Submarines have been using low and mid-frequency active sonar technology, a deafening soundwave that is dangerous even 300 miles from it's source. Some mid-frequency sonar systems can put out over 235 decibals, which is about as loud as a rocket launch.
In the past few decades 90% of the big fish in the oceans have been eaten, or otherwise disposed of.
There is a an island of plastic and trash floating in the Pacific ocean that is twice the size of Texas.
The deepest area in the ocean is 35,800ft. or 6.78 miles deep. It is located at the Mariana Trench in the Pacific ocean. The average depth of the oceans is 12,500 feet.
An iceberg is a mass of ice that has detached from an ice sheet and is floating in the ocean. Icebergs pose an extremely dangerous situation for water vessels because only about 1/8 of the iceberg mass projects above the surface of the water.
Water pressure increases 15lbs. per 33 sq. ft. The greatest amount of water pressure ever recorded in the ocean is 15,000 lbs.
The term "league" is used for measuring long distance over land and is equal to 3 miles. Just to make things confusing a nautical "league" is a different measurement & is equal to 3 nautical miles or 3.452 miles.
The Battle of Normandy was the decisive battle of World War II fought in the summer of 1944 between the Allied nations and German forces. The Normandy Invasion, or D-Day, is the largest ocean-based invasions in history with nearly three million troops participating. The battle stretched from the English Channel to Normandy, France in German-occupied Western Europe.
The Antarctic (South) is a continent surrounded by ocean while the Arctic (North) is an ocean surrounded by continents.
Canada has the longest coastline of any country, about 243,000 kilometers, because it borders three oceans and has thousands of islands.
Despite its name, genetic research suggests the Abyssinian's ancestors most likely came from coastal regions around the Indian Ocean and Southeast Asia rather than Ethiopia.
Male humpback whales sing long, complex songs, likely to attract mates, and these songs change over time and can spread across entire ocean basins like a hit song.
When a whale dies and sinks to the ocean floor, its body becomes a "whale fall" that can feed entire deep-sea ecosystems for decades.
A penguin's black back and white belly are camouflage called countershading. From above it blends with the dark ocean, and from below it blends with the bright surface.
Mauna Kea in Hawaii is the tallest mountain in the world from base to peak, more than 33,000 feet when measured from the ocean floor.
Ocean phytoplankton produce about half of Earth's oxygen.
Seawater is about 3.5% salt.
The Sea Organ in Zadar, Croatia, built in 2005 by architect Nikola Bašić, is played by ocean waves.
An octopus has three hearts: two pump blood through the gills and one pumps it to the rest of the body.
About two-thirds of an octopus's neurons are in its arms, so each arm can sense and react somewhat independently of the brain.
Octopuses can change their skin color and texture in a fraction of a second, even though scientists believe they're colorblind.
In 2016, an octopus named Inky escaped from the National Aquarium of New Zealand by squeezing through a gap in his tank and sliding down a drainpipe to the sea.
Octopuses have no bones, so they can squeeze through any opening larger than their hard beak.
The most widely accepted plural of "octopus" is "octopuses," since the word comes from Greek, not Latin.
The coconut octopus carries coconut shells around and uses them as portable shelters, one of the first known examples of tool use in invertebrates.
One deep-sea octopus was observed guarding her eggs for about 53 months, the longest brooding period known for any animal.
Octopus suckers have chemical sensors that let them taste what they touch.
The UK's 2022 Animal Welfare (Sentience) Act recognized octopuses as sentient beings.
There are seven species of sea turtles.
The temperature of the sand decides whether baby sea turtles hatch male or female. Warmer nests produce more females.
Female sea turtles often return to nest on the same beach where they hatched, possibly using Earth's magnetic field to navigate.
The leatherback is the largest sea turtle, and it feeds mainly on jellyfish.
Sea turtles can't pull their heads and flippers into their shells like land turtles can.
Sea turtles appear to cry because they release extra salt through glands near their eyes.
Only about 1 in 1,000 sea turtle hatchlings is estimated to survive to adulthood.
Traditional "tortoiseshell" products came from the shells of hawksbill sea turtles.
Archelon was a prehistoric sea turtle that grew to about 15 feet long.
A tracked leatherback sea turtle swam more than 12,000 miles across the Pacific.
Jellyfish have no brain, heart, or bones, and their bodies are about 95% water.
The "immortal jellyfish" can turn back into an earlier life stage when it's stressed, possibly letting it avoid dying of old age.
Jellyfish have existed for more than 500 million years, long before the dinosaurs.
Box jellyfish have 24 eyes.
The lion's mane jellyfish can have tentacles more than 100 feet long.
A group of jellyfish is called a "smack" or a "bloom."
Peeing on a jellyfish sting is a myth and can make it worse. Vinegar is recommended for some stings, like those from box jellyfish.
Jellyfish were sent to space aboard the Space Shuttle Columbia in 1991.
A glowing protein from the crystal jelly led to the 2008 Nobel Prize in Chemistry.
Jellyfish aren't fish, so some scientists prefer to call them "sea jellies."
Male seahorses give birth. The female deposits eggs into the male's pouch, and he carries them until they hatch.
The dwarf seahorse is considered the slowest fish, moving about five feet per hour.
Seahorses can move each eye independently.
Seahorses have no stomach, so they need to eat almost constantly.
Seahorses use their tails to grab onto seagrass and coral.
Some seahorse couples greet each other with a daily dance.
The seahorse's genus name, Hippocampus, is also the name of a part of the brain, because of its similar shape.
Pygmy seahorses are so well camouflaged on sea fans that they're nearly invisible.
International trade in seahorses has been regulated by CITES since 2004.
Seahorses can beat their small fins up to about 50 times per second.
Orcas are apex predators with no natural predators.
Different orca pods have their own dialects of calls.
In some orca populations, sons stay with their mothers for life.
Orcas are one of the few species besides humans known to go through menopause.
In 2018, an orca named Tahlequah carried her dead calf for 17 days in the Pacific Northwest.
Since 2020, orcas off Spain and Portugal have been interacting with sailboats and damaging their rudders.
The Southern Resident orcas of the Pacific Northwest are endangered, with fewer than 80 left.
Orcas off South Africa have been seen hunting great white sharks.
Keiko, the orca from "Free Willy," lived at the Oregon Coast Aquarium before being released near Iceland.
A male orca's dorsal fin can be up to six feet tall.
Sea otters have the densest fur of any animal, up to about a million hairs per square inch.
Sea otters sometimes hold hands while sleeping so they don't drift apart.
Sea otters use rocks to crack open shellfish and may keep a favorite rock in a pouch under their arm.
Sea otters eat sea urchins, which keeps urchins from destroying kelp forests.
The fur trade nearly wiped out sea otters, leaving only about 1,000 to 2,000 by the early 1900s.
Sea otters eat about 25% of their body weight every day.
Unlike most marine mammals, sea otters have no blubber.
The sea otter is the smallest marine mammal.
The Monterey Bay Aquarium pairs orphaned sea otter pups with surrogate mothers.
A sea otter known as Otter 841 became famous in 2023 for stealing surfboards in Santa Cruz, California.
Manta rays have one of the largest brain-to-body ratios of any fish.
A 2016 study suggested manta rays may recognize themselves in a mirror.
Giant manta rays can have wingspans of more than 20 feet.
Manta rays are filter feeders and don't have stingers.
Each manta ray has a unique pattern of spots on its belly.
Manta rays can leap out of the water, which is called breaching.
Manta rays are threatened by hunting for their gill plates.
Manta rays visit "cleaning stations" where small fish eat parasites off them.
Manta rays are pregnant for about a year and usually give birth to one pup.
"Manta" means "blanket" in Spanish.
Clownfish are protected from anemone stings by a special mucus coating.
All clownfish are born male, and the dominant one in a group can become female.
"Finding Nemo" increased demand for clownfish as pets.
There are about 30 species of clownfish.
Clownfish live in groups with a strict size-based hierarchy.
Male clownfish guard the eggs.
Clownfish are commonly bred in captivity.
Clownfish make popping and clicking sounds.
Clownfish and anemones help each other in a mutualistic relationship.
Clownfish develop their stripes as they mature.
Starfish aren't fish, so scientists prefer to call them sea stars.
Sea stars can regrow lost arms, and some can regrow a whole body from a single arm.
Sea stars have a simple eye at the tip of each arm.
Sea stars push their stomachs out of their bodies to eat.
Sea stars have no blood and use seawater to move nutrients through their bodies.
Sea star wasting disease, which began in 2013, killed billions of sea stars along the Pacific coast.
There are about 2,000 species of sea stars.
Sea stars move using hundreds of tiny tube feet.
The crown-of-thorns starfish eats coral and can damage reefs.
Some sea stars, like the sunflower sea star, can have more than 20 arms.
A live giant squid was photographed in the wild for the first time in 2004 and filmed in 2012.
Giant and colossal squid have the largest eyes in the animal kingdom, about the size of a dinner plate.
Giant squid can grow to about 40 feet long.
Sperm whales eat giant squid and often have sucker scars from fighting them.
The giant squid may have inspired the legend of the Kraken.
A colossal squid was filmed alive in the wild for the first time in 2025.
Squid have hard beaks.
A squid's brain is shaped like a doughnut, and its esophagus passes through the middle.
The Smithsonian has a giant squid on display.
Giant squid stay buoyant using ammonia in their tissues.
A narwhal's tusk is actually a tooth that grows through its upper lip, and it's usually found on males.
A narwhal's tusk may contain millions of nerve endings.
In medieval times, narwhal tusks were sold as unicorn horns.
Denmark's Throne Chair is made largely of narwhal tusk.
Narwhals live in the Arctic.
Narwhals don't survive well in captivity.
"Narwhal" comes from an Old Norse word meaning "corpse whale."
Rarely, a narwhal grows two tusks.
Narwhals do most of their eating in winter.
Drone footage from 2017 showed narwhals using their tusks to stun fish.
The manatee's closest living relatives are elephants.
Christopher Columbus reported seeing "mermaids" in 1493 that were probably manatees.
The manatee is Florida's official state marine mammal.
Scientists identify individual manatees by scars from boat propellers.
Manatees eat about 10% to 15% of their body weight every day.
Manatees gather near power plants in winter for the warm water.
Manatees constantly replace their teeth, which move forward in a process called "marching molars."
Manatees are called "sea cows" because they graze on plants.
Manatees were reclassified from endangered to threatened in 2017.
Resting manatees can hold their breath for up to about 20 minutes.
A sea cucumber isn't a plant. It's a sea animal.
Jupiter's moon Europa likely has an ocean beneath its icy surface, and NASA launched the Europa Clipper mission in 2024 to study it.
About 99% of international internet data travels through cables on the ocean floor, not satellites.
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