The best way to learn about the beach is to visit the beach.  Whether or not you have the chance to visit a beach with your child, here are some great beach themed ideas you can try at home with preschoolers…
Ocean Science Activities
http://littlebinsforlittlehands.com/6-awesome-ocean-science-activities-kids/


Children love to bring home their beach treasures. How great is it that many of the shells come onto the shore predrilled with a little hole perfect for stringing onto a beach necklace! You can see them in the picture above. Many preschoolers (and sometimes their parents) have asked me how that happens. Some mollusks (like whelks or conches) have a special tongue called a radula. The radula is sharp and can be used like a drill to form a perfect little round hole in the shell of a bivalve (an animal with 2 shells that open and close – a clam is a good example). Then the mollusk sucks out the animal. The empty shell later washes up on shore for your child to find and string onto a necklace.
While bringing home empty shells found on the beach is fine, please make sure there is not a live animal inside. If there is your child can help the animal by tossing it back into the sea. If you are not familiar with the animal, don’t handle it. For example, Jellyfish can still sting even if they are already dead.
My biggest tip, if you care about the ocean, is do not buy shells in those big seashell shops. Those are not shells that have washed up on the beach. Huge nets are dragged along the ocean floor, destroying habitat. The live animals are collected. The animals are killed and the shells are cleaned and polished to look lovely in the shops. It’s not just animals that live in shells; all those beautiful seahorses and starfish were captured alive and dried for sale. I cannot even walk into those shops now that I know the reality of the animal harvest without feeling sick to my stomach. I am not trying to upset anyone, but if you care about ocean habitats and animals, you do not want to accidentally support their destruction.
Lola Jane has an excellent post about this topic at…
http://lolako.com/should-you-buy-those-seashells-sold-by-the-seashore-on-beach-walks-seahorses-and-collecting-sea-shells/


Lastly, just like camping in the forest, it’s always nice to leave the beach better than you found it. I do not recommend having preschoolers pick up trash (certainly not on their own) but it is nice to bring a bag to collect a few items like soda or water bottles, which are often left on the beach, so you can put them in the trash. Garbage like plastic bags and balloons with ribbons (see photo above) kill many creatures that children love and are especially a threat to sea turtles. So lets get them off the beach. Cleaner oceans and beaches are more fun for all of us!