How you survive the coldest place on Earth - Nadia Frontier
The vast, white ice surface of Antarctica
stretches for over 3 million
square kilometers:
empty, desolate,
and almost completely silent.
But appearances can be deceiving.
On the coast of this expanse,
just a few meters beneath the ice
lies a multicolored constellation of life.
This remarkably diverse realm is home
to over 8,000 species of sea denizens
who rely on an arsenal
of otherworldly traits to survive.
So how do these species not only live,
but thrive,
in conditions most animals
would be unable to bear?
Antarctic waters are some of the most
consistently frigid in the world,
hovering below 0 degrees Celsius
for a large portion of the year.
This means burning energy
too quickly can be deadly,
so survival in this ecosystem
looks slow and steady.
Freezing temperatures persist
even in the summer,
but this season brings
a rare gift: sunlight.
For a brief period, it’s abundant,
shining through the ice
for 24 hours a day.
This infusion of energy drives intense
coastal phytoplankton blooms,
transforming the waters
into a thick green soup.
Marine life both large and small
takes advantage of this bounty,
including the giant Antarctic isopod.
Cousins of the humble pill bug,
these crustaceans can reach
up to 11 centimeters long,
and they never miss the opportunity
for a meal.
The scavengers eat a wide variety of prey,
including other giant isopods.
And by slowing their metabolisms,
they can make this food last,
with one study showing specimens surviving
for 50 days without eating.
Since this adaptation involves careful
conservation of energy,
giant isopods spend most of their time
stationary or inching across the seafloor.
Meanwhile, their tiny amphipod relatives
celebrate the summer
by releasing offspring
alongside the algal explosion,
ensuring their young have
an abundance of food.
And sea cucumbers carpeting the seafloor
hoover up the dense plankton
with outstretched
tentacles,
producing nutrient-rich feces
that nourish nearby life.
But this big summer blowout
doesn’t last long.
The first signs of autumn arrive
in fine needles of frazil ice.
These slowly coagulating crystals
form a skin across the surface,
then mix with falling snow
before freezing into a thin crust of ice.
The waters get darker and colder.
And in this swiftly dimming world,
a set of long, spiky limbs
sidle into view.
With up to six pairs of legs,
these giant sea spiders aren’t arachnids,
but rather a related class of marine
arthropod unique to the seafloor.
In addition to housing some
of the animal’s organs,
its legs are covered in tiny holes,
which grow more numerous
as the spider ages.
These holes will likely help absorb
the dissolved oxygen
that saturates these freezing
southern waters.
Since oxygen fuels growth,
many local species have evolved
to take advantage of this abundance,
and it may be one of the reasons that
gigantism is so common in this region.
Individual sea spiders, for instance,
can grow to the size of dinner plates.
But soon, these underwater giants
will be moving slower than ever.
As winter settles in,
the sea floor becomes even colder.
Waters fall to negative
1.8 degrees Celsius.
On the surface, the thin icy crust
thickens into a layer called nilas,
and young sea ice starts forming
ridges that block out the sun.
The ocean begins to mirror
the still landscape above it.
Antarctic sea cucumbers and urchins
go into dormancy for months,
and their metabolic rates fall
to the slowest on Earth.
Antarctic limpets continue feeding,
but at such a gradual pace that they're
largely still surviving
on energy reserves from the summer.
Tiny crustaceans survive off the traces
of algae
growing on their home’s icy ceiling,
raising their young in these expansive
winter nurseries.
But this seemingly endless winter
won't last forever.
As spring comes, light slowly begins
to trickle back down through the ice.
And week by week, bit by bit,
this underwater world will begin waking up
to begin its delicate,
slow-motion dance once again.
