The Science of Water
Alex Feldman & Dan Schapker
There is the same amount of water on earth as there was when the earth was formed. The water that came from your faucet could contain molecules that Neanderthals drank, there has been the same amount of water on earth for nearly 2 billion years. Of all the water on Earth, only 2.5% is fresh water. Fresh water is either groundwater or readily accessible water in lakes, streams, rivers. If all the world's water were fit into a gallon jug, the fresh water available for us to use would equal only about one tablespoon. Over 90% of the world's supply of fresh water is located in Antarctica. Less than 1% of the water supply on earth can be used as drinking water. Any marine biologist studies fresh water as well as others, other job might be an engineer working on a bridge, or someone working with the purified water we drink.
Brackish or brack water is water with a level of salinity between freshwater and seawater. In many places around the world, brackish water appears naturally, and it forms an important habitat for some animal species. It can cause environmental damage, however, since it is harmful for organisms that have not adapted to it. This becomes an issue when such water is deliberately cultivated as in some regions to farm food or fish. It is also unpleasant to drink, and it may cause health problems.
The term "brackish" was first used to describe portions of the water table that had been contaminated by salt water. The mixing of salt and fresh created mildly salty water that was not as salty as seawater, but still distasteful. Many people also noted that the water was harmful, due to microorganisms that cause human illness.
In nature, estuaries are a common site of brackish water. An estuary is a location where salt and fresh water mix, typically around the opening of a river. The estuary environment is quite distinctive, as it bridges oceans and rivers, hosting unique fish, plants, and animals. When the balance of an estuary is disrupted, it can be serious for the animals that call the area home. Many fish appreciate estuaries, because the slow change in salinity allows the fish to accustom themselves. people that need water to survive in the area they live can use brackish water and use a desalination process to make it healthy.