no one -- not Jacques Perrin, not Jacques Cousteau or Rachel Carson --

imagined that we could do anything to harm the ocean

by what we put into it or by what we took out of it.

It seemed, at that time, to be a sea of Eden,

but now we know, and now we are facing paradise lost.

I want to share with you

my personal view of changes in the sea that affect all of us

and to consider why it matters that in 50 years we've lost --

actually, we've taken, we've eaten --

more than 90 percent of the big fish in the sea,

why you should care that nearly half of the coral reefs have disappeared,

why a mysterious depletion of oxygen in large areas of the Pacific

should concern not only the creatures that are dying

but it really should concern you.

It does concern you, as well.

I'm haunted by the thought of what Ray Anderson calls "tomorrow's child,"

asking why we didn't do something on our watch

to save sharks and bluefin tuna and squids and coral reefs and the living ocean

while there still was time.

Well, now is that time.

I hope for your help

to explore and protect the wild ocean

in ways that will restore the health and,

in so doing, secure hope for humankind.

Health to the ocean means health for us.

And I hope Jill Tarter's wish to engage Earthlings includes dolphins and whales

and other sea creatures

in this quest to find intelligent life elsewhere in the universe.

And I hope, Jill, that someday

we will find evidence that there is intelligent life among humans on this planet.

(Laughter)

Did I say that? I guess I did.

For me, as a scientist,

it all began in 1953

when I first tried scuba.

It's when I first got to know fish swimming

in something other than lemon slices and butter.

I actually love diving at night.

You see a lot of fish then that you don't see in the daytime.

Diving day and night was really easy for me in 1970

when I led a team of aquanauts living underwater for weeks at a time

at the same time that astronauts were putting their footprints on the moon.

In 1979 I had a chance to put my footprints on the ocean floor

while using this personal submersible called Jim.

It was six miles off shore and 1,250 feet down.

It's one of my favorite bathing suits.

Since then, I've used about 30 kinds of submarines

and I've started three companies and a nonprofit foundation called Deep Search

to design and build systems

to access the deep sea.

I led a five-year National Geographic expedition,

the Sustainable Seas expeditions,

using these little subs.

They're so simple to drive that even a scientist can do it.

And I'm living proof.

Astronauts and aquanauts alike

really appreciate the importance of air, food, water, temperature,

all the things you need to stay alive in space or under the sea.

I heard astronaut Joe Allen explain

how he had to learn everything he could about his life support system

and then do everything he could

to take care of his life support system.

And then he pointed to this and he said: "Life support system."

We need to learn everything we can about it

and do everything we can to take care of it.

The poet Auden said, "Thousands have lived without love.

None without water."

Ninety-seven percent of Earth's water is ocean.

No blue, no green.

If you think the ocean isn't important,

imagine Earth without it.

Mars comes to mind.

No ocean. No life support system.

I gave a talk not so long ago at the World Bank

and I showed this amazing image of Earth

and I said, "There it is! The World Bank!"

That's where all the assets are!

And we've been trawling them down

much faster than the natural systems can replenish them.

Tim Worth says the economy is a wholly-owned subsidiary of the environment.

With every drop of water you drink,

every breath you take,

you're connected to the sea.

No matter where on Earth you live.

Most of the oxygen in the atmosphere is generated by the sea.

Over time, most of the planet's organic carbon

has been absorbed and stored there,

mostly by microbes.

The ocean drives climate and weather,

stabilizes temperature, shapes Earth's chemistry.

Water from the sea forms clouds

that return to the land and the seas

as rain, sleet and snow,

and provides home for about 97 percent of life in the world,

maybe in the universe.

No water, no life.

No blue, no green.

Yet we have this idea, we humans,

that the Earth -- all of it: the oceans, the skies --

are so vast and so resilient

it doesn't matter what we do to it.

That may have been true 10,000 years ago,

and maybe even 1,000 years ago

but in the last 100, especially in the last 50,

we've drawn down the assets,

the air, the water, the wildlife

that make our lives possible.

New technologies are helping us to understand

the nature of nature,

the nature of what's happening.

Showing us our impact on the Earth.

I mean, first you have to know that you've got a problem.

And, fortunately, in our time,

we've learned more about the problems than in all preceding history.

And with knowing comes caring.

And with caring, there's hope

that we can find an enduring place for ourselves

within the natural systems that support us.

But first we have to know.

Three years ago, I met John Hanke,

who's the head of Google Earth,

and I told him how much I loved being able to hold the world in my hands

and go exploring vicariously.

But I asked him: "When are you going to finish it?

You did a great job with the land, the dirt.

What about the water?"

Since then, I've had the great pleasure of working with the Googlers,

with DOER Marine, with National Geographic,

with dozens of the best institutions and scientists around the world,

ones that we could enlist,

to put the ocean in Google Earth.

And as of just this week, last Monday,

Google Earth is now whole.

Consider this: Starting right here at the convention center,

we can find the nearby aquarium,

we can look at where we're sitting,

and then we can cruise up the coast to the big aquarium, the ocean,

and California's four national marine sanctuaries

and the new network of state marine reserves

that are beginning to protect and restore some of the assets

We can flit over to Hawaii

and see the real Hawaiian islands ...

Not just the little bit that pokes through the surface,

but also what's below.

To see -- wait a minute, we can go kshhplash! --

right there, ha --

under the ocean, see what the whales see.

We can go explore the other side of the Hawaiian islands.

We can go actually and swim around on Google Earth

and visit with humpback whales.

These are gentle giants that I've had the pleasure of meeting face to face

many times underwater.

There's nothing quite like being personally inspected by a whale.

We can pick up and fly to the deepest place:

seven miles down, the Mariana Trench,

where only two people have ever been.

Imagine that. It's only seven miles,

but only two people have been there, 49 years ago.

One-way trips are easy.

We need new deep-diving submarines.

How about some X Prizes for ocean exploration?

We need to see deep trenches, the undersea mountains,

and understand life in the deep sea.

We can now go to the Arctic.

Just ten years ago I stood on the ice at the North Pole.

An ice-free Arctic Ocean may happen in this century.

That's bad news for the polar bears.

That's bad news for us too.

Excess carbon dioxide is not only driving global warming,

it's also changing ocean chemistry,

making the sea more acidic.

That's bad news for coral reefs and oxygen-producing plankton.

Also bad news for us.

We're putting hundreds of millions of tons of plastic

and other trash into the sea.

Millions of tons of discarded fishing nets,

gear that continues to kill.

We're clogging the ocean, poisoning the planet's circulatory system,

and we're taking out hundreds of millions of tons of wildlife,

all carbon-based units.

Barbarically, we're killing sharks for shark fin soup,

undermining food chains that shape planetary chemistry

and drive the carbon cycle, the nitrogen cycle,

the oxygen cycle, the water cycle,

our life support system.

We're still killing bluefin tuna, truly endangered,

And much more valuable alive than dead.

All of these parts are part of our life support system.

We kill using long lines, with baited hooks every few feet

that may stretch for 50 miles or more.

Industrial trawlers and draggers are scraping the sea floor

like bulldozers, taking everything in their path.

Using Google Earth you can witness trawlers,

in China, the North Sea, the Gulf of Mexico,

shaking the foundation of our life support system,

leaving plumes of death in their path.

The next time you dine on sushi, or sashimi,

or swordfish steak, or shrimp cocktail,

whatever wildlife you happen to enjoy from the ocean,

think of the real cost.

For every pound that goes to market,

more than 10 pounds, even 100 pounds,

may be thrown away as bycatch.

This is the consequence of not knowing

there are limits to what we can take out of the sea.

This chart shows the decline in ocean wildlife

from 1900 to 2000.

The highest concentrations are in red.

In my lifetime, imagine,

90 percent of the big fish have been killed.

Most of the turtles, sharks, tunas and whales

are way down in numbers.

But, there is good news.

10 percent of the big fish still remain.

There are still some blue whales.

There are still some krill in Antarctica.

There are a few oysters in Chesapeake Bay.

Half the coral reefs are still in pretty good shape,

a jeweled belt around the middle of the planet.

There's still time, but not a lot,

to turn things around.

But business as usual means that in 50 years,

there may be no coral reefs,

and no commercial fishing, because the fish will simply be gone.

Imagine the ocean without fish.

Imagine what that means to our life support system.

Natural systems on the land are in big trouble too,

but the problems are more obvious,

and some actions are being taken to protect trees, watersheds and wildlife.

And in 1872, with Yellowstone National Park,

the United States began establishing a system of parks

that some say was the best idea America ever had.

About 12 percent of the land around the world is now protected,

safeguarding biodiversity, providing a carbon sink,

generating oxygen, protecting watersheds.

And, in 1972, this nation began to establish a counterpart in the sea,

National Marine Sanctuaries.

That's another great idea.

The good news is

that there are now more than 4,000 places in the sea, around the world,

that have some kind of protection.

And you can find them on Google Earth.

The bad news is

that you have to look hard to find them.

In the last three years, for example,