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Imbalance of ecosystems and their impact on public health and animal husbandry Dr. Kedar Karki MV St. (Preventive Veterinary Medicine) Central Veterinary Laboratory Tripureshwor The health of humans, like all living organisms, is on an ecosystem, life in itself contributes dependent. Healthy ecosystems are the sine qua non for healthy organisms. But there are many indications that many life an increased burden to human health marketing support systems are far from healthy. In some areas of the world, winning in life expectancy and quality of life during the twentieth century will be made risk being reversed in the twenty century. The consequences of ecosystem degradation on human health are numerous, and the health risks from polluted water, air pollution, climate change, emerging new diseases and the resurgence of ancient diseases due to ecological imbalances. Reversing this hurt is possible in some cases but not in others. Prevention of environmental hurt is by far the most efficient strategy. DEFINING ECOSYSTEMS An ecological system can be used as a community of plants and animals interact with each other and are defined by their abiotic, or natural environment. Typically, the ecosystems are to be distinguished on the basis of dominant vegetation, topography, climate, or other criteria. Boreal forests, for example, are characterized by the predominance of conifers, meadows are characterized by the predominance of grasses, the arctic tundra is partly by the harsh climatic zone. In most regions of the world, the human community is an vital and often dominant component of the ecosystem. Ecosystems are not only natural areas (eg, forests, lakes, sea coasts) systems, but also by urban people constructed systems (eg ecosystems, agro-) ecosystems, impoundments. Populations are increasingly concentrated in urban ecosystems, and it is estimated that there are up to the year 2010 50 percent of the world’s population will live in urban areas. A landscape consists of a mosaic of ecosystems, which are also cities, rivers, lakes, agricultural systems, and so on. Precise boundaries between ecosystems are often hard to identify. Often Regions slipping gradually into another, over an extended “transition” zone, as for example between the boreal forest and taiga regions of Canada. Ecosystem Health It is vital to recognize the inherent difficulties in the definition of “health”, whether at the level of the individual, population, or ecosystem. The concept of health is something of a mystery, because it easily in his absence) (illness, defined as in his presence. Perhaps partly for this reason, ecologists have resistance to the application of the term “health” of ecosystems. But, ecosystems can become dysfunctional, particularly under chronic stress from human activity. Example of this can be argued that the introduction of nutrients from sewage, industrial waste and agricultural runoff into lakes or rivers affects the normal functioning of the ecosystem and can lead to severe impairments. Excessive nutrients from human activity was one of the most vital factors that seriously endangers the health of the lower Laurentian Fantastic Lakes (Lake Erie and Lake Ontario) and regions of the upper Fantastic Lakes (Lake Michigan). Unfortunately, the ecosystems are more the rule than the exception. The study of the features of degraded systems and comparisons with the systems, which has not been altered by human activity, makes it possible to identify the characteristics of healthy ecosystems. Healthy ecosystems are not only characterized by the absence of signs of pathology, but also by signs of health, including measures of force) (productivity, organization and resilience. Vigor is in relation to the metabolism (activity and productivity) will be evaluated in the system. Ecosystems vary greatly in productivity in their normal ranges. Estuaries are more productive than the open lake and marshes have higher productivity than deserts. Health is not valued by applying a standard for all systems. Organization is the structure of the living community, which forms an ecosystem and the nature of the interactions between species (plants and animals) assessed. Invariably, healthy ecosystems, diversity of flora and fauna at risk than organic systems. Resilience is the ability of an ecosystem, its structure and functions in the face of natural disturbances maintain. System with a history of chronic stress are less likely to recover from the usual problems such as drought than those systems that have relatively less stress. Healthy ecosystems can also be characterized in economic, social and human health conditions. Healthy ecosystems support a certain level of economic activity. This is not to say that the ecosystem is necessary self-sufficient, but rather that it supports economic productivity to the human community to be reasonable requirements. Inevitably, ecosystem degradation impinges on the long-term sustainability of the human economy, which is associated, although in the small term can not be seen, such as natural capital (eg soils that are over-exploited renewable resources) and to improve the temporary economic benefits. Also in terms of social well-being, healthy ecosystems provide a basis for the promotion and integration into the community. Historically, for example, native Hawaiian groups managed their ecosystem through a well-developed social cohesion, a high degree of cooperation in fisheries and agricultural activities provided. Another reflection of ecosystem health is directly in the field of public health. In spring 2000, a deadly strain of the bacterium E. coli (0157 was: H7) in the public water supply in Walkerton, Ontario, Canada, thus making seven dead and thousands ill. This small town with a population of five thousand, is located in an agricultural community. Inadequate manure management from cattle operations was the most likely cause of this tragedy. HOW ARE healthy ecosystems Pathological Stress from human activity is an vital factor in transforming healthy ecosystems to sick ecosystems. Chronic stress from human activities is different from natural disturbances. Natural disturbances (fires, floods) periodic insects are part of the dynamics of most ecosystems. These processes help to “reset” ecosystems by recycling nutrients and clearing space for repopulation of the flora and fauna that can be better adapted to changing environments. To help keep disruption to natural ecosystems healthy. In contrast, chronic and acute stress on ecosystems resulting from human activities (eg construction of large dams, the release of nutrients and toxic substances in the air, water and soil) usually results in long-term ecological dysfunction. Five major sources of man-made (anthropogenic) stresses have been identified by DJ AM Rapport and Friend (1979): physical restructuring, overfishing, waste residuals, introduction of exotic species and global change. Physical restructuring. Activities such as drainage, removal of shoals in lakes, damming of rivers and roads fragment the landscape and alter and hurt critical habitat. These activities also disrupt nutrient cycling and leads to loss of biodiversity. Overfishing. Overfishing is a truism when it comes to the harvesting of wildlife, fisheries, and forests. Over time the stocks of preferred species are reduced. For example, the redwoods, which once flourished along the California coast, only in remaining patches is due to overfishing. As the dominant species such as redwood trees (probably the world’s tallest tree, a specimen was collected at 110 meters high with a circumference of 13th 4 meters) are lost, the whole ecosystem is changed. Depletion often leads to reduced biodiversity of endemic species, while facilitating the invasion of opportunistic species. Residues. Discharges from municipal, industrial and agricultural sources into the air, water and land ecosystems of the earth, many seriously endangered. The effects are particularly apparent in aquatic ecosystems. In some lakes, no natural buffer capacity, acid precipitation has eliminated most of the fish and other organisms. While the visual impact of benefit (the clarity of the water appear) increases the impact on the ecosystem health is devastating. Systems, which in the past a variety of organisms and were highly productive (to organic) by most living things, without exception for a few acid-tolerant bacteria and sediment organisms. Introduction of exotic species. The spread of exotics is a problem in nearly all ecosystems in the world. Transport of species from their natural habitat to entirely new ecosystems can wreck havoc, as the new environments are often without natural checks and balances for the new species. In the Fantastic Lakes basin, the accidental introduction of two small pelagic fish alewife and rainbow smelt, while overfishing of natural predators such as lake trout, resulted in a significant decline in fish species combined. The introduction of the sea lamprey, an eel like predators that attacks larger fish, into Lake Erie and the upper Fantastic Lakes further destabilized the native fish community. The sea lamprey contributed to the decline of benthic deep-sea fish community of the hunt for lake trout, whitefish and burbot. This contributed to a shift in the community with fish from one, which was too large benthics one of the small pelagic (fish dominated in the upper layers of the lake found profile dominates). This shift from bottom-dwelling fish (benthic) to the surface of live fish (pelagic) has now partly covered by another accidental introduction of an exotic reversed: the zebra mussel . There is the zebra mussel, a highly efficient filter both phtyoplankton and zooplankton, its presence has reduced the available food in the surface waters of pelagic species. While, but, has won the benthic species communities again its dominance, the preferred benthic fish species not yet recovered owing to the degree the first reduction. Overall, the increasing dominance of exotics not only altered the ecology, but also significantly reduces the commercial value of fisheries. Global Change. Rapid climate change (or global warming) is an emerging potential global stress on all ecosystems on Earth. In evolution, there have of course been large fluctuations in the climate. But, for the most part these fluctuations have occurred gradually over long periods. Rapid climate change is an entirely different matter. By changing both averages and extreme rainfall, temperature and storms, and by destabilizing the El Niño Southern Oscillation (ENSO), the weather patterns in many parts of the South Pacific controls many ecosystem processes can be significantly altered. Excessive drought or unusually heavy rainfall and flooding will exceed the tolerance for many species, thus changing the biotic composition. Floods and unusually high winds contribute to soil erosion and at the same time in the nutrient load in rivers and coastal waters. These anthropogenic stress factors on ecosystem function in most regions of the world who are in the ecosystem distress syndrome (EDS) called into question. EDS is a group of characters, including changes in nutrient cycling, productivity, biodiversity and characterizes the richness, biotic structure, disease prevalence, soil fertility, and so on. The consequences of these changes on human health are not inconsiderable. Impoverished communities are natural harbors for pathogens that affect humans and other living things on. Health of ecosystems and human health An vital aspect of ecosystem degradation is the increased associated risk to human health. Traditionally, the study of contaminants were mainly industrial chemicals can have adverse effects on human development, neurological functions, reproductive functions and that appear to be pathogens in a variety of cancers. In addition to these major environmental problems (where the funds are often technological), including engineering solutions to reduce releases of pollutants, there are a large number of other risks to human health arising from ecological imbalance. Ecosystem distress syndrome leads to loss of valuable ecosystem services, including flood control, water quality, air quality, fish and wildlife diversity and recreation. One of the major signs of EDS increased incidence, both in humans and other species. Human population health should therefore be in an ecological context as an expression of integrity and are considered health food, support the development of the environment. Ecological imbalances that are triggered by global climate change and other causes responsible for the increased human health risks. Climate change and vector-borne diseases. The global infectious disease burden in the order of several hundred million cases per year. Many vector-borne diseases are climate sensitive. Malaria, dengue fever, hantavirus pulmonary syndrome and various forms of viral encephalitis are all in this category. All these diseases are the result of arthropod-borne viruses (arboviruses) are transmitted to humans as a result of bites from blood-sucking arthropods. Global climate change, particularly as it impacts both temperature and rainfall has a strong correlation with the prevalence of vector-borne diseases. For example, viruses transmitted by mosquitoes, ticks and other bloodsucking arthropods generally have increased transmission rates with rising temperatures. St. Louis encephalitis (SLE) is used as an example. The mosquito Culex tarsalis carries this virus. The proportion of bites that the outcome is dependent on the transmission of SLE on the temperature, with greater transmission capacity at higher temperatures. The temperature dependence of vector-borne diseases is also presented with malaria. Malaria is endemic in the tropics, with a high prevalence in Africa, the Indian subcontinent, Southeast Asia and parts of South and Central America and Mexico. About 2nd 4 billion people live in areas of risk associated with about 350 million new infections per year, which was approximately 2 million deaths, mainly in young children. Untreated malaria can lead to a lifelong passion common symptoms are fever, headache and malaise. The climate sensitivity of malaria caused by the nature of the interaction of parasites, vectors and hosts, all of which affect the ultimate transmission to humans. The gestation period for the parasite required to fully within the mosquito host (a process be developed sporogony) is eight-thirty-five days. When the temperatures are in the range of 20 ° C to 27 ° C, reduced the pregnancy. Rainfall and humidity also influence exercise. Both drought and heavy rains tend to reduce the population to be used by mosquitoes as vectors for malaria. In drier areas of the tropics, low rainfall and humidity limits the survival of mosquitoes. Severe flooding in scouring of rivers and the destruction of habitats for the breeding of the mosquito vector result, while the average rainfall increases vector production. Ecological imbalances. Cholera is a severe and potentially fatal disease that is caused by the bacterium Vibrio cholerae. While not nearly as widespread as malaria, there are cases, but, numerous. In 1993 there were 296,206 new cases of cholera reported in South America, 9280 cases were reported in Mexico, 62,964 cases in Africa, and 64,599 cases in Asia. Most of the outbreaks in Asia, Africa and South America have emerged in the coastal areas. Symptoms of cholera include explosive watery diarrhea, vomiting and abdominal pain. The recent pandemic of cholera affected regions more than at any previous time in the twentieth century. The disease remains in India, Bangladesh is endemic, and Africa. Vibrio cholerae was found in the United States in the Gulf Coast of Texas, Louisiana and Florida, the Chesapeake Bay and the California coast. The increase in the prevalence of V. cholerae has been strongly linked to degraded coastal marine environment. Nutrient enriched coastal waters warmer, cholerae, which stems from a combination of climate change and the use of fertilizers, provides an ideal environment for reproduction and distribution of V.. The recent outbreaks of cholera in Bangladesh, for example, are closely correlated with higher sea surface temperatures. V. cholerae on the surface of both freshwater and marine copepods basket (crustaceans), and for the roots) exposed surfaces of macrophytes (aquatic plants, such as water hyacinth, the most abundant aquatic plant in Bangladesh. Nutrient enrichment and warmer temperatures lead to algae blooms and an abundance of macrophytes. The algae provide abundant food for copepods, and copepods, and the increasing macrophyte populations provide V. cholerae with habitat. Subsequent distribution of V. cholerae in estuarine and fresh water makes contact with people who use these waters for drinking and bathing too. Global distribution of marine pathogens such as V. cholerae unloading is facilitated by ballast water of ships. Ballast water contains a virtual cocktail of pathogens, including V. cholerae. Two other examples of how ecological imbalances to the detriment of human health concern, the increased prevalence of Lyme disease and hantavirus pulmonary disease. Lyme disease, sonamed because they only had a positive impact on Lyme, Connecticut, to be identified, is a debilitating arthritic-type disease, the spirochete is transmitted by infected Ixodes ticks (deer ticks). Ticks to buy the infection of rodents, and spend part of their life cycle on deer. Three factors have helped to reduce the risk to humans of contracting Lyme disease increase, especially in North America: (1) the elimination of natural deer predators, particularly wolves, (2) reforestation of abandoned agricultural land is more favorable habitat made for deer, and (3) the creation of suburbs to find the ideal habitat for deer browsing. The result is an increasing deer population increases, the chances of people coming into more contact with ticks. Until 1995, in the southwestern United States, hantavirus infection was confirmed in ninety four persons in twenty states with 48 percent mortality rate. Variants of the strain that causes hantavirus pulmonary syndrome have been found in other regions of the country, as well as in Asia and Europe. The virus is apparently asymptomatic in rodents, and it is transmitted in their saliva and excreta. When people have a flu-like presentation, followed by acute respiratory distress syndrome. The primary reservoir in the Four Corners area in the southwestern United States is the deer mouse. Climatic disturbances) are designed in recent years, exacerbated by human activities (eg global warming, the creation of conditions appear to trigger outbreaks. To develop in the early 1990s, ENSO events initially caused drought in the southwestern United States. This led to a decline in plant and animal populations, including the natural enemies of the deer mouse. Heavy rains followed by drought in 1993, resulting in a record harvest of Piñon nuts, a major food supply for the deer mouse. Then, the deer mouse population greatly increased, thus increasing contacts with people on, and the start of the outbreak of the hantavirus. Antibiotic resistance and antibiotic resistance in agricultural practice is a growing threat to public health. Antibiotic-resistant strains of Streptococcus pneumoniae, a common bacterial pathogen in humans and a leading cause of many infections, including chronic bronchitis, pneumonia and meningitis, have greatly increased in prevalence since the mid-1970s. In some regions of the world, to be shown to 70 percent of bacterial isolates from patients resistant to penicillin and other b-lactam antibiotics. The use of large quantities of antibiotics in agriculture and aquaculture seem to have an vital factor in the development of antibiotic resistance of pathogens in farm animals were subsequently may also infect humans. One of the greatest threats to human health from such practices is vancomycin-resistant enterococci. The use of avoparcin, an animal growth promoter, appears to be at risk, the benefits of vancomycin, the last antibiotic effective against multi-drug-resistant bacteria. In areas where avoparcin was used, as in the farms in Denmark and Germany, vancomycin-resistant bacteria were detected in meat sold in supermarkets. Avoparcin was subsequently banned by the European Union. Another example is the use of ofloxacin with chickens to protect against infection and thereby improve their growth. This drug is closely related to ciprofloxacin, one of the most commonly used antibiotics in the year 2000. There have been cases of resistance to ciprofloxacin are directly related to its veterinary medicines. Developed in the United Kingdom, ciprofloxacin resistance in strains of Campylobacter, a common cause of diarrhea. Multi-drug-resistant strains of salmonella have been attributed to European egg production. Food and Water Security. Agricultural practices are also responsible for a growing number of threats to public health. Some of these are the inadequate waste management, the parasites and bacteria in the water supply has led to stand in context. Others are from very different backgrounds and involve apparent transfer of types of pathogens that can affect both animals and humans. The latest and most spectacular example is mad cow disease, known as variant Creutzfeldt-Jakob disease in humans, a neuro-degenerative condition that, in humans, is ultimately fatal. The first case of Bovine Spongiform Encephalopathy (BSE), the animal form of the disease was identified in southern England in November 1981. In autumn 2000, an outbreak had occurred in France, and isolated cases appeared in Germany, Switzerland and Spain. More than a hundred deaths in Europe were attributed to what will be called too frequently mad cow disease. Improper manure management was the most likely cause for the outbreak of E. coli 0157: H7 in Walkerton, Ontario, Canada. Other health risks associated with malfunctions agroecosystems context are periodic outbreaks of cryptosporidiosis, a parasitic disease that is spread by surface runoff contaminated by faeces from infected cattle. The parasite causes fever and diarrhea in immunocompetent individuals and severe diarrhea and even death in immunocompromised persons. Ecosystem restoration Ecosystem pathology in some cases simply be undone by the source of stress. In cases, for example, if the deterioration of the ecosystem is the result of a point-source additions of nutrients or toxic chemicals, depletion of these stresses can lead to considerable recovery of ecosystem health. A classic case is Lake Washington (near Seattle, Washington). This lake had strongly anoxic (oxygen-poor) due to sewage flows into the lake. Redirecting the sewage estuary from the lake and conversely many of the signs of pathology. Remove In the cases where it is not possible, the source of stress, more innovative engineering solutions have been tried on. For example, in the Kyrönjoki Lestijoki and rivers in western Finland, spring and fall runoff leads to sharp pulses of acidity. Appointed Spring runoff of melting water, the acid from releases or dug soils, is particularly harmful to the fish during the critical time of year to spawn. Fish reproduction is severely limited, if not eliminated all together in highly acidic water. Furthermore, there were massive fish kills were from the highly acidic waters. One possible remedy is to replace the original drains to take the runoff from the land to the rivers with new limed drains that can neutralize the acid. This solution was introduced on an experimental basis and appears to significantly reduce acid drainage. More radical treatments for hurt ecosystems involve “ecosystem surgery.” In some cases, invasion of exotic vegetation (eg mangroves in Hawaii) were removed from regions and the native vegetation has been replanted. In regions of North America where wetlands have been severely depleted by agriculture, urbanization and industrial activity, efforts have been made to make new wetlands. In most cases, but, not backward ecosystem is not possible to go pathology. Efforts to return the indigenous grasslands of the Jornada Experimental Range in the southwestern United States provide an example. Overgrazing by cattle has greatly reduced and the landscape has led to the replacement of native grasses by largely inedible shrubs, dominated by mesquite. Episodic erosion by wind and heavy rains have left areas between shrubs largely free, and subsequently developed in the underlying sand dune, like fashion over a large part of the territory. The resulting Mesquite sand dunes have been very resistant to efforts to restore native pastures, although nearly every intervention has been tried, including highly toxic defoliants (Agent Orange), fire and bulldozers. Even where it was possible to restore some of the ecological functions of ecosystems, and thus better health of ecosystems, the restoration often results in restoring the original living community. The best that can be achieved in most cases, the re-establishment of vital ecological functions that provide the required ecosystem services, such as the regulation of water, primary and secondary productivity, nutrient cycling and pollination. In all these efforts, the most vital indicators of ecosystem health (strength, productivity and resilience) are essential to monitor progress. Standard environmental indicators will be used for this purpose (eg, measures of productivity, species composition, nutrient cycling, soil fertility) and socio-economic indicators and human health. Experience strongly in the efforts to restore hurt ecosystems suggests that ecosystem-health prevention is far more effective than restoration. For marine ecosystems, with the exception of protected areas that provide refuge for fish and wildlife, is very promising. Many countries have policies on these areas with the prospect that these healthy regions in a reservoir for biota that can be used depleted in the unprotected areas to save her. But this remedy is not without limits. Restoring ecosystem health is not just a matter of replenishing lost or hurt biota. BIBLIOGRAPHY