Book 6, Question 145
Why Do Ships Have Rules About Ballast Water?
Ships take in ballast water to stay balanced, and let it out later. That water can carry tiny animals, plants, and larvae across the ocean. A ship's belly can sneak a whole zoo from one harbor to another!
From the book
Page from A Million Whys Book 6
More fun facts
- Ships carry ballast water so they are not too top-heavy and do not tip over.
- Many sea creatures live in the ballast water ships carry across oceans.
- When ships let out ballast water, some of those hitchhikers can become invasive species.
- In the late 1980s, tiny crab larvae reached California in water dumped by big ships.
- Now ships must swap their ballast water out in the open ocean or clean it with treatment systems on board.
- A mid-ocean swap happens at least 200 nautical miles from land.
Sources: Smithsonian, Smithsonian
Questions kids ask
What is ballast water?
It is water a ship carries to stay steady so it does not tip over.