I am a 12-year-old student in Kobe, Japan. I love the ocean. The sea is big and full of life. Fish, whales, corals, and tiny creatures live there. I see the ocean near my home, and I dream of exploring it. Marine life is exciting. Animals in the sea are different from animals on land. They swim, glow, and live in deep water. I want to learn more about them. What animals live in the ocean? Where do they live? Why are they special? I write this to share what I find about marine life. The ocean is like a big world, and I am happy to explore it.
The ocean covers 70% of Earth. It is home to millions of animals. Scientists say there are more species in the sea than on land. Marine life includes fish, mammals, reptiles, birds, and tiny creatures. Fish are the most common, like tuna or clownfish. Mammals, like dolphins and whales, live in water but breathe air. Reptiles, like sea turtles, swim and lay eggs on land. Birds, like penguins, dive for food. Tiny creatures, like plankton, are food for many animals. The ocean has many habitats, like coral reefs, deep water, and coasts. Each habitat has different animals.
Fish are the biggest group in the ocean. There are over 30,000 kinds. Some are small, like guppies, only a few centimeters long. Some are big, like whale sharks, over 12 meters long. Fish have fins to swim and gills to breathe water. Their colors are bright, like the yellow tang, or plain, like cod. Fish live in schools or alone. Clownfish live in sea anemones to stay safe. Sharks are fish too. They have sharp teeth and smell blood far away. My favorite fish is the angelfish because it is colorful. Fish are important because people eat them, and they keep the ocean balanced.
Marine mammals are special. They are warm, have fur or fat, and give milk to babies. Dolphins are smart and playful. They jump and talk with clicks. Whales are the biggest animals. Blue whales are 30 meters long. They eat tiny krill and sing loud songs. Seals and sea lions live near coasts. They swim but rest on rocks. Whales and dolphins breathe air, so they come to the surface. I saw a dolphin at an aquarium. It smiled and did tricks. Marine mammals are loved because they are smart and cute.
Sea reptiles are interesting. Sea turtles are the most famous. They have hard shells and swim with flippers. Green sea turtles eat plants, and leatherbacks eat jellyfish. Turtles live 80 years and swim across oceans. They lay eggs on beaches. Sea snakes are reptiles too. They have flat tails to swim and venom to catch fish. They live in warm water, like near Australia. Reptiles are special because they are old, like dinosaurs. I want to see a baby turtle go to the sea one day.
Marine birds live near the ocean. Penguins are the most famous. They don’t fly but swim with wings like flippers. Emperor penguins dive deep for fish in cold Antarctica. Seagulls and albatrosses fly over the sea. Albatrosses have long wings and travel far. Puffins dive for fish and have colorful beaks. Birds eat fish or crabs. They live on cliffs or islands. I saw seagulls at the beach. They are noisy but fun. Marine birds are important because they connect the sea and land.
Invertebrates are animals with no bones. They are many in the ocean. Jellyfish have soft bodies and sting with arms. Some glow in the dark. Octopuses are smart. They have eight arms, change color, and hide in rocks. Crabs and lobsters have hard shells and claws. Starfish eat clams and can grow new arms. Corals are tiny animals that build reefs. Reefs are like cities for fish. My favorite is the octopus because it is clever. Invertebrates are important because they are food and make habitats.
Plankton are tiny creatures. They float in water. Some are plants, called phytoplankton. They make oxygen with sunlight. Some are animals, like zooplankton. They eat phytoplankton. Plankton are food for fish, whales, and others. Without plankton, marine life cannot live. I learned about plankton in school. They are small but very important. The ocean needs them to stay healthy.
Habitats are where animals live. Coral reefs are warm and colorful. They are in places like Australia’s Great Barrier Reef. Fish, crabs, and turtles live there. Open water is the big, deep sea. Sharks, tuna, and whales swim there. Deep sea is dark, below 1,000 meters. Anglerfish use light to catch food. Coasts are near land, with waves. Seals, crabs, and birds live there. Polar seas are cold, like in Antarctica. Penguins and seals live there. Each habitat has special animals. I want to dive in a coral reef to see colors.
Animals adapt to the ocean. Fish have fins to swim fast. Dolphins have smooth skin to move easily. Deep-sea fish glow to find food or mates. Crabs have shells to hide from danger. Whales have blubber, fat to stay warm. Sea turtles hold breath for hours. These adaptations help animals live in water. I think it’s amazing how animals change to fit the sea.
Marine life behaves in special ways. Dolphins live in groups, called pods. They help each other hunt fish. Sharks swim alone, hunting at night. Clownfish stay near anemones for safety. Whales travel far, from cold to warm water, to have babies. Crabs fight with claws to protect homes. Some fish, like salmon, swim to rivers to lay eggs, then die. I saw a video of dolphins jumping together. It looked like a dance. Behaviors help animals survive and make the ocean lively.
Marine life is important for Earth. Fish feed people. In Japan, we eat sushi with tuna and salmon. Plankton make oxygen for air. Corals protect coasts from waves. Whales mix water, bringing food to the surface. Animals keep the ocean clean. Crabs eat dead things. Without marine life, the sea and land would change. I learned fish are part of a big system. We need them to keep Earth healthy.
Humans use marine life. People catch fish for food. In Japan, fishing is big. We eat octopus, shrimp, and seaweed. Pearls come from oysters. Medicine comes from sea sponges and corals. People visit aquariums to see sharks or dolphins. I went to an aquarium in Osaka. It was fun to see jellyfish glow. But humans must be careful. Too much fishing hurts animals.
Marine life has problems. Pollution is bad. Plastic bags and bottles go to the sea. Turtles eat them and get sick. Oil spills cover fish and birds. Climate change warms water. Corals die and turn white. Overfishing takes too many fish. Sharks and tuna are fewer now. People help by cleaning beaches and using less plastic. I joined a beach cleanup last summer. We found bottles and nets. Saving marine life is important for the ocean.
Marine life is in stories. In Japan, we have tales of kappas, water creatures. Whales are in old songs. Mermaids are in many countries’ stories. Movies show sharks, like in “Jaws,” or fish, like “Finding Nemo.” My favorite is Nemo because he is brave. Stories make marine life fun and teach us to love the sea.
Marine life is different in each ocean. The Pacific Ocean, near Japan, has whales, sharks, and corals. The Atlantic Ocean has cod and lobsters. The Indian Ocean has colorful fish and turtles. The Arctic Ocean has seals and polar bears. The Southern Ocean has penguins and krill. I want to see all oceans one day. Each one has special animals.
I love marine life because it is beautiful and strange. Fish are colorful. Whales are big. Octopuses are smart. The ocean is like a big home for them. I watch videos of coral reefs and deep-sea fish. They look like another world. My dream is to dive and see a dolphin. I have a fish tank with guppies. They swim and make me happy. As I write this, I look at the sea outside. Marine life is a treasure, and I want to learn more every day.