Poopó
Encyclopedia
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
in the Altiplano Mountains
Altiplano
The Altiplano , in west-central South America, where the Andes are at their widest, is the most extensive area of high plateau on Earth outside of Tibet...
in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
at an altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
of approximately 3,700 metres. Because the lake is long and wide (90 km by 32 km) it makes up the eastern half of the Oruro Department
Oruro Department
Oruro is a department in Bolivia, with an area of 53,588 km². Its capital is the city of Oruro. At the time of census 2001 it had a population of 391,870.- Provinces of Oruro :...
, a mining region in southwest Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
. The permanent part of the lake body covers approximately 1,000 km². The lake receives most of its water from the Desaguadero River
Desaguadero River (Bolivia)
The Desaguadero River in Peru and Bolivia is the river that drains Lake Titicaca. It exits the lake at the southern part of the river basin, it flows south and drains approximately five percent of the lake's flood waters into Lake Uru Uru and Lake Poopó....
which flows from Lake Titicaca
Lake Titicaca
Lake Titicaca is a lake located on the border of Peru and Bolivia. It sits 3,811 m above sea level, making it the highest commercially navigable lake in the world...
at the north end of the Altiplano. Since the lake lacks any major outlet and has a mean depth of no more than 3 m, the surface area varies greatly.
The lake has been designated as a site for conservation under the Ramsar Convention
Ramsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
.
Archaeological evidence
Archaeological investigations conducted by the San Andres University of La PazLa Paz
Nuestra Señora de La Paz is the administrative capital of Bolivia, as well as the departmental capital of the La Paz Department, and the second largest city in the country after Santa Cruz de la Sierra...
, Bolivia, shows the influence of the Wankarani culture on the Poopo area where complex central urban area
Urban area
An urban area is characterized by higher population density and vast human features in comparison to areas surrounding it. Urban areas may be cities, towns or conurbations, but the term is not commonly extended to rural settlements such as villages and hamlets.Urban areas are created and further...
s such as villages and towns were developed that expanded into the Poopo basin during the Late Formative period, (200 BCE – 200 CE), probably in conjunction with changing patterns of agriculture. Herder
Herder
A herder is a worker who lives a possibly semi-nomadic life, caring for various domestic animals, in places where these animals wander pasture lands....
s and the life style of llama
Llama
The llama is a South American camelid, widely used as a meat and pack animal by Andean cultures since pre-Hispanic times....
caravan merchants
Caravan (travellers)
A caravan is a group of people traveling together, often on a trade expedition. Caravans were used mainly in desert areas and throughout the Silk Road, where traveling in groups aided in defence against bandits as well as helped to improve economies of scale in trade.In historical times, caravans...
coexisted with more sedentary farmers in a harmonious system of exchange of goods and services. Other investigators examining the following period, the Early Regional Developments (aprox. 300 - 900 CE), shows that the size of the inhabited areas increased. The South Poopo inhabitants developed a unique style of ceramics style with triangular spirals. The Huari at the east portion of the lake displays an important Tiwanaku
Tiwanaku
Tiwanaku, is an important Pre-Columbian archaeological site in western Bolivia, South America. Tiwanaku is recognized by Andean scholars as one of the most important precursors to the Inca Empire, flourishing as the ritual and administrative capital of a major state power for approximately five...
enclave, with ceramic styles from the core Titicaca area and surrounding styles, demonstrating the interactions between different peoples in the area.
Lake dynamics
Poopó Lake gets the majority of its water (roughly 92%) from the Desaguadero River which enters the lake at the north end. There are numerous smaller inlets along the eastern shore of the lake, many of which are dry most of the year. At times of very high water levels, Poopó is connected to the salt desert Salar de Coipasa in the west. A minor outlet also leads to Salar de UyuniSalar de Uyuni
Salar de Uyuni is the world's largest salt flat at . It is located in the Potosí and Oruro departments in southwest Bolivia, near the crest of the Andes, and is elevated above the mean sea level. The Salar was formed as a result of transformations between several prehistoric lakes...
in the far south of the Altiplano, but as the lake lacks any major outlet it is classified as an endorheic basin.
When the water level of Titicaca Lake drops below 3,810 m, the flow of Desaguadero River is so low it can no longer compensate for the massive water losses due to evaporation from the surface of Poopó Lake. At this point, the lake volume begins to decrease. At its maximum in 1986, the lake had an area
Area
Area is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...
of 3,500 km². During the years that followed, the surface area steadily decreased until 1994 when the lake disappeared completely. The time period between 1975 and 1992 is the longest period in recent times with a continuous existence of a water body.
Lake Titicaca
Lake Titicaca
Lake Titicaca is a lake located on the border of Peru and Bolivia. It sits 3,811 m above sea level, making it the highest commercially navigable lake in the world...
basin's drainage system, for the most part, is able to provide Titicaca with enough water to retain its status as a freshwater lake although its evaporation rate is so high.
Salinity and geology
Arid
A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...
climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
and the high evaporation
Evaporation
Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....
from the lake surface.
In the northern end of Poopó Lake there is a dilution with freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
from Desaguadero River. This results in a salt gradient
Gradient
In vector calculus, the gradient of a scalar field is a vector field that points in the direction of the greatest rate of increase of the scalar field, and whose magnitude is the greatest rate of change....
of higher values towards the south.
The salinity varies with water volume. During October – November 2006 the salinity in the north end of the lake varied between brackish and saline
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
(15-30,000 mg/l). In the south end of the lake the water was classified as a brine
Brine
Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...
(105,000- 125,000 mg/l). The water type is a 4-2 Na-(Mg)-Cl-(SO4).
Geological sources of NaCl
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
such as halite
Halite
Halite , commonly known as rock salt, is the mineral form of sodium chloride . Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount and type of impurities...
and feldspars are present in the drainage area. These could also contribute to the salinity of Lake Poopó. The lake body is situated on top of Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
deposits, consisting mainly of unconsolidated material. These sediments are the remains of extensive prehistoric lakes, which covered the Altiplano during at least five glaciation periods.
Mining and heavy metals
There is a long tradition of miningMining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
in the Poopó Basin. Extraction of metals began in the 13th century to support the Inca army. After the Spanish colonization in the 16th century, the mining operations became more large scale. At this point the region got its current identity as one of the mining centres of Bolivia.
Cordillera Oriental
Cordillera Oriental from the Spanish language meaning "Eastern range" may refer to:* Cordillera Oriental * Cordillera Oriental * Cordillera Oriental * Cordillera Oriental -See also:...
along the eastern border of the Poopó basin. The economically most important minerals are silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
and tin
Tin
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4...
.
Studies have shown elevated concentrations of heavy metals
Heavy metals
A heavy metal is a member of a loosely-defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed—some based on density, some on atomic number or atomic weight,...
in surface and ground waters of the Poopó basin. These metals are naturally present in the bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
, from which they are released through weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...
processes. The mining activities in the area further contributes to the heavy metal pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
. Acid leaching from mines
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
and mechanical processing of ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
speed up the process.
The major part of the heavy metals transported to Lake Poopó seem to be immobilized in the bottom sediments. Still, concentrations of arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
, lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
and cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
in the lake water exceed Bolivian and WHO
Who
Who may refer to:* Who , an English-language pronoun* who , a Unix command* Who?, one of the Five Ws in journalism- Art and entertainment :* Who? , a 1958 novel by Algis Budrys...
guideline values for drinking water.
Flora and fauna
Three to four native fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate 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...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
inhabit the lake: the Mauri (a Trichomycterus
Trichomycterus
Trichomycterus is a genus of catfishes, the largest genus in the family Trichomycteridae with over 100 species currently described.-Taxonomy:This genus is defined by the lack of specializations found in other trichomycterids and is certainly polyphyletic...
catfish), and the Carache and Ispi (Orestias
Orestias (Cyprinodontidae)
Orestias is a genus of pupfish. Older systematics classified them into the own family Orestiidae. They are carnivorous plankton feeders and can reach a length between 9 and 22 centimetres. Their most characteristic feature is the absence of the ventral fin...
spp.). Two exotic fish species were introduced in the 20th century; the rainbow trout
Rainbow trout
The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....
(trucha) in 1942 and the silversides
Neotropical silversides
The neotropical silversides are a family Atherinopsidae of fish in the order Atheriniformes. The approximately 104 species in 13 genera are distributed throughout the tropical and temperate waters of the New World, including both marine and freshwater habitats...
Odontesthes bonariensis (pejerrey) in 1955. These bigger fish are now the most commercially important species. The lake has a relatively large fish population although it declines during the years of low water when the salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
is high.
The aquatic bird life is highly diverse with a total of 34 species. Most famous are the three types of flamingos which mainly live in the shallow lagoons in the northern and eastern parts of the lake. An inventory of the bird population, made in the year 2000 in cooperation with BirdLife International
BirdLife International
BirdLife International is a global Partnership of conservation organisations that strives to conserve birds, their habitats and global biodiversity, working with people towards sustainability in the use of natural resources...
, identified 6 endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
. Among these are the Chilean flamingo
Chilean Flamingo
The Chilean Flamingo is a large species closely related to Caribbean Flamingo and Greater Flamingo, with which it was sometimes considered conspecific...
and the Andean Condor
Andean Condor
The Andean Condor is a species of South American bird in the New World vulture family Cathartidae and is the only member of the genus Vultur...
.
A total of 17 superior plants and 3 species of algae have been identified in and around Lake Poopó. Due to the constant drought and flooding, the littoral zone experiences great disturbances. As a result, there is hardly any vegetation to be found on the shores of the lake.