Water can be found pretty much everywhere on Earth. Roughly 71% of the Earth's surface is covered by water, both freshwater and saltwater. However, about
96.5% of all water on Earth is held in the various oceans around the world.
There are now 5 named oceans. They are listed below:
Atlantic Ocean
Artic Ocean
Pacific Ocean
Indian Ocean
Southern (Antartic) Ocean
Obviously, not every body of water is an ocean. Other bodies of water include rivers, lakes, streams, seas, and many others!
Unless you live next to a sea or ocean, the water nearest to you is freshwater. Freshwater and saltwater are different for a couple reasons. Freshwater is typically
found in lakes, rivers, etc. and it is called freshwater because there is a low concentration of salts compared to saltwater. Freshwater is drinkable upon being sanitized,
and is also used to irrigate crops.
Saltwater is what is found in the ocean or sea, and it contains a high concentration of salts which make it unsafe to drink. Saltwater also is home to many of the sealife
that you find at the beach. Animals such as sharks, whales, lobsters, and tuna can be found living in saltwater.
How Does Freshwater and Saltwater Interact With Each Other?
When under natural conditions, the movement of freshwater prevents saltwater from encroaching on coastal aquifers. The area where these 2 types of water meet is a zone where
they mix together. But, because the freshwater is lighter (also known as less dense) than saltwater, it creates an estuary. Freshwater in an estuary is less dense, meaning that
it often times will float on top of the salt water from the ocean.
Pictured above is an example of freshwater meeting saltwater.
Some animals are able to live in this mixture of water. These animals include sharks, such as the Bull Shark which actually births its offpsring in rivers to keep them safe
from predators. There have even been records of Bull Sharks being found dozens of miles upstream in rivers like the Mississippi River! Most animals cannot live in both types of water,
and it takes millions of years of evolution for species of aquatic life to be able to handle both types of water.
