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(Describer) Titles: KQED. PBS.
(Describer) Two green appendages with black dots on them touch then separate.
Title: Deep Look.
Underwater...
(narrator)
This seagrass meadow
sways with the tides.
Peek closer,
and you'll find a humble
and hypnotic character,
(Describer) Green with black markings.
the eelgrass sea hare.
(Describer) Spelled h-a-r-e.
It's a kind of sea slug,
but looks more like a slice
of zebra-striped jello.
(Describer) It crawls on a blade of seagrass.
A sea hare gets its name
from its ear-like rhinophores,
the two tentacles
on top of its head.
(Describer) The two spotted appendages.
If you look at them
in just the right light,
you may even see
that bunny resemblance.
(Describer) It's silhouetted through a blade.
It uses its rhinophores
to sense water movement,
temperature,
and even smell,
like if a potential mate
is nearby.
(Describer) Two sea hares stand by each other.
To get fresh oxygen,
the sea hare pumps water
through gills tucked
under these foot flaps
called parapodia.
(Describer) Lines point to where they're closed near the back.
The eelgrass sea hare lives
off the Pacific Coast
of North America and dwells
almost exclusively on--
you guessed it--
eelgrass.
It's a type
of marine grass
that grows at the edges
of oceans.
Scientists believe
the two evolved together
over millions of years.
(Describer) A sea hare wraps itself around a blade.
The sea hare
grazes constantly,
all day, every day.
But it doesn't
eat the grass.
Using its radula with rows
of petal-shaped teeth,
the sea hare actually
scrapes the grass
for the microscopic
algae that coats it.
(Describer) Many rows of the rounded teeth are shown. A sea hare scrapes the end of a blade.
Slurping up the algae
on the eelgrass
lets more sunlight
hit the plants
so the meadows
can keep growing.
Seagrass meadows
help control erosion
and absorb carbon
from the atmosphere.
Also, they make
some sweet digs
for all kinds of creatures.
(Describer) ...like the eelgrass isopod and California rock crab.
On the surface...
.
Oh, hello.
(Describer) ..a sea otter floats on its back
But like old-growth forests
and coral reefs,
seagrass ecosystems
are rapidly disappearing.
So were the eelgrass meadows
of this wetland,
Elkhorn Slough.
For decades, fertilizers from
farms drained into the water,
overfeeding the algae.
Massive algal blooms
blocked the sunlight
from reaching the grasses,
and there was another problem.
Sea otters were missing.
We hunted them
for their fur,
almost to extinction.
(Describer) An otter swims.
The whole system
was out of whack.
The grasses started to die.
But in the 1980s,
scientists reintroduced
sea otters here
and things improved.
That's because sea otters
eat the crabs
that eat the sea hares.
Fewer hungry crabs means
these slug bunnies
are back in business,
once again eating algae
so this eelgrass
can flourish,
even with extreme
algal blooms.
This is called
a trophic cascade,
when a top predator
like an otter
helps to keep
an ecosystem in balance.
A healthy eelgrass
meadow also means a haven
for the sea hares' eggs
and protection
for its young,
the next generation
of this habitat's tiny,
slimy stewards.
(Describer) As a sea hare's stripes are shown, titles:
Producer/Writer: Mike Seely
Cinematographers: Josh Cassidy, Mike Seely
Narrator/Writer: Laura Klivans
Original Music: Seth Samuel
A KQED Production
Copyright 2020 KQED Inc.
Accessibility provided by the US Department of Education.
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