Earth’s oceans are home to some pretty strange animals, especially in the Southern Ocean. Hi, I’m Cameron, and this is MinuteEarth.
In the Southern Ocean, even the animals that look normal are actually quite unusual. Take the Antarctic icefish, for example. Unlike other fish that have red blood because of their oxygen-carrying red blood cells, icefish have clear blood without these cells. They also have big hearts, can absorb oxygen directly through their smooth skin, and have a natural antifreeze in their body fluids to survive the cold.
Despite the freezing temperatures, some of the longest-living animals on Earth live here. Starfish in the Southern Ocean can live up to a hundred years, while tropical starfish only live about three to five years. There’s even a sponge on the ocean floor that might be as old as 15,000 years, making it one of the oldest living animals on the planet!
Animals in the deep sea are usually large, but those in the Southern Ocean can be even bigger. The Antarctic blue whale is the largest animal on Earth, and the colossal squid is the largest invertebrate. Sea floor creatures are also huge; Antarctic sea spiders can be as big as dinner plates, scale worms can grow as large as marine biology textbooks, and 20-armed starfish can be the size of manhole covers.
The animals in the Southern Ocean are unique because the ocean itself is special. Although it looks connected to other oceans, its life is mostly isolated by a massive circular current called the Antarctic Circumpolar Current. This current is the largest, fastest, and deepest ocean current on the planet. It acts like a barrier, keeping Southern Ocean life separate from other oceans for the last 30 million years.
Being isolated has its perks. The current brings nutrients from the deep to the surface, making the Southern Ocean rich in food. The water is very salty, allowing it to get extremely cold without freezing completely. This cold water holds a lot of dissolved oxygen, which might help animals grow larger and live longer than they would elsewhere.
Scientists are exploring Antarctica’s icy, isolated oceans and the unique creatures living there to learn how life can thrive in such extreme conditions. The Southern Ocean might even be more similar to environments on other planets, like Saturn’s largest moon, than to other parts of Earth.
Even if we don’t find alien life, the Southern Ocean is an amazing wonder right here on our planet.
This video was made with help from scientists studying the Southern Ocean. This year, Dr. Holly Bik and science communicator Dr. Virginia Shutte went on a research trip to learn more about the life beneath the ice. Dr. Bik specializes in nematodes, tiny worms found everywhere on Earth. With support from the National Science Foundation, she collected samples from the Southern Ocean seafloor to discover new species and understand how these worms survive in such harsh conditions. By studying their DNA, scientists hope to learn how animals might adapt to climate change worldwide.
Using materials like clay or playdough, create a model of the Antarctic icefish. Pay special attention to its unique features, such as its clear blood and large heart. Explain to your classmates how these adaptations help the icefish survive in the cold Southern Ocean.
Imagine you are a marine biologist discovering a new species in the Southern Ocean. Draw or craft your own deep-sea creature, considering the unique conditions of the Southern Ocean. Describe how your creature’s adaptations help it survive in this extreme environment.
Research the Antarctic Circumpolar Current and its role in isolating the Southern Ocean. Prepare a short presentation or poster explaining how this current affects the ocean’s ecosystem and contributes to the unique life forms found there.
Investigate the life cycle of a starfish living in the Southern Ocean. Create a timeline or storyboard that illustrates the stages of its life, highlighting how its long lifespan compares to other starfish species. Share your findings with the class.
In groups, simulate a research expedition to the Southern Ocean. Assign roles such as marine biologist, oceanographer, and science communicator. Plan your expedition, decide what you will study, and present your research goals and expected findings to the class.
Here’s a sanitized version of the YouTube transcript:
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Earth’s oceans are full of animals that seem quite strange to us land dwellers. However, the most unusual creatures are found in the Southern Ocean. Hi, I’m Cameron, and this is MinuteEarth.
In the Southern Ocean, even the most normal-looking animals are actually quite bizarre, like the Antarctic icefish. While other fish have red blood due to their oxygen-carrying red blood cells, Antarctic icefish have clear blood that lacks these cells. Icefish also have large hearts compared to red-blooded fish, the ability to absorb oxygen directly through their smooth skin, and they possess a natural antifreeze in their body fluids.
Despite the harsh temperatures, some of the planet’s longest-living animals reside in the Southern Ocean. Starfish here can live around a hundred years, compared to the three to five years a tropical starfish might live, if it is fortunate. There is even an individual sponge on the Southern Ocean seafloor that scientists estimate could be as old as 15,000 years, based on its size and slow growth. It’s a contender for the planet’s oldest living animal.
In general, animals in the deep sea tend to be large, but those in the depths of the Southern Ocean can be even larger. Some of its giants include the Antarctic blue whale—the largest animal on the planet—and the colossal squid—the largest invertebrate. Sea floor dwellers also grow relatively large; Antarctic sea spiders can be the size of dinner plates, scale worms can reach the size of marine biology textbooks, and 20-armed starfish can be as large as manhole covers.
All of these animals that inhabit the Southern Ocean are unique because the Southern Ocean itself is distinct. Although it appears connected to the world’s other oceans, its life is largely isolated from the rest of the oceans by a massive circular current known as the Antarctic Circumpolar Current. This current is the largest and fastest ocean current on the planet, and it is also the deepest. It acts as a barrier that has prevented most Southern Ocean life from interbreeding with life from other oceans for the last 30 million years.
However, there is an advantage to being isolated by the current. As it spirals, it brings nutrients from the depths to the surface, which means that the Southern Ocean is rich in food for its unique life. Additionally, the isolated water has special properties—it is very salty, allowing it to become extremely cold without freezing completely. This cold water can hold a lot of dissolved oxygen, which may help animals grow larger and age more slowly than they would in other environments.
Scientists are studying Antarctica’s frigid, isolated oceans and the unique creatures that inhabit them to learn how life thrives in such extreme environments. In fact, conditions in the Southern Ocean may be more similar to those on other worlds, like Saturn’s largest moon, than to the rest of our planet.
Even if extraterrestrial life doesn’t exist, the Southern Ocean is an extraordinary wonder right here on Earth.
We created this video in collaboration with some friends who conduct scientific research in the Southern Ocean. This year, Dr. Holly Bik and science communicator Dr. Virginia Shutte (who wrote this video) embarked on an ice-breaking research voyage in the Southern Ocean to better understand the unique life beneath the ice. Nematodes, tiny soil-dwelling worms found on every continent, are Dr. Bik’s specialty. With support from the National Science Foundation Office of Polar Programs, she was able to gather samples of nematode life from the Southern Ocean seafloor. The goal is to describe new species and understand how Antarctic nematodes thrive in such an extreme environment. Studying their genomes can help identify adaptations to polar ecosystems and potentially inform us about how organisms worldwide may adapt to climate change.
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This version maintains the informative content while ensuring clarity and appropriateness.
Southern Ocean – The ocean surrounding Antarctica, known for its cold temperatures and unique marine life. – The Southern Ocean is home to many species that have adapted to its icy waters.
Icefish – A type of fish found in Antarctic waters that has clear blood and can survive in very cold temperatures. – Icefish have special proteins in their blood that prevent it from freezing in the cold Southern Ocean.
Starfish – A marine animal with a star-shaped body, commonly found in oceans around the world. – Starfish can regenerate lost arms, which helps them survive in their ocean habitats.
Nutrients – Substances that provide nourishment essential for growth and the maintenance of life. – Nutrients in the ocean are crucial for the growth of phytoplankton, which form the base of the marine food web.
Current – A continuous, directed movement of seawater generated by various factors such as wind, temperature, and salinity differences. – Ocean currents play a vital role in regulating the Earth’s climate by distributing heat around the planet.
Oxygen – A gas that is essential for the survival of most living organisms, including marine life. – Fish and other aquatic animals rely on dissolved oxygen in the water to breathe.
Animals – Living organisms that feed on organic matter, typically having specialized sense organs and nervous systems. – Many animals in the ocean have adapted to survive in deep, dark waters.
Freezing – The process of a liquid turning into a solid due to low temperatures. – The freezing temperatures of the Antarctic waters create a challenging environment for marine life.
Species – A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. – Scientists discovered a new species of fish living under the ice in the Southern Ocean.
Climate Change – Long-term changes in temperature and weather patterns, often caused by human activities. – Climate change is affecting the habitats of many species, forcing them to adapt or move to new areas.
