Information AboutMarine Biology |
| CATEGORIES ABOUT MARINE BIOLOGY | |
| marine biology | |
| biological oceanographymarine biology | |
| biological oceanography | |
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| oceanography | |
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Marine biology is the scientific study of Algae , Animal s and other organisms that live in the Ocean or other marine or Brackish body of water. Given that in Biology many Phyla , families and genera have some species that live in the Sea and others that live on land, marine biology classifies species based on the Environment rather than on taxonomy. Marine life represents a vast resource, providing Food , Medicine , and raw materials, in addition to helping to support Recreation and Tourism all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms produce 90% of the Oxygen we breathe and probably help regulate the earth's Climate . Shoreline s are in part shaped and protected by marine life, and some marine organisms even help create new land. OVERVIEW , which have no close terrestrial relatives).]] Marine biology covers a great deal, from the microscopic, including Plankton and Phytoplankton , which can be as small as 0.02 Micrometers and are both hugely important as the Primary Producers of the sea, to the huge Cetaceans (whales) which reach up to a reported 33 Meters (109 Feet ) in length. The habitats studied by marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in Surface Tension between the ocean and atmosphere, to the depths of the Abyssal Trenches , sometimes 10,000 meters or more beneath the surface of the ocean. It studies habitats such as Coral Reef s, Kelp Forest s, Tidepools , muddy, sandy, and rocky bottoms, and the open ocean (pelagic) zone, where solid objects are rare and the surface of the water is the only visible boundary. A large amount of all Life On Earth exists in the oceans. Exactly how large the proportion is is still unknown. While the oceans comprise about 71% of the Earth's surface, due to their depth they encompass about 300 times the habitable volume of the terrestrial habitats on Earth. Many species are economically important to humans, including the Food Fishes . It is also becoming understood that the well-being of marine organisms and other organisms are linked in very fundamental ways. Human understanding is growing of the relationship between life in the sea and important cycles such as that of matter (such as the Carbon Cycle ) and of air (such as Earth's Respiration , and movement of energy through ecosystems). Large areas beneath the ocean surface still remain effectively unexplored. Scientists know more about the moon than they know about the ocean and the life in it. SUBFIELDS The Marine Ecosystem is large, and thus there are many subfields of marine biology. Most involve studying specializations of particular species (i.e., Phycology , Invertebrate Zoology , Ichthyology ). Other subfields study the physical effects of continual immersion in Sea Water and the ocean in general, adaptation to a salty environment, and the effects of changing various oceanic properties on marine life. A subfield of marine biology studies the relationships between oceans and ocean life, and global weather and environmental issues (such as Carbon Dioxide displacement). Recent marine Biotechnology has focused largely on Marine Biomolecule s, especially Protein s, that may have uses in medicine or engineering. Marine environments are the home to many exotic biological materials that may inspire Biomimetic Material s. An interesting branch of marine biology is Aquaculture ; which some countries do a lot of in the oceans, especially Japan . Related fields Marine biology is a branch of Oceanography and is closely linked to Biology . It also encompasses many ideas from Ecology . Fisheries Science and Marine Conservation can be considered partial offshoots of marine biology. LIFEFORMS Microscopic life .]] Microscopic life undersea is incredibly diverse and still poorly understood. For example, the role of Virus es in marine ecosystems is barely being explored even in the beginning of the 21st Century . The role of Phytoplankton is better understood due to their critical position as the most numerous Primary Producers on Earth. Phytoplankton are categorized into Cyanobacteria (also called blue-green algae/bacteria), various types of Algae (red, green, brown, and yellow-green), Diatom s, Dinoflagellate s, Euglenoids , Coccolithophorid s, Cryptomonad s, Chrysophyte s, Chlorophyte s, Prasinophyte s, and Silicoflagellate s. Zooplankton tend to be somewhat larger, and not all are microscopic. Many Protozoa are zooplankton, including dinoflagellates, Zooflagellate s, Foraminiferans , and Radiolarian s. Some of these (such as dinoflaggelates) are also phytoplankton; the Plant/animal Distinction often breaks down in very small organisms. Other zooplankton include Cnidarian s, Ctenophore s, Chaetognaths , Mollusc s, Arthropod s, Urochordates , and Annelid s such as Polychaete s. Many larger animals begin their life as zooplankton before they become large enough to take their familiar forms. Two examples are fish Larva e and sea stars (also called Starfish ). Plants and algae .]] Plant life is relatively rare undersea. Most of the Niche occupied by plants on land is actually occupied by macroscopic Algae in the ocean, such as '' Sargassum '' and Kelp which are commonly known as Seaweed s. The non algae plants that do survive in the sea are often found in shallow waters, such as the Seagrasses (examples of which are eelgrass, '' Zostera '', and turtlegrass, ''Thalassia''). These plants have adapted to the high salinity of the ocean environment. The Intertidal Zone is also a good place to find plant life in the sea, where Mangroves or Cordgrass or Beach Grass might grow. Sea Kelp is very important to small sea creatures because the creatures can hide from predators. Marine invertebrates .'']] As on land, Invertebrates make up a huge portion of all life in the sea. Invertebrate sea life includes Cnidaria such as Jellyfish and Sea Anemone ; Ctenophora ; Sea Worm s including Phyla Plathyhelminthes, Nemertea, Annelida, Sipuncula, Echiura, and the Phoronida; Mollusca including Shellfish , Squid , Octopus ; Crustacean s; Porifera including Sponge s, Bryozoa , Echinodermata including starfish; and Urochordata - Sea Squirt s or Tunicate s. Fish .]] Fish have Evolved very different biological functions from other large organisms. Fish anatomy includes a two-chambered heart, Operculum , secretory Cells that produce Mucous , Swim Bladder , Scales , Fin s, Lip s and Eye s. Fish breathe by extracting Oxygen from water through their gills. Fins propel and stabilize the fish in the water. Well known fish include: Sardine s, Anchovy , Tuna , Clownfish (also known as anemonefish), and Bottom Fish which include Halibut and Ling Cod . Predator s include Shark s and Barracuda . Reptiles .]] See Also: Marine reptile Reptile s which inhabit or frequent the sea include Sea Turtle s, Marine Iguana s, sea Snake s, and saltwater Crocodile s. Since all Extant marine reptiles are Oviparous and need to return to land to lay their eggs, most reptile species live on or near land, rather than in the ocean. Some Extinct marine reptiles, such as Ichthyosaur s, evolved to be Viviparous and had no requirement to return to land. Seabirds .]] Seabird s are species of Bird s adapted to living in the marine environment, examples including Albatross , Penguin s, Gannet s, and Auk s. Although they spend most of their lives in the ocean, species such as Gull s can often be found thousands of miles inland. Marine mammals .]] There are five main types of marine mammals.
OCEANIC HABITATS Reefs Reef s comprise some of the densest and most diverse habitats in the world. The best-known types of reefs are Tropical Coral Reef s which exist in most tropical waters; however, reefs can also exist in cold water. Reefs are built up by Coral s and other Calcium -depositing animals, usually on top of a rocky outcrop on the ocean floor. Reefs can also grow on other surfaces, which has made it possible to create Artificial Reef s. Coral reefs also support a huge community of life, including the corals themselves, their symbiotic Zooxanthellae , tropical fish and many other organisms. s.]] Much attention in marine biology is focused on coral reefs and the El Niño weather phenomenon. In 1998 , coral reefs experienced a "once in a thousand years" bleaching event, in which vast expanses of reefs across the Earth died because sea surface temperatures rose well above normal. Some reefs are recovering, but scientists say that 58 % of the world's coral reefs are now endangered and predict that Global Warming could exacerbate this trend. Deep sea and trenches The ocean is deep, very deep in some places. The deepest recorded measure to date is the Mariana Trench , near the Philippines , in the Pacific Ocean at 10924 m (35838 ft). At such depths, Water Pressure is extreme and there is no sunlight, but some life still exists. Small flounder (family Soleidae ) fish and shrimp were seen by the American crew of the Bathyscaphe '' Trieste '' when it dove to the bottom in 1960 . Other notable Oceanic Trench es include Monterey Canyon , in the eastern Pacific, the Tonga Trench in the southwest at 10,882 m (35,702 feet), the Philippine Trench , the Puerto Rico Trench at 8605 m (28232 ft), the Romanche Trench at 7760 m (24450 ft), Fram Basin in the Arctic Ocean at 4665 m (15305 ft), the Java Trench at 7450 m (24442 ft), and the South Sandwich Trench at 7235 m (23737 ft). In general, the deep sea is considered to start at the Aphotic Zone , the point where sunlight loses its power of transference through the water. Many life forms that live at these depths have the ability to create their own light. Much life centers on Seamount s that rise from the deeps, where fish and other sea life congregate to spawn and feed. Hydrothermal Vent s along the Mid-ocean Ridge spreading centers act as Oases , as do their opposites, Cold Seeps . Such places support unique Biome s and many new Microbe s and other lifeforms have been discovered at these locations. Open ocean The great expanse of open ocean habitat is huge, and many species can be found passing through it and living in it. The term "open ocean" usually is meant to refer to the vast stretches of water between points of land, or between undersea mounts. Contrary to popular notions the open ocean is often not the place where marine animals spend the majority of their lives. Most species simply pass through the open ocean on their ways to other places. Larger species are the main ongoing inhabitants... Intertidal and shore Intertidal Zone s, those areas close to shore, are constantly being exposed and covered by the ocean's Tides . A huge array of life lives within this zone. Shore habitats span from the upper intertidal zones to the area where land vegetation takes prominence. It can be underwater anywhere from daily to very infrequently. Many species here are scavengers, living off of sea life that is washed up on the shore. Many land animals also make much use of the shore and intertidal habitats. A subgroup of organisms in this habitat bores and grinds exposed rock through the process of Bioerosion . HOW OCEANIC FACTORS AFFECT DISTRIBUTION OF VARIOUS ORGANISMS An active research topic in marine biology is to discover and map the Life Cycle s of various species and where they spend their time. Marine biologists study how the Ocean Current s, Tide s and many other oceanic factors affect ocean lifeforms, including their growth, distribution and well-being. This has only recently become technically feasible with advances in GPS and newer underwater visual devices. Most ocean life breeds in specific places, nests or not in others, spends time as juveniles in still others, and in maturity in yet others. Scientists know little about where many species spent different parts of their life cycles. For example, it is still largely unknown where Sea Turtle s travel. Tracking devices do not work for some life forms, and the ocean is not friendly to Technology . But these factors are being overcome in many instances. FAMOUS MARINE BIOLOGISTS , is well known for popularizing marine biology.]]
Source: List Of Biologists . SEE ALSO .]]
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