Problems related to ecosystem degradation
Introduction | Centers of Pollution and Sensitive Areas | Perceived Major Problems and their Root Causes | Analysis of the Problems and their Root Causes | Relevant Information and Detailed Analysis of the Problems | Location Map | Figures | Tables
The degradation of ecosystems is an environmental problem that diminishes the capacity of species to survive. This degradation occurs in different ways and is manifested in a reduction in the richness of the ecosystems as well as their biological diversity, and in the goods and services they can offer, thereby affecting indigenous and/or migratory species. The degradation of ecosystems due to overexploitation of their resources, though serving a short-term economic goal, has had direct negative effects on social welfare in the medium and long terms. As long as the ecosystem is not degraded, it represents a source of wealth for society, hence the importance of keeping it in good condition.
One of the main causes that contributes to the degradation of ecosystems is the deforestation due to the advance of the agriculture frontier and inappropriate forest exploitation. More lands are deforested for commercial agriculture and live-stock rearing, and due to overexploitation of forest for wood and energy. In Nicaragua deforestation rates reach over 150,000 hectares per year and in Costa Rica over 18,500 hectares per year.
At a lower scale, another problem is the uncontrolled fires used to prepare land for agricultural activities or to remove forest for the development of stock rearing areas. This practice eliminates the organic covering of the land, making it more susceptible to erosion by both wind and water. In addition, the fires cause health problems and detract from the aesthetic value of the landscape.
Accidental or natural fires are another case in point. They affect areas of natural forest. In the Upala and Los Chiles cantons, in Costa Rica, some 10,000 hectares were burned between 1998 and 1999. This problem is even more serious in the Nicaraguan territory of the basin.
Equipment is lacking and communities need to be organized to control these fires as one of the main barriers to the burning of large areas.
The construction of roads without proper drainage measures or in territories subject to penetration and settlement are high-stress factors for ecosystems, especially those which are highly fragile as a result of their weather conditions and the nature of their soil and water.
Mining and the extraction of construction materials without taking measures to cushion the impact cause drastic changes in the natural landscape while degrading its valuable ecosystems.
Wetlands are very fragile ecosystems that are being severely affected, causing a reduction in the number and diversity of the species of terrestrial flora, birds, reptiles, mammals, fish, and crustaceans. This problem results from excessive exploitation of wildlife species either to feed the population, to trade their furs, or to trade live species, and from sedimentation, which causes changes in water quality, thereby significantly affecting the reproduction of aquatic species that live and/or reproduce in the wetlands.
The SJRB wetlands are very valuable ecosystems, which regulate the hydrological cycle and provide food and shelter for hundreds of species, including large quantities of migratory birds. One major cause of the deterioration of this ecosystem is the draining of wide areas of wetlands to give access to agricultural zones or human settlements. Aerial photographs of the Caño Negro sector show how the pools of water have diminished over time, due in part to the drainage of wetlands for agricultural purposes and to the sedimentation occurring in recent years in the basin. Owing to the deterioration of these areas and the pressure of the neighboring communities on the use of the natural resources of the wetlands, it is necessary to draw up management plans to outline the socioeconomic characteristics of users and guidelines for usage, since people are highly dependent on these resources for their survival. A large portion of the ecological problems of the wetlands is due to ignorance of their benefits.
The use of inappropriate fishing techniques endangers the existence of certain species, altering the food chain of aquatic fauna and consequently deteriorating the aquatic ecosystems. This is the case of the bull shark that is now hard to find in Lake Nicaragua or in the San Juan River. In some cases, the introduction of exotic species endangers the existence of indigenous species with a high cultural value. Such is the case of the guapote, whose numbers are being reduced by the introduction of tilapias. The deterioration of ecosystems is exacerbated by the lack of an institutional presence in the territory, be it for technical or economic reasons, or a combination of both. As a result, laws on the regulation and control of natural resource use are not enforced. The participation of civil society in controlling the use and exploitation of natural resources is limited and, in many cases, very timid or markedly apathetic.
One aspect that has not been evaluated in the degradation of the ecosystems is the incidence of different phenomena on these systems. The geographic location of the SJRB and the various geographic accidents encountered there render it susceptible to the impact of various events of this kind. In the SJRB there are a number of active volcanoes, which spew gas and ash causing damage to the plant life, the soil, polluting water bodies, and causing severe damage to entire populations. These volcanoes include the Masaya, the Maderas, and the Irazú. Another natural phenomenon in the SJRB is landslides which, though located in specific areas, cause damage to the ecosystems, the soil, pollute water bodies, damage infrastructure and entire settlements. The Maderas volcano on the island Ometepe is a case in point.
Similarly, during the last century, the SJRB has suffered the destructive effects of at least three hurricanes which, with their heavy rainfall, cause flooding damaging ecosystems, eroding soil, diverting river courses, causing severe damage to infrastructure and entire populations, resulting in the loss of human lives. Other natural phenomena that have caused damage to the ecosystems of the SJRB are the droughts that have occurred as a result of the El Niño and seismic activity, which have changed river courses, particularly in the case of the Tipitapa River that provided a permanent connection between the Managua and Nicaragua lakes. As a result of an earthquake during the last century, the riverbed rose in a certain sector cutting off the existing connection between the two lakes.
The degradation of the ecosystems makes the economic and social infrastructure of the SJRB more vulnerable and increases the potential impact on the population. This vulnerability is reflected in shorter periods between the occurrence of floods or droughts and the soil becomes more unstable. Possible solutions to the problem of deterioration of the ecosystems include developing formal and informal environmental education programs to make farmers more aware of their actions; increasing enforcement of the existing legislation; promoting proper natural resource management; and promoting the organization of grassroots groups to control burning from the outset. To prevent or mitigate the damage caused by extreme conditions, such as flooding and droughts and other effects of natural phenomena, it is necessary to set up and early warning system about possible swelling of water bodies and to monitor hydrometeorological behavior. It is also necessary to set up a seismographic network to monitor the behavior of volcanoes and tectonic faults. Similarly, social organization is necessary to design and test emergency plans for natural phenomena, to reduce the damage they cause.
Institutions responsible for the control and regulation of natural resource use must be strengthened, both technically and economically, and be given the means for their mobilization. This would enable them to have a real presence in the territory. It is also necessary to create mechanisms for enforcing the current legislation.
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