Pátzcuaro lake

from Wikipedia, the free encyclopedia
Pátzcuaro lake
PatzcuaroLakeIslands fromTheTopOfJanitzioIsland PatzcuaroLake MichoacanMexico.jpg
The Lake Patzcuaro from the island of Janitzio seen from
Geographical location Mexico
Islands 5
Places on the shore Pátzcuaro , San Andrés
Data
Coordinates 19 ° 38 ′  N , 101 ° 38 ′  W Coordinates: 19 ° 38 ′  N , 101 ° 38 ′  W
Lake Pátzcuaro (Michoacán)
Pátzcuaro lake
Altitude above sea level 1920  m
surface 126.4 km²
length 19.5 km
width 9.8 km
volume 0.58 km³
scope 55 km
Maximum depth 11 m
Middle deep 5 m
Catchment area 929 km²
Template: Infobox Lake / Maintenance / EVIDENCE AREA Template: Infobox Lake / Maintenance / EVIDENCE LAKE WIDTH Template: Infobox Lake / Maintenance / EVIDENCE VOLUME Template: Infobox Lake / Maintenance / EVIDENCE SCOPE Template: Infobox Lake / Maintenance / EVIDENCE MAX - DEPTH template: Infobox Lake / Maintenance / EVIDENCE-MED-DEPTH Template: Infobox Lake / Maintenance / EVIDENCE-Catchment area

Lake Pátzcuaro ( Spanish: Lago de Pátzcuaro ) is a lake in the state of Michoacán in Mexico , 62 km west of the city of Morelia .

The lake, which lies in the Purépecha plateau , is one of the main tourist attractions in Michoacan. The lake has an area of ​​126.4 km² with an average depth of five meters. Its shoreline is 55 km long and there are five islands in the lake: Janitzio , La Pacanda , Yunuén , Tecuén y Jarácuaro and a small island called La Tecuenita . Tecuén can be reached by car.

Tourist activities mainly consist of boat trips and visits to the islands, especially Janitzio Island. The traditional Día de los Muertos , on which the locals visit the family graves on Janitzio with canoes lit by candles in order to decorate them with flowers and food, is a special attraction at the lake.

History of the lake

Investigations using the core hole drilling published in 2000 indicate that there may have been a runoff from Lake Pátzcuaro into the system of the Río Lerma between 38,000 and 25,000 years ago . During this time high lacustric deposits formed on the lake . Before and after the subsequent glacial period 25,000 to 13,000 years ago, cool freshwater conditions can be detected at Lago de Pátzcuaro. The lake must have been deeper then than it is today. Diatom species have been identified between 30,000 and 10,000 years ago that bloom in winter and spring. Before the Holocene, the pollen and plant spectrum documented cooler climatic conditions with a seasonally significantly higher humidity. About 10,000 years ago the lake became shallower and eutrophic . Today's climate developed. During the Middle Holocene 6,000 to 3,000 years ago, the lake water was now alkaline enough to deposit marl rich in ostracods. Human life at the lake has been documented for around 4,000 years.

Climate, flora and fauna around and in the lake

In its orange cultivated form, the Cambarellus patzcuarensis became the international ambassador of its home lake

The climate is subhumid , i.e. five to six humid months with a precipitation rate of 922 to 1060 millimeters measured between 1922 and 1979; the total evaporation rate between 1939 and 1985 was 1351 to 1810 millimeters. Average outside temperatures of 12 to 18 ° C are typical in the area of ​​influence of the lake.

The lake is surrounded by pine and oak forests , which are home to skunks , opossums , badgers , squirrels , rabbits and foxes . The lake itself also has a great diversity of species . The Pátzcuaro cross-toothed newt, which is threatened with extinction, is endemic here. At least five species of fish also live here: the endangered Pez blanco ( Chirostoma estor ), trout , Acúmara ( Algansea lacustris ), Tiruh and Chegua ( Alloophorus robustus ). The striped pygmy crayfish ( Cambarellus patzcuarensis ), also known only from this lake in the wild, is also an endangered species. In its orange cultivated form, it has enjoyed great popularity in European aquariums at the latest since the turn of the millennium and is an ambassador of its homeland. The Cambarellus patzcuarensis is an important basibiont in its natural environment of the Lago de Pátzcuaro. In a series of scientific studies published in 2001, a total of eight types of epistylis were identified as epibionts in different distributions on the cancer exoskeletons . These were: Epistylis bimarginata , Epistylis branchiophila , Epistylis carinogammari , Epistylis gammari , Epistylis gammari , Epistylis niagarae , Epistylis stammeri and Epistylis variabilis . In addition to the ciliates mentioned , other ciliophora from the group of sucking infusories benefit from the presence of the cancer in the lake. These are Podophrya sandy , Acineta tuberosa, and Tokophrya quadripartita . As the host of these life forms, cancer shows its great importance in the aquatic ecosystem of the lake and the need to keep it pure.

The lake's flora comprises 48 species in 22 plant families and is therefore particularly rich in species compared to other Mexican water systems. The aquatic vegetation includes, among many others, the small fatty leaf (Bacopa monnieri) , the narrow-leaved Merk (Berula erecta) , the rough horned leaf (Ceratophyllum demersum) , the marsh herb Cyperus niger , the giant needle ledge (Eleocharis montevidensis) , the buttercup-like pennywort ranunculoides) , the South American frog bite (Limnobium laevigatum) , the Lemna gibba (Lemna gibba) the Guadeloupe Nixkraut (Najas guadalupensis) , the Mexican water lily (Nymphaea mexicana) , the Illinois pondweed (Potamogeton illinoensis) , the pondweed (Potamogeton pectinatus) , the Buttercup Ranunculus dichotomus , the variable arrowhead (Sagittaria latifolia) , the Broad arrowhead (Sagittaria platyphylla) , the Totora (Scirpus californicus) , the salt-Teichbinse (Scirpus validus) , the Vielwurzelige duckweed (Spirodela polyrrhiza) , the southern cattail (Typha domingensis) , the broad-leaved cattail (Typha la tifolia) , the urinary bladder herb Utricularia macrorhiza , the duckweed family Wolffia brasiliensis and Wolffiella lingulata , the water hyacinths Eichhornia crassipes and the Mexican bald cypress Taxodium mucronatum .

Limnology

The species-rich Pátzcuaro Lake is over 2000 meters above sea level. It has an area of ​​around 9,000 hectares with an average water depth of 4.70 meters. At its deepest point, just 12 meters were measured. Due to its shallow depth, the lake has extensive wetlands at the edges , which are particularly concentrated in the shallow water zones.

The mean water temperature fluctuated between 1922 and 1979 between 15.80 and 16.70 ° C. In a study from 2014, low values ​​of 14.80 ° C (pH value: 7.20) and high values ​​of 26.80 ° C (pH value: 8.80) were measured in 2011. The mean value this year was 17.97 ° C (pH value: 8.48) in February, 22.77 ° C (pH value: 8.81) in May, and 21.18 ° C in July (pH value: 9.58) and in September at 18 ° C (pH value: 9.02). The oxygen content sank continuously from February to September from 6.39 to 4.40 mg / l. The increase in algae from July onwards was clearly noticeable. With the oxygen content, the salt content also fell in the same period from an average of 0.46 ‰ in February to 0.09 ‰ in September and the associated conductivity (February: 948.58 NS / cm; September: 130.40 NS / cm). The pH value in the lake moved from February to September in the range of 8.48 to 9.02 in 2011 and was therefore in the alkaline range . Similar pH measurement results had already been achieved between 2006 and 2007 with 7.56 to 9.91. The phosphate content in the lake is usually no more than 1 ppm, unless it has been contaminated by phosphorus fertilizers.

Destruction of the ecosystem

A traditional fisherman repairs his net on Lake Pátzcuaro

In a study from 2009, the sustainable and accelerated destruction of the ecological system at the Lago de Pátzcuaro was explained. One of the main evils lay in the failure of decades of government policy, with the authors emphasizing the fishery management that has been promoted so far, which has led to the domestic fish stocks being greatly reduced and, in some cases, being brought to the brink of extinction. In addition to this misguided concept, which promoted the introduction of various exotic species through fish plantations into the endorheic lake basin, there are countless wastewater discharges from urban and rural areas as well as from agrochemicals . The slow extinction of the native fauna in the lake also threatens the existence of traditional fishermen and their families. All these causes have led to a negative change in all previously known parameters in the lake.

There was also no respect for nature around the lake. In addition to the general pollution, agriculture and animal husbandry have taken up a lot of space. For them it was cut down, burned down and cleared without hesitation. In the meantime, programs have been launched by the neighboring communities, institutes and foundations that are intended to give direction to the unbridled goings-on.

See also

literature

  • Fernando de Buen: El Lago de Pátzcuaro. Recientes estudios limnológicos. Revista Geográfica, T. 1, No. 1 (January 1941), pp. 20-44

Remarks

  1. ^ "Descripción de la cuenca", Recuperación Ambiental del Lago de Pátzcuaro , accessed on October 18, 2009. [1]
  2. ^ Lesley Téllez: A Night to Remember
  3. ^ J. Platt Bradbury: Limnologic history of Lago de Pátzcuaro, Michoacán, Mexico for the past 48,000 years. Impacts of climate and man . In: Palaeogeography, Palaeoclimatology, Palaeoecology 163 (2000), pp. 69-95; here: p. 69.
  4. ↑ Fernando Walter Bernal-Brooks: La Limnología del Lago de Pátzcuaro. Una visión alternativa a conceptos fundamentales. National Autonomous University of Mexico (2002), Printed Dissertation, p. 17.
  5. ↑ IUCN: Cambarellus patzcuarensis
  6. ↑ Hans A. Baensch , Hans-Georg Evers : Aquarien Atlas Volume 6, Mergus, Melle 2002, ISBN 3-88244-068-6 , p. 1154.
  7. ↑ Rosaura Mayén-Estrada, Antonieta Aladro-Lubel: Epibiont Peritrichids (Ciliophora: Peritrichida: Epistylididae) on the Crayfish Cambarellus Patzcuarensis in Lake Pátzcuaro, Michoacán, Mexico. In: Journal of Crustacean Biology 2 (2001); Pp. 426-434; here: p. 427.
  8. ↑ Miguel Rodríguez Serna: Análisis ecológico y poblacional de la especie "Cambarellus patzcuarensis" del Lago de Pátzcuaro. In: Rubén I. Huerto Delgadillo, Sergio Vargas Velázquez (eds.): Estudio ecosistémico del lago de Pátzcuaro. Aportes en gestión ambiental para el fomento del desarrollo sustentable. 2, Instituto Mexicano de Tecnología del Agua, Progreso 2014, ISBN 978-607-7563-87-7 , pp. 95-133; here: p. 99.
  9. ^ Antonio Lot, Alejandro Novelo: Vegetacion y flora acuatica del lago de Patzcuaro, Michoacan, Mexico. In: The Southwestern Naturalist , 2 (1988), pp. 167-175; here: p. 167.
  10. ↑ a b c Antonio Lot, Alejandro Novelo: Vegetacion y flora acuatica del lago de Patzcuaro, Michoacan, Mexico. In: The Southwestern Naturalist , 2 (1988), pp. 167-175; here: p. 171.
  11. ↑ a b c d Antonio Lot, Alejandro Novelo: Vegetacion y flora acuatica del lago de Patzcuaro, Michoacan, Mexico. In: The Southwestern Naturalist , 2 (1988), pp. 167-175; here: p. 170.
  12. ^ A b Antonio Lot, Alejandro Novelo: Vegetacion y flora acuatica del lago de Patzcuaro, Michoacan, Mexico. In: The Southwestern Naturalist , 2 (1988), pp. 167-175; here: p. 169.
  13. ↑ Fernando Walter Bernal-Brooks: La Limnología del Lago de Pátzcuaro. Una visión alternativa a conceptos fundamentales. National Autonomous University of Mexico (2002), Printed Dissertation, p. 27.
  14. ↑ Lenin E. Medina-Orozco, Norma E. García-Calderón, Felipe García-Oliva, Elena Ikkonen: Suelos de humedal del lago de Pátzcuaro, Michoacán, México. In: Tecnología y Ciencias del Agua 5 (2014), pp. 111-124; here: p. 111.
  15. ↑ Fernando Walter Bernal-Brooks: La Limnología del Lago de Pátzcuaro. Una visión alternativa a conceptos fundamentales. National Autonomous University of Mexico (2002), Printed Dissertation, p. 17.
  16. ↑ Miguel Rodríguez Serna: Análisis ecológico y poblacional de la especie "Cambarellus patzcuarensis" del Lago de Pátzcuaro. In: Rubén I. Huerto Delgadillo, Sergio Vargas Velázquez (eds.): Estudio ecosistémico del lago de Pátzcuaro. Aportes en gestión ambiental para el fomento del desarrollo sustentable. 2, Instituto Mexicano de Tecnología del Agua, Progreso 2014, ISBN 978-607-7563-87-7 , pp. 95-133; here: p. 116.
  17. ↑ Javier Sánchez-Chávez, Luis Bravo-Inclán, Cecilia Tomasini-Ortiz, Fernando Bernal-Brooks: Calidad del agua del lago de Pátzcuaro. In: Rubén I. Huerto Delgadillo, Sergio Vargas Velázquez (eds.): Estudio ecosistémico del lago de Pátzcuaro. Aportes en gestión ambiental para el fomento del desarrollo sustentable. 2, Instituto Mexicano de Tecnología del Agua, Progreso 2014, ISBN 978-607-7563-87-7 , pp. 27-46; here: p. 36.
  18. ↑ Miguel Rodríguez Serna: Análisis ecológico y poblacional de la especie "Cambarellus patzcuarensis" del Lago de Pátzcuaro. In: Rubén I. Huerto Delgadillo, Sergio Vargas Velázquez (eds.): Estudio ecosistémico del lago de Pátzcuaro. Aportes en gestión ambiental para el fomento del desarrollo sustentable. 2, Instituto Mexicano de Tecnología del Agua, Progreso 2014, ISBN 978-607-7563-87-7 , pp. 95-133; here: p. 119.
  19. ↑ Sergio Vargas, Nohora Beatriz Guzmán Ramírez: Deterioro de la cuenca del lago de Patzcuaro. Cambios en la identidad étnica p'urhépech. 27. Congreso de la Asociación Latinoamericana de Sociología. 8. Jornadas de Sociología de la Universidad de Buenos Aires. Asociación Latinoamericana de Sociología, Buenos Aires 2009, pp. 1–2.
  20. ↑ http://recupera-patzcuaro.mx/images/memorias/Memoria_Ilustrada_2003-2007.pdf Memoria ilustrada del Programa para la Recuperación Ambiental de la Cuenca del Lago de Pátzcuaro