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52-523: The lagoon is a habitat for different aquatic organisms , such as various species of fish that are sources of income and food for communities surrounding it. The lagoon is more than 50 km long and 3–13 km wide, separated from the Atlantic Ocean by a long sand spit 2–5 km long. Its surface area is approximately 6,354.7 km². The lagoon is fairly shallow and is not plied by ocean-going ships , but by smaller barges and boats . It receives

104-453: A few more minutes unless ventilation is restored. However, under special circumstances such as hypothermia , hyperbaric oxygenation , apneic oxygenation (see below), or extracorporeal membrane oxygenation , much longer periods of apnea may be tolerated without severe detrimental consequences. Untrained humans usually cannot sustain voluntary apnea for more than one or two minutes, since the urge to breathe becomes unbearable. The reason for

156-412: A healthy adult. However, accumulation of carbon dioxide (described above) would remain the limiting factor. Apneic oxygenation is more than a physiologic curiosity. It can be employed to provide a sufficient amount of oxygen in thoracic surgery when apnea cannot be avoided, and during manipulations of the airways such as bronchoscopy , intubation , and surgery of the upper airways. However, because of

208-399: A safety guard or equipment beside the diver. Because the exchange of gases between the blood and airspace of the lungs is independent of the movement of gas to and from the lungs, enough oxygen can be delivered to the circulation even if a person is apneic, and even if the diaphragm does not move. With the onset of apnea, low pressure develops in the airspace of the lungs because more oxygen

260-415: A source of food (i.e. seafood ) and as raw material for fodders (e.g. feeder fish and fish meal ), pharmaceuticals (e.g. fish oil , krill oil , cytarabine and bryostatin ) and various industrial chemicals (e.g. chitin and bioplastics , formerly also whale oil ). The harvesting of aquatic animals, especially finfish , shellfish and inkfish , provides direct and indirect employment to

312-509: Is a popular pastime in both developed and developing countries , and the manufacturing , retail and service sectors associated with recreational fishing have together conglomerated into a multibillion-dollar industry. In 2014 alone, around 11 million saltwater sportfishing participants the United States generated USD$ 58 billion of retail revenue (comparatively, commercial fishing generated USD$ 141 billion that same year). In 2021,

364-462: Is absorbed than CO 2 is released. With the airways closed or obstructed, this will lead to a gradual collapse of the lungs and suffocation. However, if the airways are open, any gas supplied to the upper airways will follow the pressure gradient and flow into the lungs to replace the oxygen consumed. If pure oxygen is supplied, this process will serve to replenish the oxygen stored in the lungs and resume sufficient ventilation. The uptake of oxygen into

416-712: Is also applied to riparian mammals like the river otter ( Lontra canadensis ) and beavers (family Castoridae ), although they are technically semiaquatic or amphibious. Unlike the more common gill -bearing aquatic animals, these air-breathing animals have lungs (which are homologous to the swim bladders in bony fish ) and need to surface periodically to change breaths, but their ranges are not restricted by oxygen saturation in water, although salinity changes can still affect their physiology to an extent. There are also reptilian animals that are highly evolved for life in water, although most extant aquatic reptiles, including crocodilians , turtles , water snakes and

468-631: Is any animal , whether vertebrate or invertebrate , that lives in bodies of water for all or most of its lifetime. Aquatic animals generally conduct gas exchange in water by extracting dissolved oxygen via specialised respiratory organs called gills , through the skin or across enteral mucosae , although some are evolved from terrestrial ancestors that re- adapted to aquatic environments (e.g. marine reptiles and marine mammals ), in which case they actually use lungs to breathe air and are essentially holding their breath when living in water. Some species of gastropod mollusc , such as

520-422: Is commonly believed to allow the person involved to safely hold their breath for a longer period. In reality, it will give the impression that one does not need to breathe, while the body is actually experiencing a blood-oxygen level that would normally, and indirectly, invoke a strong dyspnea and eventually involuntary breathing. Some have incorrectly attributed the effect of hyperventilation to increased oxygen in

572-470: Is no movement of the muscles of inhalation , and the volume of the lungs initially remains unchanged. Depending on how blocked the airways are ( patency ), there may or may not be a flow of gas between the lungs and the environment. If there is sufficient flow, gas exchange within the lungs and cellular respiration would not be severely affected. Voluntarily doing this is called holding one's breath . Apnea may first be diagnosed in childhood, and it

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624-409: Is not possible underwater. Tolerance can in addition be trained. The ancient technique of free-diving requires breath-holding, and world-class free-divers can hold their breath underwater up to depths of 214 metres (702 ft) and for more than four minutes. Apneists, in this context, are people who can hold their breath for a long time. Voluntary hyperventilation before beginning voluntary apnea

676-661: Is recommended to consult an ENT specialist, allergist or sleep physician to discuss symptoms when noticed; malformation and/or malfunctioning of the upper airways may be observed by an orthodontist. Apnea can be involuntary—for example, drug -induced (such as by opiate toxicity), mechanically / physiologically induced (for example, by strangulation or choking ), or a consequence of neurological disease or trauma . During sleep, people with severe sleep apnea can have over thirty episodes of intermittent apnea per hour every night. Apnea can also be observed during periods of heightened emotion , such as during crying or accompanied by

728-756: Is still recorded in some countries, particularly in Africa and Asia . Overfishing and destructive fishing practices fuelled by commercial incentives have reduced fish stocks beyond sustainable levels in many world regions, causing the fishery industry to maladaptively fishing down the food web . It was estimated in 2014 that global fisheries were adding US$ 270 billion a year to global GDP , but by full implementation of sustainable fishing , that figure could rise by as much as US$ 50 billion. UN Food and Agriculture Organization projects world production of aquatic animals to reach 205 million tonnes by 2032. Where sex-disaggregated data are available, approximately 24 percent of

780-572: The American Academy of Neurology hinges on the conjunction of three diagnostic criteria: a coma , absence of brainstem reflexes, and apnea (defined as the inability of the patient to breathe unaided: that is, with no life support systems like ventilators ). The apnea test follows a delineated protocol. Apnea testing is not suitable in patients who are hemodynamically unstable with increasing vasopressor needs, metabolic acidosis, or require high levels of ventilatory support. Apnea testing carries

832-479: The Cenozoic ) remain fully aquatic in saltwater ecosystems . Amphibians , while still requiring access to water to inhabit, are separated into their own ecological classification. The majority of amphibians — except the order Gymnophiona ( caecilians ), which are mainly terrestrial burrowers — have a fully aquatic larval form known as tadpoles , but those from the order Anura ( frogs and toads ) and some of

884-502: The Valsalva maneuver when a person laughs . Apnea is a common feature of sobbing while crying, characterized by slow but deep and erratic breathing followed by brief periods of breath holding. Another example of apnea are breath-holding spells ; these are sometimes emotional in cause and are usually observed in children as a result of frustration, emotional stress and other psychological extremes. Voluntary apnea can be achieved by closing

936-597: The algae octopus (whose larvae are completely planktonic , but adults are highly terrestrial). Aquatic animals are a diverse polyphyletic group based purely on the natural environments they inhabit, and many morphological and behavioral similarities among them are the result of convergent evolution . They are distinct from terrestrial and semi-aquatic animals, who can survive away from water bodies, while aquatic animals often die of dehydration or hypoxia after prolonged removal out of water due to either gill failure or compressive asphyxia by their own body weight (as in

988-717: The eastern emerald sea slug , are even capable of kleptoplastic photosynthesis via endosymbiosis with ingested yellow-green algae . Almost all aquatic animals reproduce in water, either oviparously or viviparously , and many species routinely migrate between different water bodies during their life cycle . Some animals have fully aquatic life stages (typically as eggs and larvae ), while as adults they become terrestrial or semi-aquatic after undergoing metamorphosis . Such examples include amphibians such as frogs , many flying insects such as mosquitoes , mayflies , dragonflies , damselflies and caddisflies , as well as some species of cephalopod molluscs such as

1040-541: The hormone prolactin , while in salmon ( Salmo salar ) the hormone cortisol plays a key role during this process. Freshwater molluscs include freshwater snails and freshwater bivalves . Freshwater crustaceans include freshwater shrimps , crabs , crayfish , freshwater pirahnas and copepods . In addition to water-breathing animals (e.g. fish , most molluscs , etc.), the term "aquatic animal" can be applied to air-breathing tetrapods who have evolved for aquatic life. The most proliferative extant group are

1092-449: The kidney . Although most aquatic organisms have a limited ability to regulate their osmotic balance and therefore can only live within a narrow range of salinity, diadromous fish have the ability to migrate between fresh and saline water bodies. During these migrations they undergo changes to adapt to the surroundings of the changed salinities; these processes are hormonally controlled. The European eel ( Anguilla anguilla ) uses

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1144-479: The labyrinth organ and even primitive lungs (lungfish and bichirs). Most molluscs have gills , while some freshwater gastropods (e.g. Planorbidae ) have evolved pallial lungs and some amphibious species (e.g. Ampullariidae ) have both. Many species of octopus have cutaneous respiration that allows them to survive out of water at the intertidal zones , with at least one species ( Abdopus aculeatus ) being routinely terrestrial hunting crabs among

1196-411: The livelihood of over 500 million people in developing countries , and both the fishing industry and aquaculture make up a major component of the primary sector of the economy . The UN Food and Agriculture Organization estimates that global consumption of aquatic animals in 2022 was 185 million tonnes (live weight equivalent), an increase of 4 percent from 2020. The value of the 2022 global trade

1248-635: The marine iguana , are technically semi-aquatic rather than fully aquatic, and most of them only inhabit freshwater ecosystems . Marine reptiles were once a dominant group of ocean predators that altered the marine fauna during the Mesozoic , although most of them died out during the Cretaceous-Paleogene extinction event and now only the sea turtles (the only remaining descendants of the Mesozoic marine reptiles) and sea snakes (which only evolved during

1300-422: The marine mammals , such as those in the orders Cetacea ( whales , dolphins and porpoises , with some freshwater species ) and Sirenia ( dugongs and manatees ), who are too evolved for aquatic life to survive on land at all (where they will die of beaching ), as well as the highly aquatically adapted but land-dwelling pinnipeds ( true seals , eared seals and the walrus ). The term " aquatic mammal "

1352-725: The tidal pools of rocky shores . Aquatic animals play an important role for the environment as indicator species , as they are particularly sensitive to deterioration in water quality and climate change . Biodiversity of aquatic animals is also an important factor for the sustainability of aquatic ecosystems as it reflects the food web status and the carrying capacity of the local habitats . Many migratory aquatic animals, predominantly forage fish (such as sardines ) and euryhaline fish (such as salmon ), are keystone species that accumulate and transfer biomass between marine , freshwater and even to terrestrial ecosystems . Aquatic animals are important to humans as

1404-471: The vocal cords , simultaneously keeping the mouth closed and blocking the nasal vestibule , or constantly activating expiratory muscles, not allowing any inspiration. Under normal conditions, humans cannot store much oxygen in the body. Prolonged apnea leads to severe lack of oxygen in the blood circulation , leading to dysfunction of organ systems . Permanent brain damage can occur after as little as three minutes and death will inevitably ensue after

1456-522: The water column . Aquatic animals (especially freshwater animals) are often of special concern to conservationists because of the fragility of their environments. Aquatic animals are subject to pressure from overfishing / hunting , destructive fishing , water pollution , acidification , climate change and competition from invasive species . Many aquatic ecosystems are at risk of habitat destruction / fragmentation , which puts aquatic animals at risk as well. Aquatic animals play an important role in

1508-574: The Ogun and Osun rivers. Excessive fishing activities, sand mining and dredging , also contribute to the degradation of the Lagoon's ecosystem. In a study conducted, it was found that these wastes disposed in the lagoon are a threat to fish and mammal biology, which can in turn be harmful to humans. They contain heavy metals such as mercury and cadmium , organic compounds PCBs , Phenolsa, PAHs and organotins . Aquatic animal An aquatic animal

1560-419: The best position to rescue such a person. Static apnea blackout occurs at the surface when a motionless diver holds their breath long enough for the circulating oxygen in blood to fall below that required for the brain to maintain consciousness. It involves no pressure changes in the body and is usually performed to enhance breath-hold time. It should never be practiced alone, but under strict safety protocols with

1612-423: The blood will then remain at the usual level, and the normal functioning of the organs will not be affected. A consequence of this hyperoxygenation is the occurrence of "nitrogen washout", which can lead to atelectasis . However, no CO 2 is removed during apnea. The partial pressure of CO 2 in the airspace of the lungs will quickly equilibrate with that of the blood. As the blood is loaded with CO 2 from

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1664-459: The blood, not realizing that it is actually due to a decrease in CO 2 in the blood and lungs. Blood leaving the lungs is normally fully saturated with oxygen, so hyperventilation of normal air cannot increase the amount of oxygen available, as oxygen in blood is the direct factor. Lowering the CO 2 concentration increases the pH of the blood, thus increasing the time before blood becomes acidic enough so

1716-467: The brain when CO 2 levels are too high include strong, painful, and involuntary contractions or spasms of the diaphragm and the muscles in between the ribs. At some point, the spasms become so frequent, intense and unbearable that continued holding of the breath is nearly impossible. When a person is immersed in water, physiological changes due to the mammalian diving reflex enable somewhat longer tolerance of apnea even in untrained persons as breathing

1768-414: The brain which eventually cannot be overcome voluntarily. The accumulation of carbon dioxide in the lungs will eventually irritate and trigger impulses from the respiratory center part of the brain and the phrenic nerve . Rising levels of carbon dioxide signal the body to breathe and resume unconscious respiration forcibly. The lungs start to feel as if they are burning, and the signals the body receives from

1820-552: The case of whale beaching ). Along with aquatic plants , algae and microbes , aquatic animals form the food webs of various marine , brackish and freshwater aquatic ecosystems . The term aquatic can be applied to animals that live in either fresh water or salt water . However, the adjective marine is most commonly used for animals that live in saltwater or sometimes brackish water , i.e. in oceans , shallow seas , estuaries , etc. Aquatic animals can be separated into four main groups according to their positions within

1872-520: The discharge of the Ogun River and the Osun River . The sediments of the lagoon ranges from mangrove swamp to muddy and sandy foreshores. Lagos Lagoon empties into the Atlantic Ocean via Lagos Harbour, a main channel through the heart of the city, 0.5 km to 1 km wide and 10 km long. The principal ocean port of Lagos is located at Apapa in a broad western branch off the main channel of

1924-476: The economic sum of 17 U.S. states . [REDACTED]  This article incorporates text from a free content work. Licensed under CC BY 4.0 ( license statement/permission ). Text taken from The State of World Fisheries and Aquaculture 2024​ , FAO. Apnea Apnea (also spelled apnoea in British English ), is the temporary cessation of breathing . During apnea, there

1976-445: The harbour. Another branch off the main channel that is narrower and longer separates Lagos Island from Victoria Island , the broad sand spit which forms the coastline. The city spreads along more than 30 km of the lagoon's south-western and western shoreline. Pollution by urban and industrial waste is a major problem as a large amount of wastewater is released into the lagoon daily. The 11-km-long Third Mainland Bridge

2028-471: The limitations described above, apneic oxygenation is inferior to extracorporal circulation using a heart-lung machine and is therefore used only in emergencies, short procedures, or where extracorporal circulation cannot be accessed. Use of PEEP valves is also an accepted alternative (5 cm H 2 O in average weight patients and 10 cm H 2 O significantly improved lung and chest wall compliance in morbidly obese patients). In 1959, Frumin described

2080-524: The major producer (36% of the total), followed by India (8%), Indonesia (7%), Vietnam (5%) and Peru (3%). Total fish production in 2016 reached an all-time high of 171 million tonnes, of which 88% was utilized for direct human consumption, resulting in a record-high per capita consumption of 20.3 kg (45 lb). Since 1961 the annual global growth in fish consumption has been twice as high as population growth. While annual growth of aquaculture has declined in recent years, significant double-digit growth

2132-537: The metabolism without a way to remove it, more and more CO 2 will accumulate and eventually displace oxygen and other gases from the airspace. CO 2 will also accumulate in the tissues of the body, resulting in respiratory acidosis . Under ideal conditions (i.e., if pure oxygen is breathed before onset of apnea to remove all nitrogen from the lungs, and pure supplemental oxygen is insufflated ), apneic oxygenation could theoretically be sufficient to provide enough oxygen for survival of more than one hour's duration in

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2184-537: The middle of the lagoon are the Palaver Islands. The Lagos Lagoon, situated in one of the fastest growing megacities in the world, Lagos which is known for its rapid growth in population and industrial development, has become a hub of industrial, agricultural and domestic wastes. According to WHO and Africa UN Environment, Lagos Lagoon is the most polluted African ecosystem with its major wastes coming from oil and textile industry as well as urban sewage carried by

2236-696: The order Urodela ( salamanders ) will metamorphosize into lung -bearing and sometimes skin-breathing terrestrial adults, and most of them may return to the water to breed . Axolotl , a Mexican salamander that retains its larval external gills into adulthood, is the only extant amphibian that remains fully aquatic throughout the entire life cycle . Certain amphibious fish also evolved to breathe air to survive oxygen-deprived waters , such as lungfishes , mudskippers , labyrinth fishes , bichirs , arapaima and walking catfish . Their abilities to breathe atmospheric oxygen are achieved via skin-breathing, enteral respiration , or specialized gill organs such as

2288-496: The respiratory center becomes stimulated, as described above. While hyperventilation will yield slightly longer breath-holding times, any small time increase is at the expense of possible hypoxia , though it might not be felt as easily. One using this method can suddenly lose consciousness unnoticed—a shallow water blackout —as a result. If a person loses consciousness underwater, there is considerable danger that they will drown . An alert diving partner or nearby lifeguard would be in

2340-544: The supply chain. These practices are based on temperature reduction ( chilling and freezing ), heat treatment ( canning , boiling and smoking ), reduction of available water ( drying , salting and smoking) and changing of the storage environment ( vacuum packaging , modified atmosphere packaging and refrigeration). Aquatic animal products also require special facilities such as cold storage and refrigerated transport, and rapid delivery to consumers. In addition to commercial and subsistence fishing , recreational fishing

2392-399: The time limit of voluntary apnea is that the rate of breathing and the volume of each breath are tightly regulated to maintain constant values of CO 2 tension and pH of the blood more than oxygen levels. In apnea, CO 2 is not removed through the lungs and accumulates in the blood. The consequent rise in CO 2 tension and drop in pH result in stimulation of the respiratory centre in

2444-521: The total revenue of recreational fishing industry in the United States overtook those of Lockheed Martin , Intel , Chrysler and Google ; and together with personnel salary (about USD$ 39.5 billion) and various tolls and fees collected by fisheries management agencies (about USD$ 17 billion), contributed almost USD$ 129 billion to the GDP of the United States , roughly 1% of the national GDP and more than

2496-434: The total workforce were women; of these, 53 percent were employed in the sector on a full-time basis, a great improvement since 1995, when only 32 percent of women were employed full time. Aquatic animal are highly perishable and several chemical and biological changes take place immediately after death; this can result in spoilage and food safety risks if good handling and preservation practices are not applied all along

2548-428: The use of apneic oxygenation during anesthesia and surgery. Of the eight test subjects in this landmark study, the highest recorded PaCO 2 was 250 millimeters of mercury , and the lowest arterial pH was 6.72 after 53 minutes of apnea. Studies found spleen volume is slightly reduced during short breath-hold apnea in healthy adults. A recommended practice for the clinical diagnosis of brain death formulated by

2600-403: The world. The biodiversity of aquatic animals provide food, energy, and even jobs. Fresh water creates a hypotonic environment for aquatic organisms. This is problematic for organisms with pervious skins and gills , whose cell membranes may rupture if excess water is not excreted. Some protists accomplish this using contractile vacuoles , while freshwater fish excrete excess water via

2652-524: Was built off the western shore to by-pass congested mainland suburbs. To its north-east the lagoon is connected by a channel passing south of the town of Epe to the Lekki Lagoon . Narrow winding channels connect the system through a broad band of coastal swamps and rivers, as far away as Sapele , 250 km to the east. The areas around west-Lagos Lagoon are not well provided with roads and many communities there traditionally rely on water transport. In

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2704-437: Was estimated at USD 452 billion, comprising USD 157 billion for capture fisheries and USD 296 billion for aquaculture. Of the total 185 million tonnes of aquatic animals produced in 2022, about 164.6 million tonnes (89%) were destined for human consumption, equivalent to an estimated 20.7 kg per capita. The remaining 20.8 million tonnes were destined for non-food uses, to produce mainly fishmeal and fish oil. In 2022, China remained

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