Shellfish Reef Restoration Overview and Progress at Port Phillip Bay, Victoria

- Shellfish reefs once covered up to half

of Port Phillip Bay's sea floor.

By the late 1800s they were largely locally gone.

Overexploited to the extent

that the shellfish reef ecosystems started to collapse.

In more recent years, over-harvesting,

Catchment to Coast pollution,

and sedimentation, plus disease,

have all contributed to these reefs

not being able to recover.

- We're determined to bring back

the lost ecosystem, these shellfish reefs,

back into Port Phillip Bay

so that we can bring back more fish, cleaner water,

and more life back into Port Phillip Bay.

(gentle piano music)

- [Simon] We're doing this

using a number of different techniques

including using limestone and recycled seafood shells,

to form a base which we then seed hundreds of thousands

of hatchery grown Australian flat oysters and blue mussels.

(dramatic piano music)

(gently shimmering cymbals)

- [Chris] So these reefs

offer us a small window into the past.

In just a short period of time, life has really returned.

We've seen schools of pinkey and baby snapper,

little reef fish like pygmy leatherjackets, and hulafish,

as well as a source of inveterbrates

that are really important for the bottom of the food chain,

like sea stars and urchins,

and even octopus, top predators and seals.

(dramatic piano music)

- [Simon] Since 2015, we've restored

1.5 hectares of shellfish reefs.

This is equivalent to the size of the MCG.

As many as 60 to 85% of the seeded oysters

are surviving on the shellfish reefs.

What is more exciting is that we're starting to see

oyster hatchlings beginning to settle on the reef.

This is real confirmation that we're doing something right.

As the oyster populations of our reefs

are able to complete their lifecycle,

surviving, growing, reproducing,

and attracting baby oysters back to settle

on the home that the reefs provide.

- [Chris] So it's these ecosystems

that are foundation for life.

They're bringing back fish,

they're bringing back all the little crabs

and crustaceans that you see in the sand

and we want to breed new life back into Port Phillip Bay.

- [Simon] We are also providing opportunities

for local communities to be involved,

helping us measure and count oysters on the reef,

monitor baby hatchlings in the wild,

and cleaning and bagging up recycled shell

to settle oyster hatchlings on

before we release them onto the reefs.

- So, if we're able to restore

these shellfish reef ecosystems, in the future

they're going to be able to filter the equivalent

of the entire city of Melbourne's waste water,

acting like a huge biological filter,

really cleaning up the water in Port Phillip Bay.

(dramatic piano music)