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Marine Science for Kids
Exploring and Protecting Our Watery World Includes Cool Careers and 21 Activities
By Josh Hestermann
Chicago Review Press IncorporatedCopyright © 2017 Josh Hestermann and Bethanie Hestermann
All rights reserved.
Getting to Know the Marine Environment
Have you ever stood at the edge of the ocean, looking out across the endless blue, wondering what's out there? Pretend you're there right now. Your toes squish into the wet sand, and the sun is warm on your skin. A cool ocean breeze kisses your face. The air smells like salt and coconut-scented sunscreen. As the water pooled around your ankles gets pulled back to sea, your feet sink further into the sand. A wave comes crashing down and rushes past you with a hissss, spraying your shins with foamy seawater.
As you stand on the beach in your imagination, look out as far as you can. What do you see? Imagine that somewhere on the other side of the ocean, maybe thousands of miles away, there's another kid about your age looking out at the same endless blue. What lies between you and him may look like a bunch of nothing, but really, it's more than you can imagine.
For centuries, humans have gazed toward the horizon and wondered what mysteries the ocean holds. Some have sailed across it, returning home with tales of beautiful mermaids, salty pirates, epic storms, giant swells, spooky shipwrecks, and slithery sea monsters. Others set out to sea and never came back at all. The ocean is a place of fantasy, adventure, and danger. It's a place full of wonder that raises more questions than it answers.
Aboard HMS Challenger
When HMS Challenger set sail from England in December 1872, the scientists on board had an enormous task ahead of them — to learn everything they could about the sea. Challenger sailed for nearly four years across all major oceans except the Arctic, perhaps because the wooden Challenger couldn't take on the icy waters.
Charles Wyville Thomson, the expedition's head scientist, and his team made observations and collected samples at 362 points along the journey. At each station, they measured the depth of the seafloor, took the water temperature, observed the speed and direction of ocean currents, and gathered samples of living things at different depths.
After the expedition ended in May 1876, scientists pored over the information and examined the samples brought back by the Challenger team. They compiled the results of the journey into a 50-volume report.
The 1872-1876 Challenger expedition was the first to accomplish ocean research on such a big scale. To this day, it is one of the most important events in the history of marine science. Even though Challenger's crew did not have access to the same technology that scientists have access to today, much of the data they collected was accurate.
Humans are drawn to the sea because it makes us curious, but we also depend on it for food and other resources, as well as transportation. The ocean helps make life on Planet Earth possible. It absorbs heat from the sun and moves this heat around, keeping temperatures on land from becoming too extreme. The tiny marine plants that live in the ocean create oxygen that humans and other land animals breathe.
Even though humans can visit the underwater world, we haven't spent enough time there to know all of its secrets. Marine scientists, people who study marine science, help fill in the gaps by learning about the ocean, marine ecosystems, and marine life.
A Stroll on the Ocean Floor
If you could take a stroll along the ocean floor, would it be flat or hilly? Would there be tall mountains and steep cliffs like there are on land? By using sonar to map the seafloor, scientists know the answer to this last question is yes. Beneath the ocean's surface lie mountain ranges, volcanoes, submarine canyons, and oceanic trenches that dwarf the mountain ranges, volcanoes, and canyons on land.
Starting on the beach, if you walked straight out into the water, you'd be walking out on a continental shelf, the edge of a continent that's covered by shallow sea. If you could keep walking, you'd eventually reach a steep slope called the continental slope, followed by a gentler slope called the continental rise.
Bake a Cookie Earth
To understand why the ocean is so important, it helps to visualize how watery Earth really is. About 70 percent of the planet is covered by ocean, but to get a good sense of what this looks like, make some cookie calculations. Use a family sugar cookie recipe, or buy a package of sugar cookie mix.
ADULT SUPERVISION REQUIRED
* Sugar cookie dough
* Parchment paper
* Rolling pin
* Plastic bottle cap
* 2 cookie sheets
* Butter knife
* Blue frosting
* Green frosting
* Red frosting (optional)
1. Prepare your cookie dough by following a recipe or the directions on a package of sugar cookie mix. Using a mix often requires adding butter, an egg, and a little bit of flour.
2. Preheat the oven to whatever temperature the directions on the package or the recipe indicates.
3. Spread parchment paper on a flat surface and sprinkle some flour on top. Use clean hands to place the dough on the parchment paper.
4. Roll out the dough with a rolling pin until it's about ½-inch (1 1/4-cm) thick.
5. Use a clean plastic bottle cap as a cookie cutter to punch 50 tiny cookie cutouts in the dough. It works best to press the bottle cap into the dough and then twist it a couple of times to make sure the cookie is separated from the rest of the dough.
6. Line two cookie sheets with parchment paper and place the tiny cookies on them, about an inch (2½ cm) apart. Two batches may be necessary.
7. Bake the cookies for about 8-10 minutes (time will vary depending on the recipe you're using), keeping an eye on them to make sure they don't get brown. Finished cookies should be firm when cooled but still light in color.
8. Place the cookies on a cooling rack or plate to cool.
9. Once the cookies have completely cooled, lay parchment paper down on a flat space for decorating and place the cookies on it.
10. Spread blue frosting on 70 percent of the cookies (35 cookies). The blue cookies represent ocean.
11. Spread green frosting on the remaining 30 percent (15 cookies). The green cookies represent land, including all of Earth's continents.
12. Next, place the cookies close together in a circle to represent Planet Earth. Place the green cookies so they look like Earth's continents and fill in the spaces with ocean cookies.
13. If you have red frosting handy, plot yourself on the "map" by making a tiny red X.
14. Take a step back and observe your cookie Earth. It's mostly blue, just like the real thing. Share what you've learned about the percentage of ocean versus land on our planet with a friend or family member. (Maybe share some cookies with a friend or family member too!)
Make this project simpler by baking 10 larger (2-inch, or 5-cm) cookies to represent Earth, or make it more difficult by baking 100 bottle-capsized cookies. In both cases, frost 70 percent of the cookies blue and 30 percent of the cookies green.
Here, at the bottom of the world, you'd reach an abyssal plain, a large flat area that extends for miles. It would be dark and cold, and you'd be the only human in sight. If you walked far enough, you might suddenly find yourself at the base of a seamount, a huge underwater mountain. Many seamounts are former volcanoes.
Sometimes, active volcanoes grow so tall that they poke above the surface of the water and form islands. Mauna Loa, one of the large active volcanoes that make up the Hawaiian Islands, is a great example. Mauna Loa rises more than 30,000 feet (9,100 m) above the seafloor, though most of it is underwater. By comparison, the tallest mountain on land, Mount Everest, is about 29,000 feet (8,840 m) high, which is more than 1,000 two-story houses stacked on top of each other.
Underwater volcanoes and mountains often form where tectonic plates, large pieces of Earth's crust, shift, spread apart, or bump into each other. This shifting, spreading, and bumping can also cause earthquakes.
The longest mountain chain on Earth, the Mid-Atlantic Ridge, runs along a plate boundary in the Atlantic Ocean like a seam on a baseball. At this boundary, hot liquid rock wells up from the Earth's core, cools, and creates new seafloor as it slowly pushes the plates away from each other. Continents move along with tectonic plates, which means the continent you're on right now is moving at about the same rate that your fingernails are growing.
Along with tall volcanoes and mountains, you'd also find some very deep places if you could take a stroll on the bottom of the ocean. When two tectonic plates collide, one gets pushed under the other, often forming a deep oceanic trench.
The Grand Canyon in northern Arizona is a mile (1.6 km) deep at its deepest point, but it is a mere dip in the landscape compared to the ocean's submarine canyons and trenches. The Mariana Trench in the Pacific Ocean reaches a depth of 6.8 miles (almost 11 km). That's more than six Grand Canyons deep!
While thousands of brave people have climbed Mount Everest, the highest point on Earth, only a few explorers have descended to the deepest known point on Earth, the Challenger Deep within the Mariana Trench. Such extreme deep-sea exploration requires a lot of high-tech equipment and a fair amount of risk.
All About Water
Water has the power to give life and to take it away. It can be cold, dark, and scary, but it can also be warm, bright, and clear. When you think of water, you might think of running through the sprinklers or diving off the high board into a deep pool, but water is not always a liquid. In fact, the same stuff you spray through a water gun also makes up puffy clouds in the sky and giant icebergs floating in the Southern Ocean. This is because water can be not only a liquid but also a gas and a solid.
Water is the only substance on Earth that exists naturally in all three states — liquid, gas, and solid. A single water molecule (H2O) is made up of two hydrogen atoms bonded to the same oxygen atom, similar to the way magnets attract certain kinds of metal. A drop of liquid water is made up of billions of these water molecules that are grouped closely together, but not too closely. The molecules in a liquid can move past each other, which allows the liquid to flow.
When liquid water warms up, the molecules start moving around so fast that they can no longer hold onto each other at all. When this happens, the liquid turns into a gas or vapor. In this form, the water molecules spread out and move around freely.
When liquid water cools below 32 degrees Fahrenheit (0 degrees Celsius), the molecules slow way down and hook together to form ice. In this solid form, the water molecules pack tightly together and can barely move.
One notable property of water is its surface tension. Far from being just a boring science term, surface tension makes it possible for some animals to walk on water! The bonds that connect liquid water molecules together are stronger on the surface layer. These bonds create tension on the surface, as if a clear film were stretched across it.
When animals such as water striders and fishing spiders walk across a pond, their legs make tiny dents in the surface of the water, but the animals don't sink. The force of gravity pulling down on their bodies isn't enough to make them break through the invisible barrier created by surface tension.
Water molecules are good at dissolving other substances because one side of the molecule (the hydrogen side) has a slight positive electric charge and the other side (the oxygen side) has a slight negative charge. When you add a substance like salt to water, the water dissolves the salt by breaking apart the salt molecules.
Water, Water, Everywhere
"Water, water, everywhere, / Nor any drop to drink." This is a line from a famous poem called "The Rime of the Ancient Mariner" by Samuel Taylor Coleridge. In the poem, sailors are stranded aboard their ship and become incredibly thirsty. They're surrounded by ocean water, but they can't drink a single drop of it. Why is it dangerous to drink seawater, even in desperate situations?
When humans drink seawater, a massive amount of salt ends up in our bloodstreams. Our bodies work hard to stay balanced, so when there is too much salt in our blood, water moves from the inside of our cells to the outside to try to correct the imbalance. Too much water leaving our cells causes them to shrink and become dehydrated. Our bodies' kidneys (organs that filter blood and help get rid of waste) try to flush the extra salt out of our systems by creating urine, which can further dehydrate the body.
If the sailors in "The Rime of the Ancient Mariner" drank seawater, they'd end up thirstier than they were in the first place. Their bodies would try to get back to normal, and by doing so, their cells would also be getting rid of the water they need to keep functioning. Eventually, if the sailors kept drinking seawater, they'd get headaches and become dizzy. In extreme cases, they could die.
Salt is not an enemy though. Humans' bodies need some salt to function. The amount of salt found in salty foods, such as crackers and soup, isn't nearly enough to be dangerous. However, if you've noticed that eating salty foods makes you feel thirsty, you're not alone. Your brain tells your body to drink more water when it notices that the bloodstream is a bit too salty.
Build a Water Molecule Model
Water molecules are called H2O because they're made of two hydrogen atoms bonded to one oxygen atom. Build an oversized model of a water molecule to show off to your friends.
* Newspapers or a tablecloth safe for crafts
* 3 toothpicks
* Large (3-inch, or 8-cm) smooth foam ball (available at craft stores)
* 2 small (2-inch, or 5-cm) smooth foam balls (available at craft stores)
* Paint (two colors)
* Paintbrush and paint tray
* Black permanent marker
1. Begin by covering your workspace with newspapers or a tablecloth that's safe for crafts. Poke the bottom of the each foam ball with a toothpick, leaving at least half of the toothpick sticking out of the foam.
2. Select a paint color for the oxygen atom. Pick up the larger foam ball by the toothpick and hold it like a Popsicle. Paint your oxygen atom and set it aside to dry.
3. Paint each of the smaller foam balls a second color to represent two hydrogen atoms. When you're done, set them aside to dry.
4. Once the paint on all three "atoms" is dry, remove the toothpicks.
5. Dab a bit of glue on the end of two toothpicks and insert them halfway into the two hydrogen atoms.
6. Dab some glue on the exposed end of each toothpick and carefully insert them into the oxygen atom at a wide 104½-degree angle. Refer to the water molecule illustration on page 6 for an example. It's OK to guess!
7. Use a black permanent marker to write an O on the larger foam ball to indicate oxygen. Write an H on each of the two smaller foam balls to indicate hydrogen.
8. Show off your water molecule to a friend or family member and explain what happens as water molecules heat up and cool down.
Research the answers to these questions: What is a covalent bond? What is a hydrogen bond?
If you've ever accidentally taken a gulp of seawater, you know that seawater tastes salty. In the ocean, the most common dissolved minerals are sodium and chloride. Together, sodium and chloride make salt. Marine scientists refer to the saltiness of the ocean as salinity. The saltier the water, the higher its salinity.
Water on the Move
In 2013, a kite surfer in Croatia came across a bottle on the beach, but this was no ordinary bottle. Inside it was a message that had been written in 1985, sealed in the bottle, and then tossed into the sea near Nova Scotia, Canada. The message read: "Mary, you really are a great person. I hope we can keep in correspondence. I said I would write. Your friend always, Jonathon, Nova Scotia, 1985."
For 28 years, Jonathon's message to Mary floated in the ocean, traveling from the eastern coast of Canada across the Atlantic Ocean, the Mediterranean Sea, and the Adriatic Sea, where it finally washed ashore in the European country of Croatia. Even though Mary never got his memo, Jonathon is one of countless people throughout history who hoped the ocean's movements would deliver his message in a bottle.
The ocean never stays still. Surface currents created by the wind move water on the surface of the ocean. When wind pushes surface water away from an area, colder, nutrient-rich water gets pulled up from the deep sea to replace it. This is called upwelling. Near coasts, the nutrient-rich water that upwelling brings to the surface helps support marine life on and near the continental shelf.
Excerpted from Marine Science for Kids by Josh Hestermann. Copyright © 2017 Josh Hestermann and Bethanie Hestermann. Excerpted by permission of Chicago Review Press Incorporated.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
ContentsForeword by Stephanie Arne, host of Mutual of Omaha's Wild Kingdom,
Introduction: What Is Marine Science?,
1 Getting to Know the Marine Environment,
Bake a Cookie Earth,
Build a Water Molecule Model,
Discover Water Density,
2 Coastal Communities,
Make an Edible Coral Reef,
Mold a Miniature Tide Pool,
Promote a Coastal Community,
3 Life in the Open Sea,
Explore Marine Camouflage, Part 1: Penguin Hide-and-Seek,
Play the Lunch with Whales Game,
Solve the Creature Mystery,
4 Diving Deeper,
Construct a Squid,
Compose a Sea Monster Poem,
Explore Marine Camouflage, Part 2: Who Glows There?,
5 Rivers, Streams, Lakes, and Ponds,
Transform Salt Water into Freshwater,
Fold an Origami Frog,
Catch the Salmon! Tag Game,
6 Our Connected Earth,
Clean Up an Oil Spill,
Experiment with Ocean Acidification,
Play Ecosystem Jenga,
7 Making a Difference,
Conduct Wildlife Research,
Interview a Marine Scientist,
Create Ocean Creature Art,