of waste into the ocean.

Even Coast Guard ships like this.

The idea is that new coral will latch on

to these massive objects and attract fish.

But just because it sinks doesn't mean it will help.

In fact, some of these damaged preexisting coral.

Now a company has said their artificial reef

is safe for all marine life.

The secret ingredient?

It's made from the remains of the dead.

There are thousands of memorial reef balls

like this one off the Eastern Seaboard.

They've become successful habitats

and protect hundreds of millions of dollars

of real estate from storm surge flooding.

But with natural reefs dying off at an alarming rate,

can these underwater graveyards actually make a difference?

The two most important factors for a good reef

are the materials you use

and making sure it stays put.

Larry Beggs and his team at Reef Innovations

designed this bottom-heavy reef ball

to withstand violent sea currents.

They can weigh up to 5 tons.

The chemicals in conventional concrete

can harm sea creatures.

So Reef Innovations has to use a special mix.

Larry Beggs: The concrete is a pH-neutralized, marine-grade concrete

that is very important for coral growth.

Oysters, corals, invertebrates, and stuff that will grow

on the reef can attach to the reef ball very easily.

Narrator: The company uses fiberglass panels

to form the basic shape of the ball.

They insert an inflated buoy to keep the center hollow,

creating the holes that fish like to swim through.

Once the concrete dries, the team rinses the balls

with a mixture of sugar and water

to expose the surfaces where sea life will grow.

This is where the dead people come in.

A company called Eternal Reefs

uses Larry's creations for their memorials.

They've dropped

almost 2,500 of them

over the past 20 years.

We work with families who have lost somebody

and had their loved one cremated.

They will come to one of our project sites.

Narrator: The families mix cremated remains

with concrete to make a separate centerpiece

for the reef ball.

They call it a pearl.

George Frankel: What you're going to do is you can put your hand down,

you rock it back and forth.

We put fresh concrete on the top of the reef ball,

and then they put handprints, they write messages.

Families are invited to bring things

that represent their loved one's life,

as long as they're not environmentally harmful.

The remains replace some of the sand

normally used in concrete.

Phyllis Flowers: They give you actually the buckets and the mix,

and then you pour your remains into that mix.

And you stir it.

Narrator: Phyllis Flowers lost her son to brain cancer

when he was just 20 years old.

Phyllis: So there's my son.

I had no idea what the Eternal Reef was until John found it.

In a small way, he was giving back to the world, in his mind,

by being able to add to the ecology of the coral reef

that will save, of course, our seashores

and build back sea animals and fish.

Narrator: Families take their finished reef balls

out to the open water,

say a few words, maybe a prayer,

and drop the memorial down to the seabed.

The whole process costs about the same

as a conventional cemetery burial.

On Florida's Atlantic coast,

another company is in the underwater burial business.

The Neptune Memorial Reef is the final resting place

for over 1,000 people.

Here, the human remains are mixed into statues

shaped like starfish or stingrays.

It's also a tourist attraction.

We estimate there's probably

over 2,000 divers a month that visit the Neptune Reef.

Narrator: Over the past century,

people hoped to create scenic dive sites in other places.

They've dropped passenger airplanes, car tires,

even old battleships.

Elizabeth Mcleod: It was really companies looking for cheaper ways

of disposing products that they weren't using anymore,

or the military had ships or tanks.

And I think over time, there's increased recognition

that these were not good for the environment.

Narrator: In the early 1970s, a nonprofit working

with the Army Corps of Engineers dumped 2 million tires

off the coast of Fort Lauderdale.

The group optimistically called it the Osborne Reef.

But the coral never grew.

Seawater corroded the tires,

as well as the steel clips

and nylon bonds holding them together.

They broke apart, wiping out nearby natural reefs.

Decades later, Florida began a cleanup

expected to end by 2028.

Some 600,000 tires are still down there.

Healthy reefs provide a home for a quarter

of all marine life, protect thousands of people

from hurricane damage, and contribute

over $4 billion to Florida's economy every year.

But even the best designed artificial reefs

can't keep up with climate change.

Unless carbon emissions are reduced,

all coral reefs could be gone by 2050.

Elizabeth: It's going to take all of us, and now is the time.

This is our decade.

Narrator: For now, reef burials haven't

reached the mainstream.

Even if every one of the 3.4 million Americans

who died last year ended up in their own reef ball,

it would still only replace about 1 square mile

of Florida's shrinking reefs.

If we did that around the world,

it probably would help,

but we just, we aren't, you know.

So I feel good about what we're doing.

Narrator: Perhaps this kind of memorial is just a person's

final act of hope that things can get better.

Jim: Now's the time where we need a healthy ocean

more than ever.