Lake Junín is a highly productive ecosystem of unique biological diversity that has been subjected to strong pressures over the years due to the extraction of its resources, overgrazing, and contamination of the lake from mining wastes and municipal wastewater.
Agricultural activity
Agriculture is sparsely developed, limited to small fields and family gardens because few crops can thrive at the high altitudes of the area. Those that do prosper include the potato (Solanum tuberosum) and the maca (Lepidium meyenii), a traditional crop whose cultivation has been reintroduced and promoted since 1996.
Agricultural activity on hill slopes
Water quality studies of Lake Junín have detected the presence of agricultural insecticides, which wash into the lake from the surrounding fields and through drainage systems from villages around the lake. This is a fundamental consequence of the bad practices of farmers in the region using these products.
Ranching
Lake Junín has been a resource since ancient times, however, the utilization of natural resources has been badly managed in the last few decades, and overexploitation is occurring. Various neighboring towns currently have an overpopulation of livestock, due to the tendency to wait for better market prices for wool and meat. The problem is exacerbated during times the dry season, when all of these animals graze in the wetlands surrounding the lake, resulting in overgrazing, compaction, and loss of these highly productive environments.(19)
The livestock raised around the lake consists mainly of sheep, but there is also cattle and, to a lesser degree, alpacas and llamas. Junín department ranks third in the nation in overall sheep production, behind Puno and Cuzco, with an estimated 60,000 to 70,000 head in the area surrounding the lake.
The protected area permits the use of cultivated grasses only in the Special Use Zone. However, many people request permission to plant introduced grasses in sectors where it is not permitted, especially along the road towards Ondores.
There are many fences for livestock within the reserve. These fences fragment habitat and restrict the free circulation of wildlife populations. Livestock has reduced vegetation cover, negatively affected the health of grassland, and led to replacement of wild grasses, which are good forage for animals, by undesirable plant species. Grazing does not allow grasses to recuperate, and as livestock move on to other areas, vegetation is continuously impacted.constantemente.
Mining Activity
The Lake Junín basin, like most places in the Peruvian mountains, is not free of the mining activity which began during the period of the conquistadors, and has suffered a large amount of ecological degradation, as a result. Lake Junín has been the confluence of streams that transport significant quantities of mining wastes containing heavy metals and other substances which accumulate in the ecosystem, and consequently harm both the environment as well as human beings. This contamination limits the productivity of the lake and affects a large number of plants and animals of the lake, either directly or indirectly.
Contamination from mining waste is the main problem facing the lake. In the northeastern section, where the San Juan River drains into the lake, the water is characteristically a brick-red color and contaminates a large part of the ecosystem. These wastes not only produce chemical contamination, but also result in increased turbidity due to the high concentration of suspended particulate matter. Consequently, aquatic plants and algae die off because they are unable to carry out the process of photosynthesis. Highly concentrated, dissolved chemicals affect water quality in almost one third of the lake. Mining activity also contaminates pastures when these are flooded with water polluted by mining waste.
Mining sedimentation at the lake's shore
Over the years, studies have indicated high concentrations of total dissolved metals, low concentrations of dissolved oxygen, and high turbidity. This is mainly to the oxidation of iron and manganese and high concentrations of copper, lead, zinc, arsenic, cadmium, chromium, mercury, iron, and manganese, all of which have reduced populations of aquatic flora and fauna. Heavy metal concentrations are very high in the northern part of the lake, until just offshore of the town of San Pedro de Pari, at which point it gradually declines. High concentrations of zinc, copper, and lead extend for several kilometers into the main basin of Chinchaycocha Lake, exceeding the EPA criteria for the protection of aquatic life.(20)
Even now, after scientific advances have allowed the incorporation of new technologies to mitigate mining impacts, the reversal of ecological impacts is a slow and costly process. However, there are encouraging signs from some mining companies that they are working to mitigate the impacts caused over the years.(21)
Environmental Mitigation Programs (PAMA) have been implemented to combat pollution from mining wastes, and impacts have been reduced significantly because miners have begun to use drainage fields and residual water is being recycled. However, these programs, supervised by the Ministry of Energy and Mining, are also an indication of the slight advancement toward the completion of these programs. The PAMAs should have been completed in 2002, but are still ongoing through the solicitation of extensions, which implies that, in reality, many mines are essentially operating without PAMAs.
A closer analysis of the PAMAs shows that they address the environmental impacts of mining operations, and only partially address the mitigation of cumulative environmental damages caused by the activity. Mining activity has occurred in Pasco since colonial times, generating impacts that are not considered in the PAMAs, within the terms of current legislation. The PAMAs do not address responsibilities for the mining wastes discharged in the San Juan River course and delta, the deposition of sediments containing heavy metals in the San Juan River delta in Upamayo, and the presence of minerals on the banks of Lake Chinchaycocha. Additionally, the issue of waste disposal from carbon scrubbers in the old smelting works of Tinyahuarco is not addressed. This waste acidifies the Huachuacaja Stream during the rainy season, which flows into the San Juan River.
Mining sediments entering the lake
Mineral sedimentation on the pastures along the Mantaro River, on the stretch of the river by the communities of San Pedro de Pari and San Juan de Ondores, and fine metallic dust from the former bed of the San Juan River affect the soils, grasses, livestock, and water quality.(22)
Presently, there are three mining companies, Volcan Mining Company, Aurex Mining Company, and the Brocal Mining Society, that discharge effluent water into the lake, above the Upamayo Dam. These companies primarily mine for lead, silver, gold, and zinc. Previously, the state mining operation, Centromin, contributed significant volumes of effluent into the lake for many years. On the whole, mining activity is filling the lake with sediments that affect the aquatic and terrestrial vegetation, as well as the local residents and their activities. The community of Vicco continues to complain about the fields affected by the iron oxides and wastewater from the Brocal company. Regional governments have taken no action against the company, citing their social responsibility to protect the miners. But in reality, no action is taken because the mining and energy taxes which they receive from these activities are a guaranteed source of income.
The majority of the bird species of the lake have suffered a dramatic decline in numbers, which is primarily attributed to the prolonged contamination of the lake by mining activities. There is sufficient circumstantial evidence which confirms that this pollution is by far the most significant environmental impact on the fauna, including: a) during the dry season evidence of pollution is plainly observed and hundreds of dead birds appear on the lake shore, b) most bird populations are concentrated in the southern part of the lake, with decreasing distributions in the highly contaminated areas at the mouth of the San Juan River, and c) iron oxide sediments cover the algae on the bottom of the lake occasionally killing vegetation, leading to the desertification of large areas of the lake. These algae are a principal food source for many birds, and the impacts of desertification are obvious. Other species suffer due to the scarcity of fish, which is attributed to the lack of water quality. Heavy metal concentrations are above the recommended level for healthy animal life.(23)
The General Director of Environmental Health (DIGESA) is responsible for monitoring water quality in Lake Junín and conducts evaluations every three months. Distribution of the results of these analyses by DIGESA is slow, and INRENA only receives these reports once a year, often after the information is out of date. This does not allow INRENA to interpret this information in conjunction with events which occur in the lake (for example, bird or fish kills or increases in turbidity), which impedes their ability to take appropriate corrective measures.
Even though the Ministry of Energy and Mining supervises mining operations and DIGESA conducts environmental monitoring activities, there is a lack of public confidence in the results of evaluations conducted by the mining companies and governmental organizations, as well as a denial of their validity.(24)
Hunting and Fishing
Hunting is frequently mentioned as a factor in declining animal populations, however, there are relatively few hunters in the area and traditional practices of local hunters would be unlikely to have a significant impact on the bird populations. In general, healthy, mature birds are not caught by local hunters, rather, they pursue birds that are molting or unable to fly. After a long chase (twenty minutes to an hour) in a single-passenger canoe, the bird tires and is captured with a long stick which has two or three long nails on the end. Due to the present degraded condition of the lake, the number of active hunters has further declined. If the number of hunters increases, or their methods become more technologically advanced, the impacts of hunting could become more significant.
In Ondores, a hunting and fishing association was established 25 years ago. This association was dedicated to hunting the Junín frog for commercial use, and regulated their activities with closed seasons and size limits. Unfortunately, the drastic decrease in the frog population due to pollution and overexploitation has made it difficult for the association to continue its activities.
Birds are captured, by collecting eggs or hatchlings from their nests, both on land and on the lake using small boats. The montane guinea pig, which is part of the local diet, is hunted by burning the cattail communities where it hides. This has a negative impact on several other species that use the cattails as permanent habitat, particularly the Junín coot.25
The coot (Fulica ardesiaca) and various species of ducks are hunted commercially, especially the ruddy duck (Oxyura jamaicensis). Hunting mostly occurs in the areas of Santa Clara de Chuyro, Huayre, Ondores, and Paccha. A series of agreements permit subsistence hunting, with catch limits of 11 individuals of any species per week per hunter, and each village has a committee overseeing the rational use of natural resources.
Established closed hunting seasons are not respected by local hunters, either due to ignorance or because hunting is the only activity which meets their basic economic needs. To the extent possible, INRENA attempts to enforce the closed seasons and confiscates both equipment and products from violators.
Extraction and burning of cattails and other vegetation
The extraction of cattails occurs on a small scale, relative to its use in other wetland areas where the fiber of this species is used for the construction of rafts, baskets, and mats, among other products. In Junín, cattails are harvested for use as forage for livestock and burned to encourage shoot renewal and facilitate the hunting of montane guinea pigs.
Traditionally, sod has been extracted in the area for use as an energy source because local residents lack an alternative source of energy. Communities have organized to limit extraction by each community to 1000 blocks of sod per year (previously the extraction of 2000 to 2500 blocks was permitted). However these agreements do not apply to private landholders, and they are able to extract an unlimited amount of sod (26). The excessive removal of sod results in erosion and loss of soils.
Impacts on soils from the extraction of sod (above). Collected pieces of sod
Water use and management
Lake Junín plays an important role in electric power generation for the country, contributing approximately 29% of the overall flow of the Mantaro River in times of low water. This permits the Mantaro energy complex (hydroelectric plants of Malpaso, Santiago Antúnez de Mayolo, and Restitución) to support their operations throughout the year. The Upamayo Dam stores the water of Lake Junín during the rainy season in order to ensure an adequate supply of water for energy generation during the dry season. This process causes the water levels in the lake to fluctuate during the year.
Fluctuating water levels in the lake, controlled by the Upamayo Dam at the source of the Mantaro River, pose a threat to the ecosystem. Rising water inundates bird nesting grounds, while receding water strands schools of fish or amphibians in dry areas and exposes them to predation. Also, this fluctuation directly affects the local inhabitants by inundating areas of pasture for longer periods than usual. Ranchers use pastures on a rotating basis, using the higher areas in the rainy season (January to May) and the lower area along the lake shore during the dry season (June to December). High water levels create larger areas of inundation for longer periods of time, and as a consequence, the ranchers suffer economic losses due to the inability to use land along the lake shore as pasture for livestock. Also, the inundation of springs and wells affects public and private water sources used for human consumption.
The regulation of lake levels for hydroelectric purposes, in addition to water pollution, is a primary cause of the decline of the Junín grebe. It is responsible for the decline in the area of cattail habitat, of which relatively few areas remain in a permanently inundated condition. These areas are the preferred feeding grounds for the Junín grebe, which is suffering as much from the disappearance of the cattails as from the disappearance of its food source (fish of the Orestias genera).(27)
In October, 1993, the publicly-operated Electrocentro SA., Electro Peru SA., and Centromin Peru SA. drew up a contract for the provision and repayment of electricity, establishing coordinated procedures for regulating the use of water in Lake Junín in its ninth clause. A series of difficulties arose in the implementation of the contract due to issues with the authorization of water use licenses by the Technical Administration of Riego District, the existence of different criteria for the coordinated management of the waters of Lake Junín between the companies, changes in the quantity of water use permitted and points of extraction, petitions for additional resources through revised resolutions, etc. These problems were due to Ministerial Resolution No. 0149-98-AG which defines the limits of the water use licenses of Electroperú S.A. and Centromin Perú S.A. for the utilization of water resources in Lake Junín.
The contract established the period of water collection for the lake from January first to May 31st of each year (the floodgate remains closed). The regulated discharge of water occurs from June first until December 31st each year, operating in such a way that the following minimum reserves (as a percentage of the usable volume of stored water) are maintained in the lake: 100% as of June 1, 85% as of July 1, 70% as of August 1, 55% as of September 1, 40% as of October 1, 25% as of November 1, 10% as of December 1, and 3% as of December 31. The usable volume of stored water corresponds to the volume accumulated on May 31 of each year (28). In this way, Ministerial Resolution 149-98-AG authorized the minimum volumes of reserves required, but not precise maximum amounts of water collection and discharge.
Upamayo Dam in the northern section of the lake
The diversion of irrigation canals, sewers, and drainpipes from neighboring towns into the lake elevates the organic material content, increasing the degree of eutrophication and the concentration of ammonium, and causing the reduction of dissolved oxygen and killing many organisms.(29)
Untreated wastewater has noxious effects on the lake ecosystem. Lake Junín is naturally an oligotrophic lake (with low nutrient availability), but increased nutrient concentrations due to the influx of wastewater causes microorganism populations to increase. These microorganisms consume large quantities of dissolved oxygen, initiating the process of eutrophication which affects aquatic biota at all trophic levels. Also, solid wastes, primarily plastics, often accumulate in cattail communities. Solid wastes from the city of Cerro de Pasco, entering the lake through the San Juan River, accumulate in the northern part of Lake Junín and on the San Juan River delta.(30)
In the pas, the town of Junín discharged wastewater into the Chacachimpa River, which runs directly into the lake, causing a severe pollution problem. Today, treatment lagoons are used to treat drainage before it is discharged into the river. The town of Huayre does not have a sewage system, only latrines. The latrines do not directly contaminate the lake, but may affect groundwater quality. Carhuamayo, which is growing rapidly, has treatment lagoons that are not functional. Therefore, wastewater passes through the lagoons untreated and continues to contaminate the lake. Wastewater from Ondores flows directly into the lake, however, town officials confirm that construction of a wastewater treatment system will soon begin. In the towns of Vicco and Ninacaca, a sewage system is also currently under construction.
Wastewater discharged directly into the lake
NOTES:
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19) Plan Maestro de la Reserva Nacional de Junín. INRENA. Junín Perú. 2000. Pág. 30.
20) Comisión Multisectorial Descentralizada. Informe Final: Anexo Programático 2. Estado de Calidad de las Aguas de la Cuenca Alta del Río Mantaro. 2002. Carlos Rojas Marcos CONAM y Aldo Brigneti Consultor.
21) Plan Maestro de la Reserva Nacional de Junín. INRENA. Junín Perú. 2000. Págs. 19 – 21, y 29.
22) Comisión Multisectorial Descentralizada. Informe Final Parte C. Diagnostico de la Problemática. Ciudad de Junín, 17 de abril del 2002.
23) Plan Maestro de la Reserva Nacional de Junín. INRENA. Junín Perú. 2000. Pág. 14.
24) Comisión Multisectorial Descentralizada. Informe Final Parte C. Diagnostico de la Problemática. Ciudad de Junín, 17 de abril del 2002.
25) Plan Maestro de la Reserva Nacional de Junín. INRENA. Junín Perú. 2000. Pág. 21.
26) Plan Maestro de la Reserva Nacional de Junín. INRENA. Junín Perú. 2000. Pág. 23.
27) Comisión Multisectorial Descentralizada. Informe Final Parte C. Diagnostico de la Problemática. Ciudad de Junín, 17 de abril del 2002.
28) Resolución Ministerial No. 0149-98-AG del 27 de marzo del 1998.
29) Plan Maestro de la Reserva Nacional de Junín. INRENA. Junín Perú. 2000. Págs. 29 – 30.
30) Comisión Multisectorial Descentralizada. Informe Final Parte C. Diagnostico de la Problemática. Ciudad de Junín, 17 de abril del 2002.
