From Ecopedia

Overview

Water, a ubiquitous liquid composed of oxygen and hydrogen, is an essential element to life on earth.

Covering 71% of the planet’s surface, water continually moves through a water cycle, wherein water keeps changing states from liquid to gas through evaporation and flows back to rivers, lakes, ponds and oceans in the form of rain through condensation.

Depending on the temperature in which it is exposed to, water may take many different forms in nature such as vapour, clouds, sea water, icebergs, glaciers, hail, rain, and snow. ^[1]

Environmental Impacts

Safe and pure drinking water is essential to sustenance of all life forms on earth. However, several anthropogenic activities lead to water pollution, thereby impeding access to clean and safe drinking water.

Water Pollution

Water being a good solvent dissolves a large number of salts, sugars, alkalis, acids and several gases such as carbon dioxide (CO2) and oxygen (O2). This property of water also allows various pollutants to get dissolved in water causing water contamination and many environmental hazards.

Additionally, the presence of pathogens, microbes, toxins and chemical contaminants in water also causes water contamination, threatening the existence of various biological communities on earth.

Water contamination caused by organic and chemical pollutants is posing great threat to the ecological balance of the earth as contaminated water greatly damages plant, animal and marine life as well.

Most of the contamination could be attributed to many anthropogenic activities such as industrial activities, which discharge a large number of environment-harming chemical compounds into water, causing great harm to plant and animal development, besides affecting the health of other naturally occurring biological communities.

Oxygen-depletion

Ever increasing levels of water contamination is leading to depletion of oxygen content in water (anoxia), as a large number of chemicals present in the water absorb more and more oxygen.

Oxygen-depletion severely affects fish and other animal populations, thus, causing ecological imbalances in nature.

Untreated Waster Water and Ocean Debris

All untreated waste waters across the world enter local river streams and seas causing contamination of surface water bodies and ground water resources alike.

Human-created marine waste and deliberate ocean dumping by humans is greatly endangering the existence of sea plants and sea animals including fish, marine mammals, seabirds, marine reptiles and many more.

Human-induced waterborne plastic is especially shown to cause digestive tract obstructions in marine animals, leading to severe starvation and death.

Especially in Russia and China, industrial pollution led to the release of heavy metals and phenol into the Amur river, damaging the river’s estuary soil and completely devastating the fish population.

Even in Alberta’s Wabamun Lake in Canada, lake water contamination led to unacceptable levels of heavy metals to occur in the sediments of the lakes and inside the bodies of fish stocks.

Anthropogenic water pollution is thus causing significant reduction in marine biodiversity and productivity.

Ocean Acidification

Global climate changes are constantly raising the temperatures of ocean bodies, besides increasing carbon dioxide levels in the atmosphere. Although, oceans act as natural carbon sinks by absorbing atmospheric carbon dioxide, excessive levels of carbon dioxide in the oceans is resulting in ocean acidification.

Ocean acidification, is leading to alteration of aquatic ecosystems, besides modifying the distribution patterns of fish populations. Moreover, calcium carbonate structures are also susceptible to oceanic dissolution, affecting the shell-forming capabilities of shellfish.

Healthier, acid-free ocean ecosystems are thus, essential for mitigating environment-harming climate changes across the globe.

References

1. ↑ http://en.wikipedia.org/water