Transboundary Diagnosis Analysis - Tables
Threats to Biodiversity

Threat to Biodiversity

consequences

Hunting and fishing

 Loss of wildlife: white tailed deer (Odoicoleus virginianus), tapir (Tapirus bairdii), armadillo (Dasypus novemcinctus) and (Cabassous centralis), white-lipped peccary (Tayassu pecari), collared peccary (Tayassu tajacu), various species of monkeys like the mantled howler monkey and spider monkey (Alouatta palliata) and (Ateles geoffroyi), the agouti (Dasyprocta punctata) and the paca (Agouti paca); considered to be important cynegetic species. Other species have been hunted for their skins, particular spotted felines like the jaguar (Panthera onca), the margay (Leopardus weidii), the ocelot (Leopardus pardalis), and the oncilla (Leopardus tigrinus), the alligator or caiman and the crocodile (Caiman crocodilus y Crocodilus acutus). Birds like the great tinamou (Tinamus major), several species of duck like the great currasow (Crax rubra) and others are used for food. Fish include the cichlid Cichlasoma dovil and other species, tarpon (Tarpon atlanticus), sea bass (Centropamus spp) and gar (Atractosteus tropicus). Most of these species are in danger of extinction or seriously threatened.

Hunting: Illegal hunting is widespread in the basin, even in the protected areas. Hunting for sport is regulated by the MARENA and MINAE, but without a thorough understanding of population dynamics there can be no sustainable exploitation of the resource. This results in problems for the management of wildlife species and causes the destruction of natural habitats of noncynegetic wildlife species in favor of more usable habitats (burning of pastureland and forests). Subsistence hunting with no prohibitions or periods of protection also occurs.

Fishing: Indiscriminate fishing has caused the shark to disappear from Lake Cocibolca. The worst problem afflicting the maritime zone is also the fishing of shark and other species, and the destruction of reefs.

Logging and deforestation

 Destruction and disruption of the natural environment with the felling of mature trees (even if this takes place under management plans). Many species are affected by both the felling of trees and shrubs and by the noise of machinery, the cutting of roads, and by pollution from fuel, waste, and garbage.

Erosion and pollution: Caused by logging which, along with the cutting of roads, provides access for further extraction, with a high risk of water and soil pollution.

Fragmentation of habitats: A high and intensive occurrence in some zones of the basin (Pacific region of Nicaragua and San Carlos plains in Costa Rica). The ability to maintain complete and complex ecosystems is substantially reduced with the reduction in the size of the reserve.

Recurrent burning of pastureland

 Generally performed with a view to introducing exotic species of grass (Hyparrhemia rufa, Panicum maximun, and Panicum purpurescens), which, together with various trees, shrubs, and palms resistant to grazing and burning form the typical vegetation of the savannas.

Changes in land use: for the purpose of large scale livestock rearing, thereby causing the disappearance of large expanses of dry and rain forest in the basin.

Soil erosion: causes the exhaustion of nutrients, silting, migration of rural populations to the urban areas, displacement of farmers, and changes in land holding as a result of changes in land use.

Destruction of secondary forests, wooded corridors, or primary forests when blazes flare out of control or escape during the burning of pastureland. This also causes air pollution.

Mining activity

 Opencast mining, common in Latin America, involves methods that cause serious pollution, have widespread adverse effects, especially on the aquatic environment, destroying aquatic and land habitats. Mining settlements cause environmental damage and side effects for the health of the population. The extraction of construction materials (stone and sand) has caused the disappearance of aquatic and riparian habitats in the northern zone of CR.

As a result of the heavy environmental stress caused by these works, despite the environmental impact assessments, this activity causes problems of sedimentation, pollution, loss of habitats, and the disappearance of numerous species of fish, mammals, birds, and invertebrates. No plan has been implemented to restore these sites.

Damming or rerouting of groundwater

 Modification or rerouting and damming of watercourses for power generation, irrigation, or water supply is an activity that has a strong effect on the ecology of the area. Fish migrations are affected by the damming of rivers, even in areas far away from the dams. This also leads to shifts in human settlements, the construction of roads and highways, and the loss of wide expanses of forest by flooding.

Intensive agricultural production requires irrigation projects which, in many cases, cause erosion problems, with the resulting sedimentation in the dam and loss of useful life. Hydraulic projects for energy production and irrigation have a heavy environmental impact in ecological terms.

Unplanned and makeshift settlements

 The growth of urban centers and settlements and the encroachment of farmlands are some of the causes of the isolation and insularity of protected areas. This exerts pressure on the ecosystems and the species they support.

Large settlements of more than 30 families exert intense pressure on the protected areas (unlawful hunting, etc.) and cause water pollution, if there is no control of solid and liquid effluents, with the resulting deterioration or disappearance of aquatic or land ecosystems.

Opening of roads and highways

Road and highway infrastructure in the northern zone of Costa Rica and in the western zone of the Indio-Maíz Biological Reserve in Nicaragua, is laid before areas are opened up for agricultural development. The resulting problems are as follows: the roads are used by logging companies to gain access to new areas for forestry resource use; population growth is caused by the influx of non-farming settlers with the resulting division of the land into plots; and there is a heavy environmental impact caused the mechanical process of road construction, especially on aquatic ecosystems and more specifically on rivers..

Introduction of exotic species

These have a strong impact on the integrity of ecosystems, especially inside and on the periphery of protected areas. The introduction of the water lily (Eichhornia crrassipes) originally from Brazil, is causing clogging problems in the Tortuguero canals, Barra del Colorado, and the canals of the Indio-Maíz reserve. The introduction of the tilapia (Tilapia mossambica) originally from Africa, competes with the native communities of fish in lakes and lagoons.

Pollution from agricultural chemicals, fuels and other products

 Crops are cultivated up to the very banks of rivers, causing problems of erosion and pollution. Aerial spraying of agricultural chemicals in Costa Rica causes pesticides and fertilizers to directly impact on water bodies.

Aquatic transport can be a huge pollutant due to spills of fuels and air pollution. Numerous hot spots and more diffuse pollution by fuels and oils in the rivers can be observed.

Erosion and soil loss

Deforestation and inappropriate management of agriculture and livestock—often extended up to the very shores of the rivers—with no planning and control are the main causes of the high level of soil erosion in the basin. This mainly affects the rivers, with the resulting deterioration in the quality of water resources.

Inappropriate agricultural practices

Slash and burn agriculture is a traditional method of preparing the land for cultivation. Rotation is not practiced and there is poor management of the land on slopes, which causes degradation and loss of its agricultural capacity.

Heavy river traffic

Navigation is one of the principal methods of invasion of protected areas. Aquatic routes are used for trafficking in species, for illegal fishing and hunting, for collecting forest species, for transient farming, and unregulated tourism.

Land holding problems

The lack of land ownership results in relocation, mobility of human groups, and transient farming. Such situations are difficult to resolve in both social and economic terms. This is more important in the areas adjacent to protected areas, which become a ready source of meat and firewood consumption, in particular.

Lack of a unified conceptual framework for categories of protected area management

 The problems of financing for the conservation of biodiversity have resulted in a system of protected areas that cannot meet the long-term objectives.

The reality of conservation in Costa Rica and Nicaragua, regarding the San Juan River Basin, can be summarized as insufficient to ensure that representative ecosystems in the basin survive intact.

In relation to the management of protected areas, there are many conceptual shortcomings in terms of design, the failure to delimit buffer zones, and low budgets for the development of infrastructure and training, incompatible economic development policies and conservation goals, and inconsistencies in the application of conservation and management concepts and strategies.

Development of adjacent or surrounding areas

There are no plans for regional management and development, hence no guarantee that havens for flora and fauna, ecosystems, or complete regions will be conserved in the absence of an overarching plan.

 

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