How Do Mussels Get Their Shells?
We're heading to the coast of Maine to learn a little bit about why the sea is salty and how mussels get their shells with Zach Whitener, a research associate at the Gulf of Maine Research Institute in Portland, Maine.
We also get an answer to a question from 7-year-old Nico in Nashville, Tennessee. He wants to know how you get a ship in a bottle. We meet Colorado-based ship-in-bottle builder Daniel Siemens for an explanation.
"Why is the sea salty?" - Chase, 9, Enfield, New Hampshire.
"The ocean is the bottom of the food chain. Every stream and brook eventually gets to the ocean. Not only things like salt and mud but also your pollution goes to the bottom of the stream. Rainwater is slightly acidic. When it rains, the rain weathers rocks and pulls some of the ions, out of it, different minerals. It's not just salt, but lots of different things. Salt is the most common one. The salt comes from the rocks and it washes into the streams, then the rivers and eventually into the ocean. Since the ocean is the bottom of the line, there's nowhere else for the salt to go and it builds up in concentration."
"It's not just the ocean that's salty. The Great Salt Lake, a famous lake in Utah, is very salty because there's no outlet. There's no river from the salt lake to the ocean. So all the salts from the rain out west, they go into the salt lake."
Also in this episode we learn how to build a ship in a bottle. If you're ready to try building your own, you can find plans here.