The ocean is a vast place teeming with marine animals and sea creatures; it covers 71% of the Earth's surface and encompasses 94% of the world's wildlife. Despite this, humans have only explored 5% of the world's oceans, meaning that 95% of the oceans remain unexplored.
As a French author once said, "The sea is an underwater museum still awaiting its visitors." There is much to be discovered in the ocean, but its elusiveness also lends it a dark, mysterious undertone.
The ocean is home to many mystical sea creatures such as the Kraken or Leviathan. While many of these mythical creatures have been proven to be distorted truths, the ocean's hold on the human imagination cannot be overlooked. In this blog post, we will provide some background on oceans and seas, explore marine animals (which are not mythical), and conclude with a few helpful conservation tips.
Table of content
🌊 What is the difference between ocean and sea?
🌊 The full lists of oceans basins and seas
🌊 Helpful ocean and sea terms
🌊 Ocean mammals
🌊 Ocean fish
🌊 Other notable animals
🌊 Worksheet
🌊 How to conserve the ocean and sea?
🌊 Conclusion
What is the difference between ocean and sea?
People often use "ocean" and "sea" interchangeably, but they have different meanings. 'Sea' typically refers to the body of saltwater that is partially enclosed by land, whereas 'ocean' denotes the vast expanse of saltwater that covers the Earth's surface. Merriam-Webster provides the following definitions for these two terms.
Ocean: the whole body of salt water that covers nearly three fourths of the surface of the earth
Sea: a great body of salt water that covers much of the earth
From the Ngram graph below, we can observe that the word "sea" is used more frequently than the word "ocean." Generally, there are regional differences in the understanding and usage of "ocean" and "sea." According to the Oxford Dictionary, "In British English, the typical term for the body of saltwater covering most of the Earth's surface is 'sea,' whereas in North American English, the usual term is 'ocean.'"
The full lists of oceans basins and seas
Global ocean
The term "global ocean" refers to the interconnected body of saltwater that covers the majority of Earth's surface. It comprises several major ocean basins, such as the Pacific, Atlantic, Indian, Southern, and Arctic Oceans, as well as various smaller seas and marginal seas.
There are five ocean basins that are a part of the Global Ocean:
Arctic Ocean: The Arctic Ocean is the smallest and shallowest of Earth's five major oceans, located mostly within the Arctic Circle and surrounded by the northern coastlines of North America, Europe, and Asia.
Southern Ocean: The Southern Ocean, encircling Antarctica, is the southernmost of Earth's five major oceans.
Indian Ocean: The Indian Ocean, the third-largest of Earth's five major oceans, is bounded by Africa to the west, Asia to the north, Australia to the east, and the Southern Ocean to the south.
Atlantic Ocean: The Atlantic Ocean is the second-largest of Earth's five major oceans, bordered by the Americas to the west and Europe and Africa to the east.
Pacific Ocean: The Pacific Ocean is the largest and deepest of Earth's five major oceans, covering approximately one-third of the planet's surface.
Historically, only four oceans have been recognized (Arctic, Southern, Indian, Atlantic, and Pacific). The Southern Ocean is the newest addition, with its borders formally proposed by the International Hydrographic Organization in 2000.
Different seas:
Mediterranean Sea: The Mediterranean Sea is a large body of water bordered by Europe to the north, Africa to the south, and Asia to the east.
Caribbean Sea: The Caribbean Sea is a tropical body of water situated in the Western Hemisphere, bordered by the Greater Antilles to the north, the Lesser Antilles to the east, Central America to the south, and the Gulf of Mexico to the west.
Red Sea: The Red Sea is a narrow body of water located between northeastern Africa and the Arabian Peninsula, connecting to the Indian Ocean to the south.
Black Sea: The Black Sea is a body of water located between southeastern Europe and Asia Minor, bordered by Bulgaria, Romania, Ukraine, Russia, Georgia, and Turkey.
Other notable seas:
- Adriatic Sea
- Baltic Sea
- Arabian Sea
- South China Sea
- East China Sea
- Sea of Japan
Helpful ocean and sea terms
Oceanography: Oceanography is the scientific study of the oceans and seas, including their physical, chemical, biological, and geological characteristics.
Oceanographers: Oceanographers are scientists who specialize in the study of the oceans and seas.
Tide: A tide is the regular rise and fall of sea levels caused by the gravitational forces exerted by the Moon and the Sun on Earth's oceans.
Current: A current refers to the continuous, directional flow of water in the ocean, rivers, or other bodies of water.
Wave: A wave is an oscillation that propagates through a medium, such as water, air, or even solid materials.
Reef: A reef is a ridge or mass of rock, coral, or sand that rises from the sea floor towards or above the water's surface.
Marine life: Marine life refers to organisms that inhabit the oceans and other saltwater environments.
Estuary: An estuary is a partially enclosed coastal body of water where freshwater from rivers and streams meets and mixes with saltwater from the ocean.
Gulf: A gulf is a large body of water that is partly surrounded by land, with a narrow opening connecting it to the ocean.
Bay: A bay is a body of water partially enclosed by land, with a wide opening connecting it to the ocean or a larger body of water.
Ocean mammals
Blue whale
Number of animals left in the wild: 10,000-25,000
Conservation status on the IUCN: Endangered
Scientific name: Balaenoptera musculus
Physical characteristics:
Collective noun: a pod of whales.
Example: A pod of whales swam together in the ocean
Idiomatic phrase: whale of time
Example: After a stressful week, we went on a weekend getaway to the beach, and we had a whale of a time surfing, sunbathing, and enjoying each other's company.
Interesting fact: Blue whale is the largest animal on earth.
Common dolphin (a.k.a short-beaked common dolphin)
Number of animals left in the wild: Tens of thousands
Conservation status on the IUCN: Least concern
Scientific name: Delphinus delphis
Physical characteristics: Dolphins have streamlined bodies with smooth, rubbery skin, a dorsal fin, pectoral flippers, and a powerful tail fluke for propulsion. They breathe through a blowhole, possess a beak with teeth, and use echolocation.
Collective noun: a pod of short-beaked dolphin
Example: A pod of short-beaked dolphins swam playfully near the coast, their jumps and spins delighting onlookers gathered on the shore.
Common phrase: N/A
Example: N/A
Interesting fact: Dolphins possess the incredible ability of echolocation.
Bottlenose dolphin
Number of animals left in the wild: 600,000
Conservation status: Least concern
Scientific name: Delphinus delphis
Physical characteristics: Dolphins have streamlined bodies with smooth, rubbery skin, a dorsal fin, pectoral flippers, and a powerful tail fluke for propulsion. They breathe through a blowhole, possess a beak with teeth, and use echolocation. Typical coloration is grayish-blue.
Collective noun: a pod of bottlenose dolphins
Example: A pod of bottlenose dolphins swim gracefully across the translucent waters.
Common phrase: N/A
Example: N/A
Interesting fact: Dolphins possess the incredible ability of echolocation.
Sea Lion
Number of animals left in the wild: 502828 ~ 504228
Conservation status on the IUCN: Dependent on species
Scientific name: Otariinae
Physical characteristics: Sea lions, large marine mammals, boast streamlined bodies, external ears, and whiskers aiding in hunting.
Collective noun: a bob of sea lions
Example sentence: A bob of sea lions lounged lazily on the sun-soaked rocks
Idiomatic phrase: Sealioning
Example sentence: During the debate, he resorted to sealioning, attacking his opponents with endless questions.
Interesting fact: Sea lions are highly social animals and often form large colonies, particularly during breeding season.
Sea otter
Number of animals left in the wild: 107,000
Conservation status on the IUCN list: Endangered
Scientific name: Enhydra lutris
Physical characteristics: Sea otters have dense fur for insulation, streamlined bodies for efficient swimming, forepaws with retractable claws, small ears, binocular vision, and webbed hind paws.
Collective noun: a raft of sea otters
Example: A raft of otters floated together on the water, playing and splashing happily in the sunshine.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Sea otters were hunted for their fur for quite a while.
Orca (a.k.a Killer whale)
Number of animals left in the wild: 50,000
Conservation status on the IUCN: Data deficient
Scientific name: Orcinus orca
Physical characteristics: Orcas, or killer whales, are known for their distinctive black and white coloring, tall dorsal fin, large paddle-like pectoral fins, and conical teeth. They have a robust, streamlined body, reaching lengths of up to 32 feet and weights of 22,000 pounds.
Collective noun: a pod of killer whales
Example: A pod of killer whale, also known as an orca, jumped high out of the water, showing off its black and white colors
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Orcas are dolphins, not whales. They were given the name as they were seen hunting whales that were bigger than their size.
Ocean fish
Shark
Number of animals left in the wild: 512 described and 23 undescribed species (~100 million individual sharks)
Conservation status on the IUCN list: Depends on the shark species
Scientific name: Selachimorpha
Physical characteristics: Sharks possess streamlined bodies. Their powerful jaws have rows of sharp teeth.
Collective noun: a shiver of shark
Example: As the boat passed over the reef, the divers saw a shiver of sharks circling below.
Idiomatic phrase: swimming with the sharks
Example sentence: Sarah found herself swimming with the sharks when she was assigned to the new case that had relations with a high profile politicians.
Interesting fact: One interesting fact about sharks is that they have been around for much longer than dinosaurs.
Megalodon was a giant shark that became extinct. It is related to the Great White Shark, the species of shark depicted in Jaws, but it is significantly larger in size. The megalodon was much larger than any shark species existing today.
Common Clownfish (a.k.a Clown Anemonefish)
Number of animals left in the wild: Unknown
Conservation status on the IUCN list: Least concern
Scientific name: Amphiprion ocellaris
Physical characteristics: Clownfish, known for their bright orange bodies with three white stripes outlined in black. They have fins for swimming.
Collective noun: a school of clownfish
Example: A school of bright clownfish swam happily around their sea anemone home.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Clownfish are called "clownfish" due to their vibrant and distinctive coloring, which resembles the bright and colorful costumes of clowns.
Blue Hippo Tang
Number of animals left in the wild: Unknown
Conservation status on the IUCN list: Least concern
Scientific name: Paracanthurus hepatus
Physical characteristics: Paracanthurus hepatus, commonly known as the blue tang or regal tang, boasts a vibrant blue body with yellow accents and black markings.
Collective noun: a school of blue hippo tang
Example: In the aquarium, a school of blue hippo tang glided peacefully through the water, their vibrant colors creating a captivating display for onlookers.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Dory in Nemo was a blue hippo tang.
Yellowfin Tuna
Number of animals left in the wild: Unknown
Conservation status on the IUCN list: Least concern
Scientific name: Thunnus albacares
Physical characteristics: Yellowfin tuna, known for their yellow fins, are large, swift fish with streamlined bodies.
Collective noun: a school of yellowfin tuna
Example sentence: A school of yellowfin tuna swiftly moved through the ocean, their yellow fins glinting in the sunlight as they hunted for prey together.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: An interesting fact about yellowfin tuna is that they are capable of reaching impressive speeds in the water, with recorded speeds of up to 47 miles per hour.
Swordfish
Number of animals left in the wild: Unknown, but its numbers are stable. Swordfish has only species.
Conservation status on the IUCN list: Near-threatened
Scientific name: Xiphias gladius
Physical characteristics: Swordfish possess streamlined bodies with a distinctive sword-like bill used for hunting. They have dark blue-gray upper bodies, large oval eyes, and toothless mouths adapted for capturing prey.
Collective noun: a fleet of swordfish
Example sentence: A fleet of swordfish elegantly glided through the deep ocean waters, their sleek bodies slicing effortlessly through the currents as they pursued their prey with precision and agility.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: An interesting fact about swordfish is that they are one of the fastest fish in the ocean. They can swim at speeds of up to 50 miles per hour (80 kilometers per hour).
Pufferfish (a.k.a blowfish)
Number of animals left in the wild: Exact number is unknown, but 120 different species of pufferfish exist in the world today.
Conservation status on the IUCN list: Depends on species
Scientific name: Tetraodontidae
Physical characteristics: Blowfish, also known as pufferfish, inflate to deter predators, showcasing spiky defenses. With small fins, tapered bodies, and expressive faces, they exhibit vibrant colors and patterns.
Collective noun: a prickle of pufferfish
Example sentence: The divers were greeted by a prickle of pufferfish.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Many pufferfish contain tetrodotoxin, which is a deadly poison. This is to help ward off predators.
Stingray
Number of animals left in the wild: The exact number is unknown, but there is around 220 species.
Conservation status on the IUCN list: Dependent on species
Scientific name: Myliobatoidei
Physical characteristics: Stingrays have flat bodies resembling discs with wing-like pectoral fins for graceful swimming. They possess long, whip-like tails with venomous spines for defense.
Collective noun: a fever of stingray
Example sentence: At the aquarium, visitors gathered around the large tank to watch a fever of stingrays gracefully glide through the water
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Stingrays move by flapping their wings.
Other notable animals
Octopus
Number of animals left in the wild: 300 species, but exact number is unknown
Conservation status on the IUCN list: Differs depending on species
Scientific name: Octopus vulgaris
Physical characteristics: Octopuses have squishy bodies, big heads, and eight bendy arms with suction cups. They've got a bird-like beak in the middle of their arms for crushing food, and they're really good at changing color and texture to hide.
Collective noun: a consortium of octopuses
Example: A consortium of octopuses gracefully navigated the rocky seabed.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Octopuses have three hearts.
Squid
Number of animals left in the wild: Around 375 species, but exact number is unknown
Conservation status on the IUCN list: Differs according to species
Scientific name: Decapodiformes
Physical characteristics: Squid have torpedo-shaped bodies with a mantle holding their insides. They've got ten parts: eight arms and two longer tentacles, all with suckers. The beak grabs food, and they can quickly change color using special cells.
Collective noun: a shoal of squid
Example: In the deep, dark ocean, a shoal of squid swam together.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Squid have the largest eyes in the animal kingdom.
Seagull
Number of animals left in the wild: Around 50 species, but exact number is not known.
Conservation status on the IUCN list: Dependent on species
Scientific name: Larinae
Physical characteristics: Seagulls have sleek bodies and long wings that make flying easy. They're usually white with gray or black spots. Their hooked beaks, often yellow or orange, help them find food. They've got webbed feet and long legs for walking, wading, and swimming near the coast.
Collective noun: A flock of seagulls
Example sentence: The children laughed as they tossed breadcrumbs into the air, attracting a flock of seagulls that eagerly swooped down to snatch up the tasty treats.
Idiomatic phrase: a seagull approach
Example sentence: In the meeting, the manager exhibited a seagull approach.
Interesting fact: Seagulls are known to exhibit problem-solving skills, such as using bread as bait to catch fish or dropping shellfish onto hard surfaces to crack them open.
Pelican
Number of animals left in the wild: Eight species of pelicans, but exact number is not known.
Conservation status on the IUCN list: Dependent on species, but all fall under least concerned and near-threatened
Scientific name: Pelecanus
Physical characteristics: Pelicans are characterized by their large bill with an expandable pouch, long neck, webbed feet, and large wingspan.
Collective noun: a pod of pelicans
Example sentence: At the beach, I saw a big pod of pelicans flying together.
Idiomatic phrase: N/A
Example sentence: N/A
Interesting fact: Pelicans are ancient water birds.
Worksheet
Worksheet: Exploring Oceans and Seas
Instructions:
- Read each question carefully.
- Write your answers in the spaces provided.
- Feel free to use additional resources if needed.
1. Ocean and Sea Basics:
a. What is the main difference between an ocean and a sea?
Answer:
b. Name the five oceans of the world.
Answer:
c. List three seas.
Answer:
2. Marine Life:
a. Name three different animals that live in the ocean.
Answer:
b. Is an orca a whale or a mammal?
Answer:
c. Describe one adaptation that help a certain marine animal survive in the ocean.
Answer:
How to conserve the ocean and sea?
10 Ways to Help Our Ocean
At home
1. Conserve water: Use less water so excess runoff and wastewater does not flow into the ocean.
2. Reduce pollutants: Choose nontoxic chemicals and dispose of herbicides, pesticides, and cleaning products properly.
3. Reduce waste: Cut down on what you throw away.
Around town
4. Shop wisely: Choose sustainable seafood
5. Reduce vehicle pollution: Use fuel efficient vehicles, carpool or ride a bike.
6. Use less energy: Choose energy efficient light bulbs and keep the temperature on your thermostat low.
On the water
7. Fish responsibly: Catch and release practices to keep more fishes alive.
8. Practice safe boating anchor: Anchor in sandy areas far from coral and sea grasses. Adhere to "no wake" zone.
9. Respect Habitat: Healthy habitat and survival go hand-in-hand. Treat with care.
10. Anytime, Anywhere: Volunteer for cleanups at the beach and in your community.
Conclusion
"Just Keep Swimming" - Finding Nemo
In 2013, "Finding Nemo" was released, reawakening interest in sea animals. Although this classic tells the story of a father finding his lost son, it also touches on issues related to overfishing and habitat loss. Although people claim that the film created the "Nemo effect," studies of its sequel "Finding Dory" show that there was actually no correlation between the release of the movie and an increase in the sales of blue tang. What did happen was an increase in interest in the Blue Tang species. Raising awareness is great, but if we want fish to "just keep swimming" in the ocean, we should also actively be mindful of applying conservation practices in our daily lives.
Endangered Species How much of the Ocean has been explored? 22 Different Types of Sea Animals Sea All about otters Ocean and seas: what’s the difference? Defining the Differences Among the Bay, Gulf, Ocean & Sea TOP 10 FACTS ABOUT SHARKS Five “Real” Sea Monsters Brought to Life by Early Naturalists Sealioning Ocean Conservation Projects How can you help our ocean?
Share Article
