Why you should care about whale poo

Whales have a surprising and important job, says marine biologist Asha de Vos: these massive creatures are ecosystem engineers, keeping the oceans healthy and stable by ... well, by pooping, for a start. Learn from de Vos, a TED Fellow, about the undervalued work that whales do to help maintain the stability and health of our seas — and our planet.

In the 1600s, there were so many
right whales in Cape Cod Bay

off the east coast of the U.S.

that apparently you could
walk across their backs

from one end of the bay to the other.

Today, they number in the hundreds,
and they're endangered.

Like them, many species of whales
saw their numbers drastically reduced

by 200 years of whaling,

where they were hunted and killed
for their whale meat, oil and whale bone.

We only have whales in our waters today

because of the Save the Whales
movement of the '70s.

It was instrumental in stopping
commercial whaling,

and was built on the idea that
if we couldn't save whales,

what could we save?

It was ultimately a test
of our political ability

to halt environmental destruction.

So in the early '80s, there was
a ban on commercial whaling

that came into force
as a result of this campaign.

Whales in our waters are still
low in numbers, however,

because they do face a range
of other human-induced threats.

Unfortunately, many people still think
that whale conservationists like myself

do what we do only because these creatures
are charismatic and beautiful.

This is actually a disservice,

because whales are ecosystem engineers.

They help maintain the stability
and health of the oceans,

and even provide services
to human society.

So let's talk about why
saving whales is critical

to the resiliency of the oceans.

It boils down to two main things:

whale poop and rotting carcasses.

As whales dive to the depths to feed
and come up to the surface to breathe,

they actually release these
enormous fecal plumes.

This whale pump, as it's called,

actually brings essential limiting
nutrients from the depths

to the surface waters where they
stimulate the growth of phytoplankton,

which forms the base
of all marine food chains.

So really, having more whales
in the oceans pooping

is really beneficial
to the entire ecosystem.

Whales are also known to undertake some
of the longest migrations of all mammals.

Gray whales off America
migrate 16,000 kilometers

between productive feeding areas and less
productive calving, or birthing, areas

and back every year.

As they do so, they transport fertilizer
in the form of their feces

from places that have it
to places that need it.

So clearly, whales are really
important in nutrient cycling,

both horizontally and vertically,
through the oceans.

But what's really cool is that they're
also really important after they're dead.

Whale carcasses are some of
the largest form of detritus

to fall from the ocean's surface,
and they're called whale fall.

As these carcasses sink,

they provide a feast
to some 400-odd species,

including the eel-shaped, slime-producing
hagfish.

So over the 200 years of whaling,

when we were busy killing and removing
these carcasses from the oceans,

we likely altered the rate and geographic
distribution of these whale falls

that would descend into deep oceans,

and as a result, probably led
to a number of extinctions

of species that were most specialized

and dependent on these carcasses
for their survival.

Whale carcasses are also known
to transport about 190,000 tons of carbon,

which is the equivalent of that produced

by 80,000 cars per year

from the atmosphere to the deep oceans,

and the deep oceans
are what we call "carbon sinks,"

because they trap and hold
excess carbon from the atmosphere,

and therefore help
to delay global warming.

Sometimes these carcasses
also wash up on beaches

and provide a meal to a number
of predatory species on land.

The 200 years of whaling
was clearly detrimental

and caused a reduction
in the populations of whales

between 60 to 90 percent.

Clearly, the Save the Whales movement

was instrumental in preventing
commercial whaling from going on,

but we need to revise this.

We need to address the more modern,
pressing problems that these whales face

in our waters today.

Amongst other things, we need to stop them

from getting plowed down by container
ships when they're in their feeding areas,

and stop them from getting
entangled in fishing nets

as they float around in the ocean.

We also need to learn to contextualize
our conservation messages,

so people really understand the true
ecosystem value of these creatures.

So, let's save the whales again,

but this time, let's not just
do it for their sake.

Let's also do it for ours.

Thank you.

(Applause)