Blue Planet: The Fight to Save the World's Oceans


Videos, Infographics & Photo Galleries

Watch Divers Free Sharks and Other Marine Animals Caught in Deadly ‘Ghost Nets’

Trawlers traverse the world’s oceans with giant nets that incidentally kill hundreds of millions of marine mammals and fish not targeted by commercial fishing operators. Worse, when that gear is abandoned or becomes lost, these “ghost nets” can continue to catch fish, dolphins, seals, sea turtles, and other marine life for decades. Nonprofits around the world are forming alliances to combat this global issue.

Watch more videos from Blue Planet


We have barely begun to understand the mysteries of the ocean, yet humans have already inflicted considerable damage to marine life. Overfishing, plastic pollution, and ocean acidification are taking their toll on coral reefs and the creatures that depend on them.

The deep ocean, meanwhile, is home to a kaleidoscope of little-known sea creatures, from worms shaped like Christmas trees and an octopus that can transform itself into facsimiles of other marine animals to a light-emitting squid.

Here are just 10 of some of the most amazing animals that survive in the deepest depths of the ocean.


Christmas Tree Worms

Despite their name, Christmas tree worms don’t actually feed on firs. Picture a miniature, artificial Christmas tree, except instead of green branches, imagine them in a plethora of Technicolor shades. Each worm has a tube-like body from which two brightly colored crowns protrude. The crowns are composed of hair-like tentacles that help the worm catch its food—microscopic plants and phytoplankton—and breathe. The inch-and-a-half Christmas tree worms anchor themselves in burrows they dig into live coral, so only their crowns are visible. 

(Photo: Wild Horizons/UIG via Getty Images)


Atlantic Wolffish

These sinister-looking fish, straight out of a horror movie, produce a natural antifreeze that keeps them mobile in extremely cold waters. Their distinctive canine-like teeth help them eat a steady diet of crab and sea urchins, which would otherwise multiply more rapidly. While they look scary, they are vulnerable to commercial fishing, which has shrunk their numbers and destroyed their habitat.

(Photo: myLoupe/Universal Images Group via Getty Images)


Leafy Seadragon

Fish or plant? Ingenious at camouflage, the leafy seadragon appears to be a floating plant but is a fish with almost transparent fins that help propel it through the water. Similar to a sea horse, it lives on the Australian coast and feeds on zooplankton and shrimp by sucking them down its long tube snout. 

(Photo: Desmond Morris Collection/UIG via Getty Images)



It could win first place for the world’s saddest-looking fish. Or for its unfortunate, large, nose-like protrusion that could have been shaped by a cartoonist. The  slimy blobfish lives in the deep ocean in a high pressure environment. Life that far below the surface accounts for its appearance as its blubbery body makes it possible to stay buoyant at depths of 1,200 feet. Rarely seen by humans, the blobfish lives off  the Australian east coast, and scientists think the gelatinous fish may be close to extinction.


Red-Lipped Batfish

Instead of putting lipstick on a pig, try putting it on the batfish. At least, that’s what it looks like this fish did. The red-lipped batfish is found near the Galápagos Islands—it can’t swim well, so it "walks" on the ocean floor

(Photo: Rein Ketelaars)


Mimic Octopus

You could call this creature the shape-shifter of the seas. The mimic octopus is even more talented than the average octopus in changing color and shape to camouflage itself—it can actually impersonate other animals to fool predators. The mimic octopus can transform itself to resemble banded sea snakes or lionfish, which are less-edible forms of sea life. First spotted around the Indonesian coast in the 1990s, it has since been sighted by divers at Australia’s Great Barrier Reef.

(Photo: Steve Childs) 


Firefly Squid

Talk about Fourth of July fireworks in the sea! The firefly squid is a tiny creature whose light show puts to shame other deep-ocean bioluminescent organisms. The three-inch-long firefly squid’s body sports thousands of photophores that produce flashing light. The squids use the glow to communicate with potential mates, to throw predators off track, and to attract their own prey, typically tiny fish. When millions of them gather to spawn off the coast of Japan, they’re famous for the light show they put on.

(Photo: Facebook)


Dumbo Octopus

Nicknamed "Dumbo" after the elephant in Disney’s famous cartoon because of its floppy, ear-like fins, this eight-inch-tall oddball lives at depths of up to 13,000 feet. Dumbo, however, never flies up to the surface to see sunlight, remaining instead on the ocean floor and feeding on snails and worms. 

(Photo: NOAA)


Clown Frogfish

Yet another trickster that’s expert at camouflage, the clown frogfish lives among sheltered, rocky coral reefs. It can have warts, spots, and stripes, and comes in a variety of colors, changing its look every few weeks. Not a very social creature, it lives alone except during mating season. 

(Photo: Thesupermat) 


Giant Oarfish

Ever wonder about the origin of sea serpent tales? They may well be based on the giant oarfish, whose sinewy body can grow up to 56 feet and weigh 600 pounds. It is the world’s longest bony fish but it is not dangerous to humans, as it doesn't have teeth and it feeds on tiny plankton. Japanese folktales say giant oarfish foretell earthquakes when they show up in large numbers on shore.

(Photo: NOAA) 


Plastic pollution, overfishing, and climate change are all taking an enormous toll on the planet’s life-support system. The oceans are acidifying, sea levels are rising, and coral reefs home to myriad fish species are dying.

But it’s not all doom and gloom.

Scientists, activists, and ordinary citizens are rallying to protect the oceans and are pushing to make huge swaths of the most sensitive marine areas off-limits to oil and gas drilling and other potentially destructive development. New technologies are proving crucial in that fight.

Here are five high-tech solutions that are helping to save the seas. 


A Vacuum Cleaner for Ocean Plastic


When 17-year-old Boyan Slat went diving in Greece in 2011, he was frustrated to come across more plastic than fish. Last year, he founded The Ocean Cleanup, which has developed a technology to extract plastic pollution from the oceans. Here’s how it works: Ocean currents force plastics to accumulate in front of an array of solid floating barriers and platforms anchored to the seabed. That allows the trash to be retrieved for recycling while fish and other marine animals swim unimpeded under the barriers. Small-scale testing has been completed and the array is being ramped up for pilot testing, with full-scale deployment planned for 2019. 

(Photo: The Ocean Cleanup)


Oceangoing Robots

Dispatching ships to remote seas to investigate climate change and conduct other scientific research can cost tens of thousands of dollars a day and puts crew members’ lives at risk. Better to send in the robots. Silicon Valley start-up Liquid Robotics makes the Wave Glider, an autonomous wave- and solar-powered robot that can traverse the world’s oceans, collecting and transmitting gigabytes of data on weather conditions and water temperature, chemistry, and quality. A fleet of the 250-pound, surfboard-size ’bots is roaming the seven seas, going where no robot has gone before.

(Photo: Liquid Robotics)


Safety Nets for Sea Life

Every year, billions of pounds of marine animals are inadvertently caught in fishing nets pulled by trawlers. Commercial fishing operators also throw out tons of good fish when their haul exceeds quotas. To help reduce all that loss of marine life, a British designer has invented the SafetyNet. The net is studded with blinking LED rings that guide juvenile fish to the openings so they can escape when they accidentally get caught. A larger mesh panel allows unwanted bottom-dwelling species to escape through bigger holes. Existing fishing nets can also be retrofitted with the LED rings.

(Photo: SafetyNet Technologies)


Deep Ocean Explorers

We’ve moved on from the days of manned submersibles to explore the mysteries of the ocean to remotely operated vehicles that are highly maneuverable and can be controlled by crews on board a vessel. Equipped with robotic arms, lights, cameras, sensors, and sampling devices, ROVs can go where it’s too remote, expensive, or dangerous for scientists to venture to discover new marine life and investigate the impact of humans. 

(Photo: NOAA)


Tuna Tagging

Sushi lovers have made bluefin tuna so valuable that it isn't just overfished; it has experienced a 95 percent drop in population in the last few decades. In an effort to track bluefin tuna movements and understand their behavior to better guide conservation efforts, scientists have developed tagging technology that the Monterey Bay Aquarium humorously calls “fish and chips.” Biologists implant electronic tags into the bellies of the tuna that collect data on the fishes’ movements, body temperature, and other information. Anglers who catch the fish can return the tag for a $1,000 reward. Satellite tags are attached to tuna with dart guns and are programmed to detach from the fish. Beachgoers and fishers who find and return the tag are given a $500 reward. 

(Photo: Tag-a-Giant)