A zone in which salinity changes rapidly.
A series of measurements on a fish, such as scale counts, which are used to separate different populations or races of fish.
A semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. healthy estuaries can have high rates of biological productivi...
|exclusive economic zone (eez)|
A seazone under the law of the sea over which a state has special rights to the exploration and use of marine resources. generally a state's eez extends to a distance of 200 nautical miles (370 km...
|ocean tracking network|
A research effort using implanted acoustic transmitters to study fish migration patterns.
A region where a distinctive transition from one set of biota to another occurs. an example is the region where tropical and temperate waters mix.
A rapid excessive growth of algae, generally caused by high nutrient levels, particularly phosphorus. when the algae die, algal blooms can deplete oxygen to the point where fish cannot survive.
A predator is a species that feeds on other species. a prey is a species that is being being eaten by a predator.
A particular branch of aquaculture where marine organisms are cultivated in the open ocean, or an enclosure of the ocean, or in tanks, ponds or raceways filled with seawater. examples are the farm...
A moral and political principle which states that if an action or policy might cause severe or irreversible harm to the public or to the environment, in the absence of a scientific consensus that ...
- A method of gathering information on surface fish movement and density by visual observation and photography from low-flying aircraft.
- Воздушное фотографирование; воздушная разведка...
|turtle excluder device (ted)|
A specialized device that allows a captured sea turtle to escape when caught in a trawl net.
A species which is likely to become an endangered species unless the circumstances threatening its survival and reproduction improve.
A species which is no longer listed under the esa. see also recovered species.
A word used to identify the importance of factors other than biology in fishery management decisions. for example, if management results in more fishing income, it is important to know how the inc...
A widely used commercial fishing technique which uses a small trawl net with long wire warps. the seine boat drags the warps and the net in a circle around the fish. the motion of the warps herds ...
- A water-soluble molecule made up of nitrogen and oxygen, commonly found in agricultural fertilizers, and therefore in land runoff. too much nitrate concentration is can be toxic to marine life...
florecimiento (de hongos) del nitrato;
|highly migratory species|
A term which has its origins in the united nations convention on the law of the sea. it refers to fish species which undertake ocean migrations and also have wide geographic distributions. it usua...
A term sometimes used to describe small scale commercial or subsistence fishing practices. the term particularly applies to coastal or island ethnic groups using traditional techniques and traditi...
A term defined by the united nations as "stocks of fish such as pollock, which migrate between, or occur in both, the economic exclusion zone of one or more states and the high seas". they can con...
- A technique used by fisheries scientists. tissue samples are taken from fish, and electrophoresis is used to separate proteins such as enzymes, based on their different mobilities in an electr...
A systematic gathering of information on fish availability and abundance using underwater sound.
- A systematic (as opposed to random) movement of individuals in a fish stock from one place to another.
- The loss of plasticizer from a plastic, usually due to heat or aging. it is un...
|quota management system (qms)|
A system that limits the amount of fish that can be taken by commercial fishers. the qms sets a quota that can be taken by each commercial fisher.
A method of fishing which uses lures on a vertical line that is moved up and down, or jigged. jigging can be done manually with hand-operated spools. it is also done automatically using machines w...
применение сборочных приспособлений;
A measurement of plant production that is the start of the food chain. much primary productivity in marine or aquatic systems is made up of phytoplankton, which are tiny one-celled algae that floa...
|individual transferable quota (itq)|
A management tool by which the total allowable catch quota is allocated to individual fishers or companies who have long-term rights over the quota or can transfer it to others by sale, lease, or ...
A fishing method that involves towing trawl nets along the sea floor. bottom trawling can cause serious damage to sea floor habitats.
A fishing line with one or more hooks, held vertically in the water column with weights and generally used on the continental shelf and slope. several droplines may be operated by a vessel, either...
A downward movement (sinking) of surface water caused by onshore ekman transport, converging currents or when a water mass becomes more dense than the surrounding water.
A current of rapidly moving, sediment-laden water that is heavier than clear water and therefore flows downslope along the bottom of the sea or a lake. the term is most commonly used to describe u...
A contour line linking regions of the same depth.
- A chemical compound containing phosphorus and oxygen, commonly found in agricultural fertilizers and land runoff.
- A salt of phosphoric acid
A calcified protective cover on the upper frontal surface of crustaceans. it is particularly well developed in lobsters and crabs.
A body of shallow salt or brackish water separated from the deeper sea by a shallow or exposed sandbank, coral reef, or similar feature.
- A bimodal distribution is a distribution with two different modes which appear as distinct peaks. an example in fisheries is the length of fish in a fishery, which might show two or more modes...
A fishing technique capable of harvesting large quantities of surface-schooling pelagic fish by surrounding the school with a net. a line which passes through rings on the bottom of the net can be...
|crab pot fishery|
A fishing technique where crabs are lured by bait into portable traps, sometimes called pots.
A gel substance extracted from brown algae and used industrially as a thickening agent for food and paint.
A long fishing line with many short lines, called snoods and carrying hooks, attached at regular intervals. pelagic longlines are suspended horizontally at a fixed depth using surface floats. deme...
A line encircling antarctica where cold, northward-flowing antarctic waters meet and sink beneath the sub-antarctic waters, creating an upwelling zone which is very high in marine productivity, es...
A large purse seiner, over 70 metres long, with its own freezing and storage facilities, capable of undertaking extended transoceanic voyages for harvesting fish.
A hypothesis of how a population functions. it often uses mathematical descriptions of growth, recruitment and mortality.
A group of similar species. similar species are often difficult to differentiate without detailed examination.
A group of marine animals that includes seastars, sea urchins and sea cucumbers, abundant on the floor of the deep sea, as well as in shallower seas.
A group of freshwater and saltwater animals with no skeleton and usually one or two hard shells made of calcium carbonate. includes oysters, clams, mussels, snails, conches, scallops, squid and oc...
A group of freshwater and saltwater animals having no backbone, with jointed legs and a hard shell made of chitin. includes crabs, lobsters, crayfish, shrimp and krill.
A gillnet suspended by floats so that it fishes the top few metres of the water column. drift nets can be many kilometres long. because drift nets are not anchored to the sea bottom or connected t...
A general term for fishing methods which use fishing lines. it includes handlines, hand reels, powered reels, pole-and-line, droplines, longlines, trotlines and troll lines.