Frog Population Decrease Indicates Our Planet Is at Risk
In ecology and environmental studies, scientists have discovered indicator species that give evidence or some aspect of the environment. Frogs are an indicator of the health of an ecosystem. In ecosystems frogs are sensitive to the quality of the water and the organisms that live in it. They are also an important link in the food web as a food source for larger animals, fish, and birds.
Frog populations world-wide are plummeting, and scientists are concerned that this condition is an indicator of some wider threat that has not been identified yet. Since the decrease in frog populations is so pervasive, it seems probable that the source of the frog decline is not local, but global. There are over 6000 frog species, and a third of them are endangered or near extinction. Some species have disappeared altogether.
There are six possibilities implicated in the loss of frogs in the world.
1. Destruction of wetlands. Much wetland habitat has been drained in an attempt to produce more land for construction and development.
2. Water contamination and acid rain. Lakes, rivers, and streams catch runoff containing elements and contaminants that directly affect frog populations and reproduction
3. Non-native predator species. Aggressive and voracious aquatic species that are not native to local habitats have been introduced and are out-performing the native creatures.
4. Natural population variation. There are natural rises and declines in populations. That could mean this is not as severe as it seems.
5. Saprolegnia, a fungal disease common in hatcheries. It has spread from hatcheries to the fish and frogs in lakes and streams.
6. Loss of Ozone. Lack of the Ozone layer in the atmosphere is responsible for some cancers. Scientists do not have enough information to know what the effect of the sun is on the frogs that have a thin, water permeable skin.
Frog populations in California have been hard hit, and reasons cited are similar to those above: pesticides, introduced trout, invasive bullfrogs, and a deadly chytrid fungus that is being transported around the world by human activities. Save the Frogs! is a foundation in California that studies and documents the plight of frogs. Another problem they cite is over-harvesting for pets and as a human food source.
Jasper Carlton, director of the Biodiversity Legal Foundation in Utah has expressed concern that the extreme decline of frog populations in Utah predicts a system collapse, and the frogs are the aquatic version of the canary in the coal mine whose death indicates the presence of lethal gas.
Find out more about this important environmental issue at these sites: