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39-686: The Pantanal ( Portuguese pronunciation: [pɐ̃taˈnaw] ) is a natural region encompassing the world's largest tropical wetland area, and the world's largest flooded grasslands . It is located mostly within the Brazilian state of Mato Grosso do Sul , but it extends into Mato Grosso and portions of Bolivia and Paraguay . It sprawls over an area estimated at between 140,000 and 195,000 km (54,000 and 75,000 sq mi). Various subregional ecosystems exist, each with distinct hydrological , geological , and ecological characteristics; up to 12 of them have been defined. Roughly 80% of

78-444: A number of natural factors, but is most often a concern as a consequence of pollution and eutrophication in which plant nutrients enter a river, lake, or ocean, and phytoplankton blooms are encouraged. While phytoplankton, through photosynthesis , will raise DO saturation during daylight hours, the dense population of a bloom reduces DO saturation during the night by respiration . When phytoplankton cells die, they sink towards

117-483: Is a keystone species in Pantanal's ecosystem. When the wetlands are flooded once a year, the grass and other plants will eventually die and start to decay. During this process, decomposing microbes deplete the shallow water of all oxygen, suffocating larger decomposers. Unlike other decomposing animals, the apple snails have both gills and lungs, making it possible for them to thrive in anoxic waters where they recycle

156-558: Is a mixture of plant communities typical of a variety of surrounding biome regions: these include moist tropical Amazonian rainforest plants, semiarid woodland plants typical of northeast Brazil, Brazilian cerrado savanna plants, and plants of the Chaco savannas of Bolivia and Paraguay. Forests usually occur at higher altitudes of the region, while grasslands cover the seasonally inundated areas. The key limiting factors for growth are inundation and, even more importantly, water-stress during

195-408: Is a national park of Bolivia in the Pantanal. The entrance to Otuquis National park is through the town of Puerto Suarez. Brazil: Bolivia: Paraguay: Natural region A natural region (landscape unit) is a basic geographic unit. Usually, it is a region which is distinguished by its common natural features of geography , geology , and climate . From the ecological point of view,

234-475: Is formed, removing even more oxygen from the environment in the forms of carbon dioxide, bicarbonate ions, and carbonate. Dissolved inorganic carbon is made at a rate of 2.3–6.5 mg/(m ⋅day). As phytoplankton breakdown, free phosphorus and nitrogen become available in the environment, which also fosters hypoxic conditions. As the breakdown of this phytoplankton takes place, the more phosphorus turns into phosphates, and nitrogens turn into nitrates. This depletes

273-765: Is located in the municipality of Poconé in the State of Mato Grosso, between the mouths of the Baía de São Marcos and the Gurupi Rivers . The park was designated a Ramsar Site of International Importance under the Ramsar Convention on May 24, 1993. The SESC Pantanal Private Natural Heritage Reserve ( Reserva Particular do Patrimonio Natural SESC Pantanal ) is a privately owned reserve in Brazil, established in 1998 and 878.7 km (339.3 sq mi) in size. It

312-537: Is located in the north-eastern portion, known as "Poconé" Pantanal, not far from the Pantanal National Park. It is a mix of permanent rivers, seasonal streams, permanent and seasonal floodplain freshwater lakes, shrub-dominated wetlands and seasonally flooded forests, all dedicated to nature preservation, and was designated a Ramsar Site of International Importance under the Ramsar Convention . Otuquis National Park and Integrated Management Natural Area

351-794: Is substantial. In these areas a so-called " dead zone " can be created. Low dissolved oxygen conditions are often seasonal, as is the case in Hood Canal and areas of Puget Sound , in Washington State. The World Resources Institute has identified 375 hypoxic coastal zones around the world, concentrated in coastal areas in Western Europe, the Eastern and Southern coasts of the US, and East Asia, particularly in Japan. Hypoxia may also be

390-436: Is termed anaerobic, reducing , or anoxic . In water, oxygen levels are approximately 7 ppm or 0.0007% in good quality water, but fluctuate. Many organisms require hypoxic conditions. Oxygen is poisonous to anaerobic bacteria for example. Oxygen depletion is typically expressed as a percentage of the oxygen that would dissolve in the water at the prevailing temperature and salinity. A system with low concentration—in

429-495: Is the amount of particulate organic carbon (POC) overall at a given time, t. G(0) is the concentration of POC before breakdown takes place. k is a rate constant in year-1, and t is time in years. For most POC of phytoplankton, the k is around 12.8 years-1, or about 28 days for nearly 96% of carbon to be broken down in these systems. Whereas for anoxic systems, POC breakdown takes 125 days, over four times longer. It takes approximately 1 mg of oxygen to break down 1 mg of POC in

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468-536: The Bardenas Reales , an upland massif of acidic rock, or The Burren , in Ireland . Hypoxia (environmental) Atmospheric hypoxia occurs naturally at high altitudes . Total atmospheric pressure decreases as altitude increases, causing a lower partial pressure of oxygen, which is defined as hypobaric hypoxia. Oxygen remains at 20.9% of the total gas mixture, differing from hypoxic hypoxia , where

507-592: The giant anteater ( Myrmecophaga tridactyla ). Common species in the Pantanal include the capybara ( Hydrochoerus hydrochaeris ), ocelot (Leopardus pardalis) , and the yacare caiman ( Caiman yacare ). According to 1996 data, there were 10 million caimans in the Pantanal, making it the highest concentration of crocodilians in the world. The Pantanal is home to one of the largest and healthiest jaguar ( Panthera onca ) populations on Earth. There are thirteen species of herons and egrets , six species of ibises and spoonbills , and five species of kingfishers that use

546-484: The giant river otter ( Pteronura brasiliensis ). Parts of the Pantanal are also home to the following endangered or threatened species: the hyacinth macaw ( Anodorhyncus hyacinthinus ) (a bird endangered due to smuggling), the crowned solitary eagle ( Buteogallus coronatus ), the maned wolf ( Chrysocyon brachyurus ), the bush dog ( Speothos venaticus ), the South American tapir ( Tapirus terrestris ), and

585-699: The Pantanal as a breeding and feeding ground. There are nineteen species of parrots documented in the Pantanal, including five species of macaws . Some migratory birds include the American golden plover , peregrine falcon , and the bobolink . Most fish are detritivores , primarily ingesting fine particles from sediments and plant surfaces. This is characteristic of fish living in South American flood-plains in general. Fish migration between river channels and flood-plain regions occurs seasonally. These fish have many adaptations that allow them to survive in

624-579: The Pantanal floodplains are submerged during the rainy seasons, nurturing a biologically diverse collection of aquatic plants and helping to support a dense array of animal species. The name "Pantanal" comes from the Portuguese word pântano that means "swamp", "wetland", "bog", "quagmire", or "marsh" plus the suffix -al , that means "abundance, agglomeration, collection". The Pantanal covers about 140,000–160,000 km (54,000–62,000 sq mi) of gently-sloped basin that receives runoff from

663-429: The bottom and are decomposed by bacteria , a process that further reduces DO in the water column. If oxygen depletion progresses to hypoxia, fish kills can occur and invertebrates like worms and clams on the bottom may be killed as well. Hypoxia may also occur in the absence of pollutants. In estuaries, for example, because freshwater flowing from a river into the sea is less dense than salt water, stratification in

702-462: The dry season. According to Embrapa , approximately 2,000 different plants have been identified in the Pantanal biome and classified according to their potential, with some presenting significant medicinal promise. The Pantanal ecosystem is home to some 463 species of birds, 269 species of fishes, more than 236 species of mammals, 141 species of reptiles and amphibians, and over 9,000 subspecies of invertebrates. The apple snail ( Pomacea lineata )

741-542: The environment depends on the presence of oxygen, and once oxygen is no longer in the bodies of water, ligninperoxidases cannot continue to break down the lignin. When oxygen is not present in the water, the time required for breakdown of phytoplankton changes from 10.7 days to a total of 160 days. The rate of phytoplankton breakdown can be represented using this equation: G ( t ) = G ( 0 ) e − k t {\displaystyle G(t)=G(0)e^{-kt}} In this equation, G(t)

780-601: The environment, and therefore, hypoxia takes place quickly as oxygen is used up quickly to digest POC. About 9% of POC in phytoplankton can be broken down in a single day at 18 °C. Therefore, it takes about eleven days to completely break down phytoplankton. After POC is broken down, this particulate matter can be turned into other dissolved carbon, such as carbon dioxide, bicarbonate ions, and carbonate. As much as 30% of phytoplankton can be broken down into dissolved carbon. When this particulate organic carbon interacts with 350 nm ultraviolet light, dissolved inorganic carbon

819-517: The explanation for periodic phenomena such as the Mobile Bay jubilee , where aquatic life suddenly rushes to the shallows, perhaps trying to escape oxygen-depleted water. Recent widespread shellfish kills near the coasts of Oregon and Washington are also blamed on cyclic dead zone ecology. Phytoplankton are mostly made up of lignin and cellulose, which are broken down by oxidative mechanism, which consume oxygen. The breakdown of phytoplankton in

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858-602: The large depression area of the Pantanal. This area is also one of the distinct physiographic provinces of the larger Parana-Paraguay Plain area, which encompasses a total of 1.5 × 10 ^  km (580,000 sq mi). The Pantanal is bounded by the Chiquitano dry forests to the west and northwest, by the Arid Chaco dry forests to the southwest, and the Humid Chaco to the south. The Cerrado savannas lie to

897-419: The naturally occurring flora and fauna of the region are likely to be influenced by its geographical and geological factors, such as soil and water availability , in a significant manner. Thus most natural regions are homogeneous ecosystems . Human impact can be an important factor in the shaping and destiny of a particular natural region. The concept "natural region" is a large basic geographical unit, like

936-403: The north, east, and southeast. The Pantanal is a tropical wet and dry region with an average annual temperature of 24 °C (75 °F) and rainfall between 1,000 and 1,250 millimetres (39 and 49 in) per year. Extreme temperatures can reach a high of 41 °C (106 °F) or drop to −1 °C (30 °F). Throughout the year, temperature varies about 6.0 °C (10.8 °F) with

975-427: The nutrients. To get oxygen, they extend a long snorkel to the water surface, pumping air into their lungs. This ability allows them to consume all the dead plant matter and turn it into nutritious fertilizer available for the plants in the area. The snails themselves are also food for a variety of animals. Among the rarest animals to inhabit the wetland of the Pantanal are the marsh deer ( Blastocerus dichotomus ) and

1014-452: The oxygen-depleted flood-plain waters. In addition to the caiman , some of the reptiles that inhabit the Pantanal are the yellow anaconda ( Eunectes notaeus ), the gold tegu ( Tupinambis teguixin ), the red-footed tortoise ( Geochelone carbonaria ), and the green iguana ( Iguana iguana ). The Pantanal region includes essential sanctuaries for migratory birds, critical nursery grounds for aquatic life, and refuges for such creatures as

1053-402: The percentage of oxygen in the air (or blood) is decreased. This is common in the sealed burrows of some subterranean animals, such as blesmols . Atmospheric hypoxia is also the basis of altitude training , which is a standard part of training for elite athletes. Several companies mimic hypoxia using normobaric artificial atmosphere . An aquatic system lacking dissolved oxygen (0% saturation)

1092-455: The range between 1 and 30% saturation—is called hypoxic or dysoxic . Most fish cannot live below 30% saturation since they rely on oxygen to derive energy from their nutrients. Hypoxia leads to impaired reproduction of remaining fish via endocrine disruption . A "healthy" aquatic environment should seldom experience less than 80% saturation. The exaerobic zone is found at the boundary of anoxic and hypoxic zones. Hypoxia can occur throughout

1131-405: The surface. Hypolimnetic oxygen depletion can lead to both summer and winter "kills". During summer stratification , inputs or organic matter and sedimentation of primary producers can increase rates of respiration in the hypolimnion . If oxygen depletion becomes extreme, aerobic organisms, like fish, may die, resulting in what is known as a "summer kill". The same phenomena can occur in

1170-738: The upland areas (the Planalto highlands ) and slowly releases the water through the Paraguay River and tributaries . The formation is a result of the large, concave, pre-Andean depression of the Earth's crust, related to the Andean orogeny of the Tertiary . It constitutes an enormous internal river delta , in which several rivers flowing from the surrounding plateau merge, depositing their sediments and erosion residues, which have been filling

1209-610: The vast boreal forest region. The term may also be used generically, like in alpine tundra , or specifically to refer to a particular place. The term is particularly useful where there is no corresponding or coterminous official region. The Fens of eastern England , the Thai highlands , and the Pays de Bray in Normandy, are examples of this. Others might include regions with particular geological characteristics, like badlands , such as

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1248-509: The warmest month being November (with an average temperature of 26 °C or 79 °F) and the coldest month being June (with an average temperature of 20 °C or 68 °F). Its wettest month is January (with an average of 340 mm or 13 in) and its driest is June (with an average of 3 mm or 0.12 in). Floodplain ecosystems such as the Pantanal are defined by their seasonal inundation and desiccation . They shift between phases of standing water and phases of dry soil, when

1287-441: The water column and also at high altitudes as well as near sediments on the bottom. It usually extends throughout 20–50% of the water column, but depends on the water depth and location of pycnoclines (rapid changes in water density with depth). It can occur in 10–80% of the water column. For example, in a 10-meter water column, it can reach up to 2 meters below the surface. In a 20-meter water column, it can extend up to 8 meters below

1326-536: The water column can result. Vertical mixing between the water bodies is therefore reduced, restricting the supply of oxygen from the surface waters to the more saline bottom waters. The oxygen concentration in the bottom layer may then become low enough for hypoxia to occur. Areas particularly prone to this include shallow waters of semi-enclosed water bodies such as the Waddenzee or the Gulf of Mexico , where land run-off

1365-475: The water table can be well below the root region. Soils range from high levels of sand in higher areas to higher amounts of clay and silt in riverine areas. Elevation of the Pantanal ranges from 80 to 150 m (260 to 490 ft) above sea level. Annual rainfall over the flood basin is between 1,000 and 1,500 mm (39 and 59 in), with most rainfall occurring between November and March. Annual average precipitation ranged from 920 to 1,540 mm in

1404-417: The waters become oxygen-depleted, rendering the water environs anoxic . Many natural fish kills can occur if there are no oxygenated water refuges available. The reason for this remains speculative: it may be due to the growth of toxin -producing bacteria in the deoxygenated water rather than as a direct result of lack of oxygen. The vegetation of the Pantanal, often referred to as the "Pantanal complex ",

1443-435: The winter, but for different reasons. During winter, ice and snow cover can attenuate light, and therefore reduce rates of photosynthesis. The freezing over of a lake also prevents air-water interactions that allow the exchange of oxygen. This creates a lack of oxygen while respiration continues. When the oxygen becomes badly depleted, anaerobic organisms can die, resulting in a "winter kill". Oxygen depletion can result from

1482-589: The yacare caiman, deer, and Pantanal jaguar . Most species are not under threat due to the low deforestation rates (less than 17%) of native vegetation now in the area due to new regulations. Some of the causes which threaten the Pantanal ecosystems are: A portion of the Pantanal in Brazil has been protected as the Pantanal Matogrossense National Park . This 1,350 km (520 sq mi) park, established in September 1981,

1521-428: The years 1968-2000. In the Paraguay River portion of the Pantanal, water levels rise between two meters to five meters seasonally; water fluctuations in other parts of the Pantanal are less than this. Flood waters tend to flow slowly (2 to 10 cm (0.79 to 3.94 in) per second) due to the low gradients and high resistance offered by the dense vegetation. When rising river waters first contact previously dry soil,

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