Are you fascinated by the vast expanses of our planet’s oceans and all the mysteries they hold? The ocean is an incredible, almost otherworldly place filled with intriguing phenomena, magnificent creatures, and intricate ecosystems. It covers more than 70% of the Earth’s surface and yet, a significant portion of it remains unexplored. To celebrate the depth and breadth of the world’s oceans, we’ve curated a list of 100 ocean trivia questions and answers. Test your knowledge, challenge your friends, and dive into the unknown with these intriguing facts about our oceans. Let’s see how many you know already, and how much you’re about to learn! If you want to learn more about our oceans you can check out Ocean Insider .
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1. What is the largest ocean on Earth? Reveal Answer The Pacific Ocean 2. What percentage of Earth’s surface is covered by oceans? Reveal Answer Approximately 71% 3. How deep is the deepest part of the ocean? Reveal Answer The Mariana Trench is the deepest part, with a depth of nearly 36,000 feet (almost 11,000 meters) 4. What is the saltiest sea? Reveal Answer The Red Sea is the saltiest sea 5. What is the least salty ocean? Reveal Answer The Arctic Ocean is the least salty ocean 6. What is the largest living structure on Earth? Reveal Answer The Great Barrier Reef 7. What percentage of marine species are yet to be discovered? Reveal Answer Estimates suggest 80-90% 8. What ocean zone receives the most sunlight? Reveal Answer The Epipelagic Zone, also known as the Sunlight Zone 9. What is the average temperature of the ocean? Reveal Answer Around 2 to 3 degrees Celsius 10. Which ocean is the smallest? Reveal Answer The Arctic Ocean 11. Which country has the longest coastline? Reveal Answer Canada 12. What are baby whales called? Reveal Answer Calves 13. What is the world’s largest oceanic trench? Reveal Answer The Mariana Trench 14. What percentage of the Earth’s oxygen is produced by the ocean? Reveal Answer About 50-70% 15. What is the most common gas dissolved in seawater? Reveal Answer Nitrogen 16. What is the largest species of shark? Reveal Answer The Whale Shark 17. Which ocean is the warmest? Reveal Answer The Indian Ocean 18. Which is the largest sea on earth? Reveal Answer The Philippine Sea 19. What is the main mineral in sea water? Reveal Answer Sodium Chloride 20. How much of the world’s water is contained in the ocean? Reveal Answer About 97% 21. What ocean surrounds the Bermuda Triangle? Reveal Answer The Atlantic Ocean 22. What is the longest mountain range in the world? Reveal Answer The Mid-Oceanic Ridge 23. What ocean has the most islands? Reveal Answer The Pacific Ocean 24. What is the highest tide recorded and where? Reveal Answer The highest tide recorded was 58.8 feet in the Bay of Fundy, Canada 25. What is the largest source of marine pollution? Reveal Answer Plastics and microplastics 26. What ocean is the saltiest? Reveal Answer The Atlantic Ocean 27. What type of ocean wave is caused by an earthquake? Reveal Answer A Tsunami 28. Which ocean is the coldest? Reveal Answer The Arctic Ocean 29. What are the ‘seven seas’? Reveal Answer The ‘seven seas’ traditionally refers to the Arctic Ocean, the Atlantic Ocean, the Indian Ocean, the Pacific Ocean, the Mediterranean Sea, the Caribbean Sea, and the Gulf of Mexico 30. What is the largest sea creature? Reveal Answer The Blue Whale 31. What’s the deepest scuba dive ever recorded? Reveal Answer The deepest scuba dive ever recorded is 332.35 meters by Ahmed Gabr in 2014 32. What is the largest coral reef? Reveal Answer The Great Barrier Reef 33. What’s the fastest marine animal? Reveal Answer The Sailfish 34. What are ocean currents? Reveal Answer Ocean currents are continuous, directed movements of ocean water 35. What is the main driver of the ocean’s currents? Reveal Answer The main drivers of ocean currents are the wind, the rotation of the Earth, and the density differences in water masses 36. What’s the name of the ocean current that is also known as the ‘Global Conveyor Belt’? Reveal Answer The Thermohaline Circulation 37. What’s the most venomous marine animal? Reveal Answer The Box Jellyfish 38. What is bioluminescence? Reveal Answer Bioluminescence is the production and emission of light by a living organism, often found in marine animals 39. What is the loudest sea creature? Reveal Answer The Sperm Whale 40. What is the average lifespan of a sea turtle? Reveal Answer Depends on the species, but generally 60-80 years 41. What are ‘right whales’ named after? Reveal Answer They were considered the ‘right’ whales to hunt because they float when dead and yield a high amount of oil 42. What are the colors of a coral reef due to? Reveal Answer The colors of a coral reef are largely due to the pigments in the symbiotic algae living in their tissues 43. What are hydrothermal vents? Reveal Answer Hydrothermal vents are places where hot, mineral-rich water flows out from the seafloor 44. What marine creature can regenerate its own limbs? Reveal Answer Starfish 45. What is the most common type of pollution affecting marine turtles? Reveal Answer Plastic waste 46. What is the largest species of penguin? Reveal Answer The Emperor Penguin 47. What is the name of the small fish that clean parasites off of other fish? Reveal Answer Cleaner wrasses 48. What marine mammal is known for its ‘song’? Reveal Answer The Humpback Whale 49. What causes red tides? Reveal Answer Red tides are caused by an overgrowth of harmful algal blooms 50. What is the average depth of the world’s oceans? Reveal Answer The average depth of the world’s oceans is about 3,800 meters (12,500 feet) 51. What marine creature has the longest lifespan? Reveal Answer The Greenland Shark, with a lifespan of up to 500 years 52. What causes the ocean’s blue color? Reveal Answer The ocean appears blue because water absorbs colors in the red part of the light spectrum more quickly than colors in the blue part of the spectrum 53. Which marine creature is the heaviest on Earth? Reveal Answer The Blue Whale 54. What is the biggest threat to coral reefs? Reveal Answer Climate change, specifically warming ocean temperatures 55. What does the term ‘pelagic’ mean? Reveal Answer Pelagic refers to the open sea or ocean that is not near the coast or sea floor 56. What are mangroves? Reveal Answer Mangroves are trees and shrubs that live in tropical coastal intertidal zones 57. What are kelps? Reveal Answer Kelps are large brown algae seaweeds that make up the order Laminariales 58. Which creature creates the largest single structure made by living organisms? Reveal Answer Coral, forming the Great Barrier Reef 59. What’s the only sea without any coasts? Reveal Answer The Sargasso Sea 60. What type of fish is Nemo from the movie ‘Finding Nemo’? Reveal Answer Nemo is a Clownfish 61. What’s the largest species of dolphin? Reveal Answer The Orca, or Killer Whale 62. What is ‘brackish’ water? Reveal Answer Brackish water is water that has more salinity than fresh water, but not as much as seawater 63. What is the ‘Abyssal Zone’? Reveal Answer The Abyssal Zone is a layer of the pelagic zone of the ocean at depths of 4,000 to 6,000 meters (13,123 to 19,685 feet) 64. What’s the smallest ocean? Reveal Answer The Arctic Ocean 65. What is the ‘Twilight Zone’ in the ocean? Reveal Answer The ‘Twilight Zone’ is a part of the ocean 200 to 1,000 meters below the surface where light fades away 66. What causes ocean tides? Reveal Answer Ocean tides are caused by the gravitational forces exerted by the Moon and the Sun, and the rotation of the Earth 67. What is a group of jellyfish called? Reveal Answer A group of jellyfish is called a ‘bloom’, ‘swarm’ or ‘smack’ 68. What is the name for a large system of rotating ocean currents, particularly those involved with large wind movements? Reveal Answer Gyres 69. What is a seiche? Reveal Answer A seiche is a standing wave in an enclosed or partially enclosed body of water 70. What is a fjord? Reveal Answer A fjord is a long, deep, narrow body of water that reaches far inland, often set in a U-shaped valley with steep walls of rock on either side 71. What’s the name of the underwater mountain range in the Atlantic Ocean? Reveal Answer The Mid-Atlantic Ridge 72. What’s the term for the study of oceans? Reveal Answer Oceanography 73. What is the name of a young fish? Reveal Answer Fry or fingerling 74. What is the name of the largest oceanic dolphin? Reveal Answer Killer Whale or Orca 75. What is a group of fish called? Reveal Answer A school 76. What percentage of life on Earth is aquatic? Reveal Answer About 80% 77. Which ocean is the second largest? Reveal Answer The Atlantic Ocean 78. What is the Mariana Trench? Reveal Answer The Mariana Trench is the deepest part of the world’s oceans, located in the western Pacific Ocean 79. Which country has the most coral reefs? Reveal Answer Australia 80. What’s the oldest ocean? Reveal Answer The Pacific Ocean is considered to be the oldest ocean 81. What’s the name of the boundary that separates the lighter surface waters from the deeper, heavier waters? Reveal Answer The Pycnocline 82. What’s the scientific term for water pressure? Reveal Answer Hydrostatic pressure 83. What is the ‘Ring of Fire’? Reveal Answer The ‘Ring of Fire’ is a major area in the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur 84. What are ocean trenches? Reveal Answer Ocean trenches are long, narrow depressions on the seafloor, and are the deepest parts of the ocean 85. What are phytoplankton? Reveal Answer Phytoplankton are tiny photosynthetic organisms that live in the upper, sunlit layer of almost all oceans and bodies of fresh water 86. What is a riptide? Reveal Answer A riptide, or rip current, is a strong, offshore current that is caused by the tide pulling water through an inlet along a barrier beach 87. What are zooplankton? Reveal Answer Zooplankton are small, often microscopic animals that live in the water column of almost all water bodies, including oceans 88. What is the Great Barrier Reef? Reveal Answer The Great Barrier Reef is the world’s largest coral reef system, located off the coast of Queensland, Australia 89. What’s the average salt content in sea water? Reveal Answer About 3.5% 90. What’s the name of a famous shipwreck found in the Atlantic Ocean? Reveal Answer The Titanic 91. What is ‘Nurdles’? Reveal Answer Nurdles are tiny pellets of plastic that are shipped globally to be melted down and moulded into new plastic products 92. What’s the largest fish in the ocean? Reveal Answer The Whale Shark 93. Which fish has the highest number of species? Reveal Answer Perch 94. What is the smallest sea? Reveal Answer The Sea of Marmara 95. What’s the term for the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes? Reveal Answer Thermohaline Circulation Sharing is Caring:
