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Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species ( freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as rough fish (mainly US) or coarse fish (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 1990 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawling
Trawling is an industrial method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reel, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. mid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discards
Discards are the portion of a catch of fish which is not retained on board during commercial fishing operations and is returned, often dead or dying, to the sea. The practice of discarding is driven by economic and political factors; fish which are discarded are often unmarketable species, individuals which are below minimum landing sizes and catches of species which fishers are not allowed to land, for instance due to quota restrictions. Discards form part of the bycatch of a fishing operation, although bycatch includes marketable species caught unintentionally. Discards may also be caused by high grading, where marketable fish are discarded to make room for more valuable catches. Discarding can be highly variable in time and space as a consequence of changing economic, sociological, environmental and biological factors. Discarding patterns are influenced by catch compositions, which in turn are determined by environmental factors, such as recruitment of small fish into the fisher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shrimp
A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchiata, although some Shrimp#Non-decapods, crustaceans outside of this order are also referred to as "shrimp". Any small crustacean may also be referred to as "shrimp", regardless of resemblance. More narrow definitions may be restricted to Caridea, to smaller species of either of the aforementioned groups, or only the Marine life, marine species. Under a broader definition, ''shrimp'' may be synonymous with prawn, covering stalk-eyed swimming crustaceans with long, narrow muscular tails (Abdomen#Arthropoda, abdomens), long whiskers (Antenna (biology), antennae), and slender, Biramous, biramous legs. They swim forward by paddling the swimmerets on the underside of their abdomens, although their escape response is typically repeated flicks wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shrimp Bycatch
A shrimp (: shrimp ( US) or shrimps ( UK)) is a crustacean with an elongated body and a primarily swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchiata, although some crustaceans outside of this order are also referred to as "shrimp". Any small crustacean may also be referred to as "shrimp", regardless of resemblance. More narrow definitions may be restricted to Caridea, to smaller species of either of the aforementioned groups, or only the marine species. Under a broader definition, ''shrimp'' may be synonymous with prawn, covering stalk-eyed swimming crustaceans with long, narrow muscular tails ( abdomens), long whiskers ( antennae), and slender, biramous legs. They swim forward by paddling the swimmerets on the underside of their abdomens, although their escape response is typically repeated flicks with the tail, driving them backwards very quickly (" lobstering"). Crabs and lobsters have strong walking legs, whereas shrimp typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incidental Catch
In fishing, incidental catch refers to the portion of the catch that was unintentionally caught but retained. It can be distinguished from discards, which are the unintended catch that is caught and then returned to the sea, and bycatch, which includes all non-targeted species caught alongside the targeted species. The operational definitions used by the FAO for incidental catch and other related catches are as follows:Alverson DL, MH Freeberg, SA Murawski and Pope JG (1994A global assessment of fisheries bycatch and discardsFAO Fisheries, Technical paper 339, Rome. . * Target catch: The catch of a species or species assemblage which is primarily sought in a fishery, such as shrimp, flounders, cods * Incidental catch: Retained catch of non-targeted species * Discarded catch (usually shortened to ''discards''): That portion of the catch returned to the sea as a result of economic, legal, or personal considerations. * Bycatch: Discarded catch plus incidental catch. Notes Refere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing Fish stocks, fish stock), resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass (ecology), biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the Threatened sharks, overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include growth overfishing, recruitment overfishing, and ecosystem overfishing. Overfishing not only causes negative impacts on biodiversity and ecosystem functioning, but also reduces fish pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinniped
Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant taxon, extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals), with 34 extant species and more than 50 extinct species described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular phylogenetics, molecular evidence supports them as a monophyletic group (descended from one ancestor). Pinnipeds belong to the suborder Caniformia of the order Carnivora; their closest living relatives are musteloids (Mustelidae, weasels, Procyonidae, raccoons, skunks and red pandas), having diverged about 50 million years ago. Seals range in size from the and Baikal seal to the and southern elephant seal. Several species exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saltwater Fish
Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school. Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater fish are also caught to be eaten, or grown in aquaculture. However, many fish species have been overfished and are otherwise threatened by marine pollution or ecological changes caused by climate change. Diet Fishes that live in the ocean can be carnivores, herbivores, or omnivores. Herbivores in the ocean eat things such as algae and flowering seagrasses. Many herbivores' diets consist of primarily algae. Most saltwater fish will eat both macroalgae and microalgae. Many fish eat red, green, brown, and blue algae, but some fish prefer other types. Most saltwater fish that are carnivores will never eat algae under any circumstances. Carnivores' diets consist of shrimp, plankton, or tiny crustaceans. Captivity Saltwater aquariums are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetacea
Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel themselves through the water with powerful up-and-down movements of their tail, which ends in a paddle-like fluke, using their flipper-shaped forelimbs to steer. While the majority of cetaceans live in marine environments, a small number reside solely in brackish water, brackish or fresh water. Having a cosmopolitan distribution, they can be found in some rivers and all of Earth's oceans, and many species migrate throughout vast ranges with the changing of the seasons. Cetaceans are famous for cetacean intelligence, their high intelligence, complex social behaviour, and the enormous size of some of the group's members. For example, the blue whale reaches a maximum confirmed length of and a weight of 173 tonne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Policy
''Marine Policy'' is a monthly interdisciplinary peer-reviewed academic journal published by Elsevier concerning ocean policy studies, analyzing social science disciplines relevant to the formulation of marine policy. It was established in 1977 by founding editor Tony Loftas. The current editor-in-chief is Sebastián Villasante ( University of Santiago de Compostela). Abstracting and indexing According to the ''Journal Citation Reports'', the journal has a 2023 impact factor of 3.5. See also * List of international relations journals The following list of scholarly journals in international relations contains notable English-language academic journals on international relations. It is not comprehensive, as there are hundreds currently published. Popular magazines or other publi ... References External links * {{DEFAULTSORT:Marine Policy Elsevier academic journals English-language journals International relations journals Monthly journals Academic journals esta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stochastic
Stochastic (; ) is the property of being well-described by a random probability distribution. ''Stochasticity'' and ''randomness'' are technically distinct concepts: the former refers to a modeling approach, while the latter describes phenomena; in everyday conversation, however, these terms are often used interchangeably. In probability theory, the formal concept of a '' stochastic process'' is also referred to as a ''random process''. Stochasticity is used in many different fields, including image processing, signal processing, computer science, information theory, telecommunications, chemistry, ecology, neuroscience, physics, and cryptography. It is also used in finance (e.g., stochastic oscillator), due to seemingly random changes in the different markets within the financial sector and in medicine, linguistics, music, media, colour theory, botany, manufacturing and geomorphology. Etymology The word ''stochastic'' in English was originally used as an adjective with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
