Arctic animals in the water, or who is really not afraid of the cold

In Arctic water, every minute has a price. Rapid hypothermia, muscle stiffness, the cost of energy increasing with every movement. It’s an environment that tests the body without mercy. And yet Arctic animals are able to function in these conditions on a daily basis: they hunt, rest, breed and raise their young. How is this possible? Learn about their ways to survive.

Arctic animals in the water – masters of adaptation

Ringed seal

The ringed seal(Pusa hispida) is one of the mammals best adapted to life in Arctic water. It is the smallest and most abundant representative of its genus in Arctic waters, and the sea in which it swims can have temperatures as low as -1.8°C. Its dense fur consists of two layers: a protective exterior and an air-trapping undercoat. Under the skin is a layer of fat (blubber) 5-10 cm thick, which limits heat loss and provides an energy reserve for times of hunger.

Most impressive is the ability to create special breathing chambers and burrows under the snow. Seals maintain their breaks by using the claws of their front flippers to break up and scrape off fresh ice. This gives them a place where they regularly emerge for air when hunting under the ice cover. A ringed seal can stay underwater for up to several minutes and descend to depths of 150-200 meters. When submerged, an oxygen-saving reflex is activated in its body – the heart beats more slowly and blood circulates primarily to the brain and muscles. The vibrissae (sensory whiskers) of the ringed seal act like sonar – allowing it to detect fish and crustaceans in the total darkness prevailing under thick ice.

Protecting the young is also important. Seals use snow drifts on the ice to create chambers in which they give birth and hide their offspring. Such a snow burrow shields from the wind, muffles sounds and provides more stable thermal conditions than an open sheet. For a toddler, it is the first safe haven – if it has warmth and peace, it grows faster and builds up a reserve of energy.

Walrus

The Arctic walrus(Odobenus rosmarus) is a realcolossus– an adult male weighs as much as 1,200-1,800 kg, and its tusks can reach about 1 m in length. They help climb ice floes and maintain position on their slippery surface, and are a tool for defense if necessary. Thick skin (up to 4 cm) and a layer of fat act as thermal armor when the animal is in the water for a long time. Walruses under water move quietly and sparingly, because with such weight any unnecessary effort quickly raises the energy cost.

The walrus can dive to 80-100 meters and hold its breath for 20-30 minutes, hunting for clams, which it extracts from the bottom with its vibrissae and the sucking motion of its tongue. It lives in huge herds (sometimes several thousand individuals in one place), which provides a sense of security and warmth.

Pingwiny – ptaki, które pływają

Sea otter

The sea otter(Enhydra lutris) has a different way of protecting itself from the cold than most marine mammals. It does not rely on building a thick layer of fat – its shield is fur, the densest in the mammalian world (there are about 155,000 hairs per ^cm2 of skin). This density traps a thin layer of air, which acts as an insulator and limits the body’s direct contact with icy water. The problem is that this insulation only works if the fur is perfectly maintained.

That’s why otters spend a lot of time grooming: they clean their hair and style it to keep it tight. When this protection fails, the body cools down much faster – and since otters have a very fast metabolism, they balance this with food: they can eat up to 25% of their body weight (usually about 4-8 kg of food per day), hunting crabs, sea urchins and clams, among other things. Interestingly, sea otters have a loose fold of skin under their armpit in which they carry tools, most often a stone for breaking hard shells.

Otters also help themselves survive in adverse conditions by their lifestyle. They often rest on the surface, and when they sleep, they wrap themselves in seaweed so that the current doesn’t carry them out to sea – a simple way to conserve energy when the body needs regeneration.

Polar bear

The polar bear(Ursus maritimus) is often referred to as a sea bear – and rightly so, since it spends much of its life precisely in the water or on its border with the ice. Its wide paws with buoyant membranes act like oars, allowing it to swim for long, continuous periods – there have been cases of covering more than 100 kilometers without a break.

Under water and on ice, the bear is well protected from the cold. Its dense, translucent fur reflects light well and traps air, and underneath it is a layer of fat up to 10 centimeters thick, which not only insulates, but also provides a huge energy reserve. This allows the bear to maintain a constant body temperature (37°C), even when swimming for hours in water near 0°C.

The most effective hunting, however, takes place on the sea ice. The bear then uses patience and an excellent sense of smell – it can sense a seal under a meter-thick layer of snow and ice. Most often it lurks at the breathing hole, and when the prey emerges to breathe, it pulls it to the surface in one swift movement. In open water, capturing prey is much more difficult, so polar bears avoid long swims if they can.

In spring and summer, when the ice is stable and seals are easily accessible, bears accumulate gigantic fat reserves – up to 50 percent of their body weight. It is this reserve that allows them to survive the long months of starvation in autumn and winter, when the ice becomes unpredictable and prey less available.

Females additionally build lairs (so-called mother lairs) in the snowdrifts, where they give birth to cubs in the middle of winter and stay hidden with them for weeks. For the little ones, this is a time of rapid growth. At first they weigh only 600-800 g, but thanks to their mother’s very fat milk they grow quickly and gain strength to go out on the ice and start learning to live in a world that does not forgive mistakes.