeforms and varying amounts of organic matter. Local increases in chlorophyll a, enhanced carbon incorporation rates and changes in phytoplankton species composition are associated with guyots and other seamounts.
Guyot | Characteristics
Between 700 and 900 m depth there are large aggregations of sponges in the Condor seamount. These aggregations are dominated by the presence of glass sponge ("Pheronema carpenteri") and are also considered as habitats of conservation importance.
Condor seamount | Aggregations of sponges
All the seamounts in the group are complex northeast-southwest trending structures, consisting of parallel ridges separated by sediment-filled troughs. The ridges constructed run parallel to an ancient spreading center which has since been replaced in its role by the San Andreas Fault system. They are unique in this origin, as they are formed from the remnants of an old ocean-ridge spreading center. A series of "knobs" are aligned with the ridges; however the distinctive summit crater, evident in many oceanic volcanoes, is absent. This lack of a collapse crater suggests that magma was never stored in a chamber within the structure, as with most other volcanoes.
Davidson Seamount | Geology
Like other large seamounts, Patton acts as an ecological hub for sea life. Dives have revealed that the volcano is heavily encrusted in sea life of various forms, including sea stars, corals, king crabs, demersal rockfish, and other species.
Patton Seamount | Introduction
Numerous craters and small volcanic cones dot its flanks which bear evidence of sector collapses.
Cadamosto Seamount | Geography and geomorphology
Volcanic activity at Echo and Tropic seamounts was probably focused and generated a circular volcanic structure, while at Drago and The Paps it was controlled by lineaments and thus formed elongated edifices.
Tropic Seamount | Geology
71% of the species can be confidently classified as cosmopolitan (widespread), and sufficient data exists for 22% of the observed species to strongly suggest that their range is not limited to seamounts. The remaining 7% have only been seen in video footage. Thirteen species have been identified in other areas, but never in other seamounts.
Davidson Seamount | Ecology
Patton Seamount is ecologically vibrant: geologist Randy Keller of the Oregon State University once said "...it's just astonishing how much there is around you. You see rocky outcroppings and there's life everywhere—sponges and sea stars." Patton Seamount, like many other seamounts, serves as an "oasis of life" for resident organisms. Isolated populations found on seamounts like Patton have been shown to have high levels of endemism and specialization, and Patton Seamount is almost completely encrusted in life. Limited-scale fishing operations and scientific investigations were carried around in the 80s and 90s, mostly due to the rough nature of the seamounts, and the difficulty of sampling at such depths.
Patton Seamount | Ecology
Among the animals found on the Foundation Seamounts are the seaperch "Helicolenus lengerichi", the striped trumpeter, decapods including the genus "Paralomis" and the species "Shinkaia crosnieri", and the spiny lobster "Jasus caveorum". The Foundation Seamounts are a candidate for an Ecologically or Biologically Significant Area. The Foundation-Pacific-Antarctic-Ridge intersection is the first known deep sea hydrothermal system from the southern hemisphere. Hydrothermal communities found at the active hydrothermal venting sites include "Bathymodiolus", bythograeids, "Munidopsis", "Neolepas", polychaetes, snails and zoarcid fish. Filter feeders are found as well and include crinoids and hexactinellid sponges. Actinians, coryphaenid fish and serpulids round out the local fauna.
Foundation Seamounts | Biology
"S. thermophilus" spend most of their time on the sea floor, moving forwards or backwards by undulating their bodies and sometimes burying themselves completely in the substrate. They seem to be attracted to loose sediments, probably related to the uncovering of food, and often congregate in pits. The fish frequently rest atop one another without reaction. The vent communities that co-occur with "S. thermophilus" differs greatly between seamounts. They co-occur with large numbers of the snail "Oenopota ogasawaarna" at the Daikoku Seamount, and with the abundant shrimp "Opaepele loihi" at the Nikko Seamount. They also frequently occur with the crab "Austinograea yunohana", which are found at Nikko, Daikoku, and Kasuga-2.
Symphurus thermophilus | Biology and ecology
Compared to mid-ocean ridge seamounts, subduction zone seamounts generally have more sodium, alkali, and volatile abundances, and less magnesium, resulting in more explosive, viscous eruptions. All volcanic seamounts follow a particular pattern of growth, activity, subsidence and eventual extinction. The first stage of a seamount's evolution is its early activity, building its flanks and core up from the sea floor. This is followed by a period of intense volcanism, during which the new volcano erupts almost all (e.g. 98%) of its total magmatic volume. The seamount may even grow above sea level to become an oceanic island (for example, the 2009 eruption of Hunga Tonga).
Seamount | Geochemistry and evolution
While overall the species diversity on the seamount is lower than a comparable area on the surface, the species present have grown in greater numbers and have formed larger colonies, to the point that there was little to no bare rock surface on the seamount, and none has been found in expeditionary dives. Some endemism to the seamount has also been noted.
Cobb Seamount | Biology
This environment has been compared to a coral reef. The seamount lies close to the polar front with the East Greenland Current transporting freshwater from ice melt and ice to the seamount. The sea above Vesteris is covered by sea ice for most of the year except for August and September, and water temperatures on the surface of the seamount are around in summer.
Vesteris Seamount | Biology and climate
A common but much smaller fish was "Aldrovandia phalacra". Twenty-six species of cephalopods were collected including squid such as "Mastigoteuthis agassizii" and "Mastigoteuthis magna". Other invertebrates caught by trawls dragged along the seamount surface included 46 species of crustacean such as the prawns "Sergestes spp." and "Acanthephyra spp.", and the shrimp "Pasiphaea spp". Also present was the bank-forming deepwater coral "Lophelia pertusa", which supported a community of worms, hydroids and other corals. Brittle stars, especially "Ophiomusium lymani", were numerous as were the sea urchin "Echinus affinis", the sea star "Neomorphaster forcipatus", mysids and various scyphozoans.
Bear Seamount | Biodiversity
Large landslides and late volcanic activity affected the seamount, cutting large scars into its flanks and forming cones on its summit plateau, respectively. Volcanic activity at Tropic Seamount commenced almost 120 million years ago and ended about 60 million years ago. Later, sedimentation commenced on the seamount leading to the deposition of manganese crusts and pelagic sediments; iron and manganese accumulated in crusts over time beginning a few tens of millions of years ago.
Tropic Seamount | Introduction
The summit of the volcano is dominated by a carpet of "Hinnites multirugosus", which forms the base of a dense ecosystem of sponges and other small, sessile organisms. The species is otherwise scarce in its distribution in the Pacific; its abundance is accommodated by the scarcity of its chief predator, the sea star "Orthasterias koehleri". The reason for the sea star's disparity is unknown, as it is extremely common on nearby seamounts. The steeper flanks of the volcanoes are carpeted by coralline algae of the "Lithothamnion" and "Lithophyllum" genera. In some areas, "Borgiola pustulosa" is more common. Red-colored colonies of demosponge and related species predominant the ecosystem, which includes sea urchins, sponges, algae, anemones, and gastropods.
Cobb Seamount | Biology
An episode of crustal subsidence in the Cretaceous-Oligocene also played a role in lowering Anton Dohrn Seamount. The pinnacles on the seamount may be leftover volcanic conduits that resisted erosion. Sedimentation covered the seamount and its flanks in the Eocene and continued afterwards.
Anton Dohrn Seamount | Geologic history
The floor of the seamount is generally covered by a dense layer of seaweed, dominated by the "Cystoseira" species, a seaweed found in deeper areas. In shallower depths less than from the surface there are populations of "Laminaria" (large colonies of chestnut seaweeds). The Department of Oceanography and Fisheries at the University of the Azores (Ponta Delgada) monitors and studies these species annually through scientific missions to the reef and surrounding islets.
Dollabarat | Biome
While the official name for these features refers to knolls, researchers in different disciplines see these features in different terms. These features are often referred to as seamounts where a seamount is described as any geographic isolated topographic feature on the seafloor taller than , including ones whose summit regions may temporarily emerge above sea level, but not including features that are located on continental shelves or that are part of other major landmasses. The seamounts are the site of volcanism from the late Cenozoic era. The knolls are high, stand deep at their base and at their summit. Many of the seamounts bear marks of tidal scour from water erosion, the result of millions of years of wear by a current moving at per second.
Graveyard Seamounts | Geography and geology
The ecological conservation of seamounts is hurt by the simple lack of information available. Seamounts are very poorly studied, with only 350 of the estimated 100,000 seamounts in the world having received sampling, and fewer than 100 in depth. Much of this lack of information can be attributed to a lack of technology, and to the daunting task of reaching these underwater structures; the technology to fully explore them has only been around the last few decades. Before consistent conservation efforts can begin, the seamounts of the world must first be mapped, a task that is still in progress. Overfishing is a serious threat to seamount ecological welfare.
Seamount | Conservation
Since the first discovery of hydrothermal vents, more than 600 species have been described from vents and seeps. This is equivalent of 1 new description every 2 weeks(!). As biologists, geochemists, and physicists combine research efforts in these systems, new species will certainly be discovered. Moreover, because of the extreme conditions of the vent and seep habitat, certain species may have specific physiological adaptations with interesting results for the biochemical and medical industry. These globally distributed, ephemeral and insular habitats that support endemic faunas offer natural laboratories for studies on dispersal, isolation and evolution. Here, hydrographic and topographic controls on biodiversity and biogeography might be much more readily resolved than in systems where climate and human activity obscure their role.
Biogeography of Deep-Water Chemosynthetic Ecosystems | Background
Many of these ecosystems were only discovered in the Atlantic between 1977 and 1992.
Hydrothermal vents and seamounts of the Azores | Biome
Complex hydrographical patterns with anticyclones and Taylor columns cause water flow around the summit. Water eddies tend to disrupt this flow. A bottom trawling experiment conducted during research brought up large orange roughy ("Hoplostethus atlanticus") aggregations, as well as bycatch of benthic fauna including sponges, gorgonians, and scleractinian corals.
Sedlo Seamount | Introduction
South Chamorro Seamount is host to a variety of fauna, including mussels, gastropods, tube worms, and galatheid crabs. A borehole observatory on the summit produced 20,000 litres of microbially-altered fluid per day for study. These organisms are supported by low-temperature springs from the fissures surrounding the summit zone. The mussels are probably of the genus Bathymodiolus, which require a high concentration of methane in their food source. The fluid composition and the biological community suggests that the summit region is an active cold seep region.
South Chamorro Seamount | Ecology
The knowledge of the diversity of organisms that inhabit an area is a key requirement for the implementation of management and conservation measures. A list of species that live or visit the Condor Seamount is in preparation, using various sources of information, including field sampling, underwater observations and data provided by the users of the Condor. The number of animals identified in the Condor Seamount is around 900. Despite the identification work is still in progress there are species new to Science, others await description, and scientific name, particularly the species that live in the sediment.
Condor seamount | Biodiversity
It might have formed either through erosion of surrounding sediments by ocean currents or through isostatic subsidence.
Anton Dohrn Seamount | Geography and geomorphology
The seamount suffered a major flank collapse on its southeastern side, over which the present summit was probably formed. The summit supports an ecosystem of mussels, gastropods, tube worms, and others, suggesting that it is an active seeping region.
South Chamorro Seamount | Introduction
Non-hydrothermal chemical alteration has taken place and has formed carbonate, celadonite, chlorite, hematite, prehnite, quartz, smectite and rare zeolites. Thick ferromanganese deposits were recovered from the seamount in 1992 by the and are found especially on the western flank but also in the summit region, often over partly consolidated sediments. They have the appearance of a black crust. Components include carbonate fluorapatite, goethite and manganese dioxide as well as minor calcite and quartz; the crusts which occur on the Canary Islands Seamounts including at Tropic Seamount reach thicknesses of and are rich in cobalt and other elements of industrial importance.
Tropic Seamount | Composition
After they have subsided and sunk below the sea surface such flat-top seamounts are called "guyots" or "tablemounts". The Earth's oceans contain more than 14,500 identified seamounts of which 9,951 seamounts and 283 guyots, covering a total area of , have been mapped but only a few have been studied in detail by scientists. Seamounts and guyots are most abundant in the North Pacific Ocean, and follow a distinctive evolutionary pattern of eruption, build-up, subsidence and erosion. In recent years, several active seamounts have been observed, for example Loihi in the Hawaiian Islands. Because of their abundance, seamounts are one of the most common marine ecosystems in the world.
Seamount | Introduction
The Condor seamount has sediment of various types, including those of volcanic origin, as well as sediments composed of organic matter derived from living organisms, that, in some areas, form thick plates, sometimes with 15 cm. These sediments can contain several species, including gorgonians, sponges and other organisms.
Condor seamount | Sedimentary areas
Although it is one of over 100 underwater features in the region, Cobb Seamount is the only one known to extend well upwards into the region of the ocean penetrated by light. Like many other seamounts, Cobb Seamount is a local biological hotspot and functions as an "island of stability" for local organisms. It supports an extensive fish population, mostly "Sebastes" species and especially "Sebastes miniatus". Bird life has been noted in the area of its summit, indicating that it is a prime fishing ground. For the complete known species inventory of Cobb Seamount, see Du Preez et al., 2015.
Cobb Seamount | Biology
Thermophilic and hyperthermophilic microorganisms organism have been found at the seamount. Thermophiles found on the seafloor outside Orca Seamount may indicate that thermal waters of Orca Seamount may travel laterally through geological structures or that currents bring in thermal water from Deception Island, an active volcano.
Bransfield Strait | Description
Their gills form electrochemical gradients that mediate salt excretion in salt water and uptake in fresh water.
Ecology | Water
Seamounts can be found in every ocean basin in the world, distributed extremely widely both in space and in age. A seamount is technically defined as an isolated rise in elevation of or more from the surrounding seafloor, and with a limited summit area, of conical form. There are more than 14,500 seamounts. In addition to seamounts, there are more than 80,000 small knolls, ridges and hills less than 1,000 m in height in the world's oceans. Most seamounts are volcanic in origin, and thus tend to be found on oceanic crust near mid-ocean ridges, mantle plumes, and island arcs.
Seamount | Geography
These tops must be or more below the surface of the sea; the diameters of these flat summits can be over . Knolls are isolated elevation spikes measuring less than . Lastly, pinnacles are small pillar-like seamounts.
Seamount | Structure
At Tropic Seamount they formed from water but were also influenced by material coming from Africa.
Tropic Seamount | Composition
Others that are ecologically interesting include a parasite of water bears and the zooplankter "Daphnia".
Blastocladiomycota | Ecological roles
This flat summit is covered by high volcanic cones and features terraces at the margin of the summit as well as ridges that point due north, east, south and west. Volcanic cones are concentrated in the southern and eastern parts of the summit platform. The seamount has a volume of about , similar to other Atlantic Ocean volcanoes. Raised beaches have been reported from Tropic Seamount. The outer slopes of the seamount become steeper to the summit perhaps due to geochemical differences between the rocks that form the lower slopes and these of the upper slopes. They are cut by curved flank collapses that open to the northeast, southeast, southwest and northwest; these collapses have cut into the volcanic edifice and have left ridges between the individual collapses which give the seamount its four-point star form and deposited debris around the seamount, although the deposits are not recognizable probably because they are old and buried beneath sediments.
Tropic Seamount | Local
This seamount is about 90 x 40 km, it rises from ocean depths of about 4500 m well into the euphotic zone. The summit topography is rather disturbed with a summit plateau ~ 6 x 3 km in about 120 m and a peak reaching up to 55 m below the water surface.
Ampère Seamount | Introduction
This is finally capped by alkalic flows late in its eruptive history, as the link between the seamount and its source of volcanism is cut by crustal movement. Some seamounts also experience a brief "rejuvenated" period after a hiatus of 1.5 to 10 million years, the flows of which are highly alkalic and produce many xenoliths.
Seamount | Geochemistry and evolution
The ecosystem can be characterised as a dry deciduous forest or Bushveld.
Modimolle | Introduction
The oceanic microbiome plays a significant role in the ecological biogeochemistry of the planet's oceans.
Ecology | Biome
A thick layer of sediment covers the flat top and appears to be reworked by storms and sea currents. Mounds, slope breaks and other volcanic pinnacles are located on the flat top. The seamount tilts southeastward. Beyond the margin of the flat top, the slopes of Anton Dohrn Seamount drop down to depth. The steep slopes have been variously described as either lacking a sediment cover or featuring gravelly sediments along with outcropping bedrock. There are cliffs, ridges and rockfalls but no gullies or canyons. Parasitic cones lie on the northwestern slope. A moat surrounds the seamount and reaches depths of about .
Anton Dohrn Seamount | Geography and geomorphology
Noroît Seamount's marine habitats are well researched. Investigations by the research vessel EV "Nautilus" in 2014 found a variety of stony corals ("scleractinians"), octocorals, and sponges. Corals created habitat for brittle stars, squat lobsters and sea snails. In the sea depth there are variety of fish — Acanthonus armatus, Bathypterois phenax, Bembrops, Conger esculentus, Coryphaenoides, Hexanchus griseus, Lepidion, Luciobrotula corethromycter, and Polymixia lowei.
Noroit Seamount | Flora and fauna
The canyons and seamounts are celebrated for their rich biological diversity. The steep slopes of the canyons and seamounts interact with oceanographic currents to create localized eddies, causing upwelling. The currents lift nutrients to surface waters, fueling an outburst of phytoplankton and zooplankton that form the base of the food chain. These plankton draw large schools of small fish, and those fish draw even larger predators such as whales, sharks, tunas and seabirds to the area. In all, “the geology, currents, and productivity create diverse and vibrant ecosystems.” As a result, the area has been the subject of “intense scientific interest” and discovery since the 1970s.
Massachusetts Lobstermen's Association v. Ross | History
Given its height, during the last glacial maximum Adams was likely an island. Its slopes are covered by recent lava flows, volcanic debris and hyaloclastite. Lava flows feature aa lava characteristics and lava tubes, while deeper parts of the edifice are covered with lapilli and scoria. Parasitic vents form cones and mounds on its flanks.
Adams Seamount | Geography and geomorphology
Depending on how common these species are and what roles they play in the ecosystem, their extinction caused by such a disaster would have a large impact on the way the area's systems functioned. If nothing else, the economic hit that the tsunami would produce would be devastating due to the effects it could have on the logging, fishing, and tourism industries.
Mount Breakenridge | Social, environmental, ecological, and economic significance
A number of sea animals and fish are encountered on the seamount; active fisheries existed at Vema Seamount and caused the disappearance of some animal species.
Vema Seamount | Introduction
The complicated process that created the vents occurred between 140,000 and 70,000 years ago, and by looking at the sulfur chimneys scientists can estimate that it has taken about 260,000 years for the Green Seamount to reach its present height. There is also an iron-manganese crust on a small off-axis seamount that adjoins Green Seamount, a configuration common with sulfur-rich seamounts.
Green Seamount | Geology
Seamounts that are not clearly linked to a mantle plume indicate that regional mantle composition and tectonic activity may also play important roles in producing intraplate volcanism.
Ocean island basalt | Introduction
The structure appears to consist of lagoonal sediments surrounded by a reef, and the shallowest point of Allison Guyot lies at less than depth below sea level. Volcanic cones dot the eastern side of the summit plateau. The seamount bears traces of slumping, which on the southeastern side of Allison Guyot has removed part of the platform perimeter. The seamount rises 1.5 kilometres above the seafloor. Underneath Allison Guyot, the seafloor is about 130–119 million years old, and a 128-million year-old magnetic lineation is located nearby. The Molokai Fracture Zone forms a ridge which passes close to Allison Guyot and intersects with another ridge at the seamount.
Allison Guyot | Local setting
A number of flat-topped seamounts rise from the floor of the western Pacific Ocean to depths of below sea level. They are called guyots and are clustered in an elongated region with and between the Marshall Islands and the Tuamotus. It is presumed that hotspots generated most of these seamounts. The Marshall Islands are grouped in two chains and three groups, the Ratak Chain including Limalok Guyot, the Ralik Chain including Wōdejebato Guyot and an isolated cluster farther west including Eniwetok Island.
Ruwitūn̄tūn̄ | Geological context
In the right climatic regions, coral growth can sometimes keep pace with the subsidence, resulting in coral atoll formation, but eventually the corals dip too deep to grow and the island becomes a guyot. The greater the amount of time that passes, the deeper the guyots become. Seamounts provide data on movements of tectonic plates on which they ride, and on the rheology of the underlying lithosphere. The trend of a seamount chain traces the direction of motion of the lithospheric plate over a more or less fixed heat source in the underlying asthenosphere, the part of the Earth's mantle beneath the lithosphere.
Guyot | Formation
Suspension feeders, such as gorgonian sea fans and the cold-water corals like Lophelia pertusa, often dominate the rich benthic (seafloor-dwelling) communities. The enhanced abundance and diversity of fauna is not limited to benthic species, as fish are known to aggregate over seamounts. Unfortunately, this knowledge has led to increasing commercial exploitation of seamount fish by the fishing industry, and a number of seamount fish populations have already been depleted. Part of HERMIONE research will assess the threats and impacts of human activities on seamounts, including comparing data from seamounts in different stages of fisheries exploitation to understand more about the impacts of fishing activities., both on target species and non-target species, and their habitats.
Hotspot Ecosystem Research and Man's Impact On European Seas | Seamounts
Not all of these hotspots are necessarily fed by a deep continuous mantle plume; some may be nourished by discrete batches of melting material that rise through the mantle. Other chains may be controlled by mantle flow towards a spreading ridge, which has been proposed for the Musicians chain.
Musicians Seamounts | Geologic context
The seamounts in the field are typically less than wide but several kilometres wide; seamounts that are part of a ridge are between high. The total volume of rocks in the seamount province is about .
Rano Rahi seamounts | Geography and geomorphology
Possibly, as such a seamount or a seamount chain subducted it indented the trenches, forming a re-entrant.
Erimo Seamount | Regional
Corals from seamounts are also vulnerable, as they are highly valued for making jewellery and decorative objects. Significant harvests have been produced from seamounts, often leaving coral beds depleted.
Seamount | Conservation
Therefore, Trout-perch showed to be numerically important for the area since it seem to help to maintain the proper amount of species in its environment by serving as a food source and by preying on species, which are increasing and their increased can affect the ecosystem equilibrium.
Percopsis omiscomaycus | Ecological Role
In contrast, the knolls in the group that are affected by bottom trawling are mostly barren, with few coral and a completely different ecosystem. In 2001, witnessing the damage of bottom trawling to seamount communities, 19 seamounts off the coast of New Zealand were closed off to bottom trawling, three of them from the Graveyard group. Timed surveys of the seamounts over the years are being used to examine how well a seamount coral community recovers from the effects of dredging over time.
Graveyard Seamounts | Ecology
Tectonically the seamount is part of the Pacific Plate.
Allison Guyot | Local setting
Barnacles and brachiopods grow on the top of the seamount, and echinoderms, corals and cirripedes also occur there. On the sandy or gravelly substrate serpulids and sponges are found. The seamount may be a shark nursery. Finally, the bivalve "Xylophaga anselli" has been found at Anton Dohrn Seamount and the Hebrides slope. A number of ecosystems have been found on Anton Dohrn Seamount, including coral gardens, cold water coral reefs and sponge and xenophyophore communities; this seamount is the first place in the United Kingdom where coral gardens have been discovered. The sandy and cobbly terrain of the slopes with occasional bedrock outcrops is populated by reefs that grow on bedrock or on cobbles.
Anton Dohrn Seamount | Ecology
Deep sea corals and sponges grow on the Musicians Seamounts; corals identified include "Antipathes", "Acanthogorgia", chrysogorgidae, "Hemicorallium", isididae, "Metalagorgia", "Paracalyptrophora", "Pleurogorgia" and primnoids, while sponges include "Caulophacus", "Hyalostylus", "Poliopogon" and "Saccocalyx". In some places true "coral forests" grow on the seamounts. Animal species observed on the seamounts by remotely operated vehicles include amphipods, anemones, anglerfish, arrow worms, bristlemouths, brittle stars, cephalopods, chirons, codling fish, ctenophores, crinoids, cusk eels, fangtooth fish, halosaurs, jellyfish, larvaceans, piglet squid, polychaetes, ribbon worms, sea cucumbers, sea elephants, sea pens, sea spiders, sea stars, shrimp, siphonophores, spider crabs, squat lobsters, urchins and zoanthids.
Musicians Seamounts | Biology
The flathead sole occupies an intermediate trophic level in the food chain.
Flathead sole | Role in ecosystem
The Condor Bank fishing involves the bottom (demersal) and also pelagic fish species.
Condor seamount | <a href="Fisheries%20science">Fisheries</a>
The scale of ecological dynamics can operate like a closed system, such as aphids migrating on a single tree, while at the same time remain open with regard to broader scale influences, such as atmosphere or climate. Hence, ecologists classify ecosystems hierarchically by analyzing data collected from finer scale units, such as vegetation associations, climate, and soil types, and integrate this information to identify emergent patterns of uniform organization and processes that operate on local to regional, landscape, and chronological scales. To structure the study of ecology into a conceptually manageable framework, the biological world is organized into a nested hierarchy, ranging in scale from genes, to cells, to tissues, to organs, to organisms, to species, to populations, to communities, to ecosystems, to biomes, and up to the level of the biosphere.
Ecology | Hierarchy
Therefore, their role in the ecosystem is essential.
Scarabaeinae | Ecology
Seamount – A mountain rising from the ocean seafloor that does not reach to the water's surface
Outline of oceanography | Seamounts