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Minimum Landing Size
The minimum landing size (MLS) is the smallest fish measurement at which it is legal to keep or sell a fish. The MLS depends on the species of fish. Sizes also vary around the world, as they are legal definitions which are defined by the local regulatory authority. Commercial trawl and seine fisheries can control the size of their catch by adjusting the mesh size of their nets. Effect of selection on fish sizes The idea behind this limitation is that only the older, mature fish get taken, leaving juveniles behind to continue breeding and propagating their species. There is some criticism of this legal requirement, however, as it applies selection pressure to the fish: as the larger fish get taken, the genes for larger size are reduced or removed from the gene pool, while fish that mature at a smaller size continue breeding. The average size of fish shrinks over time. This has led to a collapse in the amount of fish being caught in some fisheries. Aboriginal Australians around Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Measurement
Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish measured from the tip of the snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate. Simply put, this measurement excludes the length of the caudal (tail) fin. * Total length (TL) is the length of a fish measured from the tip of the snout to the tip of the longer lobe of the caudal fin, usually measured with the lobes compressed along the midline. It is a straight-line measure, not measured over the curve of the body. Standard length measurements are used with Teleostei (most bony fish), while total length measurements are used with Myxini ( hagfish), Petromyzontiformes ( lampreys), and (usually) Elasmobranchii (shark Sharks are a group of elasmobranch fish characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawl
Trawling is a 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 reed, 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. midwater trawlin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seine Fishing
Seine fishing (or seine-haul fishing; ) is a method of fishing that employs a surrounding net, called a seine, that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. Seine nets can be deployed from the shore as a beach seine, or from a boat. Boats deploying seine nets are known as seiners. Two main types of seine net are deployed from seiners: ''purse seines'' and ''Danish seines''. A seine differs from a gillnet, in that a seine encloses fish, where a gillnet directly snares fish. Etymology The word ''seine'' has its origins in the Old English ''segne'', which entered the language via Latin ''sagena'', from the original Greek σαγήνη ''sagēnē'' (a drag-net). History Seines have been used widely in the past, including by Stone Age societies. For example, the Māori used large canoes to deploy seine nets which could be over a kilometer long. The nets were woven from green flax, with stone weights and light wood o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selection Pressure
Any cause that reduces or increases reproductive success in a portion of a population potentially exerts evolutionary pressure, selective pressure or selection pressure, driving natural selection. It is a quantitative description of the amount of change occurring in processes investigated by evolutionary biology, but the formal concept is often extended to other areas of research. In population genetics, selective pressure is usually expressed as a selection coefficient. Amino acids selective pressure It has been shown that putting an amino acid bio-synthesizing gene like ''HIS4'' gene under amino acid selective pressure in yeast causes enhancement of expression of adjacent genes which is due to the transcriptional co-regulation of two adjacent genes in Eukaryota. Antibiotic resistance Drug resistance in bacteria is an example of an outcome of natural selection. When a drug is used on a species of bacteria, those that cannot resist die and do not produce offspring, while tho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aboriginal Australians
Aboriginal Australians are the various Indigenous peoples of the Australian mainland and many of its islands, such as Tasmania, Fraser Island, Hinchinbrook Island, the Tiwi Islands, and Groote Eylandt, but excluding the Torres Strait Islands. The term Indigenous Australians refers to Aboriginal Australians and Torres Strait Islanders collectively. It is generally used when both groups are included in the topic being addressed. Torres Strait Islanders are ethnically and culturally distinct, despite extensive cultural exchange with some of the Aboriginal groups. The Torres Strait Islands are mostly part of Queensland but have a separate governmental status. Aboriginal Australians comprise many distinct peoples who have developed across Australia for over 50,000 years. These peoples have a broadly shared, though complex, genetic history, but only in the last 200 years have they been defined and started to self-identify as a single group. Australian Aboriginal identity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moreton Bay
Moreton Bay is a bay located on the eastern coast of Australia from central Brisbane, Queensland. It is one of Queensland's most important coastal resources. The waters of Moreton Bay are a popular destination for recreational anglers and are used by commercial operators who provide seafood to market. The Port of Brisbane coordinates large traffic along the shipping channel which crosses the northern section of the bay. The bay serves as a safe approach to the airport and reduces noise pollution over the city to the west of the runway. A number of barge, ferry and water-taxi services also travel over the bay. Moreton Bay was the site of conflict between the Quandamooka people and early European settlers. It contains environmentally significant habitats and large areas of sandbanks. The bay is the only place in Australia where dugong gather into herds. Many parts of the mainland foreshore and southern islands are settled. The waters of Moreton Bay are relatively calm, being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traditional Knowledge
Traditional knowledge (TK), indigenous knowledge (IK) and local knowledge generally refer to knowledge systems embedded in the cultural traditions of regional, indigenous, or local communities. According to the World Intellectual Property Organization (WIPO) and the United Nations (UN), traditional knowledge and traditional cultural expressions (TCE) are both types of indigenous knowledge. Traditional knowledge includes types of knowledge about traditional technologies of subsistence (e.g. tools and techniques for hunting or agriculture), midwifery, ethnobotany and ecological knowledge, traditional medicine, celestial navigation, craft skills, ethnoastronomy, climate, and others. These kinds of knowledge, crucial for subsistence and survival, are generally based on accumulations of empirical observation and on interaction with the environment. In many cases, traditional knowledge has been passed for generations from person to person, as an oral tradition. Some forms of trad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flathead Grey Mullet
The flathead grey mullet (''Mugil cephalus'') is an important food fish species in the mullet family Mugilidae. It is found in coastal tropical and subtropical waters worldwide. Its length is typically . It is known with numerous English names, including the flathead mullet, striped mullet (US, American Fisheries Society name), black mullet, bully mullet, common mullet, grey mullet, sea mullet and mullet, among others. The flathead grey mullet is a mainly diurnal coastal species that often enters estuaries and rivers. It usually schools over sand or mud bottoms, feeding on zooplankton. The adult fish normally feed on algae in fresh water. The species is euryhaline, meaning that the fish can acclimate to different levels of salinity.Minckley, W.L. 1973. Fishes of Arizona. Arizona Game and Fish Department, Phoenix. pp. 257-258. Description The back of the fish is olive-green, sides are silvery and shade to white towards the belly. The fish may have six to seven distinctive later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moreton Island
Moreton Island (Mulgumpin) is an island on the eastern side of Moreton Bay on the coast of South East Queensland, Australia. The Coral Sea lies on the east coast of the island. Moreton Island lies northeast of the Queensland capital, Brisbane. 95% of the island is contained within a national park and a popular destination for day trippers, four wheel driving, camping, recreational angling and whale watching and a 75-minute ferry ride from Brisbane. It is the third largest sand island in the world. Together with Fraser Island, Moreton Island forms the largest sand structure in the world. It was the traditional country of the Ngugi before the onset of colonization. The island is within the City of Brisbane and is gazetted into four localities, the small townships of Bulwer (on the north-west coast), Cowan Cowan (on the west coast) and Kooringal (on the south-west coast) with the bulk of the island being the locality of Moreton Island. The private Tangalooma Island Reso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Fishery MLS
In European Union member states, there exists a standard set of minimum landing sizes (MLS) for all major species of finfish and shellfish. These MLS are set under EU Council Regulation 850/98. See also * List of harvested aquatic animals by weight This is a list of aquatic animals that are harvested commercially in the greatest amounts, listed in order of tonnage per year (2012) by the Food and Agriculture Organization. Species listed here have an annual tonnage in excess of 160,000 tonnes ... References {{fishery science topics, expanded=management Fishing industry European Union fishing regulations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Harvested Aquatic Animals By Weight
This is a list of aquatic animals that are harvested commercially in the greatest amounts, listed in order of tonnage per year (2012) by the Food and Agriculture Organization. Species listed here have an annual tonnage in excess of 160,000 tonnes. This table includes mainly food fish species, but also listed are crustaceans (crabs and shrimps), cephalopods (squids and cuttlefishs), bivalves, and a reptile (softshell turtle). Note that ''Oreochromis niloticus'' and ''Penaeus monodon'' appear twice, because substantial amounts are harvested from the wild as well as being extensively raised through aquaculture. Summary The 70 wild species shown in this table total 41,925,250 tonnes. Other wild species total 49,410,980 for a world total of 91,336,230 tonnes of wild, captured animals. The 31 cultivated species shown in this table total 45,252,999 tonnes. Other cultivated species total 21,380,254 tonnes for a world total of 66,633,253 tonnes of animals cultivated through aquaculture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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