In What Ways Are Humans Impacting the Cave Ecosystems?

Caves have extremely fragile ecosystems that are especially susceptible to the effects of human activity, whether it takes place in the caves or on the surface of land that surrounds them. Home to endangered populations, caves are dark and humid, have cool temperatures and house animals evolutionarily adapted to this unique habitat. When caves get polluted, or when cave critters need to relocate to find food, it has disastrous consequences on the entire ecosystem.

Urban Development

• Urban development in the vicinity of a cave alters the food balance in the ecosystem. For example, public bathrooms installed for tourists need plumbing and a water source, which can create a diversion of water needed by cave life. Leaks from underground pipes pollute cave water with sewage. Fertilizer used on nearby land introduces new nutrients to the soil. Vegetation gets cleared for the construction of buildings, and roads get built. Common spills on those roads -- of cyanide, ink, diesel fuel and paint -- also bring deadly pollution to cave life, according to the Riverina Environmental Education Centre of the New South Wales Department of Education and Training in Australia.

Global Warming

• Global warming increases cave temperature, but cave life thrives in constant cool temperatures. The Riverina Environmental Education Centre notes that there are three parts to a typical cave -- entrance, twilight and dark -- and each increases in fragility the farther it is located from the outside world. According to the Colorado Plateau Research Station at the U.S. Geological Survey, researchers fear global warming will wipe out cave species or send them underground, forcing them to compete with other subterranean inhabitants for sustenance.

Light Changes

• Even the beam from a flashlight affects cave life.

  When cave entrances are widened for tourism, or when a flashlight is beamed inside a cave, the light changes that take place have far-reaching consequences. Lighting systems put in place for tourism encourage the growth of algae, which impacts the food chain by "introducing more food to particular points along the path causing a redistribution of animals," reads the Riverina Environmental Education Centre website. A flashlight beam alone can cause nursing bats to relocate to another cave. Other cave species aren't able to relocate and die when their environment changes.

Visitors

• Humans visitors unknowingly carry harmful features into cave ecosystems, including mold, non-native microorganisms and invasive plants, all of which disrupt the flow of nutrients in the ecosystem. Nutrient stress causes bats to abandon their caves, which in turn disrupts the food supply of animals that depend on bats. The Colorado Plateau Research Station reports that cave sediment can be compacted by visitors' footsteps, reducing fauna productivity and destroying soil micro-habitats.