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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] |
Resource Depletion
Resource depletion occurs when a natural resource is consumed faster than it can be replenished. The value of a resource depends on its availability in nature and the cost of extracting it. By the law of supply and demand, the Scarcity, scarcer the resource the more valuable it becomes. There are several types of resource depletion, including but not limited to: wetland and ecosystem degradation, soil erosion, aquifer depletion, and overfishing. The depletion of wildlife populations is called ''defaunation''. It is a matter of research and debate how humanity will be impacted and what the future will look like if resource consumption continues at the current rate, and when specific resources will be completely exhausted. History of resource depletion The depletion of resources has been an issue since the beginning of the 19th century amidst the Industrial Revolution, First Industrial Revolution. The extraction of both renewable and non-renewable resources increased drasticall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing
Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, bodies of water such as Fish pond, ponds, canals, park wetlands and reservoirs. Fishing techniques include trawling, Longline fishing, longlining, jigging, Fishing techniques#Hand-gathering, hand-gathering, Spearfishing, spearing, Fishing net, netting, angling, Bowfishing, shooting and Fish trap, trapping, as well as Destructive fishing practices, more destructive and often Illegal, unreported and unregulated fishing, illegal techniques such as Electrofishing, electrocution, Blast fishing, blasting and Cyanide fishing, poisoning. The term fishing broadly includes catching aquatic animals other than fish, such as crustaceans (shrimp/lobsters/crabs), shellfish, cephalopods (octopus/squid) and echinoderms (starfish/sea urchins). The term is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing Industry
The fishing industry includes any industry or activity that takes, cultures, processes, preserves, stores, transports, markets or sells fish or fish products. It is defined by the Food and Agriculture Organization as including recreational, subsistence and commercial fishing, as well as the related harvesting, processing, and marketing sectors.FAO Fisheries Section: Glossary''Fishing industry.''Retrieved 28 May 2008. The commercial activity is aimed at the delivery of fish and other seafood products for human consumption or as input factors in other industrial processes. The livelihood of over 500 million people in developing countries depends directly or indirectly on fisheries and aquaculture. The fishing industry is struggling with environmental and welfare issues, including overfishing and occupational safety. Additionally, the combined pressures of climate change, biodiversity loss and overfishing endanger the livelihoods and food security of a substantial portio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Ecosystem
Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in Saline water, waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts-per notation, parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, Seagrass, seagrass meadows, mangroves, rocky Intertidal zone, intertidal s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem Shift
Regime shifts are large, abrupt, persistent changes in the structure and function of ecosystems, the climate, financial and economic systems or other complex systems.Lewontin, R. (1969) Meaning of Stability. ''Brookhaven Sym Biol'', 13Holling, C.S. (1973) Resilience and stability of ecological systems. ''Annual Review of Ecology and Systematics'' 4, 1–23Biggs, R., et al. (2009) Turning back from the brink: Detecting an impending regime shift in time to avert it. ''P Natl Acad Sci Usa'' 106, 826–831 A regime is a characteristic behaviour of a system which is maintained by mutually reinforced processes or feedbacks. Regimes are considered persistent relative to the time period over which the shift occurs. The change of regimes, or the shift, usually occurs when a smooth change in an internal process (feedback) or a single disturbance (external shocks) triggers a completely different system behavior.Scheffer, M., et al. (2001) Catastrophic shifts in ecosystems. ''Nature'' 413, 591 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can be grouped into the more basal (phylogenetics), basal jawless fish and the more common jawed fish, the latter including all extant taxon, living cartilaginous fish, cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. In a break to the long tradition of grouping all fish into a single Class (biology), class (Pisces), modern phylogenetics views fish as a paraphyletic group. Most fish are ectotherm, cold-blooded, their body temperature varying with the surrounding water, though some large nekton, active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communication in aquatic animals#Acoustic, communicate acoustically with each other, such as during courtship displays. The stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overexploitation
Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife. In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threatened Sharks
__NOTOC__ Threatened species, Threatened sharks are those vulnerable to Species endangerment, endangerment (extinction) in the near future. The International Union for Conservation of Nature (IUCN) is the world's oldest global environmental organization. It evaluates threatened species, and treats threatened species not as a single category, but as a group of three categories, depending on the degree to which they are threatened: :: Vulnerable species :: Endangered species :: Critically endangered species The term ''threatened'' strictly refers to these three categories (critically endangered, endangered and vulnerable), while ''vulnerable'' is used to refer to the least at risk of these categories. The terms can be used somewhat interchangeably, as all ''vulnerable'' species are threatened, all ''endangered'' species are vulnerable and threatened, and all ''critically endangered'' species are endangered, vulnerable and threatened. Threatened species are also referred to as a r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing Down The Food Web
Fishing down the food web is the process whereby fisheries in a given ecosystem, "having depleted the large predatory fish on top of the food web, turn to increasingly smaller species, finally ending up with previously spurned small fish and invertebrates". The process was first demonstrated by the fisheries scientist Daniel Pauly and others in an article published in the journal ''Science'' in 1998. Large predator fish with higher trophic levels have been depleted in wild fisheries. As a result, the fishing industry has been systematically "fishing down the food web", targeting fish species at progressively decreasing trophic levels. The trophic level of a fish is the position it occupies on the food chain. The article establishes the importance of the mean trophic level of fisheries as a tool for measuring the health of ocean ecosystems. In 2000, the Convention on Biological Diversity selected the mean trophic level of fisheries catch, renamed the "Marine Trophic Index ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean, Antarctic/Southern, and Arctic Ocean),"Ocean." ''Merriam-Webster.com Dictionary'', Merriam-Webster, https://www.merriam-webster.com/dictionary/ocean . Accessed March 14, 2021. and are themselves mostly divided into seas, gulfs and Lists of bodies of water#Seawater bodies, subsequent bodies of water. The ocean contains 97% of Water distribution on Earth, Earth's water and is the primary component of Earth's hydrosphere, acting as a huge Ocean heat content, reservoir of heat for Earth's energy budget, as well as for its carbon cycle and water cycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wetland
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially in the soils. Wetlands form a transitional zone between waterbodies and dry lands, and are different from other terrestrial or aquatic ecosystems due to their vegetation's roots having adapted to oxygen-poor waterlogged soils. They are considered among the most biologically diverse of all ecosystems, serving as habitats to a wide range of aquatic and semi-aquatic plants and animals, with often improved water quality due to plant removal of excess nutrients such as nitrates and phosphorus. Wetlands exist on every continent, except Antarctica. The water in wetlands is either freshwater, brackish or saltwater. The main types of wetland are defined based on the dominant plants and the source of the water. For example, ''marshes'' ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trout
Trout (: trout) is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of which are members of the subfamily Salmoninae in the family Salmonidae. The word ''trout'' is also used for some similar-shaped but non-salmonid fish, such as the spotted seatrout/speckled trout (''Cynoscion nebulosus'', which is actually a croaker). Trout are closely related to salmon and have similar migratory life cycles. Most trout are strictly potamodromous, spending their entire lives exclusively in freshwater lakes, rivers and wetlands and migrating upstream to spawn in the shallow gravel beds of smaller headwater creeks. The hatched fry and juvenile trout, known as ''alevin'' and ''parr'', will stay upstream growing for years before migrating down to larger waterbodies as maturing adults. There are some anadromous species of trout, such as the steelhead (a coastal subs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
