Strangford Lough Coast

Strangford Lough is a vast inland sea -

the largest saltwater lough in the United Kingdom,

with 120 islands and 150 miles of its own twisting coastline.

This huge body of water is tidal,

connected to the sea by a narrow channel.

Twice a day, fierce currents surge through this bottleneck.

The tide's pouring in from the open sea,

and you can feel it trying to push the ferry into the lough.

The tidal torrent is the life blood of this exceptional environment.

The World Wildlife Fund

say Strangford is one of the most important wild places in Europe.

And no wonder. There are over 2,000 marine species here -

that's three-quarters of all the plants and animals

found in Northern Ireland.

For our zoologist, Miranda Krestovnikoff,

the fierce currents in the lough

will make Strangford a very difficult dive.

350 million cubic metres of sea water

flood though the lough every tide.

This twice-daily pulse of water is a living soup.

It's packed full of microscopic life

that fuels the food chain in the lough.

Surging water also makes life difficult in the deep.

Wait!

The current just takes you.

This current's moving too fast!

I'm going to try and get out of the current a bit,

and have a closer look at the marine life.

We've got fairly bad visibility.

That green colour is a bloom of plankton.

That's good news for the animals,

because that's the food they feed on.

You can just see between the timbers of this old wreck,

a beautiful conger eel, really blue with big eyes.

It's a big fish and the only way it can really survive

is by hiding and waiting for food to come to it.

Its rich marine life makes Strangford Lough

ripe for exploitation.

Dredging for scallops and prawns

has already destroyed miles of the seabed.

The bottom is scraped bare, leaving a lifeless underwater desert.

Though dredging is currently banned,

the commercial pressure is unrelenting,

and it might be permitted again if the environment recovers.

Strangford Lough is a fragile ecosystem, despite its size.

It stretches inland for 20 miles.

Here it changes into a placid, shallow sea.

The falling tide reveals enormous mudflats, literally full of life.

You can see the worm casts and a few shells and cockles on the surface,

but I guess there's more...down?

Yes, definitely. We have got loads of life in the mudflats themselves.

-If we take a chunk out and see what is in there.

-Look at that!

There is a fantastic bloodworm burrow there.

There's a ragworm.

There's quite a lot moving as well.

You can see it is teeming with life,

and this is what supports all of the different species of birds.

Over 70,000 birds come here every winter for the rich pickings.

Belfast is only 12 miles away,

with its commuters hungry for housing in such a lovely setting.

The threat of pollution from overdevelopment

hangs over the whole lough.

In an ideal world, what would you like to change for the future?

It would be great if Strangford Lough

was made a Marine National Park,

because we don't have any yet in the UK and if it was one of the first,

that would be fantastic

but it would also raise awareness of how special it is

and it is a place that needs to be protected really well.

Subtitles by Red Bee Media Ltd