Are you looking for some easy ocean science experiments? Don't want a ton of materials and spend tons of money and time gathering supplies for each experiment! Get excited, because we could be besties.
Here are the 10 ocean science experiments we did, for reals with our unit study.
Honesty time-- I lurv science and I lurv science experiments. I don't love getting them all together and buying the most random materials that I will NEVER use again, or have to specialty order and shipping costs more than the freaking product. And I'll NEVER use it again!! And we're eating beans for a month because we've blown our school budget.
So I love simple, easy, cheap experiments that teach the concept, let the kids learn and explore and get excited about the topic.
You'll see all the experiments we did, along with instructions, explanations, and pictures (when I remembered to take a few shots).
Like seriously, I forgot to take pictures of the density experiment, so I will re-do it just for you when the kids are sleeping. The sacrifices I make for those I love (that's you, in case you were wondering).
Salt Water Density
The beginning of the unit study we started learning about and discussing the actual ocean. How big it is, what it's made up of, and more. Salt water and its density seemed like a natural place to start.
- Two clear jars/vases/bowls
- Small toys
1. Fill one jar with plain water.
2. Fill another with water and then add salt. We put in about 1/3c at first. I really wanted this to work, so I put in probably closer to 1/2c. I hate when science experiments don't go as promised. :-/ Stir like crazy.
Our water was lukewarm and Little Miss (8 y.o.) suggested we use hot water to help it mix better.
3. We had a selection of toys, little sea creatures, a medium sized rubber shark, a mega block, and a knight. We started with the knight. I asked them what they thought would happen when I put the knight in the plain water. Then I dropped him in. He sunk. The mega block floated. Then the remaining items all sunk.
Then we added the egg. It also sank.
4. Then I started with the egg in the salt water. They were so excited to see it floating! We added the remaining ingredients and they all sunk. Wah-wah-wah.
The kids suggested adding more salt, and that still didn't help.
This was when I attempted to discuss density. Things with higher density sink and things with lower density float. The salt makes the water more dense making it so that more items are less dense than the salt water, meaning more things can now float.
Why is this important? The kids thought it would help the fish swim and float better. Sweet Cheeks (4 y.o.) thought it would make it so they can float while they sleep. Cute!
Then we discussed why we thought the egg floated when the other objects didn't. The kids and I talked about perhaps it was because there was "liquidy stuff" inside the egg and there's liquidy stuff inside fish too and maybe that's why. Especially since the toys don't have food and blood inside them.
We veered off course a bit and I showed them how taking the Mega Block and a crumpled piece of paper I could put the block into the water and the paper would stay dry. They each had a turn trying it themselves.
We talked about how if you tilted it the water would go inside and the paper would get wet. When they pushed the block into the water I had them go slowly so they could feel the air pressure pushing against their hand.
In the video, Ocean, it briefly mentioned the old methods of exploring the ocean. At one point, explorers would be lowered down in a wooden box that had no bottom to it. This was how they were able to stay down there for a short time without the entire box being enclosed.
Captain (9 y.o.) pointed out water displacement and brainstormed why he thought this was happening.
I loved that despite the lackluster results of this experiment (only the egg floated when I wanted more to float), so I guess it wasn't a flop, really, we were able to get our brains working and thinking about all sorts of things related to what we were doing. To me, this is the essence of science. Curiosity, thinking, and exploring.
Layers of the Ocean
- Mason jar
- Corn syrup
- Rubbing alcohol
- Dish soap (blue)
- Vegetable oil
- Food coloring (black, blue, green, purple)
- 5 Small bowls
- Measuring cup
1. Measure out 3/4c of each liquid. Pour into individual small bowls.
2. Add food coloring to each bowl and mix:
- Black food coloring to the corn syrup.
- Blue to the dish soap.
- Blue & green to the water (keep it lighter than the dish soap).
- Blue to the oil.
- Light light blue to the rubbing alcohol.
3. Add the ingredients slowly and carefully in the following order:
Corn syrup [wc_fa icon="arrow-circle-o-right" margin_left="" margin_right=""][/wc_fa] dish soap [wc_fa icon="arrow-circle-o-right" margin_left="" margin_right=""][/wc_fa] water [wc_fa icon="arrow-circle-o-right" margin_left="" margin_right=""][/wc_fa] oil [wc_fa icon="arrow-circle-o-right" margin_left="" margin_right=""][/wc_fa] rubbing alcohol
4. Add labels to each layer. Done!
Sunlight Zone - rubbing alcohol
Twilight Zone - oil
Midnight Zone - water
Abyss Zone - soap
Trench Zone - corn syrup
Discuss the density of each liquid (relate it back to salt water density experiment). Ask: would salt water be on the same level in this jar as plain water?
I'm not going to lie, I got pretty ticked at this experiment. The dish soap got too dark. Grr. We put 2 drops of red! 2 drops! We were trying to make it purple. Instead, it turned red on top and black everywhere else. Tip: if you have blue dish soap, DON'T dye it at all.
Then the water. Oh the water. It just blended in with the soap. The vegetable oil was separated nicely, though it did bubble up. Then the rubbing alcohol kinda blended in, but made swirls as well.
I let it settle and am hoping to see some separation in the morning. But really, I'm just ticked I wasted 3/4c of dish soap.
Well, the kids did enjoy it, though admittedly, they were sad that it didn't look all awesome and separate. I followed the instructions from Steve Spangler science on how to do the liquid density experiment, but apparently I don't have the correct skill set.
I may do this paper and water jar version instead. Depends on our time and energy level.
We then read the book Down, Down, Down: A Journey to the Bottom of the Sea. It shows which marine animals live in which ocean zone with beautiful illustrations.
We used our plastic sea animals along with the book to determine which zone they are in and made a chart to match.
- Toilet paper roll
- 3 pennies
- Vegetable oil
- Draw a shark on the toilet paper roll (or cut out a shark on paper and tape it on).
- Tape 3 pennies, equally spaced, on the bottom of the toilet paper roll.
- Fill the bowl with water.
- Ask: what's going to happen to the shark? Drop the shark in the water and watch him sink. Discuss.
- Fill a balloon with vegetable oil, tie closed.
- Place the balloon inside the toilet paper roll, evenly.
- Observe: it's much heavier now! Ask: what's going to happen to the shark? Place the shark in the bowl of water and watch him float. Discuss!
The oil in the shark makes him buoyant.
Application and explanation:
ASK: What is holding us to the earth? (gravity). What is gravity?
There is gravity on land AND in the ocean. All the animals in the ocean are being pulled down, just like you are. Gravity holds us to the floor, and all our houses, cars, and toys, too. It also holds the ocean and the animals in the ocean down. But they aren't on the bottom of the ocean floor like you're standing on the floor!
What are they doing? They're floating.
How is this possible? Buoyancy!
ASK: What in the world is buoyancy?
Gravity pulls us down and buoyancy pushes us up! So the fish have made it so they can balance, or float. Many of them have a bladder, kind of like a ball, inside their bodies that is filled with gas. Think of a balloon when it's filled with air. The balloon is that bladder and the air in the balloon is the gas inside it.
Sharks don't have a bladder filled with gas. So what is helping them float? Their bodies do not have ANY bones, instead, they have cartilage. This cartilage is less dense. Remember, when we saw how less dense items floated easier in the water? Your ears and tip of your nose is made out of cartilage, too! Sharks also have a very large liver, and fins that help them steer and stay afloat.
Their bodies are still pretty heavy, of course, heavier and more dense than water. Their fins help them to move forward all the time. They never stop moving!
Their liver is much larger than ours. It's filled with oil, like what we just used in our experiment. It is similar to the bladder in the fish we just talked about. It gives the sharks neutral buoyancy. That means that it's not getting pushed up and it's not sinking down, but staying at the same level.
All of these things combine to help sharks stay afloat and not sink to the bottom of the ocean floor! Pretty cool, huh!?
The kids really loved this one. Their favorite part? Wiggling their ears with wonder as they realized that sharks were made of the cartilage.
How Whales Stay Warm
- 2 Ziplock baggies (sandwich or quart size)
- Rubber band (big enough to fit around hand)
- Fill bowl with water and add lots of ice. You want it cold!
- Scoop a bunch of crisco into the first ziplock bag.
- Place the 2nd bag inside the first.
- Place your hand inside and secure both bags onto your hand with a rubber band.
- Squish the crisco around your fingers and hand. Use your free hand to do help. Don't worry, your hand will stay grease free!
- Place your free hand into the ice water. Yikes!
- Now, place your crisco hand into the water. It's not freezing!
The fat keeps the whales warm!
When I worked at a wilderness therapy program, we lived and hiked in snowy mountains. We'd hike and sleep in near-blizzards. We only had a tarp, sleeping pad, and sleeping bag to keep us warm (besides our clothes). No tents! We ate bacon at every meal. We added butter to our hot chocolate and anything we were making. We ate as much fat as we could every day to help keep us warm.
I still was freezing cold, so I'm not sure how much it helped, but I'm alive so it must have helped some!
They loved this experiment! They were shocked that their hand didn't get cold at all! It was a pretty cool feeling.
Maybe I'll slather myself in crisco when I head to the cold pools this summer? Get a wicked sunburn at the same time. Win-win, right?
You know I'm kidding, right?
- Roasting pan
- Sand (optional)
- Plastic sea animals
- Water (of course)
- Clay/Play doh (optional)
Create a tide pool with your rocks. Look at pictures of real tide pools to see what they look like. Layer and build your rocks. Add sand, if you have it and want to.
You can also use play doh or clay to build up your tide pool.
Add in plastic animals in various locations of your tide pool. Try to add those that would actually be in your tide pool and leave out those that aren't.
Fill with water as the high tide comes in... and then empty as the low tide goes out. Then fill again and play!!
We watched a few videos on tide pools. [insert links]
- Water bottle
- Place sand on one side of the pan. Make it a steep slope
- Pour water into the other side, until it's halfway up your sand slope.
- Place your water bottle on the end with the water. Push the bottle down to create small waves. Do this, consistently and evenly for 1 whole minute. Write down what you observe.
- Push again with your water bottle for another minute. You may make your waves bigger, or keep them the same size. Make observations.
- Empty ketchup bottle (or other narrow-necked bottle with lid)
- Corn syrup
- Blue food coloring
- Vegetable oil
- Long spoon
Fill the bottle 1/4 of the way with corn syrup.
Add a few drops of blue food coloring and mix with spoon handle.
Slowly pour in vegetable oil until the bottle is halfway full.
Put cap on. Make sure it's real tight.
Turn the bottle on its side, tilt it slowly so the capped end is down at a slight angle. The corn syrup will crest in the bottle's neck.
- Mixing bowl
- Cornmeal (a pinch)
Fill the mixing bowl with water, almost to the top.
Sprinkle the cornmeal into the bowl.
Blow steadily across the water surface (not into the bowl). Make sure it's not too gentle or too forceful (you can experiment with wind intensity later).
The cornmeal will be swirled around by the currents just as in the ocean. The northern hemisphere is clockwise and the souther, counter clockwise.
- 9x13 pan
- Ice pack (or baggie of ice)
- Food Coloring
- Fill the 9x13 with an inch of water. Make sure the water is room-temperature (or slightly warmer).
- Set the ice pack (or baggie) against the edge of one side of the pan (inside the water).
- Place 1 drop of food coloring right in front of the ice pack and 1 drop on the opposite side of the pan.
- Observe and discuss.
The drop near the ice pack will move forward because the cold water is pushing the warm water away. The drop on the other side stays there because the cold water keeps it from moving.
- Mason jar
- Craft foam, black & white
- Glue stick
- Black paper
- Cut a 2" square out of the black and white craft foam.
- Glue them together and cut out a penguin shape.
- Fill the mason jar halfway with water and place the penguin, black side down on top of the water. Hold the jar under a light source (lamp, lightbulb, flashlight) and look at the penguin from the bottom of the jar. It should be easy to see.
- Now, turn the penguin over, white side down. Now look through the bottom of the jar again. This is the way penguins swim! It's much harder to see now because the light and the white blend together, making it harder for predators to see from underneath.
- This time, place the jar on top of the black paper. The black paper represents the darkness of the ocean. Take a look from above the jar to see how the black side of the penguin helps blend into the water from this angle!
That wraps up all our ocean science experiments! We had so many great conversations with each experiment and it's always a treasure to hear them talk about and relate other things to the new things they've learned.
As we've studied the ocean these have really added a great depth to their understanding and grasping of each concept. I highly recommend doing as many of these as you can.
If you're on the hunt for even more experiments (simple ones) with accompanying explanations I highly highly recommend the book Awesome Ocean Science! There are many experiments and activities for many aspects of the ocean. It covers all the topics, not just the water portion. I learned quite a bit just thumbing through the book! Seriously, go check it out. You'll thank me later. ;-)