Seawater: The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.Gills: Paired respiratory organs of fishes and some amphibians that are analogous to lungs. They are richly supplied with blood vessels by which oxygen and carbon dioxide are exchanged directly with the environment.Water Microbiology: The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.Ostreidae: A family of marine mollusks in the class BIVALVIA, commonly known as oysters. They have a rough irregular shell closed by a single adductor muscle.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Fresh Water: Water containing no significant amounts of salts, such as water from RIVERS and LAKES.Marine Biology: The study of the origin, structure, development, growth, function, genetics, and reproduction of organisms which inhabit the OCEANS AND SEAS.DNA, Ribosomal: DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Salinity: Degree of saltiness, which is largely the OSMOLAR CONCENTRATION of SODIUM CHLORIDE plus any other SALTS present. It is an ecological factor of considerable importance, influencing the types of organisms that live in an ENVIRONMENT.Vibrio: A genus of VIBRIONACEAE, made up of short, slightly curved, motile, gram-negative rods. Various species produce cholera and other gastrointestinal disorders as well as abortion in sheep and cattle.Oceans and Seas: A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).Acclimatization: Adaptation to a new environment or to a change in the old.Gammaproteobacteria: A group of the proteobacteria comprised of facultatively anaerobic and fermentative gram-negative bacteria.Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.Rhodobacteraceae: A family in the order Rhodobacterales, class ALPHAPROTEOBACTERIA.Fundulidae: Family of small, surface-dwelling fish that inhabit fresh and brackish waters, and coastal marine areas.Bivalvia: A class in the phylum MOLLUSCA comprised of mussels; clams; OYSTERS; COCKLES; and SCALLOPS. They are characterized by a bilaterally symmetrical hinged shell and a muscular foot used for burrowing and anchoring.Flavobacteriaceae: A family of bacteria in the order Sphingobacteriales, class Sphingobacteria. They are gram-negative rods, mostly saprophytic in terrestrial and aquatic habitats.Anthozoa: A class in the phylum CNIDARIA, comprised mostly of corals and anemones. All members occur only as polyps; the medusa stage is completely absent.AnguillaPacific OceanCalcium Carbonate: Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Eels: Common name for an order (Anguilliformes) of voracious, elongate, snakelike teleost fishes.Water-Electrolyte Balance: The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.Alphaproteobacteria: A class in the phylum PROTEOBACTERIA comprised mostly of two major phenotypes: purple non-sulfur bacteria and aerobic bacteriochlorophyll-containing bacteria.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Salmo salar: A commercially important species of SALMON in the family SALMONIDAE, order SALMONIFORMES, which occurs in the North Atlantic.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Aquaculture: Cultivation of natural faunal resources of water. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Fish Diseases: Diseases of freshwater, marine, hatchery or aquarium fish. This term includes diseases of both teleosts (true fish) and elasmobranchs (sharks, rays and skates).Heterotrophic Processes: The processes by which organisms utilize organic substances as their nutrient sources. Contrasts with AUTOTROPHIC PROCESSES which make use of simple inorganic substances as the nutrient supply source. Heterotrophs can be either chemoheterotrophs (or chemoorganotrophs) which also require organic substances such as glucose for their primary metabolic energy requirements, or photoheterotrophs (or photoorganotrophs) which derive their primary energy requirements from light. Depending on environmental conditions some organisms can switch between different nutritional modes (AUTOTROPHY; heterotrophy; chemotrophy; or PHOTOTROPHY) to utilize different sources to meet their nutrients and energy requirements.Antarctic Regions: The continent lying around the South Pole and the southern waters of the Atlantic, Pacific, and Indian Oceans. It includes the Falkland Islands Dependencies. (From Webster's New Geographical Dictionary, 1988, p55)Tilapia: A freshwater fish used as an experimental organism and for food. This genus of the family Cichlidae (CICHLIDS) inhabits Central and South America (one species extends north into Texas), West Indies, Africa, Madagascar, Syria, and coastal India.Mediterranean SeaPlankton: Community of tiny aquatic PLANTS and ANIMALS, and photosynthetic BACTERIA, that are either free-floating or suspended in the water, with little or no power of locomotion. They are divided into PHYTOPLANKTON and ZOOPLANKTON.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Shellfish: Aquatic invertebrates belonging to the phylum MOLLUSCA or the subphylum CRUSTACEA, and used as food.Bacterial Typing Techniques: Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.Genes, rRNA: Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Geologic Sediments: A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Water Pollution, Chemical: Adverse effect upon bodies of water (LAKES; RIVERS; seas; groundwater etc.) caused by CHEMICAL WATER POLLUTANTS.Water Pollution: Contamination of bodies of water (such as LAKES; RIVERS; SEAS; and GROUNDWATER.)Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Dinoflagellida: Flagellate EUKARYOTES, found mainly in the oceans. They are characterized by the presence of transverse and longitudinal flagella which propel the organisms in a rotating manner through the water. Dinoflagellida were formerly members of the class Phytomastigophorea under the old five kingdom paradigm.Crassostrea: A genus of oysters in the family OSTREIDAE, class BIVALVIA.Vibrio parahaemolyticus: A species of bacteria found in the marine environment, sea foods, and the feces of patients with acute enteritis.Fishes: A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.Aerobiosis: Life or metabolic reactions occurring in an environment containing oxygen.Pigments, Biological: Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.Korea: Former kingdom, located on Korea Peninsula between Sea of Japan and Yellow Sea on east coast of Asia. In 1948, the kingdom ceased and two independent countries were formed, divided by the 38th parallel.Ecosystem: A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Decapodiformes: A superorder of CEPHALOPODS comprised of squid, cuttlefish, and their relatives. Their distinguishing feature is the modification of their fourth pair of arms into tentacles, resulting in 10 limbs.Coral Reefs: Marine ridges composed of living CORALS, coral skeletons, calcareous algae, and other organisms, mixed with minerals and organic matter. They are found most commonly in tropical waters and support other animal and plant life.Alteromonadaceae: A family of marine, gram-negative PROTEOBACTERIA including the genera ALTEROMONAS; Colwellia; Idiomarina; MARINOBACTER; MORITELLA; PSEUDOALTEROMONAS; and SHEWANELLA.Petroleum: Naturally occurring complex liquid hydrocarbons which, after distillation, yield combustible fuels, petrochemicals, and lubricants.Vibrio Infections: Infections with bacteria of the genus VIBRIO.Biofouling: Process by which unwanted microbial, plant or animal materials or organisms accumulate on man-made surfaces.Bays: An area of water mostly surrounded by land, usually smaller than a gulf, and affording access to the sea.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Brachyura: An infraorder of chiefly marine, largely carnivorous CRUSTACEA, in the order DECAPODA, including the genera Cancer, Uca, and Callinectes.Fish Proteins: Proteins obtained from species of fish (FISHES).Eukaryota: One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.Water Pollutants, Chemical: Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.Carbonates: Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)Water Pollutants, Radioactive: Pollutants, present in water or bodies of water, which exhibit radioactivity.Vibrio vulnificus: A species of halophilic bacteria in the genus VIBRIO, which lives in warm SEAWATER. It can cause infections in those who eat raw contaminated seafood or have open wounds exposed to seawater.Flounder: Common name for two families of FLATFISHES belonging to the order Pleuronectiformes: left-eye flounders (Bothidae) and right-eye flounders (Pleuronectidae). The latter is more commonly used in research.Quinones: Hydrocarbon rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.Tenacibaculum: A genus of gram-negative, rod-shaped bacteria in the family FLAVOBACTERIACEAE. Tenacibaculum adheres to surfaces of marine organisms and is pathogenic to fish.Porifera: The phylum of sponges which are sessile, suspension-feeding, multicellular animals that utilize flagellated cells called choanocytes to circulate water. Most are hermaphroditic. They are probably an early evolutionary side branch that gave rise to no other group of animals. Except for about 150 freshwater species, sponges are marine animals. They are a source of ALKALOIDS; STEROLS; and other complex molecules useful in medicine and biological research.SvalbardSewage: Refuse liquid or waste matter carried off by sewers.Bacteroidetes: A phylum of bacteria comprised of three classes: Bacteroides, Flavobacteria, and Sphingobacteria.Pseudoalteromonas: A genus of GRAM-NEGATIVE AEROBIC BACTERIA of marine origin. Many species were formerly classified under ALTEROMONAS.Mollusca: A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.Filtration: A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Mytilus: A genus of marine mussels in the family MYTILIDAE, class BIVALVIA. The species MYTILUS EDULIS is the highly edible common mussel.Phytoplankton: Free-floating minute organisms that are photosynthetic. The term is non-taxonomic and refers to a lifestyle (energy utilization and motility), rather than a particular type of organism. Most, but not all, are unicellular algae. Important groups include DIATOMS; DINOFLAGELLATES; CYANOBACTERIA; CHLOROPHYTA; HAPTOPHYTA; CRYPTOMONADS; and silicoflagellates.Sulfonium Compounds: Sulfur compounds in which the sulfur atom is attached to three organic radicals and an electronegative element or radical.Vitamin K 2: A group of substances similar to VITAMIN K 1 which contains a ring of 2-methyl-1,4-naphthoquinione and an isoprenoid side chain of varying number of isoprene units. In vitamin K 2, each isoprene unit contains a double bond. They are produced by bacteria including the normal intestinal flora.Geological Phenomena: The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.Colony Count, Microbial: Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.Salmon: Fish of the genera ONCORHYNCHUS and Salmo in the family SALMONIDAE. They are anadromous game fish, frequenting the coastal waters of both the North Atlantic and Pacific. They are known for their gameness as a sport fish and for the quality of their flesh as a table fish. (Webster, 3d ed).Bryozoa: A phylum of small sessile aquatic animals living as small tufted colonies. Some appear like hydroids or corals, but their internal structure is more advanced. Most bryozoans are matlike, forming thin encrustations on rocks, shells, or kelp. (Storer & Stebbins, General Zoology, 6th ed, p443)Calcification, Physiologic: Process by which organic tissue becomes hardened by the physiologic deposit of calcium salts.Killifishes: Small oviparous fishes in the family Cyprinodontidae, usually striped or barred black. They are much used in mosquito control.Aquatic Organisms: Organisms that live in water.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.Sodium-Potassium-Exchanging ATPase: An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.Flatfishes: Common name for the order Pleuronectiformes. A very distinctive group in that during development they become asymmetrical, i.e., one eye migrates to lie adjacent to the other. They swim on the eyeless side. FLOUNDER, sole, and turbot, along with several others, are included in this order.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Amphipoda: An order of mostly marine CRUSTACEA containing more than 5500 species in over 100 families. Like ISOPODA, the other large order in the superorder Peracarida, members are shrimp-like in appearance, have sessile compound eyes, and no carapace. But unlike Isopoda, they possess thoracic gills and their bodies are laterally compressed.Cytophaga: A genus of gram-negative gliding bacteria found in SOIL; HUMUS; and FRESHWATER and marine habitats.Salt-Tolerance: The ability of organisms to sense and adapt to high concentrations of salt in their growth environment.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Sea Urchins: Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.Water Pollutants: Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.Protozoan Infections, Animal: Infections with unicellular organisms formerly members of the subkingdom Protozoa. The infections may be experimental or veterinary.Oceanography: The science that deals with the ocean and its phenomena. (Webster, 3d ed)Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Trout: Various fish of the family SALMONIDAE, usually smaller than salmon. They are mostly restricted to cool clear freshwater. Some are anadromous. They are highly regarded for their handsome colors, rich well-flavored flesh, and gameness as an angling fish. The genera Salvelinus, Salmo, and ONCORHYNCHUS have been introduced virtually throughout the world.Arctic Regions: The Arctic Ocean and the lands in it and adjacent to it. It includes Point Barrow, Alaska, most of the Franklin District in Canada, two thirds of Greenland, Svalbard, Franz Josef Land, Lapland, Novaya Zemlya, and Northern Siberia. (Webster's New Geographical Dictionary, 1988, p66)Polychaeta: A class of marine annelids including sandworms, tube worms, clamworms, and fire worms. It includes also the genus Myxicola infundibulum.Chlorides: Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Hydrothermal Vents: Hot springs on the ocean floor. They are commonly found near volcanically active places such as mid-oceanic ridges.Hepatopancreas: A primitive form of digestive gland found in marine ARTHROPODS, that contains cells similar to those found in the mammalian liver (HEPATOCYTES), and the PANCREAS.Atlantic OceanLocomotion: Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.Indian Ocean: A body of water covering approximately one-fifth of the total ocean area of the earth, extending amidst Africa in the west, Australia in the east, Asia in the north, and Antarctica in the south. Including the Red Sea and the Persian Gulf, it constitutes the third largest ocean after the ATLANTIC OCEAN and the PACIFIC OCEAN. (New Encyclopaedia Britannica Micropaedia, 15th ed, 1990, p289)Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Animal Shells: The hard rigid covering of animals including MOLLUSCS; TURTLES; INSECTS; and crustaceans.Rhodophyta: Plants of the division Rhodophyta, commonly known as red algae, in which the red pigment (PHYCOERYTHRIN) predominates. However, if this pigment is destroyed, the algae can appear purple, brown, green, or yellow. Two important substances found in the cell walls of red algae are AGAR and CARRAGEENAN. Some rhodophyta are notable SEAWEED (macroalgae).Republic of Korea: The capital is Seoul. The country, established September 9, 1948, is located on the southern part of the Korean Peninsula. Its northern border is shared with the Democratic People's Republic of Korea.Spectrophotometry, Atomic: Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.Serratia: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the natural environment (soil, water, and plant surfaces) or as an opportunistic human pathogen.Water Movements: The flow of water in enviromental bodies of water such as rivers, oceans, water supplies, aquariums, etc. It includes currents, tides, and waves.Arbacia: A genus of SEA URCHINS in the family Arbaciidae. They have only one spheridium (stalked body) per ambulacral area (contains tube feet); most sea urchins have several spheridia per area.Alteromonas: A genus of gram-negative, straight or curved rods which are motile by means of a single, polar flagellum. Members of this genus are found in coastal waters and the open ocean. (From Bergey's Manual of Determinative Bacteriology, 9th ed)HydrocarbonsDiatoms: The common name for the phylum of microscopic unicellular STRAMENOPILES. Most are aquatic, being found in fresh, brackish, and salt water. Diatoms are noted for the symmetry and sculpturing of their siliceous cell walls. They account for 40% of PHYTOPLANKTON, but not all diatoms are planktonic.