what would we do without water no really
what would we do without it probably not
very much because we need fresh water to
live but some living things have found
ways to get a lot out of very little
we've talked about fresh water and the
fact that there's not very much of it on
earth to give you an idea of how little
there really is think of it this way if
all of the Earth's water were placed
into a gallon jug the fresh water would
equal a single teaspoon that's it but
this picture does an especially good job
of showing just how much of each kind of
water there is on earth see the three
blue dots the biggest one represents all
of the water on our planet salt and
fresh so that includes all of the water
in the oceans glaciers lakes rivers plus
all of the groundwater and the water in
the atmosphere and even the water in you
and me the medium-sized dot next to it
represents all of our planet's liquid
fresh water including the fresh water
that's underground and locked in
glaciers and what about that teeny tiny
dot yeah that little guy well that's all
of the surface fresh water that humans
plants and animals actually can get to
if you think that's a really small
amount of fresh water for all the living
things on our planet well you're right
it is with plants and animals live and
thrive all over the earth in places with
lots of fresh water and in places with
very little fresh water so how do they
survive
let's take a look at two different kinds
of environments one with plenty of fresh
water and one with very little to see
how living things make it work in both
places
we'll start somewhere with a lot of
fresh water I can't think of a better
example than Russia's Lake Baikal
the deepest lake in the world and holds
about 1/5 of the world's fresh water the
nearly 2,000 plant and animal species
that live in like michael have adapted
to their super huge and wet but very
cold home Michael's most famous resident
that'd be the nurple the nura is one of
the world's only species of freshwater
seal no one really knows how these guys
ended up in a freshwater lake but
they've adapted pretty well to their
landlocked habitats want an example
check out their flippers their flippers
are bigger and stronger than other seals
flippers why well during the winter
almost the head lake is covered with
thick ice saltwater seals live under the
ice in winter too but it's usually easy
for them to find places in the ocean
where they can get to the surface to
breathe like Michael however can
completely freeze over in the winter in
the nurple unfortunately sometimes finds
itself trapped under the ice that's when
they use those super strong flippers to
make big breathing holes they stay near
their holes for long periods of time
constantly scratching at them to keep
them from freezing over Napa's also have
more blood about two liters more than
other seals which lets them store oxygen
for longer and therefore stay underwater
longer than some of their other seal
buddies okay so the nura is awesome and
a wonderful example of an animal that's
adapted to the presence of lots of fresh
water let's go someplace warmer to see
what life can be like when there's not a
lot of fresh water around
welcome to the Sahara in Africa deserts
have very little water with sources of
surface water that can change throughout
the year depending on things like
rainfall the Sahara has some bodies of
water that many plants and animals
depend on for fresh water but there's
not very many of them one of these lakes
located on the edges of the Sahara is
called Lake Chad it's tiny compared to
Lake Baikal in Russia
let's compare Lake Chad and Lake Baikal
side-by-side using bar graphs one shows
the surface area of each Lake and the
other shows how deep they are
there's definitely a lot more fresh
water for the animals near Lake Michael
than at Lake Chad according to these
graphs good thing a lot of the animals
in the Sahara rarely need to drink water
why not because they've adapted to their
really really warm home in the case of
the Attucks antelope they actually
change the color of their hair so how
does that help them deal with a lack of
water well in the summer the Attucks has
a white coat that reflects sunlight that
helps it keep cool in the winter their
coat turns to light brown to help them
absorb more heat this trick keeps their
body temperature stable year-round and
this means that in the summer they don't
need as much water as you or I might to
cool ourselves off makes me kind of wish
I could change my hair color what do you
guys think about purple no okay so what
have we learned from our trips to Russia
and Africa some animals live near lots
of fresh water and some don't and both
kinds can thrive thanks to their
adaptations to the places where they
live so to answer our big question yes
living things can survive with limited
freshwater but only if they can adapt so
I'm off to try on a purple wig to see
how it looks it's probably not going to
look that great
Oh