1.
Ocean
–
An ocean is a body of saline water that composes much of a planets hydrosphere. On Earth, an ocean is one of the major divisions of the World Ocean. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, the word sea is often used interchangeably with ocean in American English but, strictly speaking, a sea is a body of saline water partly or fully enclosed by land. The ocean contains 97% of Earths water, and oceanographers have stated that less than 5% of the World Ocean has been explored, the total volume is approximately 1.35 billion cubic kilometers with an average depth of nearly 3,700 meters. As the world ocean is the component of Earths hydrosphere, it is integral to all known life, forms part of the carbon cycle. The world ocean is the habitat of 230,000 known species, but because much of it is unexplored, the origin of Earths oceans remains unknown, oceans are thought to have formed in the Hadean period and may have been the impetus for the emergence of life. Extraterrestrial oceans may be composed of water or other elements and compounds, the only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan, although there is evidence for the existence of oceans elsewhere in the Solar System. Early in their histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, compounds such as salts and ammonia dissolved in water lower its freezing point so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice. Unconfirmed oceans are speculated beneath the surface of many planets and natural satellites, notably. The Solar Systems giant planets are thought to have liquid atmospheric layers of yet to be confirmed compositions. Oceans may also exist on exoplanets and exomoons, including surface oceans of water within a circumstellar habitable zone. Ocean planets are a type of planet with a surface completely covered with liquid. The concept of Ōkeanós has an Indo-European connection, Greek Ōkeanós has been compared to the Vedic epithet ā-śáyāna-, predicated of the dragon Vṛtra-, who captured the cows/rivers. Related to this notion, the Okeanos is represented with a dragon-tail on some early Greek vases, though generally described as several separate oceans, these waters comprise one global, interconnected body of salt water sometimes referred to as the World Ocean or global ocean. This concept of a body of water with relatively free interchange among its parts is of fundamental importance to oceanography. The major oceanic divisions – listed below in descending order of area and volume – are defined in part by the continents, various archipelagos, Oceans are fringed by smaller, adjoining bodies of water such as seas, gulfs, bays, bights, and straits. The Mid-Oceanic Ridge of the World are connected and form the Ocean Ridge, the continuous mountain range is 65,000 km long, and the total length of the oceanic ridge system is 80,000 km long
2.
Marine life
–
Marine life, or sea life or ocean life, refers to the plants, animals and other organisms that live in the salt water of the sea or ocean, or the brackish water of coastal estuaries. At a fundamental level, marine life helps determine the nature of our planet. Marine organisms produce much of the oxygen we breathe, shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land. Most life forms evolved initially in marine habitats, oceans provide about 99 percent of the living space on the planet. The earliest vertebrates appeared in the form of fish, which live exclusively in water, some of these evolved into amphibians which spend portions of their lives in water and portions on land. Other fish evolved into mammals and subsequently returned to the ocean as seals. Plant forms such as kelp and algae grow in the water and are the basis for some underwater ecosystems, plankton, and particularly phytoplankton, are key primary producers forming the general foundation of the ocean food chain. Marine vertebrates must obtain oxygen to survive, and they do so in various ways, fish have gills instead of lungs, although some species of fish, such as the lungfish, have both. Marine mammals, such as dolphins, whales, otters, some amphibians are able to absorb oxygen through their skin. Invertebrates exhibit a range of modifications to survive in poorly oxygenated waters including breathing tubes. However, as invertebrate life evolved in an aquatic habitat most have little or no specialisation for respiration in water. Altogether there are 230,000 documented marine species, including over 16,000 species of fish, there is no life without water, which has been characterised as the solvent of life. The Nobel prize winner Albert Szent-Györgyi referred to water as the mater und matrix, the abundance of water on earths surface is a unique feature that distinguishes earth from other planets in the Solar System. Earths hydrosphere consists chiefly of the oceans, but technically includes all surfaces in the world, including inland seas, lakes, rivers. The deepest underwater location is Challenger Deep of the Mariana Trench in the Pacific Ocean with a depth of 10,911.4 m, the mass of the oceans is approximately 1. 35×1018 metric tons, or about 1/4400 of Earths total mass. The oceans cover an area of 3. 618×108 km2 with a depth of 3682 m. If all of Earths crustal surface was at the elevation as a smooth sphere. About 97. 5% of the water is saline, the remaining 2. 5% is fresh water, Most fresh water, about 68. 7%, is present as ice in ice caps and glaciers
3.
Sea
–
A sea is a large body of salt water that is surrounded in whole or in part by land. More broadly, the sea is the system of Earths salty. The sea moderates Earths climate and has important roles in the cycle, carbon cycle. Although the sea has been traveled and explored since prehistory, the scientific study of the sea—oceanography—dates broadly to the British Challenger expedition of the 1870s. Owing to the present state of continental drift, the Northern Hemisphere is now equally divided between land and sea but the South is overwhelmingly oceanic. Salinity in the ocean is generally in a narrow band around 3. 5% by mass, although this can vary in more landlocked waters, near the mouths of large rivers. About 85% of the solids in the sea are sodium chloride. Deep-sea currents are produced by differences in salinity and temperature, surface currents are formed by the friction of waves produced by the wind and by tides, the changes in local sea level produced by the gravity of the Moon and Sun. The direction of all of these is governed by surface and submarine land masses, former changes in sea levels have left continental shelves, shallow areas in the sea close to land. The most diverse areas surround great tropical coral reefs, whaling in the deep sea was once common but whales dwindling numbers prompted international conservation efforts and finally a moratorium on most commercial hunting. Life may have started there and aquatic microbial mats are generally credited with the oxygenation of Earths atmosphere, the sea is an essential aspect of human trade, travel, mineral extraction, and power generation. It is the scene of activities including swimming, diving, surfing. However, population growth, industrialization, and intensive farming have all contributed to marine pollution. Atmospheric carbon dioxide is being absorbed in increasing amounts, lowering its pH in a known as ocean acidification. The shared nature of the sea has made overfishing an increasing problem, both senses of sea date to Old English, the larger sense has required a definite article since Early Middle English. Seas are generally larger than lakes and contain salt water, while the defining elements of size and being bounded are generally used, there is no formally accepted technical definition of sea among oceanographers. In international law, the United Nations Convention on the Law of the Sea states that all the ocean is the sea. Earth is the known planet with seas of liquid water on its surface, although Mars possesses ice caps
4.
Biology
–
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, identification and taxonomy. Modern biology is a vast and eclectic field, composed of branches and subdisciplines. However, despite the broad scope of biology, there are certain unifying concepts within it that consolidate it into single, coherent field. In general, biology recognizes the cell as the unit of life, genes as the basic unit of heredity. It is also understood today that all organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable, the term biology is derived from the Greek word βίος, bios, life and the suffix -λογία, -logia, study of. The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus used biologi in his Bibliotheca botanica, the first German use, Biologie, was in a 1771 translation of Linnaeus work. In 1797, Theodor Georg August Roose used the term in the preface of a book, karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological, physiological and psychological perspective. The science that concerns itself with these objects we will indicate by the biology or the doctrine of life. Although modern biology is a recent development, sciences related to. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, Egypt, the Indian subcontinent, however, the origins of modern biology and its approach to the study of nature are most often traced back to ancient Greece. While the formal study of medicine back to Hippocrates, it was Aristotle who contributed most extensively to the development of biology. Especially important are his History of Animals and other works where he showed naturalist leanings, and later more empirical works that focused on biological causation and the diversity of life. Aristotles successor at the Lyceum, Theophrastus, wrote a series of books on botany that survived as the most important contribution of antiquity to the plant sciences, even into the Middle Ages. Scholars of the medieval Islamic world who wrote on biology included al-Jahiz, Al-Dīnawarī, who wrote on botany, biology began to quickly develop and grow with Anton van Leeuwenhoeks dramatic improvement of the microscope. It was then that scholars discovered spermatozoa, bacteria, infusoria, investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining. Advances in microscopy also had a impact on biological thinking. In the early 19th century, a number of biologists pointed to the importance of the cell. Thanks to the work of Robert Remak and Rudolf Virchow, however, meanwhile, taxonomy and classification became the focus of natural historians
5.
Taxonomy (biology)
–
Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
6.
Genus
–
A genus is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of classification, genus comes above species. In binomial nomenclature, the name forms the first part of the binomial species name for each species within the genus. Felis catus and Felis silvestris are two species within the genus Felis, Felis is a genus within the family Felidae. The composition of a genus is determined by a taxonomist, the standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. Moreover, genera should be composed of units of the same kind as other genera. The term comes from the Latin genus, a noun form cognate with gignere, linnaeus popularized its use in his 1753 Species Plantarum, but the French botanist Joseph Pitton de Tournefort is considered the founder of the modern concept of genera. The scientific name of a genus may be called the name or generic epithet. It plays a role in binomial nomenclature, the system of naming organisms. The rules for the names of organisms are laid down in the Nomenclature Codes. The standard way of scientifically describing species and other lower-ranked taxa is by binomial nomenclature, the generic name forms its first half. For example, the gray wolfs binomial name is Canis lupus, with Canis being the name shared by the wolfs close relatives. The specific name is written in lower-case and may be followed by names in zoology or a variety of infraspecific names in botany. Especially with these names, when the generic name is known from context. Because animals are typically only grouped within subspecies, it is written as a trinomen with a third name. Dog breeds, meanwhile, are not scientifically distinguished, there are several divisions of plant species and therefore their infraspecific names generally include contractions explaining the relation. For example, the genus Hibiscus includes hundreds of other species apart from the Rose of Sharon or common garden hibiscus, Rose of Sharon doesnt have subspecies but has cultivars that carry desired traits, such as the bright white H. syriaca Diana. Hawaiian hibiscus, meanwhile, includes several separate species, since not all botanists agree on the divisions or names between species, it is common to specify the source of the name using author abbreviations
7.
Environment (biophysical)
–
The biophysical environment can vary in scale from microscopic to global in extent. It can also be subdivided according to its attributes, examples include the marine environment, the atmospheric environment and the terrestrial environment. The number of environments is countless, given that each living organism has its own environment. The term environment is used as a short form for the biophysical environment. The expression the environment often refers to a global environment in relation to humanity. All life that has survived must have adapted to conditions of its environment, temperature, light, humidity, soil nutrients, etc. all influence any species, within any environment. However life in turn modifies, in forms, its conditions. Some long term modifications along the history of our planet have been significant and this process consisted in the breakdown of carbon dioxide by anaerobic microorganisms that used the carbon in their metabolism and released the oxygen to the atmosphere. This led to the existence of oxygen-based plant and animal life, other interactions are more immediate and simple, such as the smoothing effect that forests have on the temperature cycle, compared to neighboring unforested areas. Environmental science is the study of the interactions within the biophysical environment, part of this scientific discipline is the investigation of the effect of human activity on the environment. Ecology, a sub-discipline of biology and a part of environmental sciences, is mistaken as a study of human induced effects on the environment. Environmental studies is an academic discipline that is the systematic study of interaction of humans with their environment. It is a field of study that includes the natural environment, built environments. Environmentalism is a social and philosophical movement that, in a large part, seeks to minimise. The issues of concern for environmentalists usually relate to the environment with the more important ones being climate change, species extinction, pollution. One of the studies related include employing Geographic Information Science to study the biophysical environment, biophysics subject to the context List of conservation topics List of environmental issues Lists of environmental topics Miller, G. Tyler. McCallum, Malcolm L. Gwendolynn W. Bury, google search patterns suggest declining interest in the environment
8.
Life
–
Various forms of life exist, such as plants, animals, fungi, protists, archaea, and bacteria. The criteria can at times be ambiguous and may or may not define viruses, viroids, biology is the primary science concerned with the study of life, although many other sciences are involved. The definition of life is controversial, the current definition is that organisms maintain homeostasis, are composed of cells, undergo metabolism, can grow, adapt to their environment, respond to stimuli, and reproduce. However, many other definitions have been proposed, and there are some borderline cases. Modern definitions are more complex, with input from a diversity of scientific disciplines, biophysicists have proposed many definitions based on chemical systems, there are also some living systems theories, such as the Gaia hypothesis, the idea that the Earth itself is alive. Another theory is that life is the property of systems, and yet another is elaborated in complex systems biology. Abiogenesis describes the process of life arising from non-living matter. Properties common to all organisms include the need for certain chemical elements to sustain biochemical functions. Life on Earth first appeared as early as 4.28 billion years ago, soon after ocean formation 4.41 billion years ago, Earths current life may have descended from an RNA world, although RNA-based life may not have been the first. The mechanism by which began on Earth is unknown, though many hypotheses have been formulated and are often based on the Miller–Urey experiment. The earliest known forms are microfossils of bacteria. In July 2016, scientists reported identifying a set of 355 genes believed to be present in the last universal ancestor of all living organisms. Since its primordial beginnings, life on Earth has changed its environment on a time scale. To survive in most ecosystems, life must often adapt to a range of conditions. Some microorganisms, called extremophiles, thrive in physically or geochemically extreme environments that are detrimental to most other life on Earth, Aristotle was the first person to classify organisms. Later, Carl Linnaeus introduced his system of nomenclature for the classification of species. Eventually new groups and categories of life were discovered, such as cells and microorganisms, cells are sometimes considered the smallest units and building blocks of life. There are two kinds of cells, prokaryotic and eukaryotic, both of which consist of cytoplasm enclosed within a membrane and contain many such as proteins
9.
Surface tension
–
Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible. Surface tension allows insects, usually denser than water, to float, at liquid-air interfaces, surface tension results from the greater attraction of liquid molecules to each other than to the molecules in the air. The net effect is a force at its surface that causes the liquid to behave as if its surface were covered with a stretched elastic membrane. Thus, the surface becomes under tension from the imbalanced forces, because of the relatively high attraction of water molecules for each other through a web of hydrogen bonds, water has a higher surface tension compared to that of most other liquids. Surface tension is an important factor in the phenomenon of capillarity, Surface tension has the dimension of force per unit length, or of energy per unit area. The two are equivalent, but when referring to energy per unit of area, it is common to use the surface energy. In materials science, surface tension is used for either surface stress or surface free energy, the cohesive forces among liquid molecules are responsible for the phenomenon of surface tension. In the bulk of the liquid, each molecule is pulled equally in every direction by neighboring liquid molecules, the molecules at the surface do not have the same molecules on all sides of them and therefore are pulled inwards. This creates some internal pressure and forces liquid surfaces to contract to the minimal area, Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a shape by the imbalance in cohesive forces of the surface layer. In the absence of forces, including gravity, drops of virtually all liquids would be approximately spherical. The spherical shape minimizes the necessary wall tension of the surface according to Laplaces law. Another way to view surface tension is in terms of energy, a molecule in contact with a neighbor is in a lower state of energy than if it were alone. The interior molecules have as many neighbors as they can possibly have, for the liquid to minimize its energy state, the number of higher energy boundary molecules must be minimized. The minimized quantity of boundary molecules results in a surface area. As a result of surface area minimization, a surface will assume the smoothest shape it can, since any curvature in the surface shape results in greater area, a higher energy will also result. Consequently, the surface will push back against any curvature in much the way as a ball pushed uphill will push back to minimize its gravitational potential energy. Bubbles in pure water are unstable, the addition of surfactants, however, can have a stabilizing effect on the bubbles
10.
Oceanic trench
–
The oceanic trenches are linear oceanographic features which are topographic depressions of the sea floor, relatively narrow in width, but hemispheric-scale in length. They are the deepest parts of the ocean floor, a trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to an island arc, and about 200 km from a volcanic arc. Oceanic trenches typically extend 3 to 4 km below the level of the surrounding oceanic floor, the greatest ocean depth to be sounded is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m below sea level. Oceanic lithosphere moves into trenches at a rate of about 3 km2/yr. Globally, there are over 50 major ocean trenches covering an area of 1.9 million km2 or about 0. 5% of the oceans and this applies to Cascadia, Makran, southern Lesser Antilles, and Calabrian trenches. Trenches are related to but distinguished from continental collision zones, where continental crust enters the subduction zone, when buoyant continental crust enters a trench, subduction eventually stops and the convergent plate margin becomes a collision zone. Trenches were not clearly defined until the late 1940s and 1950s, the bathymetry of the ocean was of no real interest until the late 19th and early 20th centuries, with the initial laying of Transatlantic telegraph cables on the seafloor between the continents. Even then the elongated bathymetric expression of trenches was not recognized until well into the 20th century, the term “trench” does not appear in Murray and Hjort’s classic oceanography book. Instead they applied the term “deep“ for the deepest parts of the ocean, the term was first used in a geologic context by Scofield two years after the war ended to describe a structurally controlled depression in the Rocky Mountains. Johnstone, in his 1923 textbook An Introduction to Oceanography, first used the term in its sense for any marked. His measurements revealed that trenches are sites of downwelling in the solid Earth, the concept of downwelling at trenches was characterized by Griggs in 1939 as the tectogene hypothesis, for which he developed an analogue model using a pair of rotating drums. World War II in the Pacific led to improvements of bathymetry in especially the western and northern Pacific. The rapid growth of deep sea research efforts, especially the use of echosounders in the 1950s and 1960s confirmed the morphological utility of the term. The important trenches were identified, sampled, and their greatest depths sonically plumbed, the heroic phase of trench exploration culminated in the 1960 descent of the Bathyscaphe Trieste, which set an unbeatable world record by diving to the bottom of the Challenger Deep. This has been termed trench rollback or hinge retreat and this is one explanation for the existence of back-arc basins. Slab rollback is a process which occurs during the subduction of two tectonic plates resulting in the motion of the trench. Forces acting perpendicular to the slab at depth are responsible for the migration of the slab in the mantle and ultimately the movement of the hinge
11.
Coral reef
–
Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals. Coral reefs are built by colonies of tiny animals found in waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups, the polyps belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons which support, most reefs grow best in warm, shallow, clear, sunny and agitated waters. Often called rainforests of the sea, shallow coral reefs form some of the most diverse ecosystems on Earth, paradoxically, coral reefs flourish even though they are surrounded by ocean waters that provide few nutrients. They are most commonly found at depths in tropical waters. Coral reefs deliver ecosystem services to tourism, fisheries and shoreline protection, the annual global economic value of coral reefs is estimated between US$29. 8-375 billion. However, coral reefs are fragile ecosystems, partly because they are sensitive to water temperature. Most of the coral reefs we can see today were formed after the last glacial period when melting ice caused the sea level to rise and this means that most modern coral reefs are less than 10,000 years old. As communities established themselves on the shelves, the reefs grew upwards, Reefs that rose too slowly could become drowned reefs. They are covered by so much water there was insufficient light. Coral reefs are found in the sea away from continental shelves, around oceanic islands. The vast majority of islands are volcanic in origin. The few exceptions have tectonic origins where plate movements have lifted the deep ocean floor on the surface. In 1842 in his first monograph, The Structure and Distribution of Coral Reefs, Charles Darwin set out his theory of the formation of atoll reefs and he theorized uplift and subsidence of the Earths crust under the oceans formed the atolls. Darwin’s theory sets out a sequence of three stages in atoll formation and it starts with a fringing reef forming around an extinct volcanic island as the island and ocean floor subsides. As the subsidence continues, the reef becomes a barrier reef. Darwin predicted that underneath each lagoon would be a bed rock base, where the level of the underlying earth allows, the corals grow around the coast to form what he called fringing reefs, and can eventually grow out from the shore to become a barrier reef
12.
Kelp forest
–
Kelp forests are underwater areas with a high density of kelp. They are recognized as one of the most productive and dynamic ecosystems on Earth, smaller areas of anchored kelp are called kelp beds. Kelp forests occur worldwide throughout temperate and polar coastal oceans, in 2007, kelp forests were also discovered in tropical waters near Ecuador. Physically formed by brown macroalgae, kelp forests provide a unique, over the last century, they have been the focus of extensive research, particularly in trophic ecology, and continue to provoke important ideas that are relevant beyond this unique ecosystem. For example, kelp forests can influence coastal oceanographic patterns and provide ecosystem services. However, the influence of humans has often contributed to kelp forest degradation, of particular concern are the effects of overfishing nearshore ecosystems, which can release herbivores from their normal population regulation and result in the overgrazing of kelp and other algae. This can rapidly result in transitions to barren landscapes where relatively few species persist, the term kelp refers to marine algae belonging to the order Laminariales. Though not considered a taxonomically diverse order, kelps are highly diverse structurally and functionally, the most widely recognized species are the giant kelps, although numerous other genera such as Laminaria, Ecklonia, Lessonia, Alaria, and Eisenia are described. Many marine mammals and birds are found, including seals, sea lions, whales, sea otters, gulls, terns, snowy egrets, great blue herons. Frequently considered an ecosystem engineer, kelp provides a physical substrate, in algae, the body of an individual organism is known as a thallus rather than as a plant. The stipe is analogous to a plant stalk, extending vertically from the holdfast, the fronds are leaf- or blade-like attachments extending from the stipe, sometimes along its full length, and are the sites of nutrient uptake and photosynthetic activity. In addition, many species have pneumatocysts, or gas-filled bladders. These structures provide the necessary buoyancy for kelp to maintain a position in the water column. The environmental factors necessary for kelp to survive include hard substrate, high nutrients, water flow and turbulence facilitate nutrient assimilation across kelp fronds throughout the water column. Water clarity affects the depth to which sufficient light can be transmitted, in ideal conditions, giant kelp can grow as much as 30-60 cm vertically per day. Some species, such as Nereocystis, are annuals, while others such as Eisenia are perennials, in perennial kelp forests, maximum growth rates occur during upwelling months and die-backs correspond to reduced nutrient availability, shorter photoperiods, and increased storm frequency. Kelps are primarily associated with temperate and arctic waters worldwide, the region with the greatest diversity of kelps is the northeastern Pacific, from north of San Francisco, California, to the Aleutian Islands, Alaska. Although kelp forests are unknown in tropical waters, a few species of Laminaria have been known to occur exclusively in tropical deep waters
13.
Seagrass
–
Seagrasses are flowering plants belonging to four families, all in the order Alismatales, which grow in marine, fully saline environments. There are 12 genera with some 60 species known, like all autotrophic plants, seagrasses photosynthesize so are limited to growing in the submerged photic zone, and most occur in shallow and sheltered coastal waters anchored in sand or mud bottoms. Most species undergo submarine pollination and complete their life cycle underwater. Seagrasses form extensive beds or meadows, which can be either monospecific or in mixed beds where more than one species coexist. In temperate areas, usually one or a few species dominate, whereas tropical beds usually are more diverse, some fish species that visit/feed on seagrasses raise their young in adjacent mangroves or coral reefs. Also, seagrasses trap sediment and slow down water movement, causing suspended sediment to fall out, the trapping of sediment benefits coral by reducing sediment loads in the water. Their importance for associated species is due to provision of shelter. Seagrass meadows account for more than 10% of the total carbon storage. Per hectare, it twice as much carbon dioxide as rain forests. Yearly, seagrasses sequester about 27.4 million tons of CO2, global warming models suggest, some seagrasses will go extinct – Posidonia oceanica is expected to go extinct, or nearly so, by 2050. This would result in CO2 release, historically, seagrasses were collected as fertilizer for sandy soil. This was an important use in the Ria de Aveiro, Portugal and it was also used for bandages and other purposes. Currently, seagrass is used in furniture, and woven like rattan, natural disturbances, such as grazing, storms, ice-scouring, and desiccation, are an inherent part of seagrass ecosystem dynamics. Seagrasses display a high degree of phenotypic plasticity, adapting rapidly to changing environmental conditions. Seagrasses are in decline, with some 30,000 km2 lost during recent decades. The main cause is human disturbance, most notably eutrophication, mechanical destruction of habitat, excessive input of nutrients is directly toxic to seagrasses, but most importantly, it stimulates the growth of epiphytic and free-floating macro- and micro-algae. This weakens the sunlight, reducing the photosynthesis that nourishes the seagrass, decaying seagrass leaves and algae fuels increasing algal blooms, resulting in a positive feedback. This can cause a regime shift from seagrass to algal dominance
14.
Seamount
–
A seamount is a mountain rising from the ocean seafloor that does not reach to the waters surface, and thus is not an island. Seamounts are typically formed from volcanoes that rise abruptly and are usually found rising from the seafloor to 1. They are defined by oceanographers as independent features that rise to at least 1,000 m above the seafloor, 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 time, the largest seamounts may reach the sea surface where wave action erodes the summit to form a flat surface. Seamounts and guyots are most abundant in the North Pacific Ocean, 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, 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 fishing industry. There are ongoing concerns on the impact of fishing on seamount ecosystems. 95% of ecological damage is done by bottom trawling, which scrapes whole ecosystems off seamounts, because of their large numbers, many seamounts remain to be properly studied, and even mapped. Bathymetry and satellite altimetry are two technologies working to close the gap, there have been instances where naval vessels have collided with uncharted seamounts, for example, Muirfield Seamount is named after the ship that struck it in 1973. Seamounts can be found in every ocean basin in the world, a seamount is technically defined as an isolated rise in elevation of 1,000 m or more from the surrounding seafloor, and with a limited summit area, of conical form. If small knolls, ridges and hills less than 1,000 m in height are included there are over 100,000 seamounts in the world ocean. Most seamounts are volcanic in origin, and thus tend to be found on oceanic crust near mid-ocean ridges, mantle plumes, and island arcs. Overall, seamount and guyot coverage is greatest as a proportion of area in the North Pacific Ocean. The Arctic Ocean has only 16 seamounts and no guyots, the 9,951 seamounts mapped cover an area of 8,088,550 km2. The largest seamount has an area of 15,500 km2, guyots cover a total area of 707,600 km2 and have an average area of 2,500 km2, more than twice the average size of seamounts. Nearly 50% of guyot area and 42% of the number of guyots occur in the North Pacific Ocean, the largest three guyots are all in the North Pacific, the Kuko Guyot, Suiko Guyot and the Pallada Guyot. Seamount chain redirects here, for a broader coverage related to this topic, Seamounts are often found in groupings or submerged archipelagos, a classic example being the Emperor Seamounts, an extension of the Hawaiian Islands
15.
Hydrothermal vent
–
A hydrothermal vent is a fissure in a planets surface from which geothermally heated water issues. Hydrothermal vents are found near volcanically active places, areas where tectonic plates are moving apart, ocean basins. Hydrothermal vents exist because the earth is both active and has large amounts of water on its surface and within its crust. Common land types include hot springs, fumaroles and geysers, under the sea, hydrothermal vents may form features called black smokers. Chemosynthetic bacteria and archaea form the base of the chain, supporting diverse organisms, including giant tube worms, clams, limpets. Active hydrothermal vents are believed to exist on Jupiters moon Europa, and Saturns moon Enceladus, Hydrothermal vents in the deep ocean typically form along the mid-ocean ridges, such as the East Pacific Rise and the Mid-Atlantic Ridge. These are locations where two plates are diverging and new crust is being formed. The proportion of each varies from location to location, in contrast to the approximately 2 °C ambient water temperature at these depths, water emerges from these vents at temperatures ranging from 60 to as high as 464 °C. Due to the hydrostatic pressure at these depths, water may exist in either its liquid form or as a supercritical fluid at such temperatures. The critical point of water is 375 °C at a pressure of 218 atmospheres, however, introducing salinity into the fluid raises the critical point to higher temperatures and pressures. The critical point of seawater is 407 °C and 298.5 bars, accordingly, if a hydrothermal fluid with a salinity of 3.2 wt. % NaCl vents above 407 °C and 298.5 bars, furthermore, the salinity of vent fluids have been shown to vary widely due to phase separation in the crust. The critical point for lower salinity fluids is at lower temperature and pressure conditions than that for seawater, for example, a vent fluid with a 2.24 wt. % NaCl salinity has the point at 400 °C and 280.5 bars. Thus, water emerging from the hottest parts of some hydrothermal vents can be a supercritical fluid, examples of supercritical venting are found at several sites. Sister Peak vents low salinity phase-separated, vapor-type fluids, sustained venting was not found to be supercritical but a brief injection of 464 °C was well above supercritical conditions. A nearby site, Turtle Pits, was found to vent low salinity fluid at 407 °C, which is above the critical point of the fluid at that salinity. A vent site in the Cayman Trough named Beebe, which is the worlds deepest known hydrothermal site at ~5000 m below sea level, has shown sustained supercritical venting at 401 °C and 2.3 wt% NaCl
16.
Tide pool
–
Tide pools, or rock pools, are rocky pools on the sea shore which are filled with seawater. Many of these pools exist as separate pools only at low tide, Tidal pools exist in the intertidal zones. These zones are submerged by the sea at high tides and during storms, at other times the rocks may undergo other extreme conditions, baking in the sun or exposed to cold winds. Few organisms can survive harsh conditions. Lichens and barnacles live in this region, in this zone, different barnacle species live at very tightly constrained elevations. Tidal conditions precisely determine the height of an assemblage relative to sea level. The intertidal zone is exposed to sun and wind, which desiccate barnacles. Their calcite shells are impermeable, and they possess two plates which they slide across their mouth opening when not feeding and these plates also protect against predation. The high tide zone is flooded during high tide. Organisms must survive wave action, currents, and exposure to the sun and this zone is predominantly inhabited by seaweed and invertebrates, such as sea anemones, starfish, chitons, crabs, green algae, and mussels. Marine algae provide shelter for nudibranches and hermit crabs, the same waves and currents that make life in the high tide zone difficult bring food to filter feeders and other intertidal organisms. Also called the Lower Littoral Zone and this area is usually under water - it is only exposed when the tide is unusually low. This sub region is mostly submerged, but it is exposed only during low tide, often it teems with life and has much more marine vegetation, especially seaweeds. Organisms in this zone do not have to be as well adapted to drying out, low tide zone organisms include abalone, anemones, brown seaweed, chitons, crabs, green algae, hydroids, isopods, limpets, mussels, and sometimes even small vertebrates such as fish. This area is relatively protected from large predators because of the wave action. Tide pools provide a home for hardy organisms such as starfish, mussels, inhabitants must be able to deal with a frequently changing environment — fluctuations in water temperature, salinity, and oxygen content. Hazards include waves, strong currents, exposure to midday sun, waves can dislodge mussels and draw them out to sea. Gulls pick up and drop sea urchins to break them open, starfish prey on mussels and are eaten by gulls themselves
17.
Pelagic zone
–
Any water in a sea or lake that is neither close to the bottom nor near the shore can be said to be in the pelagic zone. The word pelagic is derived from Greek πέλαγος, meaning open sea, the pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes from the surface of the sea almost to the bottom. Conditions differ deeper in the water such that as pressure increases with depth. Depending on the depth, the column, rather like the Earths atmosphere. The pelagic zone occupies 1,330 million km3 with a depth of 3.68 km. Pelagic life decreases with increasing depth and it is affected by light intensity, pressure, temperature, salinity, the supply of dissolved oxygen and nutrients, and the submarine topography, which is called bathymetry. In deep water, the zone is sometimes called the open-ocean zone. In other contexts, coastal water not near the bottom is still said to be in the pelagic zone, the pelagic zone can be contrasted with the benthic and demersal zones at the bottom of the sea. The benthic zone is the region at the very bottom of the sea. It includes the sediment surface and some subsurface layers, Marine organisms living in this zone, such as clams and crabs, are called benthos. The demersal zone is just above the benthic zone and it can be significantly affected by the seabed and the life that lives there. Demersal fish are known as bottom feeders and groundfish. Depending on how deep the sea is, the zone can extend over up to five horizontal layers in the ocean. From the top down, these are, From the surface down to around 200 m This is the zone at the surface of the sea where enough light is available for photosynthesis. Nearly all primary production in the ocean occurs here, consequently, plants and animals are largely concentrated in this zone. Examples of organisms living in this zone are plankton, floating seaweed, jellyfish, tuna, many sharks, from 200 m down to around 1,000 m The name for this zone stems from Greek μέσον, meaning middle. Although some light penetrates this second layer it is insufficient for photosynthesis, at about 500 m the water also becomes depleted of oxygen. Organisms survive this environment by having more efficient gills or by minimizing movement, examples of animals that live here are swordfish, squid, Anarhichadidae or wolffish and some species of cuttlefish
18.
Phytoplankton
–
Phytoplankton /ˌfaɪtoʊˈplæŋktən/ are the autotrophic components of the plankton community and a key part of oceans, seas and freshwater basin ecosystems. The name comes from the Greek words φυτόν, meaning plant, most phytoplankton are too small to be individually seen with the unaided eye. Phytoplankton are photosynthesizing microscopic organisms that inhabit the upper layer of almost all oceans. They are agents for primary production, the creation of organic compounds from carbon dioxide dissolved in the water, Phytoplankton obtain energy through the process of photosynthesis and must therefore live in the well-lit surface layer of an ocean, sea, lake, or other body of water. Phytoplankton account for half of all activity on Earth. Their cumulative energy fixation in carbon compounds is the basis for the vast majority of oceanic, the effects of anthropogenic warming on the global population of phytoplankton is an area of active research. Additionally, changes in the mortality of phytoplankton due to rates of zooplankton grazing may be significant, as a side note, one of the more remarkable food chains in the ocean – remarkable because of the small number of links – is that of phytoplankton-feeding krill feeding baleen whales. Phytoplankton are also dependent on minerals. However, across large regions of the World Ocean such as the Southern Ocean and this has led to some scientists advocating iron fertilization as a means to counteract the accumulation of human-produced carbon dioxide in the atmosphere. Large-scale experiments have added iron to the oceans to promote phytoplankton growth, however, controversy about manipulating the ecosystem and the efficiency of iron fertilization has slowed such experiments. Phytoplankton depend on other substances to survive as well, in particular, Vitamin B is crucial. Areas in the ocean have been identified as having a lack of Vitamin B. While almost all species are obligate photoautotrophs, there are some that are mixotrophic and other. Of these, the best known are dinoflagellate genera such as Noctiluca and Dinophysis, the term phytoplankton encompasses all photoautotrophic microorganisms in aquatic food webs. Phytoplankton serve as the base of the food web, providing an essential ecological function for all aquatic life. However, unlike terrestrial communities, where most autotrophs are plants, phytoplankton are a group, incorporating protistan eukaryotes. There are about 5,000 known species of marine phytoplankton, how such diversity evolved despite scarce resources is unclear. In terms of numbers, the most important groups of phytoplankton include the diatoms, cyanobacteria and dinoflagellates, one group, the coccolithophorids, is responsible for the release of significant amounts of dimethyl sulfide into the atmosphere
19.
Zooplankton
–
Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word zooplankton is derived from the Greek zoon, meaning animal, individual zooplankton are usually microscopic, but some are larger and visible with the naked eye. Zooplankton is a categorization spanning a range of organism sizes including small protozoans, although zooplankton are primarily transported by ambient water currents, many have locomotion, used to avoid predators or to increase prey encounter rate. Ecologically important protozoan zooplankton groups include the foraminiferans, radiolarians and dinoflagellates and this wide phylogenetic range includes a similarly wide range in feeding behavior, filter feeding, predation and symbiosis with autotrophic phytoplankton as seen in corals. Zooplankton feed on bacterioplankton, phytoplankton, other zooplankton, detritus, as a result, zooplankton are primarily found in surface waters where food resources are abundant. Just as any species can be limited within a geographical region, however, species of zooplankton are not dispersed uniformly or randomly within a region of the ocean. As with phytoplankton, ‘patches’ of zooplankton species exist throughout the ocean, zooplankton patchiness can also be influenced by biological factors, as well as other physical factors. Biological factors include breeding, predation, concentration of phytoplankton, the physical factor that influences zooplankton distribution the most is mixing of the water column that affects nutrient availability and, in turn, phytoplankton production. Since they are small, zooplankton can respond rapidly to increases in phytoplankton abundance, for instance. Zooplankton can also act as a disease reservoir, crustacean zooplankton have been found to house the bacterium Vibrio cholerae, which causes cholera, by allowing the cholera vibrios to attach to their chitinous exoskeletons. This symbiotic relationship enhances the ability to survive in an aquatic environment, as the exoskeleton provides the bacterium with carbon. A global coverage database of zooplankton biomass and abundance data
20.
Cetacea
–
Cetacea are a widely distributed and diverse clade of aquatic mammals that today consists of the whales, dolphins, and porpoises. Most species live in the sea, some in rivers, the name is derived from the Latin cetus whale and Greek ketos huge fish. The extinct ancestors of modern whales are the Archaeoceti, while cetaceans were historically thought to have descended from mesonychids, molecular evidence supports them as a relative of Artiodactyls. Cetaceans belong to the order Cetartiodactyla and their closest living relatives are hippopotamuses and other hoofed mammals, having diverged about 50 million years ago. Cetaceans range in size from the 1 m and 50 kg Mauis dolphin to the 29.9 m and 190,000 kg blue whale and they have streamlined bodies and two limbs that are modified into flippers. Dolphins are able to very tight turns while swimming at high speeds. The hindlimbs of cetaceans are internal, and are thought to be vestigial, baleen whales have short hairs on their mouth, unlike the toothed whales. Cetaceans have well-developed senses—their eyesight and hearing are adapted for both air and water, and baleen whales have a system in their vibrissae. They have a layer of fat, or blubber, under the skin to maintain body heat in cold water, Some species are well adapted for diving to great depths. Although cetaceans are widespread, most species prefer the waters of the Northern and Southern Hemispheres. They spend their lives in the water, having to mate, give birth, molt or escape predators, like killer whales. This has drastically affected their anatomy to be able to do so and they feed largely on fish and marine invertebrates, but a few, like the killer whale, feed on large mammals and birds, such as penguins and seals. Some baleen whales are specialised for feeding on benthic creatures, male cetaceans typically mate with more than one female, although the degree of polygyny varies with the species. Cetaceans are not shown to have pair bonds, male cetacean strategies for reproductive success vary between herding females, defending potential mates from other males, or whale song which attracts mates. Calves are typically born in the fall and winter months, cetaceans produce a number of vocalizations, notably the clicks and whistles of dolphins, the moaning songs of the humpback whale. The meat, blubber and oil of cetaceans have traditionally used by indigenous peoples of the Arctic. Cetaceans have been depicted in cultures worldwide. Dolphins are commonly kept in captivity and are sometimes trained to perform tricks and tasks
21.
Marine ecosystem
–
Marine ecosystems are among the largest of Earths aquatic ecosystems. Examples include salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, the sea. They can be contrasted with freshwater ecosystems, which have a salt content. Marine waters cover two-thirds of the surface of the Earth, such places are considered ecosystems because the plant life supports the animal life and vice versa. Marine ecosystems are essential for the health of both marine and terrestrial environments. According to the World Resource Center, coastal habitats account for about one-third of marine biological productivity, estuarine ecosystems, such as salt marshes, seagrass meadows and mangrove forests, are among the most productive ecosystems on the planet. Coral reefs provide food and shelter to the highest levels of diversity in the world. Marine ecosystems usually have a large biodiversity and are thought to have a good resistance against invasive species. However, exceptions have been observed, and the mechanisms responsible in determining the success of an invasion are not yet clear, barange M, Field JG, Harris RP, Eileen E, Hofmann EE, Perry RI and Werner F Marine Ecosystems and Global Change Oxford University Press. ISBN 978-0-19-955802-5 Boyd IL, Wanless S and Camphuysen CJ Top predators in marine ecosystems, their role in monitoring, ISBN 978-0-521-84773-5 Davenport J Challenges to Marine Ecosystems, Proceedings of the 41st European Marine Biology Symposium Volume 202 of Developments in hydrobiology. ISBN 978-1-4020-8807-0 Levner E, Linkov I and Proth J Strategic management of marine ecosystems Springer, Volume 50 of NATO Science Series IV. ISBN 978-1-4020-3158-8 Mann KH and Lazier JRN Dynamics of marine ecosystems, ISBN 978-1-4051-1118-8 Moustakas A and Karakassis I How diverse is aquatic biodiversity research. U. S. Environmental Protection Agency—EPA, Marine Ecosystems Encyclopædia Britannica Online, Marine ecosystem —, smithsonian Institution, Ocean Portal Marine Ecosystems Research Programme
22.
Recreation
–
Recreation is an activity of leisure, leisure being discretionary time. The need to do something for recreation is an element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasure and are considered to be fun. The term recreation appears to have used in English first in the late 14th century, first in the sense of refreshment or curing of a sick person. Other factors that account for a role of recreation are affluence, population trends. This direction of thought has even extended to the view that leisure is the purpose of work, and a reward in itself. Leisure is considered a right under the Universal Declaration of Human Rights. Recreation is difficult to separate from the concept of play. Children may playfully imitate activities that reflect the realities of adult life, a traditional view holds that work is supported by recreation, recreation being useful to recharge the battery so that work performance is improved. Many activities may be work for one person and recreation for another, or, at a level, over time recreational activity may become work. Thus, for a musician, playing an instrument may be at one time a profession, similarly, it may be difficult to separate education from recreation as in the case of recreational mathematics. Recreation is an part of human life and finds many different forms which are shaped naturally by individual interests. Recreational activities can be communal or solitary, active or passive, outdoors or indoors, healthy or harmful, a significant section of recreational activities are designated as hobbies which are activities done for pleasure on a regular basis. Some recreational activities - such as gambling, recreational use, or delinquent activities - may violate societal norms. Public space such as parks and beaches are venues for many recreational activities. Tourism has recognized that many visitors are attracted by recreational offerings. In support of recreational activities government has taken an important role in their creation, maintenance, and organization, many recreational activities are organized, typically by public institutions, voluntary group-work agencies, private groups supported by membership fees, and commercial enterprises. Examples of each of these are the National Park Service, the YMCA, the Kiwanis, Recreation has many health benefits, and, accordingly, Therapeutic Recreation has been developed to take advantage of this effect
23.
Tourism
–
Tourism is travel for pleasure or business, also the theory and practice of touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tours. Tourism may be international, or within the travellers country, Tourism can be domestic or international, and international tourism has both incoming and outgoing implications on a countrys balance of payments. Today, tourism is a source of income for many countries. International tourism receipts grew to US$1.03 trillion in 2011, the ITB Berlin is the worlds leading tourism trade fair. The word tourist was used by 1772 and tourism by 1811. It is formed from the tour, which is derived from Old English turian, from Old French torner, from Latin tornare, to turn on a lathe. Tourism is an important, even vital, source of income for many regions and it also creates opportunities for employment in the service sector of the economy associated with tourism. This is in addition to goods bought by tourists, including souvenirs, in 1936, the League of Nations defined a foreign tourist as someone traveling abroad for at least twenty-four hours. Its successor, the United Nations, amended this definition in 1945 and it includes movements for all purposes. In 1981, the International Association of Scientific Experts in Tourism defined tourism in terms of particular activities chosen and undertaken outside the home, in this context, travel has a similar definition to tourism, but implies a more purposeful journey. The terms tourism and tourist are sometimes used pejoratively, to imply a shallow interest in the cultures or locations visited, by contrast, traveler is often used as a sign of distinction. The sociology of tourism has studied the values underpinning these distinctions. International tourist arrivals reached 1.035 billion in 2012, up from over 996 million in 2011, the World Tourism Organization reports the following ten destinations as the most visited in terms of the number of international travellers in 2016. International tourism receipts grew to US$1.2 trillion in 2014, based upon air traffic, the MasterCard Global Destination Cities Index reports the following cities as the top ten most popular destinations of international tourism worldwide. MasterCard reports the following cities as the top ten biggest earners on international tourism worldwide in 2015, as early as Shulgi, however, kings praised themselves for protecting roads and building waystations for travelers. During the Roman Republic, spas and coastal resorts such as Baiae were popular among the rich, pausanias wrote his Description of Greece in the 2nd century AD. In ancient China, nobles sometimes made a point of visiting Mount Tai and, on occasion, the Islamic hajj is still central to its faith and Chaucers Canterbury Tales and Wu Chengens Journey to the West remain classics of English and Chinese literature. The 10th- to 13th-century Song dynasty also saw secular travel writers such as Su Shi, under the Ming, Xu Xiake continued the practice
24.
Oxygen cycle
–
The oxygen cycle is the biogeochemical cycle of oxygen within its three main reservoirs, the atmosphere, the total content of biological matter within the biosphere, and the Earths crust. Failures in the cycle within the hydrosphere can result in the development of hypoxic zones. The main driving factor of the cycle is photosynthesis, which is responsible for the modern Earths atmosphere. By far the largest reservoir of Earths oxygen is within the silicate and oxide minerals of the crust, only a small portion has been released as free oxygen to the biosphere and atmosphere. The tiny marine cyanobacterium Prochlorococcus was discovered in 1986 and accounts for more than half of the photosynthesis of the open ocean, an additional source of atmospheric free oxygen comes from photolysis, whereby high-energy ultraviolet radiation breaks down atmospheric water and nitrous oxide into component atoms. The lithosphere also consumes free oxygen by chemical weathering and surface reactions, an example of surface weathering chemistry is formation of iron oxides,4 F e O + O2 ⟶2 F e 2 O3 Oxygen is also cycled between the biosphere and lithosphere. Marine organisms in the biosphere create calcium carbonate shell material that is rich in oxygen, when the organism dies, its shell is deposited on the shallow sea floor and buried over time to create the limestone sedimentary rock of the lithosphere. Weathering processes initiated by organisms can also free oxygen from the lithosphere, plants and animals extract nutrient minerals from rocks and release oxygen in the process. OXYSPHERE - A Beginners Guide to the Biogeochemical Cycling of Atmospheric Oxygen, http, //seis. natsci. csulb. edu/rmorris/oxy/Oxy. htm
25.
Climate
–
Climate is the statistics of weather, usually over a 30-year interval. Climate differs from weather, in that weather only describes the conditions of these variables in a given region. A regions climate is generated by the system, which has five components, atmosphere, hydrosphere, cryosphere, lithosphere. The climate of a location is affected by its latitude, terrain, climates can be classified according to the average and the typical ranges of different variables, most commonly temperature and precipitation. The most commonly used classification scheme was the Köppen climate classification, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region. Paleoclimatology is the study of ancient climates, Climate models are mathematical models of past, present and future climates. Climate change may occur long and short timescales from a variety of factors. For example, a 3°C change in mean annual temperature corresponds to a shift in isotherms of approximately 300–400 km in latitude or 500 m in elevation, therefore, species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones. Climate is commonly defined as the weather averaged over a long period, the standard averaging period is 30 years, but other periods may be used depending on the purpose. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations, the classical period is 30 years, as defined by the World Meteorological Organization. These quantities are most often surface variables such as temperature, precipitation, Climate in a wider sense is the state, including a statistical description, of the climate system. The World Meteorological Organization describes climate normals as reference points used by climatologists to compare current climatological trends to that of the past or what is considered normal, a Normal is defined as the arithmetic average of a climate element over a 30-year period. A30 year period is used, as it is enough to filter out any interannual variation or anomalies. The WMO originated from the International Meteorological Organization which set up a commission for climatology in 1929. At its 1934 Wiesbaden meeting the commission designated the thirty-year period from 1901 to 1930 as the reference time frame for climatological standard normals. In 1982 the WMO agreed to update climate normals, and in these were completed on the basis of climate data from 1 January 1961 to 31 December 1990. The difference between climate and weather is usefully summarized by the popular phrase Climate is what you expect, weather is what you get. Over historical time spans there are a number of nearly constant variables that determine climate, including latitude, altitude, proportion of land to water and these change only over periods of millions of years due to processes such as plate tectonics
26.
Shore
–
A shore or a shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. Shores are influenced by the topography of the landscape, as well as by water induced erosion. The geological composition of rock and soil dictates the type of shore which is created, Riviera is an Italian word for shoreline, ultimately derived from Latin ripa. It came to be applied as a name to the coast of the Ligurian Sea, in the form riviera ligure. Historically, the Ligurian Riviera extended from Capo Corvo south of Genoa, north and west into what is now French territory past Monoco, now it is divided into the Italian Riviera and the French Riviera. Although the French use the term Riviera to refer to the Italian Riviera, as a result of the fame of the Ligurian rivieras, the term came into English to refer to any shoreline, especially one that is sunny, topographically diverse and popular with tourists. Such places using the term include the Australian Riviera in Queensland, offshore or Intertidal zone Ballantine Scale Coastal path Shorezone Anders, F. J. and Byrnes, M. R. Accuracy of shoreline change rates as determined from maps and aerial photographs Shore and Beach, v.59, processes influencing the transport and fate of contaminated sediments in the coastal ocean—Boston Harbor and Massachusetts Bay, U. S. Geological Survey Circular 1302, pp. 1–89. Equilibrium beach profiles—characteristics and applications Journal of Coastal Research, v.7, the Budget of Littoral Sediments—Concepts and Applications Shore and Beach, v.64, pp. 18–26. Meade, R. H. Sources, sinks and storage of river sediments in the Atlantic drainage of the United States Journal of Geology, v.90, an Assessment of the Nations Shorelines, USA Shore and Beach v.71, no. Stockdon, H. F. Sallenger, A. H. List, J. H. and Holman, estimation of shoreline position and change using airborne topographic lidar data Journal of Coastal Research, v.18, no. The use of models to predict beach behavior for U. S. coastal engineering—A critical review Journal of Coastal Research, v.16. Media related to Shores at Wikimedia Commons shore, the American Heritage Dictionary of the English Language
27.
Carbon cycle
–
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. The global carbon budget is the balance of the exchanges of carbon between the reservoirs or between one specific loop of the carbon cycle. An examination of the budget of a pool or reservoir can provide information about whether the pool or reservoir is functioning as a source or sink for carbon dioxide. The carbon cycle was discovered by Joseph Priestley and Antoine Lavoisier. Carbon-based molecules are crucial for life on Earth, because it is the component of biological compounds. Carbon is also a component of many minerals. Carbon also exists in forms in the atmosphere. Carbon dioxide is responsible for the greenhouse effect and is one of the most important human-contributed greenhouse gases. In the past two centuries, human activities have altered the global cycle, most significantly in the atmosphere. Although carbon dioxide levels have changed naturally over the past several thousand years, changes in the amount of atmospheric CO2 are considerably altering weather patterns and indirectly influencing oceanic chemistry. The Earths interior, carbon from the Earths mantle and crust, the ocean contains the largest active pool of carbon near the surface of the Earth. The natural flows of carbon between the atmosphere, ocean, terrestrial ecosystems, and sediments is fairly balanced, so that carbon levels would be stable without human influence. Carbon in the Earths atmosphere exists in two forms, carbon dioxide and methane. Both of these gases absorb and retain heat in the atmosphere and are responsible for the greenhouse effect. Carbon dioxide leaves the atmosphere through photosynthesis, thus entering the terrestrial, Carbon dioxide also dissolves directly from the atmosphere into bodies of water, as well as dissolving in precipitation as raindrops fall through the atmosphere. When dissolved in water, carbon reacts with water molecules and forms carbonic acid. It can then be absorbed by rocks through weathering and it also can acidify other surfaces it touches or be washed into the ocean. g. by burning fossil fuels and manufacturing concrete. The terrestrial biosphere includes the carbon in all land-living organisms
28.
General circulation model
–
A general circulation model is a type of climate model. It employs a model of the general circulation of a planetary atmosphere or ocean. It uses the Navier–Stokes equations on a sphere with thermodynamic terms for various energy sources. These equations are the basis for computer programs used to simulate the Earths atmosphere or oceans, Atmospheric and oceanic GCMs are key components along with sea ice and land-surface components. GCMs and global models are used for weather forecasting, understanding the climate. Versions designed for decade to century time scale climate applications were created by Syukuro Manabe and Kirk Bryan at the Geophysical Fluid Dynamics Laboratory in Princeton. These models are based on the integration of a variety of fluid dynamical, chemical, the acronym GCM originally stood for General Circulation Model. Recently, a second meaning came into use, namely Global Climate Model, while these do not refer to the same thing, General Circulation Models are typically the tools used for modelling climate, and hence the two terms are sometimes used interchangeably. In 1956, Norman Phillips developed a model that could realistically depict monthly. It became the first successful climate model, following Phillipss work, several groups began working to create GCMs. The first to combine both oceanic and atmospheric processes was developed in the late 1960s at the NOAA Geophysical Fluid Dynamics Laboratory, by the early 1980s, the United States National Center for Atmospheric Research had developed the Community Atmosphere Model, this model has been continuously refined. In 1996, efforts began to model soil and vegetation types, later the Hadley Centre for Climate Prediction and Researchs HadCM3 model coupled ocean-atmosphere elements. The role of gravity waves was added in the mid-1980s, gravity waves are required to simulate regional and global scale circulations accurately. Atmospheric and oceanic GCMs can be coupled to form a coupled general circulation model. With the addition of such as a sea ice model or a model for evapotranspiration over land. Thus a carbon CTM may allow a GCM to better predict anthropogenic changes in carbon dioxide concentrations, in addition, this approach allows accounting for inter-system feedback, e. g. chemistry-climate models allow the possible effects of climate change on ozone hole to be studied. Climate prediction uncertainties depend on uncertainties in chemical, physical and social models, significant uncertainties and unknowns remain, especially regarding the future course of human population, industry and technology. Three-dimensional GCMs apply discrete equations for fluid motion and integrate these forward in time and they contain parameterisations for processes such as convection that occur on scales too small to be resolved directly
29.
Ecosystem
–
An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are regarded as linked together through nutrient cycles, as ecosystems are defined by the network of interactions among organisms, and between organisms and their environment, they can be of any size but usually encompass specific, limited spaces. Energy, water, nitrogen and soil minerals are other essential components of an ecosystem. The energy that flows through ecosystems is obtained primarily from the sun and it generally enters the system through photosynthesis, a process that also captures carbon from the atmosphere. By feeding on plants and on one another, animals play an important role in the movement of matter and they also influence the quantity of plant and microbial biomass present. Ecosystems are controlled both by external and internal factors, other external factors include time and potential biota. Ecosystems are dynamic entities—invariably, they are subject to disturbances and are in the process of recovering from some past disturbance. Ecosystems in similar environments that are located in different parts of the world can have different characteristics simply because they contain different species. The introduction of species can cause substantial shifts in ecosystem function. Internal factors not only control ecosystem processes but are controlled by them and are often subject to feedback loops. Other internal factors include disturbance, succession and the types of species present, although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate. Biodiversity affects ecosystem function, as do the processes of disturbance, classifying ecosystems into ecologically homogeneous units is an important step towards effective ecosystem management, but there is no single, agreed-upon way to do this. The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley, Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment. He later refined the term, describing it as The whole system, including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment. Tansley regarded ecosystems not simply as natural units, but as mental isolates, Tansley later defined the spatial extent of ecosystems using the term ecotope. G. Raymond Lindeman took these ideas one step further to suggest that the flow of energy through a lake was the driver of the ecosystem. Most mineral nutrients, on the hand, are recycled within ecosystems. Ecosystems are controlled both by external and internal factors, external factors, also called state factors, control the overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem
30.
History of marine biology
–
Marine biology is a hybrid subject that combines aspects of organismal function, ecological interaction and the study of marine biodiversity. The earliest studies of marine biology trace back to the Phoenicians, the first recorded observations on the distribution and habits of marine life were made by Aristotle. Observations made in the earliest studies of marine biology provided an impetuous for the age of discovery, during this time, a vast amount of knowledge was gained about life that exists in the oceans. Individuals who contributed significantly to this pool of knowledge include Captain James Cook, Charles Darwin and these individuals took part in some of the more well-known expeditions of all time, making foundation contributions to marine biology. The subsequent creation of laboratories was another important development because marine scientists now had places to conduct research. Technological advances, such as sound ranging, scuba diving gear, submersibles and remotely operated vehicles and this allowed marine biologists to explore depths people once thought never existed. The history of biology can be traced as far back as 1200 BC when the Phoenicians. Phoenicians and Greeks were some of the first known explorers to leave their local communities bordering the Mediterranean Sea and they ventured outside the Mediterranean to the Atlantic Ocean with their knowledge of tides, currents and seasonal changes. It wasn’t until much later at around 450 BC when observations of phenomena related to the oceans started getting recorded. Herodotus wrote of the tides in the Persian Gulf, the deposition of silt in the Nile Delta. It was during time when many of the first recorded observations about the composition of the oceans. Aristotle was one of the most notable Greek philosophers to examine, Aristotle identified a large range of species such as crustaceans, echinoderms, mollusks and fish. The Polynesians were among the first to go out and explore the mysteries of the ocean, in the years that followed the Polynesian efforts, there were minimal efforts that aimed to further man’s understanding of the sea. This ended with the Age of Discovery in the late 15th century, between the late 15th century and early 20th century, humans explored the oceans like never before creating new maps and charts and collecting specimens to bring back to their home ports. Most of the exploration that took place during time was fueled by European countries such as Spain, Portugal, France, Italy, Scotland. Some of the explorers of marine biology carried out their famous work during this time period. Explorers such as Captain James Cook, Charles Darwin and Wyville Thomson made revolutionary contributions to the history of marine biology during this time of exploration. James Cook is well known for his voyages of exploration for the British Navy in which he mapped out a significant amount of the uncharted waters
31.
Embryo
–
An embryo is an early stage of development of a multicellular diploid eukaryotic organism. In general, in organisms that reproduce sexually, an embryo develops from a zygote, the zygote possesses half the DNA of each of its two parents. In plants, animals, and some protists, the zygote will begin to divide by mitosis to produce a multicellular organism, the result of this process is an embryo. First attested in English in the mid-14c, the word embryon derives from Medieval Latin embryo, itself from Greek ἔμβρυον, lit. Young one, which is the neuter of ἔμβρυος, lit, growing in, from ἐν, in and βρύω, swell, be full, the proper Latinized form of the Greek term would be embryum. In animals, the development of the zygote into an embryo proceeds through specific stages of blastula, gastrula. The blastula stage typically features a fluid-filled cavity, the blastocoel, surrounded by a sphere or sheet of cells, in a placental mammal, an ovum is fertilized in a fallopian tube through which it travels into the uterus. An embryo is called a fetus at an advanced stage of development. In humans, this is from the week of gestation. During gastrulation the cells of the blastula undergo coordinated processes of cell division, invasion, in triploblastic organisms, the three germ layers are called endoderm, ectoderm, and mesoderm. The position and arrangement of the layers are highly species-specific, however. For example, in neurogenesis, a subpopulation of cells is set aside to become the brain, spinal cord. Modern developmental biology is extensively probing the molecular basis for every type of organogenesis, including angiogenesis, chondrogenesis, myogenesis, osteogenesis, and many others. In botany, a plant embryo is part of a seed, consisting of precursor tissues for the leaves, stem. Once the embryo begins to germinate — grow out from the seed — it is called a seedling, bryophytes and ferns also produce an embryo, but do not produce seeds. In these plants, the embryo begins its existence attached to the inside of the archegonium on a parental gametophyte from which the egg cell was generated, the structure and development of the rest of the embryo varies by group of plants. Once the embryo has expanded beyond the enclosing archegonium, it is no longer termed an embryo, embryos are used in various fields of research and in techniques of assisted reproductive technology. An egg may be fertilized in vitro and the embryo may be frozen for later use
32.
Dusky smooth-hound
–
The dusky smooth-hound, also called the smooth dogfish or the dog shark is a species of houndshark, and part of the family Triakidae. This shark is a grey or brown in color. Females live to 16 years and males have a lifespan of 10 years, Mustelus canis was the first shark recognised to have viral infections. Mustelus canis can be known as smooth dogfish, Atlantic smooth dogfish, dusky smooth-hound, grayish, nurse shark, smooth dog, Mustelus canis were originally named Squalls canis, but was later changed. In Latin, mustelus translates to weasel-like and canis translates to dog, Mustelus canis has an allopatric relationship with Mustelus mustelus and a sympatric relationship with Mustelus norrisi. M. canis are found in marine and brackish waters and are demersal and they can be found between 42° N to 44°S and 100° W-46° W. M. canis in the North Atlantic migrate in response to changing temperature. In winter, they can be found in the Carolinas to the outlet of the Chesapeake Bay and they are most abundant on the east coast, from Massachusetts to Florida, Brazil to Argentina, and in the Gulf of Mexico. They are mostly found in waters shallower than 60 ft, but can be found up to 665 ft. Smooth dogfish are relatively small and they have elongated, oval shaped eyes with a spiracle located directly behind on each side. Their first and second dorsal fin are well-serrated and nearly equal in size, the second dorsal fin is slightly smaller than the first and twice as large as the anal fin. The caudal fin has two lobes, the lower is smaller and rounder and the upper has a deep notch. They do not have any fin spines, unlike the Spiny dogfish and they have a tapering, blunt snout. They can be gray to brown and their underside can be white to yellowish gray, Smooth dogfish have the ability to change colors using melanophores to help them camouflage. Newborns have lighter gray edges on their fins and have tail fins edged in white, on average, smooth dogfish are about 48 inches long, but can reach up to 5 feet. One main characteristic of elasmobranch fishes is their ability to replace the teeth in their upper and lower jaw. Smooth dogfish differ from sharks because of their 10 rows of flat. The teeth in the upper and lower jaw are similar in size and are asymmetrical with a rounded cusp and these teeth are used to crush and grind food, rather than bite it. Their unique dentition is important for their crustacean-based diet, in smooth dogfish, tooth replacement is related to body growth. Smooth dogfish grow about 10 cm per every six rows of teeth replaced and that is an increase of 0.03 nm per replaced tooth
33.
Aristotle
–
Aristotle was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidice, on the northern periphery of Classical Greece. His father, Nicomachus, died when Aristotle was a child, at seventeen or eighteen years of age, he joined Platos Academy in Athens and remained there until the age of thirty-seven. Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, teaching Alexander the Great gave Aristotle many opportunities and an abundance of supplies. He established a library in the Lyceum which aided in the production of many of his hundreds of books and he believed all peoples concepts and all of their knowledge was ultimately based on perception. Aristotles views on natural sciences represent the groundwork underlying many of his works, Aristotles views on physical science profoundly shaped medieval scholarship. Their influence extended from Late Antiquity and the Early Middle Ages into the Renaissance, some of Aristotles zoological observations, such as on the hectocotyl arm of the octopus, were not confirmed or refuted until the 19th century. His works contain the earliest known study of logic, which was incorporated in the late 19th century into modern formal logic. Aristotle was well known among medieval Muslim intellectuals and revered as The First Teacher and his ethics, though always influential, gained renewed interest with the modern advent of virtue ethics. All aspects of Aristotles philosophy continue to be the object of academic study today. Though Aristotle wrote many elegant treatises and dialogues – Cicero described his style as a river of gold – it is thought that only around a third of his original output has survived. Aristotle, whose means the best purpose, was born in 384 BC in Stagira, Chalcidice. His father Nicomachus was the physician to King Amyntas of Macedon. Aristotle was orphaned at a young age, although there is little information on Aristotles childhood, he probably spent some time within the Macedonian palace, making his first connections with the Macedonian monarchy. At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Platos Academy and he remained there for nearly twenty years before leaving Athens in 348/47 BC. Aristotle then accompanied Xenocrates to the court of his friend Hermias of Atarneus in Asia Minor, there, he traveled with Theophrastus to the island of Lesbos, where together they researched the botany and zoology of the island. Aristotle married Pythias, either Hermiass adoptive daughter or niece and she bore him a daughter, whom they also named Pythias. Soon after Hermias death, Aristotle was invited by Philip II of Macedon to become the tutor to his son Alexander in 343 BC, Aristotle was appointed as the head of the royal academy of Macedon. During that time he gave not only to Alexander
34.
Lesbos
–
Lesbos, sometimes referred to as Mytilini after its capital, is a Greek island located in the northeastern Aegean Sea. It has an area of 1,632.819 square kilometres with 320 kilometres of coastline and it is separated from Turkey by the narrow Mytilini Strait and in late Palaeolithic/Mesolithic times was joined to the Anatolian mainland before the end of the last glacial period. Lesbos is a regional unit of the North Aegean region. The others are Chios, Ikaria, Lemnos, and Samos, the total number of islands governed by the North Aegean are nine, Lesbos, Chios, Psara, Oinousses, Ikaria, Fournoi Korseon, Lemnos, Agios Efstratios and Samos. The capital of the North Aegean Region is Mytilene, the population of Lesbos is approximately 86,000, a third of whom live in its capital, Mytilene, in the southeastern part of the island. The remaining population is distributed in small towns and villages, the largest are Plomari, Kalloni, the Gera Villages, Agiassos, Eresos, and Molyvos. In fact the archaeological and linguistic record may indicate a late Iron Age arrival of Greek settlers although references in Late Bronze Age Hittite archives indicate a likely Greek presence then, the name Mytilene itself seems to be of Hittite origin. According to Homers Iliad, however, Lesbos was part of the kingdom of Priam in what is now Turkey, much work remains to be done to determine just what was happening and when. In the Middle Ages, it was under Byzantine and then Genoese rule, Lesbos was conquered by the Ottoman Empire in 1462. The Ottomans then ruled the island until the First Balkan War in 1912, according to Classical Greek mythology, Lesbos was the patron god of the island. Macar was reputedly the first king whose many daughters bequeathed their names to some of the present larger towns, in Classical myth his sister, Canace, was killed to have him made king. The place names with female origins are likely to be much earlier settlements named after local goddesses, homer refers to the island as Macaros edos, the seat of Macar. The abundant grey pottery ware found on the island and the worship of Cybele, the island was governed by an oligarchy in archaic times, followed by quasi-democracy in classical times. For a short period it was a member of the Athenian confederacy, its apostasy from which is recounted by Thucydides in the Mytilenian Debate, in Hellenistic times, the island belonged to various Successor kingdoms until 79 BC when it passed into Roman hands. During the Middle Ages it belonged to the Byzantine Empire, in 802, the Byzantine Empress Irene was exiled to Lesbos after her deposition, and died there. The island served as a base for the fleet of the rebel Thomas the Slav in the early 820s. In the 10th century, it was part of the theme of the Aegean Sea, in the 1090s, the island was briefly occupied by the Turkish emir Tzachas, but he was unable to capture Methymna, which resisted throughout. In the 12th century, the became a frequent target for plundering raids by the Republic of Venice
35.
Samuel Gottlieb Gmelin
–
Samuel George Gottlieb Gmelin was a German physician, botanist and explorer. Gmelin was born at Tübingen in a known family of naturalists. His father was Johann Conrad Gmelin, an apothecary and surgeon and his uncle was Johann Georg Gmelin, who was also uncle to Johann Friedrich Gmelin. Samuel earned his degree in 1763 from the University of Leiden at the young age of 18. While living in the Dutch Republic, Gmelin developed a keen interest in marine algae, in 1766 he was appointed professor of botany at St Petersburg. In the following year he was sent on an expedition to study the history of the Russian Empire. He explored the rivers Don and Volga, and the western and eastern coasts of the Caspian Sea, whilst travelling in the Caucasus he was taken hostage by Usmey Khan of Khaïtakes and died of ill treatment in captivity in Akhmedkent. He was only 30 years of age and his death led to Russian punitive expedition which briefly conquered Derbent. Gmelin was the author of Historia Fucorum, the first work dedicated to marine biology, dealing exclusively with algae and it includes elaborate illustrations of seaweed and marine algae on folded leaves. However, algal specimens used by Gmelin in the Historia fucorum are thought to no longer exist, the results of his travels were published in Reise durch Russland zur untersuchung der drey natur-reiche. The final volume was to be completed by Guldenstadt but was edited by Peter Simon Pallas after Guldenstadts death. In 1772, he married Anna von Chappuzeau, granddaughter of the naval captain Jacob Chappuzeau, hero of the battle of Osel Island in 1719
36.
Algae
–
Algae is an informal term for a large, diverse group of photosynthetic organisms which are not necessarily closely related, and is thus polyphyletic. Included organisms range from unicellular genera, such as Chlorella and the diatoms, to forms, such as the giant kelp. Most are aquatic and autotrophic and lack many of the cell and tissue types, such as stomata, xylem, and phloem. No definition of algae is generally accepted, one definition is that algae have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells. Some authors exclude all prokaryotes thus do not consider cyanobacteria as algae, Algae constitute a polyphyletic group since they do not include a common ancestor, and although their plastids seem to have a single origin, from cyanobacteria, they were acquired in different ways. Green algae are examples of algae that have primary chloroplasts derived from endosymbiotic cyanobacteria, diatoms and brown algae are examples of algae with secondary chloroplasts derived from an endosymbiotic red alga. Algae exhibit a range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction. Algae lack the various structures that characterize land plants, such as the phyllids of bryophytes, rhizoids in nonvascular plants, and the roots, leaves, and other organs found in tracheophytes. Most are phototrophic, although some are mixotrophic, deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy, myzotrophy, or phagotrophy. Some other heterotrophic organisms, such as the apicomplexans, are derived from cells whose ancestors possessed plastids. Fossilized filamentous algae from the Vindhya basin have been dated back to 1.6 to 1.7 billion years ago, the singular alga is the Latin word for seaweed and retains that meaning in English. Although some speculate that it is related to Latin algēre, be cold, a more likely source is alliga, binding, entwining. The Ancient Greek word for seaweed was φῦκος, which could mean either the seaweed or a red dye derived from it, the Latinization, fūcus, meant primarily the cosmetic rouge. It could be any color, black, red, green, accordingly, the modern study of marine and freshwater algae is called either phycology or algology, depending on whether the Greek or Latin root is used. The name Fucus appears in a number of taxa, most algae contain chloroplasts that are similar in structure to cyanobacteria. Chloroplasts contain circular DNA like that in cyanobacteria and presumably represent reduced endosymbiotic cyanobacteria, however, the exact origin of the chloroplasts is different among separate lineages of algae, reflecting their acquisition during different endosymbiotic events. The table below describes the composition of the three groups of algae. Their lineage relationships are shown in the figure in the upper right, many of these groups contain some members that are no longer photosynthetic
37.
Binomial nomenclature
–
Such a name is called a binomial name, a binomen, binominal name or a scientific name, more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs, for example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of system of naming species is credited to Carl Linnaeus. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus. Although the general principles underlying binomial nomenclature are common to these two codes, there are differences, both in the terminology they use and in their precise rules. Similarly, both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a name is usually given, at least when it is first mentioned. In zoology Patella vulgata Linnaeus,1758, the original name given by Linnaeus was Fringilla domestica, the parentheses indicate that the species is now considered to belong in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, in botany Amaranthus retroflexus L. – L. is the standard abbreviation used in botany for Linnaeus. – Linnaeus first named this bluebell species Scilla italica, Rothmaler transferred it to the genus Hyacinthoides, the ICN does not require that the dates of either publication be specified. Prior to the adoption of the binomial system of naming species. Together they formed a system of polynomial nomenclature and these names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description, such polynomial names may sometimes look like binomials, but are significantly different. For example, Gerards herbal describes various kinds of spiderwort, The first is called Phalangium ramosum, Branched Spiderwort, is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia. The Latin phrases are short descriptions, rather than identifying labels, the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné. It was in his 1753 Species Plantarum that he first began using a one-word trivial name together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as an epithet or specific name
38.
Carl Linnaeus
–
Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
39.
Edward Forbes
–
Professor Edward Forbes FRS, FGS was a Manx naturalist. Forbes was born at Douglas, in the Isle of Man, from his fifth to his eleventh year, delicacy of health precluded his attendance at any school, but in 1828 he became a day scholar at Athole House Academy in Douglas. In June 1831 he left the Isle of Man for London, in October, however, having given up the idea of making painting his profession, he returned home, and in the following month he matriculated as a medical student in the University of Edinburgh. In 1832, he pursued studies in the history of the Isle of Man. His brother David was a notable mineralogist, in 1833 he made a tour in Norway, the botanical results of which were published in Loudons Magazine of Natural History for 1835–1836. In the summer of 1834 he devoted time to dredging in the Irish Sea. The winter of 1836–1837 found him at Paris, where he attended the lectures at the Jardin des Plantes on natural history, comparative anatomy, geology and mineralogy. Leaving Paris in April 1837, he went to Algiers, and there obtained materials for a paper on land and freshwater Mollusca, published in the Annals of Natural History, vol. ii. p.250. In the autumn of the year he registered at Edinburgh as a student of literature, and in 1838 appeared his first volume, Malacologia Monensis. During the summer of 1838 he visited Styria and Carniola, and his Azoic hypothesis was extinguished after 25 years when evidence of starfish and worms were found on the deep seabed. In 1841 was published his History of British star-fishes, embodying extensive observations and containing 120 illustrations, inclusive of humorous tail-pieces, from April 1841 until October 1842 he was employed in investigating the botany, zoology and geology of the Mediterranean region. Towards the end of the year 1842 Forbes, whom family misfortunes had now thrown upon his own resources, sought, to the duties of that post he added in 1843 those of the professorship of botany at Kings College London. In November 1844 he resigned the curatorship of the Geological Society, in 1846, he published in the Memoirs of the Geological Survey, i. On this subject Forbess brilliant generalizations are now regarded as partially true. In the autumn of 1848 Forbes married the daughter of General Sir Charles Ashworth, the year as publication of his monograph. In 1852 was published the fourth and concluding volume of Forbes and S. Hanleys History of British Mollusca, one of Forbes achievements was to have advised and helped the young Thomas Henry Huxley before, during and after the latters voyage on HMS Rattlesnake. During the voyage Huxley sent details of his discoveries back to Forbes, Forbes provided important introductions for Huxley, wrote a favorable review of his work, and helped him to gain entry to the Royal Society at the age of 26. It seemed that at length he was to find leisure to reduce to order his stores of biological information
40.
HMS Challenger (1858)
–
HMS Challenger was a steam-assisted Royal Navy Pearl-class corvette launched on 13 February 1858 at the Woolwich Dockyard. She was the flagship of the Australia Station between 1866 and 1870, as part of the North America and West Indies Station she took part in 1862 in operations against Mexico, including the occupation of Vera Cruz. Assigned as the flagship of Australia Station in 1866 and in 1868 undertook an operation against some Fijian natives to avenge the murder of a missionary. She left the Australian Station in late 1870 and she was picked to undertake the first global marine research expedition, the Challenger expedition. The Challenger carried a complement of 243 officers, scientists and crew when she embarked on her 68, the United States Space Shuttle Challenger was named after the ship. Her figurehead is on display in the foyer of the National Oceanography Centre, the Challenger Expedition was a grand tour of the world during covering 68,000 nautical miles organized by the Royal Society in collaboration with the University of Edinburgh. Charles Thomson was the leader of a scientific team. W. Thomson, Report on the results of the voyage of HMS Challenger during the years 1873-76… prepared under the superintendence of the late Sir C. H. N. Moseley, Notes by a naturalist on the Challenger, spry, The cruise of the Challenger. To enable her to probe the depths, all but two of the Challengers guns had been removed and her spars reduced to more space available. Laboratories, extra cabins and a special dredging platform were installed, in all she was supplied with 181 miles of Italian hemp for sounding, trawling and dredging. The Challengers crew was the first to sound the deepest part of the ocean and she was commissioned as a Coast Guard and Royal Naval Reserve training ship at Harwich in July 1876. In 1878 Challenger went through an overhaul by the Chief Constructor at Chatham Dockyard with a view to converting the vessel into a ship for boys of the Royal Navy. She was found suitable and it was planned to take the place of HMS Eurydice which sank off the Isle of Wight on 24 March 1878, nothing, apart from her figurehead, now remains. This is on display in the foyer of the National Oceanography Centre, european and American voyages of scientific exploration Bastock, John, Ships on the Au Station, Child & Associates Publishing Pty Ltd, Frenchs Forest, Australia. ISBN 0-86777-348-0 Winfield, Rif & Lyon, David, the Sail and Steam Navy List, All the Ships of the Royal Navy 1815–1889. Media related to HMS Challenger at Wikimedia Commons
41.
Challenger expedition
–
The Challenger expedition of 1872–76 was a scientific exercise that made many discoveries to lay the foundation of oceanography. The expedition was named after the vessel, HMS Challenger. The expedition, led by Captain George Nares, sailed from Portsmouth, England, other naval officers included Commander John Maclear. Under the scientific supervision of Thomson himself, she traveled nearly 70,000 nautical miles surveying and exploring, the result was the Report Of The Scientific Results of the Exploring Voyage of H. M. S. Challenger during the years 1873-76 which, among other discoveries. John Murray, who supervised the publication, described the report as the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries, Challenger sailed close to Antarctica, but not within sight of it. As recently as the late 19th century, human knowledge of the oceans was confined to the topmost few fathoms of the water, sailors and scientists knew almost nothing of the ocean depths. The Royal Navys efforts to all of the worlds coastlines in the mid-19th century reinforced the vague idea that most of the ocean was very deep. As exploration ignited both popular and scientific interest in the regions and Africa, so too did the mysteries of the unexplored oceans. To enable her to probe the depths, Challengers guns were removed, laboratories, extra cabins and a special dredging platform were installed. Because of the novelty of the expedition, some of the equipment was invented or specially modified for the occasion, in all, she was supplied with 181 miles of Italian hemp for sounding. On her 68, 890-nautical-mile journey circumnavigating the globe,492 deep sea soundings,133 bottom dredges,151 open water trawls and 263 serial water temperature observations were taken, also about 4,700 new species of marine life were discovered. The scientific work was conducted by Wyville Thomson, John Murray, John Young Buchanan, Henry Nottidge Moseley, Frank Evers Beddard was appointed Prosector. The official expedition artist was John James Wild, as well as Nares and Maclear, others that were part of the naval crew included Pelham Aldrich, Lord George Granville Campbell, and Andrew Francis Balfour. Also among the officers was Thomas Henry Tizard, who had carried out important hydrographic observations on previous voyages, though he was not among the civilian scientific staff, Tizard would later help write the official account of the expedition, and also become a Fellow of the Royal Society. The original ships complement included 21 officers and around 216 crew members, by the end of the voyage, this had reduced to 144 due to deaths, desertions, being left ashore due to illness, and planned departures. Challenger reached Hong Kong in December 1874, at which point Nares, the new captain was Frank Tourle Thomson. The second-in-command, and the most senior officer present throughout the expedition, was Commander John Maclear
42.
Age of Discovery
–
It also marks the rise of the period of widespread adoption in Europe of colonialism and mercantilism. Many lands previously unknown to Europeans were discovered during this period, from the perspective of many non-Europeans, the Age of Discovery marked the arrival of settlers and invaders from a previously unknown continent. This represented one of the most-significant global events concerning ecology, agriculture and it also allowed for the expansion of Christianity throughout the world with the spread of missionary activity, becoming the worlds largest religion. The Portuguese began systematically exploring the Atlantic coast of Africa from 1418, in 1488 Bartolomeu Dias reached the Indian Ocean by this route. In 1492 the Catholic Monarchs of Castile and Aragon funded Christopher Columbuss plan to sail west to reach the Indies by crossing the Atlantic and he landed on a continent uncharted by Europeans and seen as a new world, the Americas. In 1498, a Portuguese expedition commanded by Vasco da Gama reached India by sailing around Africa, soon, the Portuguese sailed further eastward, to the valuable Spice Islands in 1512, landing in China one year later. In 1513, Spanish Vasco Núñez de Balboa crossed the Isthmus of Panama, thus, Europe first received news of the eastern and western Pacific within a one-year span around 1512. Meanwhile, from the 1580s to the 1640s, Russians explored and conquered almost the whole of Siberia, another source was the Radhanite Jewish trade networks of merchants established as go-betweens between Europe and the Muslim world during the time of the Crusader states. Knowledge about the Atlantic African coast was fragmented and derived mainly from old Greek and Roman maps based on Carthaginian knowledge, the Red Sea was barely known and only trade links with the Maritime republics, the Republic of Venice especially, fostered collection of accurate maritime knowledge. Indian Ocean trade routes were sailed by Arab traders, between 1405 and 1421, the Yongle Emperor of Ming China sponsored a series of long range tributary missions under the command of Zheng He. The fleets visited Arabia, East Africa, India, Maritime Southeast Asia, by 1400 a Latin translation of Ptolemys Geographia reached Italy coming from Constantinople. The rediscovery of Roman geographical knowledge was a revelation, both for mapmaking and worldview, although reinforcing the idea that the Indian Ocean was landlocked, a prelude to the Age of Discovery was a series of European expeditions crossing Eurasia by land in the late Middle Ages. A series of Europeans took advantage of these to explore eastwards, most were Italians, as trade between Europe and the Middle East was controlled mainly by the Maritime republics. The close Italian links to the Levant raised great curiosity and commercial interest in countries which lay further east, christian embassies were sent as far as Karakorum during the Mongol invasions of the Levant, from which they gained a greater understanding of the world. The first of these travellers was Giovanni da Pian del Carpine, dispatched by Pope Innocent IV to the Great Khan, about the same time, Russian prince Yaroslav of Vladimir, and subsequently his sons Alexander Nevsky and Andrey II of Vladimir, travelled to the Mongolian capital. Though having strong political implications, their journeys left no detailed accounts, other travellers followed, like French André de Longjumeau and Flemish William of Rubruck, who reached China through Central Asia. After returning, he dictated an account of his journeys to a scholar he met in Granada, the Rihla, between 1357 and 1371 a book of supposed travels compiled by John Mandeville acquired extraordinary popularity. These overland journeys had little immediate effect, the Mongol Empire collapsed almost as quickly as it formed and soon the route to the east became more difficult and dangerous
43.
HMS Beagle
–
HMS Beagle was a Cherokee-class 10-gun brig-sloop of the Royal Navy, one of more than 100 ships of this class. The vessel, constructed at a cost of £7,803, was launched on 11 May 1820 from the Woolwich Dockyard on the River Thames, there was no immediate need for Beagle so she lay in ordinary, moored afloat but without masts or rigging. She was then adapted as a barque and took part in three survey expeditions. The Cherokee-class of 10-gun brig-sloops was designed by Sir Henry Peake in 1807, the Beagles keel was laid in June 1818, construction cost £7,803, and the ship was launched on 11 May 1820. In July of that year she took part in a review on the River Thames. Captain Pringle Stokes was appointed captain of Beagle on 7 September 1825, on 27 September 1825 Beagle docked at Woolwich to be repaired and fitted out for her new duties. Her guns were reduced from ten cannon to six and a mizzen mast was added to improve her handling, Beagle set sail from Plymouth on 22 May 1826 on her first voyage, under the command of Captain Stokes. Faced with the difficult part of the survey in the desolate waters of Tierra del Fuego. At Port Famine on the Strait of Magellan he locked himself in his cabin for 14 days, then after getting over-excited and talking of preparing for the next cruise, shot himself on 2 August 1828. Following four days of delirium Stokes recovered slightly, but then his condition deteriorated, Captain Parker King then replaced Stokes with the First Lieutenant of the Beagle, Lieutenant W. G. Skyring as commander, and both ships sailed to Montevideo. On 13 October King sailed the Adventure to Rio de Janeiro for refitting, when the Beagle arrived, Otway put the ship under the command of his aide, Flag Lieutenant Robert FitzRoy. The 23-year-old aristocrat FitzRoy proved an able commander and meticulous surveyor, in one incident a group of Fuegians stole a ships boat, and FitzRoy took their families on board as hostages. Eventually he held two men, a girl and a boy, who was given the name of Jemmy Button, during this survey, the Beagle Channel was identified and named after the ship. A kind uncle heard of this and contacted the Admiralty, soon afterwards FitzRoy heard that he was to be appointed commander of HMS Chanticleer to go to Tierra del Fuego, but due to her poor condition Beagle was substituted for the voyage. FitzRoy was re-appointed as commander on 27 June 1831 and the Beagle was commissioned on 4 July 1831 under his command, with Lieutenants John Clements Wickham, Beagle was immediately taken into dock at Devonport for extensive rebuilding and refitting. As she required a new deck, FitzRoy had the upper-deck raised considerably, the Cherokee-class ships had the reputation of being coffin brigs, which handled badly and were prone to sinking. Additional sheathing added to the hull added about seven tons to her burthen, the ship was one of the first to be fitted with the lightning conductor invented by William Snow Harris. To reduce magnetic interference with the instruments, FitzRoy proposed replacing the iron guns with brass guns
44.
Charles Darwin
–
Charles Robert Darwin, FRS FRGS FLS FZS was an English naturalist, geologist and biologist, best known for his contributions to the science of evolution. Darwin published his theory of evolution with compelling evidence in his 1859 book On the Origin of Species, by the 1870s, the scientific community and much of the general public had accepted evolution as a fact. In modified form, Darwins scientific discovery is the theory of the life sciences. Darwins early interest in nature led him to neglect his education at the University of Edinburgh, instead. Studies at the University of Cambridge encouraged his passion for natural science, puzzled by the geographical distribution of wildlife and fossils he collected on the voyage, Darwin began detailed investigations and in 1838 conceived his theory of natural selection. Although he discussed his ideas with several naturalists, he needed time for extensive research and he was writing up his theory in 1858 when Alfred Russel Wallace sent him an essay that described the same idea, prompting immediate joint publication of both of their theories. Darwins work established evolutionary descent with modification as the dominant scientific explanation of diversification in nature, in 1871 he examined human evolution and sexual selection in The Descent of Man, and Selection in Relation to Sex, followed by The Expression of the Emotions in Man and Animals. His research on plants was published in a series of books, Darwin has been described as one of the most influential figures in human history, and he was honoured by burial in Westminster Abbey. Charles Robert Darwin was born in Shrewsbury, Shropshire, on 12 February 1809, at his familys home and he was the fifth of six children of wealthy society doctor and financier Robert Darwin and Susannah Darwin. He was the grandson of two prominent abolitionists, Erasmus Darwin on his fathers side, and Josiah Wedgwood on his mothers side, both families were largely Unitarian, though the Wedgwoods were adopting Anglicanism. The eight-year-old Charles already had a taste for history and collecting when he joined the day school run by its preacher in 1817. From September 1818, he joined his older brother Erasmus attending the nearby Anglican Shrewsbury School as a boarder and he found lectures dull and surgery distressing, so neglected his studies. He learned taxidermy in around 40 daily hour-long sessions from John Edmonstone, one day, Grant praised Lamarcks evolutionary ideas. Darwin was astonished by Grants audacity, but had recently read similar ideas in his grandfather Erasmus journals, Darwin was rather bored by Robert Jamesons natural-history course, which covered geology - including the debate between Neptunism and Plutonism. He learned the classification of plants, and assisted with work on the collections of the University Museum, as Darwin was unqualified for the Tripos, he joined the ordinary degree course in January 1828. He preferred riding and shooting to studying, when his own exams drew near, Darwin focused on his studies and was delighted by the language and logic of William Paleys Evidences of Christianity. In his final examination in January 1831 Darwin did well, coming out of 178 candidates for the ordinary degree. Darwin had to stay at Cambridge until June 1831, inspired with a burning zeal to contribute, Darwin planned to visit Tenerife with some classmates after graduation to study natural history in the tropics
45.
Evolution
–
Evolution is change in the heritable characteristics of biological populations over successive generations. Evolutionary processes give rise to biodiversity at every level of organisation, including the levels of species, individual organisms. In July 2016, scientists reported identifying a set of 355 genes from the LUCA of all living on Earth. The fossil record includes a progression from early biogenic graphite, to microbial mat fossils, existing patterns of biodiversity have been shaped both by speciation and by extinction. More than 99 percent of all species that lived on Earth are estimated to be extinct. Estimates of Earths current species range from 10 to 14 million, more recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described. In the mid-19th century, Charles Darwin formulated the theory of evolution by natural selection. This teleonomy is the quality whereby the process of natural selection creates and preserves traits that are fitted for the functional roles they perform. The processes by which the changes occur, from one generation to another, are called evolutionary processes or mechanisms, the four most widely recognized evolutionary processes are natural selection, genetic drift, mutation and gene migration. Natural selection and genetic drift sort variation, mutation and gene migration create variation, consequences of selection can include meiotic drive, nonrandom mating and genetic hitchhiking. In the early 20th century the modern evolutionary synthesis integrated classical genetics with Darwins theory of evolution by natural selection through the discipline of population genetics, the importance of natural selection as a cause of evolution was accepted into other branches of biology. Moreover, previously held notions about evolution, such as orthogenesis, evolutionism, evolutionary computation, a sub-field of artificial intelligence, involves the application of Darwinian principles to problems in computer science. The proposal that one type of organism could descend from another type goes back to some of the first pre-Socratic Greek philosophers, such as Anaximander, such proposals survived into Roman times. The poet and philosopher Lucretius followed Empedocles in his masterwork De rerum natura, in contrast to these materialistic views, Aristotelianism considered all natural things as actualisations of fixed natural possibilities, known as forms. This was part of a teleological understanding of nature in which all things have an intended role to play in a divine cosmic order. In the 17th century, the new method of modern science rejected the Aristotelian approach, however, this new approach was slow to take root in the biological sciences, the last bastion of the concept of fixed natural types. The biological classification introduced by Carl Linnaeus in 1735 explicitly recognized the nature of species relationships. Other naturalists of this time speculated on the change of species over time according to natural laws
46.
Species diversity
–
Species diversity is the number of different species that are represented in a given community. The effective number of species refers to the number of equally abundant species needed to obtain the mean proportional species abundance as that observed in the dataset of interest. Species diversity consists of two components, species richness and species evenness, species richness is a simple count of species, whereas species evenness quantifies how equal the abundances of the species are. Species diversity in a dataset can be calculated by first taking the average of species proportional abundances in the dataset. In the equation, S is the number of species in the dataset. The proportional abundances themselves are used as weights, the equation is often written in the equivalent form, q D =1 / The value of q defines which kind of mean is used. Q =0 corresponds to the harmonic mean, which is 1/S because the p i values cancel out. Q =1 is undefined, except that the limit as q approaches 1 is well defined, as q approaches infinity, the generalized mean approaches the maximum p i value. Consequently, large values of q lead to species diversity than small values of q for the same dataset. If all species are abundant in the dataset, changing the value of q has no effect. Negative values of q are not used, because then the number of species would exceed the actual number of species. As q approaches infinity, the generalized mean approaches the minimum p i value. In many real datasets, the least abundant species is represented by a single individual, the same equation can be used to calculate the diversity in relation to any classification, not only species. Often researchers have used the values given by one or more diversity indices to quantify species diversity, such indices include species richness, the Shannon index, the Simpson index, and the complement of the Simpson index. When interpreted in terms, each one of these indices corresponds to a different thing. Species richness quantifies the actual rather than number of species. The Shannon index equals log, and in practice quantifies the uncertainty in the identity of an individual that is taken at random from the dataset. The Simpson index equals 1/qD and quantifies the probability that two individuals taken at random from the dataset represent the same species, the Gini-Simpson index equals 1 - 1/qD and quantifies the probability that the two randomly taken individuals represent different species
.jpg)
. PMID 21625431.
