Ask Jimmy and the Bug

Jimmy and the Bug
there is a picture of Jimmy with his arms in the air with salty fries.

Hey Bug! Taylor C., Grade 4, wants to know: “Why is the ocean salty?”

Seawater contains lots of dissolved chemicals, including the one you shake over your fries. Sodium chloride—better known as table salt—is the most common of all the chemicals found in the ocean. There are about 35 pounds of it in every 1,000 pounds of seawater. That's enough to cover the entire planet with a layer of salt 500 feet high—as tall as a 50-story skyscraper.

there is a drawing of Bug
There is a picture of Bug a TV with a view of mountains and an ocean.

Where does all the salt in the ocean come from? Nature “weathers” rocks and grinds down mountains, releasing locked-in mineral salts. Rain and melting snow carry these chemicals into rivers and out into the sea. Also, hot water (hydrothermal) vents on ridges in the ocean floor pump chemical-rich water into the sea. Even underwater volcanoes add salt to the ocean.

Freshwater in streams, rivers, and lakes contains salt, too—about one pound in a thousand pounds of water. It doesn't taste salty because the concentration, or amount, of dissolved salt is too low for the taste buds on your tongue to detect. In most lakes, water flows in one end and out the other, keeping the salt concentration low. But salt can build up in lakes if they have no outlets. The Great Salt Lake in Utah is 10 times saltier than the ocean. When water flows into the Great Salt Lake, it can't flow out. Some water escapes by evaporation, but the salt it contained is left behind.

there is a drawing of Bug
there is a picture of Jimmy holding a giant salt shaker.

A little salt goes a long way!


  1. The oceans contain many useful materials. Salt is harvested from the ocean by people around the world. In addition to flavoring food, how else do people use salt? Name and describe two other uses for salt.
    [anno: Answers will vary but could include that salt is put on roads to melt ice in the winter, that it is used to cure certain meats, or that it is used as a preservative.]
  2. What other nonliving materials do people use that come from lakes or oceans? Name and describe the uses for two other nonliving materials that come from lakes or oceans.
    [anno: Answers will vary but could include that people use freshwater as drinking water and stones from lakes for building materials.]