Thousands of metres below the ocean’s surface, incredible deep sea creatures live in the cold darkness.
Creatures like the ghost fish, dumbo octopus and deep sea urchin are examples of animals that have adapted to their unique deep-ocean environment.
But their habitat and that of many other marine creatures could be under threat if deep sea mining gets the go-ahead.
The deep sea is broadly defined as the depth where there is less light, at about 200 metres below the surface and below – extending thousands of meters below the surface. Freezing temperatures and high pressure make it an especially difficult environment to explore.
Many of the lifeforms of the ocean floor are yet to be discovered and have been as yet undisturbed by human activity. Over 80% of the oceans remain unexplored.
Creatures of the Pacific Ocean zone proposed for deep sea mining
Scientists from the US’s National Oceanic and Atmospheric Administration (NOAA) have discovered these creatures living near the ocean floor, in the Clarion-Clipperton Zone (CCZ) in the Pacific Ocean.
They are threatened by proposals for deep sea mining. Huge machines would dredge up the seafloor to collect potato-sized polymetallic nodules containing manganese, cobalt, nickel and copper.
To survive the harsh environment with little sunlight or food, in the constant cold and under extreme pressure, deep sea creatures have developed some remarkable adaptations. Many are transparent like the ones pictured above, to remain hidden from predators.
Deep sea fish are characterised by big sharp teeth, expandable bodies and large mouths, whilst some creatures produce their own light.
Meet some of the incredible creatures that could be under threat from deep sea mining
Dumbo octopus
Dumbo octopuses live in the deep ocean, up to 4000 metres down. Their dots are clear windows in the skin that gather additional light.
Their ear-like fins – used for moving slowly around – are reminiscent of Disney’s flying elephant, hence the name.
Deep-water decapod
Young Sergestes crayfish have finely branched antennae that allow them to float freely in the water. Adult Sergestes crayfish are able to prevent casting shadows in the twilight by using weak bioluminescence (self-produced light) on the underside of their bodies, camouflaging themselves from predators lurking below. The intensity of their glow is adapted to the amount of light coming from above.
Swimming sea cucumber
Swimming sea cucumbers – also known as “headless chicken monsters” – have a special “flap” which they use to “lift” themselves off the seafloor, up to 1000 metres through the water column.
They lack lungs or gas-filled spaces, making them more well-adapted to the intense pressures of the deep ocean. The transparent body reveals the sediment-filled intestine looping around from the mouth (top) to the anus (bottom).
Egg case of a catshark
In 2018, scientists found a translucent egg case with a catshark embryo actively swimming inside. Catsharks lay their eggs in a leathery egg case made of keratin – the protein found in hair and nails – onto the seabed.
Inside the egg case the embryo feeds on the egg yolk. It can take 5–11 months for it to hatch.
Bobtail squid
Bobtails, sometimes referred to as “dumpling squid”, usually live in shallow coastal waters. They are about as big as your thumb and have a special light organ in their body allowing them to generate a glow, cancelling out their shadow and thereby camouflaging them. This bobtail is a benthic species, which means it lives at the bottom of the ocean.
Helmet jellyfish
The Helmet jellyfish species is very sensitive to light due to its red pigment. It lives in the much deeper parts of the oceans to avoid light.
The red pigment is very useful for warning predators and for sending signals amongst themselves. Helmet jellyfish don’t have eyes or a brain, but instead use a simple sensory bulb that detects changes in light.
Ghost fish
The ghost fish is found at around 1,850 metres below the surface of the ocean. These fish are distant relatives of sharks and have skeletons made out of cartilage.
The lateral lines running across are “mechano-receptors” that detect pressure waves, just like ears. The dotted lines on the frontal portion of the face help detect disturbances in electrical fields created by other living organisms.
Whipnose angler and Common fangtooth
The Whipnose angler has an enlarged first filament of its dorsal fin – called the illicium – with a bioluminescent light-emitting organ at its end.
The teeth of the Common fangtooth are so long that the fish can only close its mouth by stowing them in two cavities to the right and left of its brain.
Imagine these slow-moving creatures, in an environment with almost no light being confronted with an enormous, loud mining machine with headlights on each side. Deep sea mining will be hugely disruptive and could wipe out these habitats and their uniquely adapted species.
Take action
Deep sea mining could do long lasting and irreversible damage to the oceans. Tell the government to ban deep sea mining.