Kind: captions
Language: en
some ocean scientists are raving about
kelp there's a lot to like about kelp
particularly in its ecosystems benefits
because they think the seaweed can
potentially help solve major problems in
our oceans today
including dead zones areas of the ocean
where oxygen levels have dropped killing
off all kinds of sea life oxygen is
declining so low that fish other
invertebrates they actually suffocate so
why is this happening
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in many cases it starts with nitrogen
and phosphorus often found in fertilizer
the stuff we use for agriculture or even
our lawns or gardens
rainwater washes it into streams and
rivers
and it makes its way into the ocean if
there's too much nutrients that run down
from watersheds into a bay for example
it stimulates these phytoplankton blooms
phytoplankton are single-celled algae
and these blooms can grow out of control
sometimes even visible from space
choking off oxygen from the water and
blocking sunlight to the plants below
eventually the phytoplankton die and
they sink even though they're really
small when they sink they decompose and
that decomposition process
bacteria will use up the oxygen that's
near the sea floor in many cases this
process is what causes the loss of
oxygen in the water
and that's what happened in the gulf of
mexico
the mississippi empties here
bringing high levels of nitrogen and
phosphorus into the gulf
this is where kelp comes in so we sort
of created this little miniature farm
here
one of the great attributes of seaweeds
is it's a potent way of absorbing all
this luxurious nutrients it's far too
much for the ocean to really fully
absorb
in addition it also is great at
capturing carbon at rates 50 times
higher than trees on land
carbon sequestration is one of the key
goals for climate change that we need to
address
so there's a lot of interest in growing
seaweeds simply for sucking
carbon and nitrogen out of the waters
and putting them into more stable form
but to make an impact you need a lot of
kelp sucking up nutrients and it would
take a decent amount of space in the
ocean to grow it all when you when you
look at it on a map in congregate it
would be about as big as iowa but spread
out all along the shoreline and i'd say
we're still at that level of trying to
distinguish between what's real and
what's possible
so i marked the perimeter of the farm
with farm buoys you can see one's over
there
and then you need to harvest it to
prevent it from dying and releasing all
of the absorbed nitrogen and phosphorus
back into the water that's a good
looking kelp
and for farmers to want to grow this
much kelp they'd need a market to sell
it
and the market for kelp in the us is
still emerging you know it's interesting
that when we have more complex food
systems we don't value traditional foods
seaweed also has an important cultural
significance
some indigenous communities in the u.s
have been harvesting it for centuries
like in hawaii where seaweed is known as
limu
limu traditionally has been used in our
practices in the way we live not just in
our eating
and the prospect of large-scale
production raises a red flag for some
there's concerns in the community about
you know mass
limu we've had a lot of history where
people have come in from outside of
hawaii
and they've done these
different types of activities but
they're not really giving back to the
communities here that's one of the
questions i always think house is
helping my community and if we grew huge
quantities of kelp for carbon capture
what would we do with it all
some scientists are exploring the
possibility of sinking kelp deep down
into the ocean several thousand feet
below the surface potentially
sequestering the carbon for millions of
years but there are still a lot of
unknowns what does happen to that carbon
and the seaweed when it goes to a
thousand meters deep it's not like it's
a complete desert down there there are
still organisms growing is that a free
lunch for somebody are we gonna have a
great bloom of something else and some
unintended consequences
we need to precede doing those grand
ideas with experiments to see what the
impact might be
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