The enigmatic depths of the Arctic deep sea, are a realm where extraordinary animals have evolved to survive one of the planet’s harshest environments.
From the red hues of deep-sea anemones to the scavenging behaviours of armoured isopods, each organism plays a critical role in maintaining the delicate balance of life in the Arctic’s deep ocean.
The incredible species featured in these photos are from The Nippon Foundation-Nekton Ocean Census Arctic Deep Expedition in May 2024. The Ocean Census, in collaboration with UiT, will be hosting a taxonomic workshop in October – where scientists will be unveiling further details of our Arctic Deep samples.
Featured image credits: The Ocean Census
Red in the Deep Arctic Ocean
Bright red isn’t something you would normally associate with the Arctic, let alone in the depths of the arctic ocean, where there is no light, there are many varied species with red colouration. This is because being red acts as an effective form of camouflage due to the absence of red light past a certain depth. Red light is absorbed and scattered by water, causing red objects to appear black and blend into the dark surroundings, making red-coloured sea creatures nearly invisible to predators.
But even at the extreme depths of the arctic deep expedition, thousands of metres below any sunlight, the team still encountered many red creatures. Scientists believe this is because red pigmentation is more energy-efficient to produce than other colours.
Some creatures produce their own light through bioluminescence. These bioluminescent organisms often emit blue or green light, which travels further in water. Since red fish don’t reflect blue or green light well, they remain largely undetectable even when near bioluminescent organisms.
This led to some stunning colourful images taken on expedition of which we will go into below.
Threadfin Snailfish
Found at a depth of 2461 metres at the Jøtul Vent Field, the Threadfin Snailfish thrives under the extreme conditions of the Arctic deep-sea. This member of the Liparidae (snailfish) family is distinguished by its delicate whisker-like barbels, which are sensory organs that help it detect movement and vibrations in the pitch-black waters.
‘Hairy’ Decapod Shrimp
Thriving at a depth of 3000 metres near the hydrothermal vents of the Jøtul Vent Field, the ‘Hairy’ Decapod Shrimp shows a fascinating cohabitation.
The “hairs” are actually bacteria that perform a remarkable chemical transformation, converting the vent’s toxic hydrogen sulphide into energy. This unique adaptation allows the bacteria to exploit the chemical-rich waters of their extreme environment, turning deadly gases into a source of sustenance.
Mysid Shrimp
Small but formidable survivors of the deep ocean’s extreme environment. These shrimps are distinguished by their large, sensitive eyes that allow them to detect the faintest light in near-total darkness. Covering their bodies and antennae are fine, sensory hairs called setae. These setae detect chemical signals and movements in the water, aiding in navigation and the location of food particles.
Scavenging in the Arctic Deep Sea
Arctic deep-sea species rely on scavenging to survive, feeding on dead animals, organic matter, and other detritus that sinks from the upper ocean layers. The lack of sunlight prevents photosynthesis, so there is little plant life or primary production.
This opportunistic feeding strategy is crucial in such a nutrient-poor environment, allowing these creatures to make the most of any available resources to sustain themselves.
Armoured isopods
These crustaceans, equipped with formidable exoskeletons, are superbly adapted to the extreme conditions of hydrothermal vents and cold seeps found at great depths. Armoured isopods, with their rigid, segmented shells protect them from predation. Isopods primarily as scavengers, breaking down detritus.
Ampharetidae Worms
This family of polychaete worms constructs intricate burrows or tubes within the ocean floor’s sediment, which serve not only as their homes but also as crucial structures for the surrounding ecosystem. These burrows enhance the sediment’s stability and facilitate nutrient cycling, playing a vital role in the sediment ecosystem.
White sea star
The white sea star stands out not just for its striking colour but also for its crucial role in the deep-sea ecosystem. As a prominent benthic predator and scavenger, this sea star contributes significantly to the ecological balance by consuming dead or decaying matter along with small organisms.
Red Sea Star
Found at a depth of 2776 metres on the Knipovich Ridge, this Red Sea Star is a vibrant example of deep-sea biodiversity. Its striking red coloration stands out against the dark ocean floor. Sea stars like this play a critical role in their ecosystems, acting as both predators and scavengers.
Armed for survival in the Arctic Deep
Arctic deep sea creatures often have long arms to enhance their ability to capture food and navigate their environment. In the dark, vast expanses of the deep ocean, long arms allow them to reach and grasp prey or food particles that might be sparse and widely dispersed.
These extended limbs also help in sensing their surroundings, as they can detect vibrations, chemical signals, and movements in the water, which are crucial for locating food and avoiding predators in the pitch-black depths. Additionally, long arms can aid in mobility, helping these creatures move across the seafloor or through the water more efficiently.
Comatulid Crinoid
Commonly known as feather stars, this species demonstrates an astonishing level of adaptability. These crinoids are free-moving and utilise their long, feather-like arms both for locomotion and as efficient tools to capture floating food particles in their deep-sea habitat.
Dark Red Anemone
The anemone’s deep red may be a result of its diet. Seen here with its familiar tentacles retracted, anemones like this are important players in their ecosystem, serving as habitats for a variety of marine species while also capturing small creatures with their venomous tentacles.
Keep up to date with all of our further findings from the Arctic Deep workshop, commencing on the 1st October, by following The Ocean Census on our socials.
