Trouble at Sea The Last Seabird Summer?

Just off the west coast of Scotland, in the Outer Hebrides,

is a little known cluster of islands called the Shiants.

The name means haunted or enchanted.

And while the last people left over a century ago,

every summer, these deserted shores

become the stage for an extraordinary show.

Great waves of sea birds return here from far out in the Atlantic,

coming back to mate and breed.

For many of us, the sea bird is a noisy scavenger,

gulls that plague our seafronts.

But these annual visitors to the Shiants

are altogether more mysterious and surprising.

The unmistakably gaudy puffin,

the sleek and stylish razorbill,

the chocolaty elegance of the guillemot

and the prehistoric, fearsome shag.

I'm Adam Nicolson, a writer,

and for summer after summer,

I've been able to witness this great spectacle

ever since my father first brought me here as a boy 50 years ago.

The more you get to know about these birds

the more extraordinary they are.

Any idea that somehow we have a monopoly

on ingenuity or resilience or persistence

in the face of difficulty absolutely goes out of the window.

But now, despite this resilience,

throughout the North Atlantic, sea birds are in steep decline.

In Scotland, 40% have already been lost...

This is a photo taken back in the '80s

of this exact same cliff, full of birds.

And now there are literally three or four.

That's incredible.

..and in Iceland, traditionally a sea bird stronghold,

the crisis has hit even harder,

with some colonies all but wiped out.

In some cases, we come to a colony

which all the chicks died within framework of few days -

130,000 some dead chicks everywhere.

So, what is going on?

Could all this pulsating life be coming to an end?

Are we really facing the last of our great sea bird summers?

So far, I've spent the last few months on the Shiants

following the progress of the birds.

It's puffins. They're all puffins in that.

It's phenomenal,

this annual re-emergence of life like this.

I've begun to look at

how man's relationship with the sea bird has changed,

how they were once a valuable source of food...

There used to be cormorant soup at one time.

Puffins were a very delicacy then.

They were tasty, you know? Yeah.

..and how they were slaughtered in their thousands

for feathers to make hats,

even driving one bird to extinction.

They literary herded them into their ships.

I've been exploring how our relationship in Britain

has become one of conservation.

Lovely guillemot. Look at that. Isn't that beautiful?

But in Iceland, the sea bird heartland,

I found puffin hunting to be still very much part of everyday life.

Well, look, there, if you like, is the Icelandic tradition made flesh.

I've discovered that there are striking local variations

in the crisis.

In the far north of Iceland,

there was kittiwake abundance like I'd never seen...

That is a wonderful, wonderful sight.

Just a sort of blizzard of sea life.

..and yet, less than 150 miles from the Shiants, in Orkney,

the RSPB's Phil Taylor explained

how 90% of the kittiwakes had been lost.

There is apparently no food available for them

to bring back to the chicks, let alone feed themselves.

This patch of sea, lovely and blue though it looks to you and I,

obviously, isn't in particularly good condition.

But whatever is happening to our seas,

so far at least, the Shiants appear to have escaped.

This is as good as I've ever seen here.

As I continue to follow the story of the birds on the Shiants,

I'm going to investigate the forces driving the crisis elsewhere.

It's now early July,

the most critical part of the birds' year.

I'm on my way to the island's main sea bird colony,

the best place on the Shiants to get a snapshot

of how the birds are doing.

By now, the chicks will be hatched and demanding food.

It's not only the survival of the adult birds that matters,

it's how good the feeding of the young ones are,

cos it's what happens now which governs

what happens in their first crucial winter.

They've got to be fed well now,

and if they're not fed well now, they will die over the winter.

This landscape of fallen boulders and towering cliffs

might seem forbidding to us,

but it's actually perfect for the birds.

The chicks will all be hidden safely out of sight -

the puffins in their burrows on the grassy slopes

and the razorbills and guillemots

concealed in the nooks and crannies between the rocks.

BIRDS CALL

And even though I can't yet see the chicks,

I can certainly hear them.

There's...there's a razorbill just arrived,

its mouth just stuffed with fish.

Completely delicious-looking sand eels.

Exactly the kind of fish that their chicks need.

And into its...down into its hole.

They look like these fantastic silvered moustaches.

A great big drooping walrus moustache of fish.

You know, that is the goodness of the ocean.

I mean, that's everything good out there

being delivered to the chicks in here.

A plentiful supply of fish is essential

because the chicks have voracious appetites.

This view from inside the burrow, filmed on the Shiants,

shows what the adult bird is up against.

CHICK CALLS

Each chick, or puffling, has to be fed up to five or six times a day

and will eat about two and a half kilos of fish

in the month before it's ready to leave the burrow.

There's a family of guillemots there with a little chick.

Very downy still.

They're incredibly loyal husband and wives,

you know, guillemot marriages, 90% of them last from year to year,

and they do this kind of creche thing.

You know, it's not only the parents of the guillemots

that look after the chick -

it could easily be a load of

sisters...brothers and sisters in there.

To see this here now means, for the time being,

here, for this summer, it looks as if the supply is good.

But it's perfectly clear that

these birds here won't go on being here,

unless that sea provides what they need

and provides the fish that you can see them all

bringing in here this morning.

It's a relief to be surrounded by birds on the Shiants...

..because, in Iceland, some colonies have suffered dramatic collapse.

While I was there,

I left the abundance of the north of the country

and travelled to the worst hit colonies in the south.

The Westman Islands, an archipelago off Iceland's south-west coast,

have been home to the world's largest puffin populations.

The Westman Islands has been

this incredible place for sea birds forever,

but in the last ten years,

they've had really catastrophic breeding failures,

so something truly disastrous is happening here.

The main island, Heimaey, was hit by a massive volcanic eruption in 1973,

but luckily the harbour survived

and is still the biggest fishing port on Iceland's south coast.

But if industry on the Westmans is all about cod,

then the culture here is resolutely about the puffin.

The focus of the tourist trade,

puffins are also at the heart of an ancient hunting tradition.

Before the puffin declines began,

Westman Islanders were catching more than a 100,000 a year

for food and feathers

from a total population of around two million birds.

We have been utilising sea birds

ever since the settlement of this country 1,100 years ago,

and the reason being is that these birds, they have been

really important to the sustenance of the people in the past,

but it's still a part of the culture,

a quite strong part of the culture, especially in certain places.

These nets called fleygs originated in the Faroe Islands

and are still in use by hunters today.

As well as eating the birds,

another valuable part of the Icelanders' diet

has always been sea bird eggs...

..particularly razorbill and guillemot.

Most of the bird cliffs were descended

in a rope,

very dangerous business.

Going down 100m, 200m to collect the eggs.

You needed a big long rope, and that was expensive.

It was only the richer people that were able to do that,

so they were more or less controlling

how much was being taken.

Today, with the birds declining,

the question of hunting sustainably seems more important than ever.

I think, in general, people think

this should be a sustainable resource,

but we should continue to be allowed to harvest.

Going out in an island, watching the behaviour of the birds,

living among them, even, in many cases...

..people get to know a lot about these birds.

It's this first-hand knowledge I want to tap into.

I've already encountered puffin hunting

in the far north of the country

where the birds were abundant,

but I want to spend time with hunters here in the south

who've come face-to-face with the puffin declines.

How long ago was it that you first went out to Alsey?

-50 years ago.

-50? So, we've got the 50th anniversary.

-Yeah.

-How old were you then when you first went?

-Five years old.

-Really?

I'm spending a couple of days with them,

and I'm hoping they'll have some ideas about

what's behind the crisis

and what the future might hold for the birds.

I used to be a fisherman.

Are you a millionaire now?

-No.

-THEY LAUGH

There's a wonderful, otherworldly feel about this place,

not unlike the Shiants.

On the larger islands of the archipelago,

the puffin hunters have organised themselves

into long established clubs.

Well, that's Alsey there. That's their island,

the island we're going to.

How far from here? About...four miles?

-Two and a half.

-Two and a half miles.

-So, how many times have you been there, all of you...?

-Phew...

If you count every time...

-a few hundred.

-A few hundred? All of you?

Yeah, if you've been there about 20 years

you go maybe four or five times each year.

Yeah. So, you've been 100, you've been 5,000 times.

LAUGHTER

As we get closer to Alsey,

and it becomes clear that there are no birds,

the atmosphere changes.

When you were last here, were there many puffins here then?

-No, not nearly.

-No.

Even in the evening, when they came in?

No, not many.

But it's...I think, this summer,

we had never seen as few puffins as this summer.

Is that right?

14, 15 years ago, what would it look like when you arrived?

When you came here, it was completely white here.

Of course, there's green grass

but it was...looks more white than green.

-White with their white chests?

-Yeah, their white chest.

And all the sea was black

because...because it was a black back.

So, it was everywhere birds, everywhere perfect,

all the...all the sea, all the island, everywhere.

-You could hardly believe it today.

-No.

There might be no sign of any puffins on Alsey,

but the skies above the neighbouring island were alive with birds -

gannets.

Much bigger than puffins,

gannets are capable of surviving on a wide range of fish.

It's like a whole ballroom of gannets.

They're just circling now...

Gannets are doing really well

-right next to the puffins that are doing really badly.

-Yeah.

-Why is that?

-Mackerel.

When the mackerel comes over,

-he get all the sand eel...

-Yeah.

..so there's nothing left for the puffin.

Because the mackerel are here, the gannets are doing well

-and because the mackerel are here the puffins are doing badly.

-Yeah.

But it's more that's a single cause,

so maybe there are more causes.

Yeah, of course.

The reason why the mackerel is here is warmer ocean.

-It is like everything in nature is a circle...

-Mm-hm.

..and the circle...

-When the mackerel goes away, the puffin comes up again...

-Yeah.

..and then it goes down...

I hadn't expected to hear the blame for the crisis

put on an influx of mackerel.

But as we approach the island,

my immediate concern is how we get ashore.

It looks quite difficult.

Can be.

Yeah. Say when.

Bit more.

Left. Left, left. Left, left.

Up, up, up, up, up, up.

THEY SPEAK INAUDIBLY

There's been a hunters' lodge on this site for over 100 years...

..and from its humble origins,

it's evolved into something really impressive.

The men sometimes stay here for a couple of weeks

and have even installed an ingenious pulley system

for getting the supplies onto land.

You know...you'd have to be mad not to love this, wouldn't you?

I mean, this is like the ideal life.

I could live here.

Just tie up the RIB down there.

It feels deeply connected to the way people have done this

for a very long time here.

People have lived on these islands for 1,000 years...

MAN SHOUTS IN ICELANDIC ...and you can know,

from the very beginning,

that they would have come to these islands.

This, you know, 500,000... MAN CONTINUES TO SHOUT

LAUGHING: ..500,000, 700,000 puffins,

and they would have been here taking them.

And you can connect this, you can feel it.

The way of life isn't lost here.

As the RIB goes back to Heimaey to pick up more club members,

I'm struck by the extraordinary beauty of this place.

But when Didi produces his net,

it's a reminder that everything here

revolves around the hunt for puffins.

-There was an old puffin hunter from this island.

-Yeah?

-He made this for me.

-Oh, did he?

-Yeah.

Obviously, it's exciting and lovely and deeply pleasurable,

but it's also...kind of terrible.

No, you... Just like other hunter, you get used to it, so...

Yeah, yeah.

-They who are hunting other animals, they get used to it.

-Well, yeah.

Well, do you think you'll catch some tonight?

I mean, they're flying here, aren't they?

I think that we...I think that we will catch some.

The boat returns with more hunters.

The club president and his son, Gulli.

-Hello.

-Hae, hae.

For generations, their family has been deeply rooted

in the Icelandic puffin hunting tradition.

First of all, this was to keep, you know, to get food

to, er, survive through the winter.

And then when did that need for puffins last until?

Well, I remember my grandmother peeling the feathers off the birds

to use it for pillows...

-Till what year...?

-..and I was maybe ten years old.

Ever since seven years old, I have been out here for every summer.

Now I have brought my sons, you know,

and he has brought his son,

and so that's what we've been doing, trying to keep the...

-Tradition.

-Yeah, the tradition and the way how we...how this is done,

because now, since we do not have a lot of puffin here,

it's going to be lost.

In the past, when this colony was still at full strength,

all the members of the club would've come out hunting.

I think the puffins will come over there,

and we'll try to catch them, catch three of them.

How does it look to you in numbers?

Ah, I think that we will catch some.

But with so few birds,

it's just Didi to show me how it's done here.

-Ready?

-Yeah, I am.

-Come. Follow me.

Oh, God.

'Dusk is when puffins usually turn up in force...'

It's long, the grass.

'..so making our way up these virtually empty slopes

'is a grim reminder that only 12 years ago

'this island was still supporting hundreds of thousands of birds.'

-It's riddled with burrows.

-..able to come here.

What an incredible place, though. Look at it.

Puffins only love beautiful places, don't they?

Yeah, that's the way.

-You never find it in an ugly spot.

-No.

Er...it's good...good up here.

It's so quiet and, er, beautiful landscape.

Why do you have a flag?

Er, because...the young birds, they are so curious.

When they see the flag, they stick around, look at the flag,

fly here very slowly, and then I try to catch them.

-Nab them.

-Yeah.

So, where do we put it?

We put it... I always do this one here

-and put it two or three metres higher than...

-OK.

-..the stick.

-OK?

-I'll stick it in.

Kind of here?

Yeah, or a little bit higher, a little bit...

-Yeah. There, there.

-In here?

-Yes.

If that flag, Didi, is to attract the immature birds,

-and the breeding has failed for ten, 13 years here...

-Yeah.

-..are there any immatures to attract?

-No, of course not.

But this is the way we do it all the time,

so I'm not going to change the way we do it.

-It's pure tradition.

-Yeah.

There are clearly a few puffins here,

but the local government sets the length of the hunting season

according to the abundance of birds.

Such a beautiful sight, seeing them coming towards you, isn't it?

Yeah, it is.

This year, here in the crisis-hit south,

it's been restricted to just three days.

-Yay!

-Ush!

-Not long.

Oh, growling away. PUFFIN CALLS

So...can you tell his age?

-I can tell this is not a...

-Not a very old one.

-Not very old one.

-He hasn't got any grooves in his...

-I can see because he's very light...

-Yes.

-..and his nose is not so very big.

-No.

But this is the first bird that I catch,

-so I speak to him a little bit...

-Go on, then.

..and I say to him give me good luck of hunt this year...

-I think he needs...

-..and I will give you a freedom. OK.

He needs to hear that in Icelandic - he doesn't...

IN ICELANDIC:

OK.

You leaned forward like a dog.

It's like looking like a...a spaniel.

Eyes looking everywhere.

What have been your usual catches here?

Er, in 2013,

we only caught 100 adults that year.

And was that the worst year?

No. Last year, we didn't catch...catch one.

-You didn't catch a single puffin?

-No.

-Why not?

-Because there weren't any.

-Even on an evening like this, they wouldn't come in?

-No.

Wow.

And we know the situation isn't good, so we just let them fly

-and...try to build up, you know?

-Mm.

We know it will take five or ten years

to be same as it was at the best time.

So, you just have to wait, be patient

and just to have fun with my...my friends,

see how beautiful this place is, and that gives me a lot of pleasure.

Didi's clearly convinced that the birds will return.

I'm not so sure.

I wonder if that's just the voice of hope?

But, for the moment, it's clear that

they're trying not to take too many birds.

I would say maybe ten, 20 max.

-And that'll be the ceiling on it?

-Yes, yes.

-And is...

-Just to have one dinner, traditional dinner,

puffin dinner at home, bring the family together

and say, "OK, we'll do it once this year."

The next morning, I found photo albums

that exhaustively documented their hunting history on Alsey.

There are pictures of these men here...as boys.

That's Gulli.

And that's his father and that's his grandfather.

Wow, look at that. That is thick.

Incredible numbers. Like...like midges.

But then, looking at that, that's not unlike a very good evening

on the north slope in the Shiants.

It can feel that you're looking out through a field of puffins,

and that's what it looks like there.

Looking at their photos,

I was struck by how Gulli and I both had childhoods intertwined

in the life of these birds.

But the relationship my father gave me with the Shiants puffins

was completely different -

arm's length, detached,

a pair of binoculars, not a fleyg net.

Gulli's relationship, on the other hand, was immediate,

physical and driven by centuries of Icelandic tradition.

-But there is a...there is a mountain of puffins there, isn't there?

-Yes.

Look at that.

I mean, how many in there? Can you reckon how many?

-Er...

-1,200.

-A few hundred?

Maybe...maybe 2,000.

They're not all visible, but that's probably 1,500, 2,000.

So, a good day's work for you.

Er...a good day, maybe say 200 to 500 is a very, very good day.

-For one catcher?

-Yeah.

We kind of regret we can't go out and catch -

that's really what we're missing.

But it must be... It's almost like the glue of the event's missing,

-the thing that binds it together is not here.

-Yes, yes.

-But you must miss that, don't you?

-Yeah. Oh, yeah.

-Surely.

You know...

Looking at these images,

I'm reminded that less than 50 years ago

people in Scotland were still taking sea birds -

even on the Shiants.

It is a sort of pan-Atlantic phenomenon, this,

and the reason that it's stopped in Scotland

was that the mainstream culture didn't like it,

whereas the mainstream culture here celebrates this.

This is somehow the heart of Iceland.

You know, maybe what they're riding on here

is the same memory of poverty

that was there in the Hebrides too.

And if you remember a time,

even sort of half-genetically remember a time

when life was incredibly difficult and up against it,

then this is a gift from nothing, isn't it?

This is almost literally manna from heaven.

And...those kind of cultural memories

are incredibly long-lasting,

and they almost last beyond their justification

and I think that's what's happening here.

It is difficult to believe that taking so many puffins

hasn't played a part in their decline.

But the Alsey men do seem to try and hunt sustainably.

They don't take any breeding bird bringing fish in for its young.

Even so, especially in the current situation,

it seems crazy to take any puffins at all.

Back on the Shiants,

it was good to be surrounded by so many thousands of birds.

But it's impossible to forget that the wider crisis among the sea birds

might be coming here.

Everything that you see and hear in Iceland,

the really shocking levels of failure to breed there,

hang just beyond that horizon as a threat here.

But could what has happened there happen here?

You know, could my life be the last life

in which you can come to places like this

and know that this is what you get to see?

I mean, that is a live question.

But there are things we can do.

It's hoped that the Shiants could act as a sort of seed bank,

exporting sea birds to other places.

And to lift a significant burden from the colonies here

and maximise their chances of survival,

the RSPB have begun a major programme

to eradicate the birds' only non-indigenous predator -

the black rat.

These alien invaders came ashore from ships

wrecked on the Shiants in the 18th century.

They prey on sea bird eggs and chicks

and prevent some species from nesting here at all.

Costing nearly a million pounds and taking over a year to complete,

the project is led by Biz Bell.

Do people say that to you quite often, Biz?

-"Are you the rat lady?" Yes.

-Are you the rat, lady?

What is it about rats? No, we'll have that conversation over there.

'She's seen the impact of removing unwanted predators

'on islands all over the world.'

I mean, the whole thing is usually your ecosystem's really suppressed

and so once that predator and competitor is gone,

everything suddenly comes out.

-That is so exciting, that...

-I've been in Mauritius,

and within three weeks,

we had some lizards that we'd never seen before

-and they hadn't been recorded for five years...

-Really?

-..and they thought they were extinct.

-Fantastic.

And they were just small ones managing to survive in the crevices,

but any bigger, when they couldn't live in the crevices,

they got nobbled by rats.

There is one species it would be really exciting

to have return to the Shiants -

the storm petrel,

one of our most entrancing sea birds,

named after St Peter, who walked on water.

It's effortlessly at home out to sea,

but on land, it's hopelessly vulnerable to predators like rats.

Storm petrels, they're tiny, you know, mouse-size

and they live in little crevices,

and so, of course, so do all the rats and things,

and they're just easy prey.

And the thing is, is they could be trying every year to establish here,

-but unfortunately, you know, they're probably...

-Getting done.

-..being predated by rats.

-Yes.

Eventually, the rats will be killed using over a thousand bait stations

each containing blocks of poison.

It's going to be a tall order to get every last one,

but Biz has a reputation as the best in the world.

STORM PETREL CALL PLAYS OVER LOUDSPEAKER

This bizarre sound is actually the cry of a storm petrel

massively amplified.

These speakers and nets have been set up by a team of bird ringers,

here to monitor the sea bird colonies.

The idea is to try and encourage nearby storm petrels

to investigate the Shiants as a possible home.

-Oh! There's one, there's one. Oh, there's one here.

-Yeah.

There's one in there, there's one in there.

The birds are caught so they can be ringed, recorded,

and their movements tracked.

All done. That's him free.

-So, in the bag, just to keep it calm.

-Yeah.

Hey, look at that! How lovely is that?

Oh, that is... What an exquisite thing. Look at that.

This tiny bird flies thousands of miles every year

from the seas off South Africa

to breeding colonies in Britain and Ireland.

The ringing team is led by Jim Lennon.

They always appear very delicate,

they're, obviously, very tough creatures

to survive in the southern oceans.

I can't believe this animal travels so far.

-2580173.

-Yeah.

Does it ever feel slightly wrong to you, this,

to put something so human on something so wild?

Erm...no cos it doesn't affect the way they live.

It helps us understand how they live

and therefore, we can help, erm...conserve them.

-So, you're going to weigh it?

-Yes, yeah.

There we go. OK.

That's the weirdest environment it's ever been in.

Hopefully.

And...what are you getting?

-24.8g.

-Yeah.

-That's less than a bag of crisps.

-Yeah.

-This creature that travels the Atlantic and back.

-That's right.

Once it's been ringed and fully documented,

each bird is released, apparently untraumatised by its ordeal.

So, you put it in your pa...put it on your palm now

-and let it take off when it feels like it.

-On here?

It might take a while cos there's not much breeze.

OK. So, it's sitting there, I can barely feel its presence,

it's just shuffling, just moving...

-and it's gone!

-Wow. Cool.

-ADAM LAUGHS

-I never tire of that.

Jim and his team went on to catch 23 storm petrels that night,

suggesting there's plenty around to establish a new colony here.

STORM PETREL CALL PLAYS OVER LOUDSPEAKER

But if the storm petrels do return,

they'll only stay if the seas around the Shiants remain plentiful.

As I saw for myself in Iceland,

no colony can continue without the food to sustain it.

Somehow these waters are still fertile enough

to bring the birds back every summer.

It may be to do with particular local conditions.

Notoriously powerful tides here force the water over rough seabeds,

stirring up nutrients that feed

the plankton the sand eels depend on.

I've always found these seas to be incredibly rich.

Ever since I first started coming here with my father,

it has seemed almost too easy to catch a fish,

and that's still true today.

Well, you can catch...pollock, very nice pollock,

mackerel, er, coley.

I caught a cod once.

HE CHUCKLES Once in 50 years.

Everything feeds on sand eels.

Sand eels are like the rice of the ocean -

they're just...they're just everywhere.

And...I've got a fish.

HE CHUCKLES That's ridiculous.

There's fertility for you.

Ooh, that's pulling hard.

Oh! Mr Pollock. HE CHUCKLES

That is magnificent.

Oh, yes.

And it's triple hooked.

You see, so hungry for the sand eels.

Look at that. You see, that is... Isn't that a splendid creature?

Look at what the ocean can give you here.

I've always assumed that, like me,

the Shiants birds fish not far from the colonies,

but until recently, exactly where sea birds feed

has always been a mystery.

An RSPB team has come to the Shiants to map the birds' fishing trips

in these waters around the islands known as the Minch.

Ecologist Emily Scragg is using GPS technology to track the birds.

-Wow, it's so miniaturised, isn't it?

-Yeah.

-It's incredible.

So, what are you going to do with this?

-We'll put on the tags...

-OK.

-..onto the birds backs,

-which will go out and collect data.

-Incredibly light.

And when they come back,

they transmit the data to these base stations,

and we can come and pick up the base station

and look at the data.

So, is that going to go on a...on a razorbill?

-Razorbill or a guillemot.

-Yeah. Lovely. Today?

Er, possibly. Hopefully!

They're coming to the end of six-week programme

to fit trackers on about 50 guillemots and razorbills

from all the main colonies.

'Emily catches her birds without the use of a net...'

(Oh, he's in a bag! He's in a bag!)

'..and to try and minimise their disturbance,

'insists on quiet while she works.

'Emily's colleague, Jerry, attaches the transmitter

'to the back of a razorbill.'

This is like A & E.

(OK. So, there's the tag with GPS tracker.)

'The tag will constantly record and store the bird's journeys,

'downloading the data to a base station

'every time it comes back to the nest.'

(We just check that it's secure.)

How is that? OK.

Yay.

The sticky tape and battery last about a week

before the tracker falls off.

With their programme complete and all the data collected,

Emily and Jerry have built up a map that reveals for first time

the movements of the Shiants' birds.

That's amazing.

-The entire Minch within 20 miles...

-20km.

-20...

Well, 20km, 15 miles, something like that

is solid with sea bird tracks.

I mean that...

It's...it's quite a rainbow with the...

SHE CHUCKLES My God, it's busy.

Each coloured line represents the journey of an individual bird

looking for fish for its young.

What sort of...what's the average distance they're going?

-It's between five miles and ten miles.

-Yeah?

-On the shorter side of what sea birds tend to do.

-Right.

Some of the razor bills and guillemots

we've tracked off Fair Isle have gone quite a distance,

and the birds here have gone comparatively not very far.

These results are graphic confirmation that for now, at least,

the local seas round the Shiants are providing what the birds need.

But in the south west of Iceland, this is clearly not the case.

The decline of the puffin colonies

means that their seas must be changing.

Iceland's leading puffin expert, Erpur Hansen,

took me to one of the worst-hit puffin colonies

in the Westman Islands

only a few miles from Alsey.

He's been studying the connection between the state of the seas

and what's happening to the birds.

In the '90s, this would be packed with birds on a good day

just like up in Scotland, but that's now history.

This is 13th year in a row

we have seen a breeding failure of larger or greater extent...

..and...so they...they were never born.

And now we're only seeing the remains of the adult population,

slowly going down in numbers by the years.

-This sight is the sight I dread.

-Yeah, I agree.

It's very shocking to me to kind of feel...feel the absence.

What I think is happening, the...the wintering grounds are,

as far as we know, are OK.

It's the local summer food supply, which is the key problem.

On the Shiants, the GPS results had shown the birds foraging

no more than 20km from the colony.

How far out are they fishing?

It's normally within 60km or so.

They can be seen up to over 120,

but, these parents are burning

half their body weight per day in energy.

So, the chick gets less and less to eat the further away they fly,

and this applies to all sea birds.

But these guys are very high on maintenance,

that's why they are a bit sensitive to changes in food supply.

Back at his house, Erpur explained some of the causes

driving the changes in the ocean system.

We are very dependent on this major current here

called the Irminger.

It's an off shoot from the Gulf Stream.

It's sort of like the key player,

and the warming in the south and west,

where the main populations of puffins are,

basically collapsed the sand eel.

In 2003, it really started.

So, warmer current coming up to the south-west corner of Iceland

has meant a drop in the sand eel population?

Yeah, we see this intensity

with the increased flow of this current

meaning it's just warming everything up.

That has huge impact on...on...marine life.

One degree Celsius, it causes a regime-shift,

-as they call them....

-What do you mean by that?

Total reorganisation of the whole system.

Some key species fall out, move or will vanish.

So, there's a lot of major change, which is...goes on for decades.

Erpur also showed me some research

which added another dimension I was not expecting.

This complicated-looking graph disguises a simple truth -

that these temperature changes are part of a cycle.

This is the third period of ocean warming

in the last 100 years or so,

and each time, there's been a corresponding failure

of the puffins to breed.

So, the current one we're looking at is quite intense.

There is no chick production.

We're measuring the chick production here,

and it's virtual zero.

In 2020, it should reverse or start to cool again.

But if you add global warming on top of the natural oscillation anyway,

that is a major uncertainty added to the system, isn't it?

That's the name of the game.

So, the question seems to be, is this a natural oscillation

or an irreversible man-made warming of the sea

or a bit of both?

Are the Alsey puffin hunters right -

that we might be on the point of returning to cooler conditions?

Looking for answers, I've come to

the National Oceanographic Centre in Southampton

to see one of the senior scientists, Penny Holliday,

whose work focuses on the mechanics of the North Atlantic.

The waters south of Iceland are influenced by

the deep ocean currents.

So, this whole region between the UK, Iceland,

Greenland and Canada

is the subpolar North Atlantic,

and it has this large recirculating ocean current system

that we call the subpolar gyre.

They're giant swirls

of 3,000 miles wide or something.

Yes, it's a massive swirling pot of ocean water

that mixes up warm water from the sub tropics

that comes from the Gulf Stream

and cold fresh water from the Arctic.

How come the sea around Iceland has changed

apparently as radically as this?

What's actually happened?

There is a boundary between

the cold fresh water in the centre of the gyre

and the warm salty water that's lying, basically,

-to the west of us in the UK.

-Right.

But in the mid-1990s, there was quite a change

in the shape and the circulation.

That boundary moved westwards

and that allowed more sub-tropical water

to flood this area west of the UK

and basically to bathe this deep ocean south of Iceland

with much warmer water.

Some of that water also made its way onto

the continental shelf around the UK

and so that'll be influencing the conditions

in the Western Isles and also in the Orkneys.

I wondered what Penny thought the future might hold?

It's difficult to untangle the signal of global warming

and the signal of these natural variations in the North Atlantic.

But, at the moment, our models do predict that

this whole area will cool again over the next five to ten years.

So, the Icelanders might be right -

the whole area might start to cool in the next few years.

And can you say it will go back to being as cool as it was?

No, I don't...I wouldn't be confident of saying that at all.

Whatever the impact of climate change may be on natural cooling,

there's no doubt that warmer seas are disastrous for the birds.

To find out why, I went to see an ornithologist

who's advised the Scottish Government

on sea birds and fisheries, Bob Furness.

Changes in temperature have a huge impact on plankton,

not only on the abundance of plankton

but on the composition of the species that are there.

Plankton are microscopic organisms

at the bottom of the marine food chain.

They're made up of two types - algae, known as phytoplankton,

and tiny animals called zooplankton.

As the sea temperature rises,

the plant-based phytoplankton will bloom.

But the sort of zooplankton which the fish like to eat

are replaced by a much less nutritious warm water species.

Long-term monitoring of the plankton has shown

that warming sea temperatures has resulted in

about a 70% decline in the copepod,

which is the favourite food of sand eels and young herring,

so this is clearly a vital link in the system.

And it seems that warming seas are also bringing in

new predators at the top of the food chain,

like the mackerel.

It appears that mackerel are changing their migration patterns

in association with changes in water temperature.

So, in recent years, they've been tending to go further north

than they used to do in the past.

Predatory fish feeding on small fish like sand eels

change the food supply for sea birds,

and my guess is that the mackerel predation impact

is really quite an important part of the story.

The Alsey puffin hunters believe this too.

And at Peterhead, on the east coast of Scotland,

there is evidence of a mackerel boom.

The catch landed by Scottish boats in the last 15 years

has nearly trebled.

This boat has returned from the North Sea

with 800 tonnes of mackerel.

Catches on this scale are no longer unloaded by hand.

Instead, they're pumped direct from the ship to the processing factory.

Well, just look at the number of fish that are here.

Like columns of mackerel coming out of that.

In 2014, over a quarter of a million tonnes of mackerel

were caught by British trawlers.

You look at this, and you think

the competition this represents the sand eels,

these are the rivals that the sea birds have got to compete with.

The impact of the mackerel story in Iceland could be even greater.

Their annual catch has gone from next to nothing 15 years ago

to over 160,000 tonnes today.

But is it really possible that these shifts in the ocean regime

are simply in line with natural fluctuations?

I went to see the director of the Icelandic Marine Research Institute,

Johann Sigurjonsson.

The trouble with the...with the sea birds,

I think it is quite evident that it can be linked

to temperature changes,

changes in temperature regime.

-So, can you say...?

-So, how exactly it...

I mean, what exactly has happened...

-Is more difficult.

-That's difficult.

I mean, although the decline in the sea birds is taking place,

that does not necessarily mean that it's an unhealthy ocean.

It's just a variability in nature.

So, I mean, in my view, I would take that...point of view

before concluding that there is something unhealthy going on.

So, you have to accept failure of sea bird populations

as a natural event?

Yeah.

It...in my view, it is a natural event.

I think...I think everything points to that direction.

Other people in Iceland thought the same -

that sea temperature changes are a natural phenomenon.

But elsewhere, not everyone agrees.

I think the idea that sea bird population changes

are all simply a result of natural cycles

and that we'll return to the same point that we were at in the past

is a very naive view.

There are so many human impacts superimposed

on these natural cycles

that it's very unlikely that the populations

that we end up with in the future

will be the same as what we had in the past.

Ian Mitchell is from the body that advises the government

on nature conservation.

In 2000, he ran the last comprehensive census

of British sea birds

and has a picture of what the future might bring.

In terms of whether there's enough food around for them to eat...

..that depends on what happens.

The one sort of hope is,

even if our sea temperatures continue to warm like they are

and we lose species like the sand eel,

which they feed on at the moment,

we may get new warm water species in,

like the anchovy, for instance.

We'd expect the Shiants, because its already quite far north,

probably to retain northern species, like the puffin,

but as the UK warms over the next century,

we may end up with Orkney and Shetland

and the most northern tip of Scotland

being the only place that we can see certain species.

So in the future, it seems likely that

the make-up of our sea bird world will shift.

Birds from the Mediterranean are already off the Cornish coast,

chasing the sardines and anchovies attracted by warming seas.

Less adaptable specialist shallow feeders, like the kittiwake,

may continue to decline.

Deep divers, like the razorbills, guillemots and puffins,

will probably cope better.

One thing, though, seems increasingly certain -

the world in which the sea birds live is changing.

There is a resident on the Shiants that clearly shows

how man has already had an impact on ocean life -

the fulmar.

The best flyer on the islands,

it first appeared here in the early-20th century.

When I came here as a boy in the '60s,

the fulmar population was doing well

both here and throughout the North Atlantic.

The fascinating thing about the fulmar

is that it's almost the only bird that has thrived

because of what people have done to the sea.

With the growth of industrial fishing in the early-20th century,

they boomed, feeding on the offal and all the discards.

When quotas were introduced in the 1970s,

fishermen were forced to dump

thousands of tonnes of disallowed catch into the sea.

And on the back of that, in the '90s, fulmar numbers peaked.

But as industrialised fishing has shrunk

and discard bans have come into effect,

the fulmar population has gone into decline.

But the fulmar's not the only bird

whose fortunes have depended on what man has done to the sea.

The great skua first arrived here during the boom 30 years ago

and is also now struggling to survive.

Nesting on the ground away from the shore,

I've always admired its utter fearlessness

in defence of its territory.

HE LAUGHS

The bird is a brilliant opportunist, a pirate of the skies,

getting its food however it can.

This footage shows typical skua behaviour,

harassing a gannet in flight until it drops its prey.

But as the crisis has taken hold,

the skua has started preying increasingly on other sea birds.

In one colony, a few hundred pairs

recently killed tens of thousands of smaller birds,

like the kittiwake, during a single season.

But perhaps the clearest vision of a future sea bird world

can be glimpsed on a small island

just a mile off the east coast of Scotland.

That is a... Wow.

Bass Rock has been home to a nobleman, prisoners and sheep...

..but now it's entirely colonised by a single sea bird.

150,000 of them.

Look at that, look at that!

It's just a universe of birds.

It's the biggest colony of northern gannets in the world.

Well, I've never seen anything like it in my life.

The gannet population here has increased dramatically

throughout the 20th century

and in the last ten years has more than doubled.

I've never seen anything like that,

I've never ever seen anything...so enveloping.

You know, it's not that you're coming to see

a bit of nature over there -

it's just like you're embedded in the whole thing.

With a wing span of up to 6ft,

this spectacular creature is

the largest sea bird in the British Isles.

They come here every spring after wintering in the Mediterranean

and off the west coast of Africa.

Gannets are incredibly successful animals.

They can travel huge distances in fishing trips,

300, 400 miles out from here.

They can dive shallow, they can dive relatively deep,

they can take little prey, they can take big prey,

so they are the great generalists,

that anything the world throws at them

they can take advantage of,

and this is the result - you know, total abundance.

In sharp contrast, when I was in Orkney,

I saw kittiwake colonies that used to be teeming with birds

now reduced to empty cliffs.

If you think of the kittiwake, which is really specialised -

it can only take sand eels or fish very like that,

it can't dive, it can't travel that far,

that they're stuck in their niche -

but these guys, their niche is the whole ocean.

They don't have a niche. They have a world.

A gannet boom may well be

an expression of the very problem the kittiwakes are suffering from -

warm seas, big fish, lots of gannets,

warm seas, fewer little fish, fewer kittiwakes.

I mean, it's terrible to say so, but maybe this is like a weed.

I mean, that's a spooky idea, isn't it?

That these beautiful things are, themselves,

symptoms of a system wobbling into the future.

Is this really what the sea bird world is going to be like?

The gannets are undoubtedly spectacular, aggressive,

wide-ranging, adaptable...

..but will we lose the wonderful variety

of puffin and guillemot, razorbill and kittiwake

and be left with a kind of bird monoculture

of big bruisers like gulls and gannets?

On the Shiants, over the last 50 years,

it seems I've lived through

a period of dazzling prosperity for the birds.

But now we're clearly into an era of deep change.

Local extinction may become the new normal.

And while we're doing all we can for our sea birds on land,

the horror, in my mind, is that the warmer seas

may have pushed the world they rely on too far.

The people who lived on the Shiants for thousands of years

left a century ago

in a world that could no longer sustain them.

I only hope the birds aren't going to follow.