Sea animals: Different sizes andshapes, same steps

Image 1. This baby sea turtle has a tracker attached to it. Scientists use tracking devices like these to study the movements of sea

animals. Photo by James Abernethy/Barcroft Media/Getty Images.

If the ocean were a dance floor, it would be full of surprising pairs. Black-footed albatrosses

measure up to 6 pounds. Short-finned pilot whales weigh about 6,600 pounds. To equal the

height of a hammerhead shark, 20 little penguins would need to stand on top of each

other. A polar bear would probably rather eat a California sea lion than dance with it.

But according to a new study, these animals move around their environment in similar ways.

Recently, scientists from around the world worked together to understand how animals move in

the ocean. They compared how and where thousands of animals moved from day to day. The

scientists found that many animals, from big to small, move in similar patterns.

By Atlas Obscura, adapted by Newsela staff on 03.06.18

Word Count 744

Level 840L

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How animals fly, scurry or swim is controlled by both their bodies and the environment. Body size

is important: big animals can usually run or swim farther than small animals. But smaller creatures

might move more easily through a forest than bigger animals. Some animals thrive in desert

sands or snowy mountains. Others can't live in extreme hot or cold. People have wanted to figure

out the influences on how and where animals move since at least 350 B.C. Around then, the

Greek thinker and scientist Aristotle wrote about the need to "investigate" animal movement.

Gathering Data From Tracking Devices

Scientists today can use a new tool to understand animals: remote tracking devices. These

devices are attached to animals. They let scientists far away track where and how the animals

move. The new study used data collected from previous projects using remote tracking devices.

The scientists realized if they shared their data with one other, they would have much more

information to examine.

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The scientists used tracking data from 2,600 animals belonging to 50 different species. These

animals traveled to 2.8 million places around the world. Some of the information comes from

studies that are more than 20 years old. Other data were collected as recently as 2015. Using all

this data, the scientists were able to ask questions about many different kinds of animals. They

could compare the fast-flying albatross to the fast-swimming shark. They could look at whales

and turtles side by side.

Environment More Important Than Size

The results surprised the scientists. Previous studies on land found that an animal's body,

especially its body size, determined how it moves. In the oceans, the environment proved more

important. One animal might be 10 billion times larger than another. Yet both of them moved

through the ocean in similar ways.

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Some animals hunt for food, while others eat kelp or ocean grass. Some creatures paddle, some

swim and some fly. These factors didn’t make much difference in how animals moved through

their environment. Instead, one of the biggest influences was where animals lived. Animals that

spend most of their time along the coast, such as beluga whales and green turtles, move in

complicated ways. They turn often and retrace their steps.

In the open ocean, things are simpler. Animals who prefer it there, such as black-footed

albatrosses and whale sharks, will pick a spot in the distance and shoot for it.

An Even But Changing Playing Field

For all kinds of animals, how they move is influenced by their environment. And the

ocean itself plays a part. Seawater surrounds animals on all sides. It allows them to float along the

ocean currents. The ocean creates an even playing field for creatures of all different sizes and

shapes.

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But this playing field is changing quickly. Arctic ice is melting and coasts are rearranging. Sea

levels are rising as oxygen levels in the ocean are falling. Scientists hope that understanding how

animals move will help us predict what they might do in the future. They think animals living along

the shore might be able to adapt to the shifting coastlines. Animals who live in the open ocean

may have more trouble adapting.

Predictions May Help Endangered Animals

Now the patterns of how animals move through the ocean are better understood.

Scientists can even make predictions about endangered animals. These predictions may help

protect endangered animals when they interact with humans. If people want to live alongside

these ocean animals, it helps to know how the animals dance.

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